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The usage, occurrence and dietary intakes of white mineral oils and waxes in Europe
Food and Chemical Toxicology 42 (2004) 481–492 www.elsevier.com/locate/foodchemtox
The usage, occurrence and dietary intakes of white mineral oils and waxes in Europe D.R. Tennant* Food Chemical Risk Analysis. 14 St Mary’s Square, Brighton BN2 1FZ, UK Received 2 July 2003; accepted 21 October 2003
Abstract Dietary exposures to mineral hydrocarbons were estimated from information about patterns of usage, concentrations in foods and quantities of foods consumed. An industry survey showed that the largest usage of food-grade white mineral oils was in plastics manufacture although the majority are used in non-food applications. The largest volumes of wax usage were in packaging. Conservative estimates indicated that daily intakes of white mineral oils ranged from 0.39 to 0.91 mg/kg bw/day for adults and from 0.75 to 1.77 mg/kg bw/day for children (mean and 97.5th percentiles). Total wax intakes ranged from 0.08 to 0.19 mg/kg bw/ day for adults and 0.23 to 0.64 mg/kg bw/day for pre-school children. When usage factors were applied, estimates of chronic intakes of white oils were reduced to 0.09–0.20 mg/kg bw/day for adults and to 0.17–0.39 mg/kg bw/day for children. Total wax intakes were reduced to 0.01–0.02 mg/kg bw/day for adults and to 0.02–0.06 mg/kg bw/day for children. For white mineral oils the principal source of exposure for most consumers was imported de-dusted grain. The principal source of potential wax exposure was from glazing agents on confectionery. There was no evidence of intakes exceeding SCF ADIs for microcrystalline waxes or certain white mineral oils and levels of exposure were similar to those of naturally-occurring mineral hydrocarbons in foods. # 2003 Elsevier Ltd. All rights reserved. Keywords: Mineral hydrocarbons; White oils; Paraffin; Microcrystalline waxes; Food additives; Usage; Intake; Exposure; Risk assessment
1. Introduction White mineral oils, waxes and petrolatum are widely used in cosmetics, pharmaceuticals, packaging and plastics but also have a variety of minor food-related applications. The Scientific Committee on Food (SCF) of the EU Commission has assessed the available information on the toxicity of mineral and synthetic hydrocarbons (Scientific Committee for Food, 1997). The SCF assigned an acceptable daily intake (ADI) of 0–20 mg/kg bw/day for microcrystalline waxes and a temporary ADI of 0–4 mg/kg bw/day for certain white mineral oils. The function of the SCF has now been transferred to the panel on food additives, flavourings, processing aids and materials in contact with food (AFC) of the European Food Safety Authority (EFSA). In order to estimate intakes to compare with SCF ADIs, it is necessary to identify all uses of mineral hydrocarbons where there is any possibility of transfer * Tel.: +44-1273-241-753; fax: +44-1273-276-358. E-mail address: [email protected] (D.R. Tennant). 0278-6915/$ - see front matter # 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.fct.2003.10.011
to food. These could include use as food additives or components of materials and articles intended to come into contact with food. When a food-related use has been identified, the range of possible levels of particular mineral hydrocarbons in potentially affected foods must be determined. These levels can then be combined with other information about patterns of usage and data on food consumption to create estimates of intake. Usage data were collected for four categories of mineral hydrocarbons: White mineral oils with viscosity of < 65 cSt at 40 C White mineral oils with viscosity of > 65 cSt at 40 C Microcrystalline wax Paraffin wax Petrolatum This was to ensure compatibility with the distinctions used in the SCF evaluation (Scientific Committee for Food, 1997), with JECFA (Joint FAO/WHO Expert Committee on Food Additives and Contaminants) definitions (JECFA, 1995) and with a survey carried out
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previously in the USA for the American Petroleum Institute (API) (Heimbach et al., 2002).
2. Materials and methods 2.1. Usage survey Member companies of the oil industries environment organisation (CONCAWE) were approached to provide data on their white oil sales and respondents included all major manufacturers, which accounted for more than 90% of annual sales volume. The European Wax Federation (EWF) organised a separate survey of major wax and petrolatum producers, which represented over 95% of market volume. Additional information from re-sellers of mineral hydrocarbon products confirmed the usage patterns provided by the producers.
It was estimated that 140,000 tonnes of white oil is used in the EU for food-related applications per annum (Table 1). Oils less than 65 cSt at 40 C account for about 10% of total usage and the remainder is oils greater than 65 cSt at 40 C. The major applications are plastics and elastomer manufacture and food machinery lubricants, which together account for about 97% of white oil sales. Gross European wax usage is estimated to be about 50,000 tonnes per annum (Table 2). The principal foodrelated applications are: wax-coated packaging, cheese coatings and in chewing gum base. About 60% of sales are used in packaging applications. Petrolatum is a blend of approximately equal proportions of white oils and waxes. Total European sales in food-related uses are estimated to be no more than 600 tonnes (Table 3). About 83% of this volume is associated with bottle seals including cork lubricants.
Table 1 European uses of white mineral oils in food-related applications (1999) Application
Percentage of total usage
Percentage of volume <65 cSt @ 40 C
Polystyrene Food machinery lubricants Elastomers Polyethylene Bakery release agents Polypropylene Confectionery Jute batching oil Sausage skin Divider oils Miscellaneous
85 6 4 2 1 1 <1 <1 <1 <1 1
>65 cSt @ 40 C 100 32 45 100 36 77
68 55 64 23 100 100 100 100a
*
a The white oil industry estimates that the ratio of oils <65 cSt to oils >65 cSt used as dough dividers is 40:60 at the time of publication of this report. This ratio will be used in intake calculations.
Table 2 European uses of mineral wax in food-related applications (1999) Application
Percentage of total usage
Percentage of volume Paraffin
Flexible packaging Wax-coated Wax laminateda Corrugated cartons Curtain coatinga Saturating wax Cheese coatings Chewing gum/base Fruit coatings Poultry de-feathering Folding cartons Paper cold drinks containers Bottle sealing (inc. corks) Confectionery (excluding chocolate) Miscellaneous a
Limited direct contact with food.
Micro-crystalline
33 8
90 40
10 60
10 7 16 14 2 3 2 2 1 <1 <1
83 100 50 25
17
75 100 80 100
50 75 100 25 20 100
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3. Data on levels and incidences of mineral hydrocarbons in foods 3.1. White mineral oils Potential levels of mineral hydrocarbons in food were identified in a review of the scientific literature and from information provided by industry and other sources (Tables 4 and 5). White mineral oils with viscosity greater than 65 cSt at 40 C are used as plasticisers in the production of polystyrene and styrene-containing co-polymers. The Ministry of Agriculture Fisheries and Food (MAFF) UK investigated the migration of mineral hydrocarbons from drinks containers used in drinks vending machines (Castle et al., 1992). Levels of hydrocarbons in drinks held in polystyrene containers would not be expected to exceed 1 mg/kg under the most extreme circumstances (Table 4). MAFF also conducted studies on the migration of hydrocarbons from polystyrene and acrylonitrile/ butadiene/styrene copolymers from containers for fats and dairy products (Castle et al., 1993a). No migration of mineral hydrocarbons from standard sized pots into yoghurt or cream was detected. About 1.4% of the available mineral oil migrated into milk and cream packaged in individual portion containers. MAFF reported further studies of migration of mineral oils from polystyrene into individual serving containers (Jickells et al., 1995). Levels of mineral hydrocarbons were generally below limits of detection. A Polystyrene Work Group of the US Society of the Plastics Industry (SPI) has also investigated potential exposure to mineral oil from food-contact use of polystyrene resins (Polystyrene Work Group, 1996). The group concluded that potential exposure to mineral oil from food-contact uses of polystyrene was insignificant (0.001 mg/kg bw/day). About 30% of European production of low density polyethylene is manufactured using a process that requires the use of white oil as a lubricant, which can become incorporated into the polyethylene. Grob et al. investigated the transfer of mineral oils from films containing 0.83% paraffins into vacuum packed cheese and found 4 mg/kg in the surface layer (Grob et al., 1991a). A second polyethylene film sample contained 1.7% mineral oil and vacuum-packed salami slices (1 mm) in direct contact with the film contained 35 mg/kg. Table 3 European uses of petrolatum in food-related applications Application
Percentage of volume
Confectionery (as processing aid) Bottle sealing (inc. corks) Miscellaneous
17 83 <1
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If a salami pack contained 10 stacked slices then the average concentration would be 7 mg/kg (Table 4). Given the very small white mineral oil sales volume for polypropylene compared to polystyrene and polyethylene, combined with information about the very low migration from those polymers, polypropylene was not expected to be a significant source of exposure. Before the introduction of ‘non-stick’ materials, mechanised bread manufacture required the use of lubricants to prevent bread from adhering to the pans and for the lubrication of dough handling machinery. In 1991 Grob et al. detected hydrocarbons in the bottom crusts of bread (Grob et al., 1991a). MAFF scientists also reported that mineral oils were present in UK bread samples at raised levels (Castle et al., 1994). Largely as a consequence of these findings, the majority of mineral hydrocarbons used as bakery release agents have been replaced by water/vegetable oil emulsions. Some minor use of dough divider oils in older mechanised bread equipment was reported. To cover this limited use the average core level reported by Castle et al. (243 mg/kg, Table 4) was taken to represent a conservative estimate (Castle et al., 1994). MAFF UK analysed samples of skinless sausages to investigate levels of mineral hydrocarbons (Castle et al., 1993b). The average mineral hydrocarbon concentration in all of the skinless sausage products tested was 28.3 mg/kg (Table 4). MAFF UK reported the presence of lubricants in canned foods and beverages in 1994 (Jickells et al., 1994). In retail food samples, mineral oil levels ranged from < 0.1 to 4.2 mg/kg and the weighted average was approximately 0.6 mg/kg. Industry sources advised that white mineral oils are no longer used in aluminium can manufacture and that emulsions (based on fatty materials but not white oil) are used in their place. Exposure was therefore not significant (Table 4). Machinery that is used in the manufacture, processing and presentation of food requires lubrication and food grade white mineral oils and petrolatum are frequently used for this function (Anon, 1995). MAFF UK found that processed meat products are not significantly contaminated with mineral hydrocarbons (Jickells et al., 1994). In 1991 Grob et al. reported that white oil concentrations were raised in eight out of 24 boiled sweets and caramels analysed (Grob et al., 1991a). Extensive enquiries were made throughout the confectionery industry and no current use of white mineral oils in direct contact with food was reported. Natural products are now used for this purpose. Exposure was therefore not significant (Table 4). Jute sacking requires dressing with oil (jute batching) in order to maintain flexibility and to act as a preservative. In 1991 Grob et al. analysed samples of cocoa bean kernels and found levels of about 10 mg/kg (Grob et al., 1991b). MAFF UK analysed 40 samples of
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for dust suppression, then the effect on mineral hydrocarbon (MHC) intakes can be considered. Levels of MHCs in imported grain were taken from the report prepared for the American Petroleum Institute (Heimbach et al., 2002, Table 4). Trade statistics were used to estimate the proportion of the domestic supply that is imported. The possibility that white bread consumed in France could be made from wheat treated with white mineral oils was accounted for by assuming that 100% of white bread is produced from such grain.
chocolate which contained < 1 to 60 mg/kg (average=7 mg/kg, Table 4) (Ministry of Agriculture, Fisheries and Food, 1993). Except in France (which has a temporary approval for the use of white oil less than 65 cSt at 40 C for dust suppression in granaries for white bread manufacture), white mineral oils are not used as grain de-dusting agents in Europe. As part of a submission to the French authorities it was shown that the addition of 200 mg/kg to grain leads to a maximum level of mineral oil in bread of 10 mg/kg (Table 4). The use of white mineral oils for grain dust suppression is common practice in some non-European countries that export grain to Europe. If it is assumed that all of the cereals and vegetable oils imported into the EU are derived from countries that permit the use of white oil
3.2. Mineral waxes Because of their hydrophobic nature, mineral hydrocarbon waxes are not expected to migrate into non-fatty foods. Where transfer into foods does occur,
Table 4 Potential levels of white mineral oils in food reported in literature Application medium
Mineral oil concentration (mg/kg)
Comment
<65 cSt at 40 C
> 65 cSt at 40 C
– – –
<1 <1 < 5–93
n.s. n.s.
n.s. n.s.
n.s.
n.s.
Polyethylene Containers Delicatessen meats Surface coating of tableware
– – –
n.s. 7 n.s.
Bakery release agents/divider oils Bread
243
Polypropylene Food wraps
n.s.
Confectionery Sugar confectionery Chocolate
250 50
Polystyrene Drink containers Milk/yoghurt containers Individual milk/cream containers Food machine lubricants Press lubricants Other lubricants Elastomers Seals
Jute batching oil Chocolate Temporary sausage skins Skinless sausages Grain/seed de-dusting Bread Flours and cereals Vegetable oils Miscellaneous n.s. Not a significant source of exposure.
or
243
Not significant—occasional use
Very limited use
n.s.
or or
250 50
7
–
28.3
–
10 9–42 110
– –
n.s.
n.s.
Now obsolete Now obsolete
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paper showed little or no wax transfer. A study by the NATEC Institute (NATEC Institute fu¨r naturwissenschaftlich technische Dienste) found relatively low migration of 9 mg/dm2, which is more consistent with the TNO results (Figge and Beiber, 1987). The French packaging organisation ADRIAC (Reims Champagne Ardenne University, Research and Development Centre on Food Packaging.) investigated migration into cheese and meat (ADRIAC, 1999). The results indicated that migration can occur, which increases with duration of contact. The average concentration measured in cheese spread after 1 week was 7 mg/kg (Table 5). For fatty ham, no wax was detected above the detection limit of 1.0 mg/kg (Table 5).
this is not governed by diffusion but by adhesion or incomplete removal of coatings from the food. Between 1975 and 1979 TNO (The Netherlands Organisation for Applied Scientific Research) investigated migration of wax from various paper coatings into foods (Van Battum and Rijk, 1975, 1977, 1979). Migration of wax into foods was low suggesting that wax-coated paper was unlikely to be a significant source of exposure. Grob et al. analysed fat from meat samples that had been kept for 4 days in a refrigerator in a wax-coated card box and found paraffin wax levels to be less than 1 mg/kg (Grob et al., 1991c, Table 5). High paraffin wax concentrations were detected in individual salami slices stored in direct contact with waxed paper. However, slices not in direct contact with the Table 5 Potential levels of mineral waxes in food reported in literature Application
Medium
Wax concentration (mg/kg) Paraffinic
Comment Micro-crystalline
Flexible packaging Wax coated Sliced cheese Sliced meats Biscuits Cereals Bread Sugar confectionery Ice-cream Bouillon cubes Wax laminated Cartons Curtain coated Saturating wax Milk/cream
7 <1 105 105 29 52 n.s. n.s. n.s.
or or or or or or
n.s.
.
<1
7 <1 105 105 29 52 n.s. n.s. n.s.
No direct contact No direct contact
n.s.
No direct contact
–
No direct contact
Obsolete
Cheese coatinga Gouda, Edam, etc. Chewing gum/base
4.4
or
4.4
n.s.
n.s.
–
200
Fruit coatings Tropical fruit peel
No direct contact
Poultry de-feathering Duck meat
9
or
9
Folding cartons
n.s.
–
Paper cold drink cups
n.s.
n.s.
Bottle sealing
n.s.
Confectionery Chewing gum Non-chocolate confectionery Miscellaneous
– –
200 200
n.s.
n.s
n.s. Not a significant source of exposure. a Only a small proportion of wax-coated cheeses have direct contact between cheese and wax.
Glazing agent Glazing agent
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MAFF UK investigated the migration of waxes from waxed paperboard milk containers (Castle et al., 1993a). Levels were below detection limits. Later studies showed that packing crispbreads, crackers and cereals in waxed paper could result in mineral hydrocarbon concentrations of 20–185 mg/kg (average=105 mg/kg, Table 5) (Castle et al., 1994). Retail samples of bread were analysed for mineral waxes in the base, outer crust and the core material separately (Castle et al., 1994). Wax concentrations were highest on the bread surfaces, indicating transfer from the waxed paper. The overall average concentration in bread wrapped in waxed paper was 29 mg/kg (Table 5). Retail samples of confectionery that were wrapped in waxed paper were analysed for mineral hydrocarbons in 1991 (Grob et al., 1991a). Boiled sweets were found to have lower wax levels (average, 104 mg/kg) than the more ‘sticky’ chews and toffees (average, 560 mg/kg). It was also found that bonbons wrapped in waxed paper contained up to 200 mg/kg paraffin waxes (Castle et al., 1994). In contrast, Kemp and Beemsterboer found levels less than 20 mg/kg in 1992 and of this only about 25% appeared to come from the wrapper (Kemp and Beemsterboer, 1992). In 1994 the German Food Surveillance authorities analysed 29 types of commercially available sweets for hydrocarbon contamination. The average concentration was 52 mg/kg (ranging from 10 to 556 mg/kg, Table 5). The European sugar confectionery industry has largely moved to more suitable materials such as higher melting wax blends (with more cohesive strength due to polymer addition) or products based on non-mineral waxes. It can therefore be expected that current levels of MHC in confectionery are lower than those reported previously. Several traditional varieties of cheese employ a wax coating that protects the cheese from desiccation and mould growth. Some cheeses may be matured in polyvinyl acetate and then ‘packed’ in a wax coating for protection during storage and transport. MAFF UK analysed samples of wax-coated cheese with, and without the polyvinyl acetate barrier layer (Castle et al., 1993b). Levels of mineral hydrocarbons ranged from < 1.0 to 27 mg/kg. Four samples that had a plastic barrier layer showed no detectable residues. The average concentration in cheese coated with wax was 4.4 mg/kg (Table 5). The Netherlands Institute for Dairy Research found that mineral hydrocarbons were concentrated in the first 1 mm of the cheese rind, which is normally discarded by the consumer (Van den Berg et al., 1989). Grob found levels of 3–25 mg/kg in the 5mm top layer of cheese nearest to the wax (Grob et al., 1991a). The use of mineral waxes in chewing gum base is not regulated as a food additive (European Parliament and Council, 1995). Under normal conditions of mastication, mineral hydrocarbons do not leach into gastro-intestinal fluids or saliva (Modderman, 1992).
Even in the presence of food lipids, leachates did not contain mineral hydrocarbons above the analytical limit of determination. European Directive 98/72/EC amends Directive 95/2/ EC to permit the use of microcrystalline wax as a the surface treatment and allocates an E-number (E 905). Microcrystalline wax may be used quantum satis in: Confectionery excluding chocolate; Chewing gum; Melons, papaya, mango and avocado. The use of microcrystalline wax as a glazing agent on confectionery and chewing gum commands only 100 tonnes of product throughout Europe annually, suggesting that this is a minor use. The maximum concentration of wax detected in confectionery was 200 mg/kg and so this figure was used as a conservative default in intake calculations (Table 5). The peel of melons, papaya, mango and avocado are unlikely to be consumed and so were excluded from intake calculations. Ducks may be dipped in wax after slaughter and plucking in order to assist the removal of residual feathers. MAFF UK (Dennis et al., 1987) and EWF (Kemp, 1991) have investigated levels of wax in and on ducks. No hydrocarbons were reported in flesh and levels of 8–120 mg/kg were reported on the skin. The average concentration of mineral hydrocarbon in whole duck, based on the MAFF data would be 9 mg/kg (Table 5). Coatings for paper cold drink cups and other disposable containers are a minor use for waxes. Their use in beverage cups and disposable plates is unlikely to result in significant exposure because migration into milk is below detection limits (Castle et al., 1993a). Most of such containers do not use wax but instead employ a polyethylene coating. 3.3. Petrolatum Very low volumes of petrolatum are associated with confectionery. Any minor use in confectionery manufacture will have been represented in the oil and wax studies (Tables 4 and 5) because petrolatum is a mixture of oil and wax. The only other potentially significant source of exposure to mineral hydrocarbons from petrolatum is from bottle sealing. MAFF UK have analysed corks and samples of wine for mineral hydrocarbons (Jickells et al., 1995). The migration of mineral hydrocarbons from treated corks into wines was not detectable above background levels.
4. Estimating consumer intakes The EU Scientific Committee for Food has issued no specific guidance on methods for estimating intakes.
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However, there is a general recommendation that individuals with high level intakes should be considered (Pascal, 1995). In order to provide accurate intake estimates for high consumers it is necessary to have access to the raw data from food consumption surveys conducted at an individual level, that includes children. An important potential source of mineral hydrocarbon exposure is from packaging and from processed foods, which tend to be associated with each other. MPA (Maurice Palmer Associates) survey data suggest that the Benelux countries (Belgium, Luxembourg, The Netherlands) and the UK have the highest packaging use (Maurice Palmer Associates, 1997). However, this result may be misleading because Benelux countries, particularly the Netherlands are net exporters of packaged foods, whereas the UK is a net importer. UK consumers therefore probably represent a ‘worst case’ example of European countries for mineral hydrocarbon intake studies. Anticipated levels of white mineral oils and waxes reported in Tables 4 and 5. In reality, mineral hydrocarbons exist in a competitive market and there are usually alternatives available. Therefore intake estimates based on Tables 4 and 5 will provide an upper bound estimate. Intake estimates should be averaged over a time period that corresponds to that used in the toxicology studies that were used as the basis for calculating the ADI (Renwick, 1999). In the case of mineral hydrocarbons the most recent studies were of 2 years duration, which would be equivalent to about 70 years
for man. Intake estimates based on four or seven day food consumption surveys are likely to over-estimate relevant intakes. In addition, differentiation between intakes of different classes of mineral hydrocarbons (i.e. less than or greater than 65 cSt oils; paraffin or microcrystalline wax) requires consideration of the distribution of uses given in Tables 1 and 2. Where more than one class of oil or wax could be used, the MPA survey of flexible packaging products (Maurice Palmer Associates, 1997) provides data on the quantities of packaging used in various sectors including certain food sectors. The results of packaging market share surveys for waxed paper can be combined with other information about wax usage to generate realistic adjustment factors for long-term exposure (Table 6). Few data are available for white oil uses to make realistic adjustments for long-term intakes. However, the MPA report includes the results of a survey of industrial bread production in western Europe during 1995. Where adjustment factors were not available, a factor of 100% was used in order to maintain a conservative approach. The sources of food consumption data from the UK used in this study were the National Dietary and Nutrition Surveys (NDNS) of adults aged 16–65 (Gregory et al., 1990) and of children aged 1 1/2 to 4 1/2 years (Gregory et al., 1995). The data comprise 7 day or 4 day records of all foods consumed by approximately 2000 individuals in each survey. Each food that was consumed was individually weighed and recorded and
Table 6 Usage volume ratios and adjustment factors for moderating mineral hydrocarbon exposures Application
White oil Polyethylene Bakery divider oils Confectionery Confectionery Jute batching oil Temp sausage skins Grain de-dusting Wax Waxed paper
Cheese coating Fruit/vegetable coatings Duck de-feathering Confectionery n.a. not available. n.s. not significant.
Medium
Usage ratio
Adjustment factor
<65 cSt
>65 cSt
Sliced meats Bread Sugar confectionery Chocolate Chocolate Skinless sausages Cereals
– 40 68 68 100 100 100
100 60 32 32 – –
n.a. 20 n.a. n.a. n.a. n.a. 6 to 31
Sliced cheese Sliced meats Biscuits Cereals Bread Sugar confectionery Gouda, Edam, etc. Tropical fruit Duck meat Chewing gum Non-chocolate confectionery
90 90 90 90 90 90 50 – 75 – –
10 10 10 10 10 10 50 100 25 100 100
8 4 8 4 7 9 10 n.s. 100 10 10
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as used in the intake calculations for white mineral oils and waxes. Consumption figures are provided for the entire sample population (per capita) and for only those who reported consumption of each food (consumers only). Note that in distributional analyses columns of figures relating to upper percentiles and ‘consumers only’ means do not add up to the total for consumers of all the foods. This is because the individual food statistics represent sub-populations who consumed those foods.
over 4000 food descriptions are included in the databases. Since data are available for each individual who participated in the surveys it is possible to derive distributional statistics (90th and 97.5th percentiles) to represent ‘high-level’ consumption. Data can also be provided on a bodyweight basis by dividing food consumption by each individual’s body weight. Tables 7 and 8 provide data on the amounts of foods consumed, Table 7 Food consumption figures used in white mineral oil intake calculations Source
Food
Food consumption (g/day) Consumers (%)
Per capita
Consumers only
Mean
90th%ile
97.5th%ile
Mean
90th%ile
97.5th%ile
Adults Polyethylene Divider oils Jute batching Temporary skins Grain de-dusting All sources
Sliced meats Bread Chocolate Sausages Cerealsa
44 98 59 56 100 100
6 88 4 11 110 219
18 160 11 30 179 357
32 225 22 53 228 475
13 90 6 20 110 219
27 164 14 40 179 357
41 228 27 63 228 475
Pre-school children Polyethylene Divider oils Jute batching Temporary skins Grain de-dusting All sources
Sliced meats Bread Chocolate Sausages Cerealsa
19 96 71 47 100 100
1 34 5 7 49 96
6 61 12 23 79 152
12 85 23 39 103 198
7 35 7 16 49 96
14 64 14 31 79 152
22 87 26 47 103 198
a
Consumption of cereal-containing foods.
Table 8 Food consumption figures used in mineral wax intake estimates Source
Food
Food consumption (g/day) Consumers (%)
Adults Waxed paper
Cheese coating Poultry de-feathering Confectionery glazing All sources Pre-school children Waxed paper
Cheese coating Poultry de-feathering Confectionery glazing All sources
Per capita
Consumers only
Mean
90th%ile
97.5th%ile
Mean
90th%ile
97.5th%ile
Sliced cheese Biscuits/crackers Bread Sugar confectionery Wax-coated cheese Duck Sugar confectionery
76 78 100 20 6 1 20 100
14 15 111 1 1 0 1 142
34 36 191 4 0 IC 4 236
55 61 263 15 11 IC 15 312
19 19 111 7 12 14 7 143
38 40 191 18 24 IC 18 236
58 68 263 32 43 IC 32 313
Sliced cheese Biscuits/crackers Bread Sugar confectionery Wax-coated cheese Duck Sugar confectionery
47 79 97 43 4 0 43 100
4 10 38 5 0 0 5 57
13 23 71 15 0 IC 15 95
23 36 95 27 5 IC 27 128
9 12 39 11 9 9 11 57
19 26 71 23 16 IC 23 95
28 37 96 34 24 IC 34 128
IC—Insufficient consumers.
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The ‘bread’ category used for wax intakes from wrapped bread is slightly broader than that used for white mineral oils from divider oils. This is because the wax category includes some speciality breads that might be wrapped in waxed paper but are unlikely to be industrially produced. Intakes were calculated using distributional methods based on raw data from the food consumption surveys. A mineral or naturally occurring hydrocarbon concentration is assigned to each relevant food and then multiplied by the amount of food consumed on each eating occasion to generate an intake figure. The total intake is summed for each individual and then divided by the number of days in the survey and the individuals’ body weight to give the average daily intake for that individual.
5. Results 5.1. White mineral oils Conservative estimates for consumers only, indicate that total potential intakes of white mineral oils range from 0.39 to 0.91 mg/kg bw/day for adults and 0.75– 1.77 mg/kg bw/day for children, at the mean and 97.5th percentiles (Table 9). The principal source of intake appears to be the use of white mineral oils as bakery divider oils, approximately equally divided between oils less that 65 cSt and oils greater than 65 cSt. The use of white mineral oils as dough divider oils is a declining practice limited to older designed industrial bakeries and so higher intakes would be limited to a small minority of
Table 9 White mineral oil intakes—consumers only Source
Food
Oil concn. (mg/kg)
Intake (mg/kg bw/day) Consumers (%)
Adults Polyethylene Divider oils Jute batching Temporary skins Grain de-dusting All sources
Sliced meats Bread Chocolate Sausages Cereals
Pre-school children Polyethylene Divider oils Jute batching Temporary skins Grain de-dusting All sources
Sliced meats Bread Chocolate Sausages Cereals
7 243 7 28 40- 110
7 243 7 28 40–110
<65 cSt
>65 cSt
Mean
90th
97.5th
44 98 59 56 100 100
0.127 0.001 0.008 0.077 0.206
0.226 0.002 0.016 0.127 0.347
0.311 0.003 0.025 0.166 0.459
19 96 71 47 100 100
0.237 0.003 0.030 0.161 0.406
0.430 0.007 0.061 0.258 0.677
0.600 0.013 0.090 0.345 0.908
Total
Mean
90th
97.5th
Mean
90th
97.5th
0.001 0.191
0.003 0.340
0.004 0.468
0.187
0.340
0.467
0.001 0.317 0.001 0.008 0.077 0.393
0.003 0.566 0.002 0.016 0.127 0.683
0.004 0.780 0.003 0.025 0.166 0.911
0.004 0.357
0.007 0.647
0.011 0.898
0.343
0.642
0.873
0.004 0.594 0.003 0.030 0.161 0.749
0.007 1.077 0.007 0.061 0.258 1.352
0.011 1.495 0.013 0.090 0.345 1.772
Table 10 White mineral oil intakes- consumers only, application adjusted Source
Food
Oil conc. (mg/kg)
Intake (mg/kg bw/day) Consumers (%)
Adults Polyethylene Divider oils Jute batching Temporary skins Grain de-dusting All sources Pre-school children Polyethylene Divider oils Jute batching Temporary skins Grain de-dusting All sources
Sliced meats Bread Chocolate Sausages Cereals
Sliced meats Bread Chocolate Sausages Cereals
7 243 7 28 40–110
7 243 7 28 40- 110
< 65 cSt
>65 cSt
Mean
90th
97.5th
44 98 59 56 100 100
0.025 0.001 0.008 0.018 0.044
0.045 0.002 0.016 0.030 0.078
0..62 0.003 0.025 0.042 0.106
19 96 71 47 100 100
0.048 0.003 0.030 0.038 0.100
0.086 0.007 0.061 0.061 0.163
0.119 0.013 0.090 0.087 0.213
Total
Mean
90th
97.5th
Mean
90th
97.5th
0.001 0.038
0.003 0.068
0.004 0.094
0.038
0.068
0.095
0.001 0.068 0.001 0.008 0.018 0.086
0.003 0.113 0.002 0.016 0.030 0.146
0.004 0.156 0.003 0.025 0.042 0.198
0.004 0.071
0.007 0.129
0.011 0.180
0.069
0.129
0.177
0.004 0.119 0.003 0.030 0.038 0.169
0.007 0.215 0.007 0.061 0.061 0.282
0.011 0.299 0.013 0.090 0.087 0.390
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D.R. Tennant / Food and Chemical Toxicology 42 (2004) 481–492
consumers who consistently purchased and consumed bread produced in such plants. For the majority of consumers the most important source of exposure is probably form de-dusting agents in imported cereals. When the proportion of bread that is industrially manufactured, and the proportion of cereals that are imported are taken into account (see Table 6), total white oil intakes are reduced to 0.09–0.20 mg/kg bw/day for adults and to 0.17–0.39 mg/kg bw/day for pre-school children (Table 10). True high level intakes probably lie between those calculated on that basis of all potential foods containing white mineral oils (Table 9) and those calculated using the proportions of industrially manufactured bread and imported cereals (Table 10). This is because consumers could always select industrially produced bread and foods made from imported cereals, but this is unlikely to be sustained in the longer term.
However, when the proportion of foods that are wrapped in waxed paper or to which wax is applied are taken into account (see Table 6), total wax intakes are reduced to 0.01–0.02 mg/kg bw/day for adults and to 0.02 to 0.06 mg/kg bw/day for pre-school children (Table 12). The use of microcrystalline wax as a confectioneryglazing agent (E905) followed by transfer from waxed paper into biscuits/crackers and bread remain the principal sources of exposure. True high level intakes probably lie between those calculated on that basis of all potential foods containing waxes (Table 11) and those calculated using the proportions of food wrapped in wax paper or coated (Table 12). This is because although consumers could always select wax paper wrapped or wax-coated foods, this is unlikely to occur in the longer term.
6. Discussion 5.2. Mineral waxes Total wax potential intakes ranged from 0.08 to 0.19 mg/kg bw/day for adults and 0.23 to 0.64 mg/kg bw/day for pre-school children at the mean and 97.5th percentiles (Table 11). For adults the principal sources of exposure were the use of paraffin waxed paper to wrap bread, biscuits and crackers. For pre-school children the most important source of exposure was the use of microcrystalline wax as a confectionery-glazing agent (E905) followed by the transfer of paraffin wax from waxed paper into biscuits/crackers and bread.
Hydrocarbons occur as natural constituents of many foods, particularly those that are fatty or oily. Reich et al. have reviewed the literature on levels of naturally occurring alkanes (Reich et al., 1997). Total US intake was reported to be 0.189 mg/kg bw/day. Using the same data on levels, average intakes of naturally occurring hydrocarbons by European consumers were estimated to range from 0.33 mg/kg bw/day in the UK to 0.61 mg/ kg bw/day in Germany (European average is 0.47 mg/ kg bw/day). The principal sources of exposure were apples, wheat and dairy fat.
Table 11 Mineral wax intake–consumers only Source
Food
Wax concn. (mg/kg)
Intake (mg/kg bw/day) Consumers (%)
ADULTS Waxed paper
Cheese coating Poultry de-feathering Confectionery glazing All sources Pre-school children Waxed paper
Cheese coating Poultry de-feathering Confectionery glazing All sources
Sliced cheese Biscuits/crackers Bread Sugar confectionery Wax-coated cheese Duck Sugar confectionery All above foods
7 105 29 52 4.4 9 200
Sliced cheese Biscuits/crackers Bread Sugar confectionery Wax-coated cheese Duck Sugar confectionery All above foods
7 105 29 52 4.4 9 200
Paraffin
Microcrystalline
Total
Mean
90th
97.5th
Mean
90th
97.5th
Mean
90th
97.5th
76 78 98 20 6 1 20 100
0.002 0.027 0.042 0.005 0.000 0.001
0.003 0.057 0.071 0.013 0.001 IC
0.005 0.096 0.096 0.025 0.001 IC
0.066
0.111
0.152
0.000 0.003 0.005 0.001 0.000 0.000 0.021 0.012
0.000 0.006 0.008 0.001 0.001 IC 0.054 0.021
0.001 0.011 0.011 0.003 0.001 IC 0.108 0.056
0.002 0.030 0.047 0.006 0.001 0.002 0.021 0.077
0.004 0.064 0.078 0.014 0.002 IC 0.054 0.133
0.006 0.106 0.107 0.028 0.003 IC 0.108 0.192
47 79 96 43 4 0 43 100
0.004 0.082 0.071 0.034 0.001 0.004
0.008 0.166 0.128 0.073 0.002 IC
0.012 0.247 0.166 0.102 0.003 IC
0.150
0.266
0.348
0.000 0.009 0.008 0.004 0.001 0.001 0.145 0.079
0.001 0.018 0.014 0.008 0.002 IC 0.308 0.231
0.001 0.027 0.018 0.011 0.003 IC 0.434 0.402
0.005 0.091 0.079 0.038 0.003 0.005 0.145 0.229
0.009 0.185 0.142 0.081 0.005 IC 0.308 0.444
0.014 0.275 0.184 0.113 0.007 IC 0.434 0.640
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D.R. Tennant / Food and Chemical Toxicology 42 (2004) 481–492 Table 12 Mineral wax intake- consumers only, application adjusted Source
Food
Wax concn. (mg/kg)
Intake (mg/kg bw/day) Application (%)
Adults Waxed paper
Cheese coating Poultry de-feathering Confectionery glazing All sources Pre-school children Waxed paper
Cheese coating Poultry de-feathering Confectionery glazing All sources
Sliced cheese Biscuits/crackers Bread Sugar confectionery Wax-coated cheese Duck Sugar confectionery All above foods
7 105 29 52 4.4 9 52
Sliced cheese Biscuits/crackers Bread Sugar confectionery Wax-coated cheese Duck Sugar confectionery All above foods
7 105 29 52 4.4 9 52
8 8 7 9 100 100 10
8 8 7 9 100 100 10
Estimates of total potential intakes of white mineral oils for EU consumers ranged from 0.09 to 0.91 mg/kg bw/day for adults and 0.17 to 1.77 mg/kg bw/day for children, at the mean and 97.5th percentiles respectively, depending on assumptions made (e.g. manufactured bread, imported cereals). The main source of potential intake appears to be the use of white mineral oils as bakery divider oils although for most consumers the most important source of exposure is probably form de-dusting agents in imported cereals. Potential intakes of total wax for EU consumers ranged from 0.01 to 0.19 mg/kg bw/day for adults and 0.02 to 0.64 mg/kg bw/day for pre-school children at the mean and 97.5th percentiles respectively, depending on assumptions made (e.g. use of packaging). For adults the principal sources of potential exposure was the use of paraffin waxed paper. For pre-school children the most important source of potential exposure was the use of microcrystalline wax as a confectionery-glazing agent (E905). No single figure can adequately represent the intake of any substance. This is because levels of chemicals in food are variable as are the amounts of food consumed by different individuals. Furthermore the accuracy of estimates of intake are affected by three sources of uncertainty: 1. The quality of data on the levels and occurrence of hydrocarbons in food; 2. The quality of data on the consumption of affected foods; and
Paraffin
Microcrystalline
Total
Mean
90th
97.5th
Mean
90th
97.5th
Mean
90th
97.5th
0.000 0.002 0.003 0.000 0.000 0.001
0.000 0.005 0.005 0.001 0.001 IC
0.000 0.008 0.007 0.002 0.001 IC
0.005
0.008
0.012
0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.001
0.000 0.001 0.001 0.000 0.001 IC 0.005 0.002
0.000 0.001 0.001 0.000 0.001 IC 0.011 0.005
0.000 0.002 0.003 0.001 0.001 0.002 0.002 0.006
0.000 0.005 0.005 0.001 0.002 IC 0.005 0.010
0.000 0.009 0.007 0.003 0.003 IC 0.011 0.015
0.000 0.007 0.005 0.003 0.001 0.004
0.001 0.013 0.009 0.007 0.002 IC
0.001 0.020 0.012 0.009 0.003 IC
0.011
0.021
0.027
0.000 0.001 0.000 0.000 0.001 0.001 0.014 0.008
0.000 0.001 0.001 0.001 0.002 IC 0.031 0.023
0.000 0.002 0.001 0.001 0.003 IC 0.043 0.040
0.000 0.007 0.006 0.003 0.003 0.005 0.014 0.019
0.001 0.015 0.010 0.007 0.005 IC 0.031 0.038
0.001 0.022 0.013 0.010 0.007 IC 0.043 0.058
3. Assumptions inherent in the method used for analysis. Data on the levels and occurrence of mineral hydrocarbons in food are generally drawn from analytical studies which are several years old and which have limited numbers of samples. Such samples may have been selected because the analyst is expecting to find traces and thus some bias could be introduced. Nevertheless data have been obtained about all significant uses of mineral hydrocarbons associated with food and used as the basis for intake calculations. Mineral hydrocarbon intake estimates based on the assumption that all foods that might contain traces of mineral hydrocarbons actually do, are likely to over-estimate true intakes in the longer term. Information about the proportion of foods that contain traces of mineral hydrocarbons can be used to make more realistic estimates of chronic intake. However, the possibility that certain consumers could always choose particular foods that contain traces of mineral hydrocarbons means that true intakes probably lie between these extremes. Obtaining precise estimates of mineral hydrocarbon intakes is extremely difficult because of uncertainties in the data. However, intake estimates based on the most conservative assumptions provide no indication that the SCF ADIs for certain white mineral oils (0–4 mg/kg bw/ day) and microcrystalline waxes (0–20 mg/kg bw/day) would be exceeded. Levels of exposure are similar to those experienced with naturally-occurring mineral hydrocarbons in foods.
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Acknowledgements The author wishes to thank the European oil industry environment organisation (CONCAWE) and the European Wax Federation (EWF) for supplying information and financial support for this project.
References ADRIAC 1999. Interactions de materiaux cellulosiques et plastiques enduits avec aliments gras. Convention DGCCRF No 97-002. Anon, 1995. Contamination des produits alimentaires: le choix des lubricants. Process 35/1104. Castle, L., Kelly, M., Gilbert, J., 1992. Migration of mineral hydrocarbons into foods. 1. Polystyrene containers for hot and cold beverages. Food Additives and Contaminants 8/6, 693–700. Castle, L., Kelly, M., Gilbert, J., 1993a. Migration of mineral hydrocarbons into foods. 2. Polystyrene, ABS, and waxed paperboard containers for dairy products. Food Additives and Contaminants 10/2, 167–174. Castle, L., Kelly, M., Gilbert, J., 1993b. Migration of mineral hydrocarbons into foods. 3. Cheese coatings and temporary casings for skinless sausages. Food Additives and Contaminants 10/2, 175–184. Castle, L., Kelly, M., Gilbert, J., 1994. Migration of mineral hydrocarbons into foods. 4. Waxed paper for packaging dry goods including bread, confectionery and for domestic use including microwave ovens. Food Additives and Contaminants 11/1, 79–89. Dennis, M.J., Massey, R.C., McWeeny, D.J., 1987. A method of analysis for paraffinic waxes on ducks. International Journal of Environmental Analytical Chemistry 30, 29–35. European Parliament and Council Directive No 95/2/EC of 20 February 1995 on food additives other than colours and sweeteners. Article 1, paragraph 5c, OJ No L 61/1. 18.3.95. Figge, K., Beiber W.-D., 1987. NATEC Institute fu¨r naturewissenschaftlich-technische Dienste GmbH. Parraffin-Migration Unser Project NA 87 9655. Gregory, J.R., Collins, D.L., Davies, P.S.W., Hughes, J.M., Clarke, P.C., 1995. National Diet and Nutrition Survey; Children aged 1 1/2 to 4 1/2 years. HMSO, London. Gregory, J., Tyler, H., Wiseman, M., 1990. The Dietary and Nutritional Survey of British Adults. HMSO, London. Grob, K., Artho, A., Biedermann, M., Egli, J., 1991a. Food contamination by hydrocarbons from lubricating oils and release agents: determined by LC–GC. Food Additives and Contaminants 8/4, 437–446. Grob, K., Lanfranchi, F., Iyenger, J.R., 1991b. Determination of food contamination by mineral oil from jute sacks using coupled LC–GC. J. of the Association of Official Analytical Chemists 74, 506–512. Grob, K., Biedermann, M., Artho, A., Egli, J., 1991c. Food contamination by hydrocarbons from packaging materials determined by coupled LC–GH, Z. Lebensm Unters Forsch 193, 213–219. Heimbach, J.T., Bodor, A.R., Douglass, J.S., Barraj, J.S., Cohen, S.C., Biles, R.W., Faust, H.R., 2002. Dietary exposures to mineral
hydrocarbons from food-use applications in the United States. Food and Chemical Toxicology 40, 555–571. Jickells, S.M., Nichols, J., Castle, L., 1994. Migration of mineral hydrocarbons into foods. 6. Press lubricants used in food and beverage cans. Food Additives and Contaminants 11/5, 595–604. Jickells, S.M., Nichols, J., Castle, L., 1995. Migration of mineral hydrocarbons into foods. 5. Miscellaneous applications of mineral Hydrocarbons on food contact articles. Food Additives and Contaminants 12/3, 333–341. Joint WHO/FAO Expert Committee on Food Additives (JECFA), 1995. Report of the 44th meeting. Kemp, G., Beemsterboer, K., 1992. Paraffin Wax Levels in Sweets Packed With Wax-coated Paper. Paramelt Syntac BV. Kemp, G., 1991. Paraffin Wax Levels in Ducks After De-feathering With Wax. European Wax Federation. Maurice Palmer Associates, 1997. The European Flexible Packaging Products Market 1996–2001. Maurice Palmer Associates Ltd. August 1997. Ministry of Agriculture, Fisheries and Food, 1993. Hydrocarbons in chocolate. Food Surveillance Information Sheet, No 15. Modderman, J., 1992. Ingestion and safety assessment of chewing gum base ingredients. Proceedings of the Toxicology Forum Special Meeting on Mineral Hydrocarbons. Green College, Oxford. Pascal, G., 1995. Risk Assessment: How does science contribute to policies of the European Union? In: Kardinaal, A.F.M., Lowick, M.R.H. and van der Heij, D.G. (Eds). Dietary Exposure to Contaminants and Additives: Risk Assessment in Europe. TNO Topics in Nutrition and Food Research 2. pp. 77–80. Polystyrene Work Group, 1996. Report on Potential Exposure to Mineral Oil from Food-Contact use of Polystyrene Resins. Food, Drug and Cosmetic Packaging Materials Committee. Society of the Plastics Industry. Renwick, A., 1999. Intake of intense sweeteners. In: Corti, A. (Ed.), Low Calorie Sweeteners: Present and Future, vol 85. World Rev. Nutr, Diet, Basel, Karger, pp. 178–200. Reich, A.G., Waylett, D.K., van der Reit, B.E., Doyle, E., Douglass, J.S., Eickhoff, J.C., Heimbach, J.T., 1997. Intake of Naturally Occurring Alkanes. TAS-ENVIRON, (unpublished). Scientific Committee for Food, 1997. Opinion on mineral and synthetic hydrocarbons expressed on 22 September 1995. Reports of the Scientific Committee for Food (37th Series). Office for Official Publications of the European Communities. pp 31–39. Van Battum, D., Rijk, M.A.H., 1975. Migration Experiments With Waxed Papers. TNO Central Institute for Nutrition and Food Research. Report No. o 4813/75, September. Van Battum, D., Rijk, M.A.H., 1977. Migration Experiments With Waxed Papers. Third Report—Determination of Microcrystalline Wax and Paraffin in Fats and Fatty Foods. TNO Central Institute for Nutrition and Food Research. Report No. B76/0110, November. Van Battum, D., Rijk, M.A.H., 1979. Migration experiments with waxed papers. Fifth Report—Results Obtained With Various Foodstuffs. TNO Central Institute for Nutrition and Food Research. Report No. B77/2694, December. Van den Berg, G., Olieman, C., van Riel, J., 1989. Investigation into the Possible Migration of Wax Components Into Cheese. Netherlands Institute for Dairy Research.
The usage, occurrence and dietary intakes of white mineral oils and waxes in Europe D.R. Tennant* Food Chemical Risk Analysis. 14 St Mary’s Square, Brighton BN2 1FZ, UK Received 2 July 2003; accepted 21 October 2003
Abstract Dietary exposures to mineral hydrocarbons were estimated from information about patterns of usage, concentrations in foods and quantities of foods consumed. An industry survey showed that the largest usage of food-grade white mineral oils was in plastics manufacture although the majority are used in non-food applications. The largest volumes of wax usage were in packaging. Conservative estimates indicated that daily intakes of white mineral oils ranged from 0.39 to 0.91 mg/kg bw/day for adults and from 0.75 to 1.77 mg/kg bw/day for children (mean and 97.5th percentiles). Total wax intakes ranged from 0.08 to 0.19 mg/kg bw/ day for adults and 0.23 to 0.64 mg/kg bw/day for pre-school children. When usage factors were applied, estimates of chronic intakes of white oils were reduced to 0.09–0.20 mg/kg bw/day for adults and to 0.17–0.39 mg/kg bw/day for children. Total wax intakes were reduced to 0.01–0.02 mg/kg bw/day for adults and to 0.02–0.06 mg/kg bw/day for children. For white mineral oils the principal source of exposure for most consumers was imported de-dusted grain. The principal source of potential wax exposure was from glazing agents on confectionery. There was no evidence of intakes exceeding SCF ADIs for microcrystalline waxes or certain white mineral oils and levels of exposure were similar to those of naturally-occurring mineral hydrocarbons in foods. # 2003 Elsevier Ltd. All rights reserved. Keywords: Mineral hydrocarbons; White oils; Paraffin; Microcrystalline waxes; Food additives; Usage; Intake; Exposure; Risk assessment
1. Introduction White mineral oils, waxes and petrolatum are widely used in cosmetics, pharmaceuticals, packaging and plastics but also have a variety of minor food-related applications. The Scientific Committee on Food (SCF) of the EU Commission has assessed the available information on the toxicity of mineral and synthetic hydrocarbons (Scientific Committee for Food, 1997). The SCF assigned an acceptable daily intake (ADI) of 0–20 mg/kg bw/day for microcrystalline waxes and a temporary ADI of 0–4 mg/kg bw/day for certain white mineral oils. The function of the SCF has now been transferred to the panel on food additives, flavourings, processing aids and materials in contact with food (AFC) of the European Food Safety Authority (EFSA). In order to estimate intakes to compare with SCF ADIs, it is necessary to identify all uses of mineral hydrocarbons where there is any possibility of transfer * Tel.: +44-1273-241-753; fax: +44-1273-276-358. E-mail address: [email protected] (D.R. Tennant). 0278-6915/$ - see front matter # 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.fct.2003.10.011
to food. These could include use as food additives or components of materials and articles intended to come into contact with food. When a food-related use has been identified, the range of possible levels of particular mineral hydrocarbons in potentially affected foods must be determined. These levels can then be combined with other information about patterns of usage and data on food consumption to create estimates of intake. Usage data were collected for four categories of mineral hydrocarbons: White mineral oils with viscosity of < 65 cSt at 40 C White mineral oils with viscosity of > 65 cSt at 40 C Microcrystalline wax Paraffin wax Petrolatum This was to ensure compatibility with the distinctions used in the SCF evaluation (Scientific Committee for Food, 1997), with JECFA (Joint FAO/WHO Expert Committee on Food Additives and Contaminants) definitions (JECFA, 1995) and with a survey carried out
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previously in the USA for the American Petroleum Institute (API) (Heimbach et al., 2002).
2. Materials and methods 2.1. Usage survey Member companies of the oil industries environment organisation (CONCAWE) were approached to provide data on their white oil sales and respondents included all major manufacturers, which accounted for more than 90% of annual sales volume. The European Wax Federation (EWF) organised a separate survey of major wax and petrolatum producers, which represented over 95% of market volume. Additional information from re-sellers of mineral hydrocarbon products confirmed the usage patterns provided by the producers.
It was estimated that 140,000 tonnes of white oil is used in the EU for food-related applications per annum (Table 1). Oils less than 65 cSt at 40 C account for about 10% of total usage and the remainder is oils greater than 65 cSt at 40 C. The major applications are plastics and elastomer manufacture and food machinery lubricants, which together account for about 97% of white oil sales. Gross European wax usage is estimated to be about 50,000 tonnes per annum (Table 2). The principal foodrelated applications are: wax-coated packaging, cheese coatings and in chewing gum base. About 60% of sales are used in packaging applications. Petrolatum is a blend of approximately equal proportions of white oils and waxes. Total European sales in food-related uses are estimated to be no more than 600 tonnes (Table 3). About 83% of this volume is associated with bottle seals including cork lubricants.
Table 1 European uses of white mineral oils in food-related applications (1999) Application
Percentage of total usage
Percentage of volume <65 cSt @ 40 C
Polystyrene Food machinery lubricants Elastomers Polyethylene Bakery release agents Polypropylene Confectionery Jute batching oil Sausage skin Divider oils Miscellaneous
85 6 4 2 1 1 <1 <1 <1 <1 1
>65 cSt @ 40 C 100 32 45 100 36 77
68 55 64 23 100 100 100 100a
*
a The white oil industry estimates that the ratio of oils <65 cSt to oils >65 cSt used as dough dividers is 40:60 at the time of publication of this report. This ratio will be used in intake calculations.
Table 2 European uses of mineral wax in food-related applications (1999) Application
Percentage of total usage
Percentage of volume Paraffin
Flexible packaging Wax-coated Wax laminateda Corrugated cartons Curtain coatinga Saturating wax Cheese coatings Chewing gum/base Fruit coatings Poultry de-feathering Folding cartons Paper cold drinks containers Bottle sealing (inc. corks) Confectionery (excluding chocolate) Miscellaneous a
Limited direct contact with food.
Micro-crystalline
33 8
90 40
10 60
10 7 16 14 2 3 2 2 1 <1 <1
83 100 50 25
17
75 100 80 100
50 75 100 25 20 100
D.R. Tennant / Food and Chemical Toxicology 42 (2004) 481–492
3. Data on levels and incidences of mineral hydrocarbons in foods 3.1. White mineral oils Potential levels of mineral hydrocarbons in food were identified in a review of the scientific literature and from information provided by industry and other sources (Tables 4 and 5). White mineral oils with viscosity greater than 65 cSt at 40 C are used as plasticisers in the production of polystyrene and styrene-containing co-polymers. The Ministry of Agriculture Fisheries and Food (MAFF) UK investigated the migration of mineral hydrocarbons from drinks containers used in drinks vending machines (Castle et al., 1992). Levels of hydrocarbons in drinks held in polystyrene containers would not be expected to exceed 1 mg/kg under the most extreme circumstances (Table 4). MAFF also conducted studies on the migration of hydrocarbons from polystyrene and acrylonitrile/ butadiene/styrene copolymers from containers for fats and dairy products (Castle et al., 1993a). No migration of mineral hydrocarbons from standard sized pots into yoghurt or cream was detected. About 1.4% of the available mineral oil migrated into milk and cream packaged in individual portion containers. MAFF reported further studies of migration of mineral oils from polystyrene into individual serving containers (Jickells et al., 1995). Levels of mineral hydrocarbons were generally below limits of detection. A Polystyrene Work Group of the US Society of the Plastics Industry (SPI) has also investigated potential exposure to mineral oil from food-contact use of polystyrene resins (Polystyrene Work Group, 1996). The group concluded that potential exposure to mineral oil from food-contact uses of polystyrene was insignificant (0.001 mg/kg bw/day). About 30% of European production of low density polyethylene is manufactured using a process that requires the use of white oil as a lubricant, which can become incorporated into the polyethylene. Grob et al. investigated the transfer of mineral oils from films containing 0.83% paraffins into vacuum packed cheese and found 4 mg/kg in the surface layer (Grob et al., 1991a). A second polyethylene film sample contained 1.7% mineral oil and vacuum-packed salami slices (1 mm) in direct contact with the film contained 35 mg/kg. Table 3 European uses of petrolatum in food-related applications Application
Percentage of volume
Confectionery (as processing aid) Bottle sealing (inc. corks) Miscellaneous
17 83 <1
483
If a salami pack contained 10 stacked slices then the average concentration would be 7 mg/kg (Table 4). Given the very small white mineral oil sales volume for polypropylene compared to polystyrene and polyethylene, combined with information about the very low migration from those polymers, polypropylene was not expected to be a significant source of exposure. Before the introduction of ‘non-stick’ materials, mechanised bread manufacture required the use of lubricants to prevent bread from adhering to the pans and for the lubrication of dough handling machinery. In 1991 Grob et al. detected hydrocarbons in the bottom crusts of bread (Grob et al., 1991a). MAFF scientists also reported that mineral oils were present in UK bread samples at raised levels (Castle et al., 1994). Largely as a consequence of these findings, the majority of mineral hydrocarbons used as bakery release agents have been replaced by water/vegetable oil emulsions. Some minor use of dough divider oils in older mechanised bread equipment was reported. To cover this limited use the average core level reported by Castle et al. (243 mg/kg, Table 4) was taken to represent a conservative estimate (Castle et al., 1994). MAFF UK analysed samples of skinless sausages to investigate levels of mineral hydrocarbons (Castle et al., 1993b). The average mineral hydrocarbon concentration in all of the skinless sausage products tested was 28.3 mg/kg (Table 4). MAFF UK reported the presence of lubricants in canned foods and beverages in 1994 (Jickells et al., 1994). In retail food samples, mineral oil levels ranged from < 0.1 to 4.2 mg/kg and the weighted average was approximately 0.6 mg/kg. Industry sources advised that white mineral oils are no longer used in aluminium can manufacture and that emulsions (based on fatty materials but not white oil) are used in their place. Exposure was therefore not significant (Table 4). Machinery that is used in the manufacture, processing and presentation of food requires lubrication and food grade white mineral oils and petrolatum are frequently used for this function (Anon, 1995). MAFF UK found that processed meat products are not significantly contaminated with mineral hydrocarbons (Jickells et al., 1994). In 1991 Grob et al. reported that white oil concentrations were raised in eight out of 24 boiled sweets and caramels analysed (Grob et al., 1991a). Extensive enquiries were made throughout the confectionery industry and no current use of white mineral oils in direct contact with food was reported. Natural products are now used for this purpose. Exposure was therefore not significant (Table 4). Jute sacking requires dressing with oil (jute batching) in order to maintain flexibility and to act as a preservative. In 1991 Grob et al. analysed samples of cocoa bean kernels and found levels of about 10 mg/kg (Grob et al., 1991b). MAFF UK analysed 40 samples of
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for dust suppression, then the effect on mineral hydrocarbon (MHC) intakes can be considered. Levels of MHCs in imported grain were taken from the report prepared for the American Petroleum Institute (Heimbach et al., 2002, Table 4). Trade statistics were used to estimate the proportion of the domestic supply that is imported. The possibility that white bread consumed in France could be made from wheat treated with white mineral oils was accounted for by assuming that 100% of white bread is produced from such grain.
chocolate which contained < 1 to 60 mg/kg (average=7 mg/kg, Table 4) (Ministry of Agriculture, Fisheries and Food, 1993). Except in France (which has a temporary approval for the use of white oil less than 65 cSt at 40 C for dust suppression in granaries for white bread manufacture), white mineral oils are not used as grain de-dusting agents in Europe. As part of a submission to the French authorities it was shown that the addition of 200 mg/kg to grain leads to a maximum level of mineral oil in bread of 10 mg/kg (Table 4). The use of white mineral oils for grain dust suppression is common practice in some non-European countries that export grain to Europe. If it is assumed that all of the cereals and vegetable oils imported into the EU are derived from countries that permit the use of white oil
3.2. Mineral waxes Because of their hydrophobic nature, mineral hydrocarbon waxes are not expected to migrate into non-fatty foods. Where transfer into foods does occur,
Table 4 Potential levels of white mineral oils in food reported in literature Application medium
Mineral oil concentration (mg/kg)
Comment
<65 cSt at 40 C
> 65 cSt at 40 C
– – –
<1 <1 < 5–93
n.s. n.s.
n.s. n.s.
n.s.
n.s.
Polyethylene Containers Delicatessen meats Surface coating of tableware
– – –
n.s. 7 n.s.
Bakery release agents/divider oils Bread
243
Polypropylene Food wraps
n.s.
Confectionery Sugar confectionery Chocolate
250 50
Polystyrene Drink containers Milk/yoghurt containers Individual milk/cream containers Food machine lubricants Press lubricants Other lubricants Elastomers Seals
Jute batching oil Chocolate Temporary sausage skins Skinless sausages Grain/seed de-dusting Bread Flours and cereals Vegetable oils Miscellaneous n.s. Not a significant source of exposure.
or
243
Not significant—occasional use
Very limited use
n.s.
or or
250 50
7
–
28.3
–
10 9–42 110
– –
n.s.
n.s.
Now obsolete Now obsolete
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paper showed little or no wax transfer. A study by the NATEC Institute (NATEC Institute fu¨r naturwissenschaftlich technische Dienste) found relatively low migration of 9 mg/dm2, which is more consistent with the TNO results (Figge and Beiber, 1987). The French packaging organisation ADRIAC (Reims Champagne Ardenne University, Research and Development Centre on Food Packaging.) investigated migration into cheese and meat (ADRIAC, 1999). The results indicated that migration can occur, which increases with duration of contact. The average concentration measured in cheese spread after 1 week was 7 mg/kg (Table 5). For fatty ham, no wax was detected above the detection limit of 1.0 mg/kg (Table 5).
this is not governed by diffusion but by adhesion or incomplete removal of coatings from the food. Between 1975 and 1979 TNO (The Netherlands Organisation for Applied Scientific Research) investigated migration of wax from various paper coatings into foods (Van Battum and Rijk, 1975, 1977, 1979). Migration of wax into foods was low suggesting that wax-coated paper was unlikely to be a significant source of exposure. Grob et al. analysed fat from meat samples that had been kept for 4 days in a refrigerator in a wax-coated card box and found paraffin wax levels to be less than 1 mg/kg (Grob et al., 1991c, Table 5). High paraffin wax concentrations were detected in individual salami slices stored in direct contact with waxed paper. However, slices not in direct contact with the Table 5 Potential levels of mineral waxes in food reported in literature Application
Medium
Wax concentration (mg/kg) Paraffinic
Comment Micro-crystalline
Flexible packaging Wax coated Sliced cheese Sliced meats Biscuits Cereals Bread Sugar confectionery Ice-cream Bouillon cubes Wax laminated Cartons Curtain coated Saturating wax Milk/cream
7 <1 105 105 29 52 n.s. n.s. n.s.
or or or or or or
n.s.
.
<1
7 <1 105 105 29 52 n.s. n.s. n.s.
No direct contact No direct contact
n.s.
No direct contact
–
No direct contact
Obsolete
Cheese coatinga Gouda, Edam, etc. Chewing gum/base
4.4
or
4.4
n.s.
n.s.
–
200
Fruit coatings Tropical fruit peel
No direct contact
Poultry de-feathering Duck meat
9
or
9
Folding cartons
n.s.
–
Paper cold drink cups
n.s.
n.s.
Bottle sealing
n.s.
Confectionery Chewing gum Non-chocolate confectionery Miscellaneous
– –
200 200
n.s.
n.s
n.s. Not a significant source of exposure. a Only a small proportion of wax-coated cheeses have direct contact between cheese and wax.
Glazing agent Glazing agent
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MAFF UK investigated the migration of waxes from waxed paperboard milk containers (Castle et al., 1993a). Levels were below detection limits. Later studies showed that packing crispbreads, crackers and cereals in waxed paper could result in mineral hydrocarbon concentrations of 20–185 mg/kg (average=105 mg/kg, Table 5) (Castle et al., 1994). Retail samples of bread were analysed for mineral waxes in the base, outer crust and the core material separately (Castle et al., 1994). Wax concentrations were highest on the bread surfaces, indicating transfer from the waxed paper. The overall average concentration in bread wrapped in waxed paper was 29 mg/kg (Table 5). Retail samples of confectionery that were wrapped in waxed paper were analysed for mineral hydrocarbons in 1991 (Grob et al., 1991a). Boiled sweets were found to have lower wax levels (average, 104 mg/kg) than the more ‘sticky’ chews and toffees (average, 560 mg/kg). It was also found that bonbons wrapped in waxed paper contained up to 200 mg/kg paraffin waxes (Castle et al., 1994). In contrast, Kemp and Beemsterboer found levels less than 20 mg/kg in 1992 and of this only about 25% appeared to come from the wrapper (Kemp and Beemsterboer, 1992). In 1994 the German Food Surveillance authorities analysed 29 types of commercially available sweets for hydrocarbon contamination. The average concentration was 52 mg/kg (ranging from 10 to 556 mg/kg, Table 5). The European sugar confectionery industry has largely moved to more suitable materials such as higher melting wax blends (with more cohesive strength due to polymer addition) or products based on non-mineral waxes. It can therefore be expected that current levels of MHC in confectionery are lower than those reported previously. Several traditional varieties of cheese employ a wax coating that protects the cheese from desiccation and mould growth. Some cheeses may be matured in polyvinyl acetate and then ‘packed’ in a wax coating for protection during storage and transport. MAFF UK analysed samples of wax-coated cheese with, and without the polyvinyl acetate barrier layer (Castle et al., 1993b). Levels of mineral hydrocarbons ranged from < 1.0 to 27 mg/kg. Four samples that had a plastic barrier layer showed no detectable residues. The average concentration in cheese coated with wax was 4.4 mg/kg (Table 5). The Netherlands Institute for Dairy Research found that mineral hydrocarbons were concentrated in the first 1 mm of the cheese rind, which is normally discarded by the consumer (Van den Berg et al., 1989). Grob found levels of 3–25 mg/kg in the 5mm top layer of cheese nearest to the wax (Grob et al., 1991a). The use of mineral waxes in chewing gum base is not regulated as a food additive (European Parliament and Council, 1995). Under normal conditions of mastication, mineral hydrocarbons do not leach into gastro-intestinal fluids or saliva (Modderman, 1992).
Even in the presence of food lipids, leachates did not contain mineral hydrocarbons above the analytical limit of determination. European Directive 98/72/EC amends Directive 95/2/ EC to permit the use of microcrystalline wax as a the surface treatment and allocates an E-number (E 905). Microcrystalline wax may be used quantum satis in: Confectionery excluding chocolate; Chewing gum; Melons, papaya, mango and avocado. The use of microcrystalline wax as a glazing agent on confectionery and chewing gum commands only 100 tonnes of product throughout Europe annually, suggesting that this is a minor use. The maximum concentration of wax detected in confectionery was 200 mg/kg and so this figure was used as a conservative default in intake calculations (Table 5). The peel of melons, papaya, mango and avocado are unlikely to be consumed and so were excluded from intake calculations. Ducks may be dipped in wax after slaughter and plucking in order to assist the removal of residual feathers. MAFF UK (Dennis et al., 1987) and EWF (Kemp, 1991) have investigated levels of wax in and on ducks. No hydrocarbons were reported in flesh and levels of 8–120 mg/kg were reported on the skin. The average concentration of mineral hydrocarbon in whole duck, based on the MAFF data would be 9 mg/kg (Table 5). Coatings for paper cold drink cups and other disposable containers are a minor use for waxes. Their use in beverage cups and disposable plates is unlikely to result in significant exposure because migration into milk is below detection limits (Castle et al., 1993a). Most of such containers do not use wax but instead employ a polyethylene coating. 3.3. Petrolatum Very low volumes of petrolatum are associated with confectionery. Any minor use in confectionery manufacture will have been represented in the oil and wax studies (Tables 4 and 5) because petrolatum is a mixture of oil and wax. The only other potentially significant source of exposure to mineral hydrocarbons from petrolatum is from bottle sealing. MAFF UK have analysed corks and samples of wine for mineral hydrocarbons (Jickells et al., 1995). The migration of mineral hydrocarbons from treated corks into wines was not detectable above background levels.
4. Estimating consumer intakes The EU Scientific Committee for Food has issued no specific guidance on methods for estimating intakes.
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However, there is a general recommendation that individuals with high level intakes should be considered (Pascal, 1995). In order to provide accurate intake estimates for high consumers it is necessary to have access to the raw data from food consumption surveys conducted at an individual level, that includes children. An important potential source of mineral hydrocarbon exposure is from packaging and from processed foods, which tend to be associated with each other. MPA (Maurice Palmer Associates) survey data suggest that the Benelux countries (Belgium, Luxembourg, The Netherlands) and the UK have the highest packaging use (Maurice Palmer Associates, 1997). However, this result may be misleading because Benelux countries, particularly the Netherlands are net exporters of packaged foods, whereas the UK is a net importer. UK consumers therefore probably represent a ‘worst case’ example of European countries for mineral hydrocarbon intake studies. Anticipated levels of white mineral oils and waxes reported in Tables 4 and 5. In reality, mineral hydrocarbons exist in a competitive market and there are usually alternatives available. Therefore intake estimates based on Tables 4 and 5 will provide an upper bound estimate. Intake estimates should be averaged over a time period that corresponds to that used in the toxicology studies that were used as the basis for calculating the ADI (Renwick, 1999). In the case of mineral hydrocarbons the most recent studies were of 2 years duration, which would be equivalent to about 70 years
for man. Intake estimates based on four or seven day food consumption surveys are likely to over-estimate relevant intakes. In addition, differentiation between intakes of different classes of mineral hydrocarbons (i.e. less than or greater than 65 cSt oils; paraffin or microcrystalline wax) requires consideration of the distribution of uses given in Tables 1 and 2. Where more than one class of oil or wax could be used, the MPA survey of flexible packaging products (Maurice Palmer Associates, 1997) provides data on the quantities of packaging used in various sectors including certain food sectors. The results of packaging market share surveys for waxed paper can be combined with other information about wax usage to generate realistic adjustment factors for long-term exposure (Table 6). Few data are available for white oil uses to make realistic adjustments for long-term intakes. However, the MPA report includes the results of a survey of industrial bread production in western Europe during 1995. Where adjustment factors were not available, a factor of 100% was used in order to maintain a conservative approach. The sources of food consumption data from the UK used in this study were the National Dietary and Nutrition Surveys (NDNS) of adults aged 16–65 (Gregory et al., 1990) and of children aged 1 1/2 to 4 1/2 years (Gregory et al., 1995). The data comprise 7 day or 4 day records of all foods consumed by approximately 2000 individuals in each survey. Each food that was consumed was individually weighed and recorded and
Table 6 Usage volume ratios and adjustment factors for moderating mineral hydrocarbon exposures Application
White oil Polyethylene Bakery divider oils Confectionery Confectionery Jute batching oil Temp sausage skins Grain de-dusting Wax Waxed paper
Cheese coating Fruit/vegetable coatings Duck de-feathering Confectionery n.a. not available. n.s. not significant.
Medium
Usage ratio
Adjustment factor
<65 cSt
>65 cSt
Sliced meats Bread Sugar confectionery Chocolate Chocolate Skinless sausages Cereals
– 40 68 68 100 100 100
100 60 32 32 – –
n.a. 20 n.a. n.a. n.a. n.a. 6 to 31
Sliced cheese Sliced meats Biscuits Cereals Bread Sugar confectionery Gouda, Edam, etc. Tropical fruit Duck meat Chewing gum Non-chocolate confectionery
90 90 90 90 90 90 50 – 75 – –
10 10 10 10 10 10 50 100 25 100 100
8 4 8 4 7 9 10 n.s. 100 10 10
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as used in the intake calculations for white mineral oils and waxes. Consumption figures are provided for the entire sample population (per capita) and for only those who reported consumption of each food (consumers only). Note that in distributional analyses columns of figures relating to upper percentiles and ‘consumers only’ means do not add up to the total for consumers of all the foods. This is because the individual food statistics represent sub-populations who consumed those foods.
over 4000 food descriptions are included in the databases. Since data are available for each individual who participated in the surveys it is possible to derive distributional statistics (90th and 97.5th percentiles) to represent ‘high-level’ consumption. Data can also be provided on a bodyweight basis by dividing food consumption by each individual’s body weight. Tables 7 and 8 provide data on the amounts of foods consumed, Table 7 Food consumption figures used in white mineral oil intake calculations Source
Food
Food consumption (g/day) Consumers (%)
Per capita
Consumers only
Mean
90th%ile
97.5th%ile
Mean
90th%ile
97.5th%ile
Adults Polyethylene Divider oils Jute batching Temporary skins Grain de-dusting All sources
Sliced meats Bread Chocolate Sausages Cerealsa
44 98 59 56 100 100
6 88 4 11 110 219
18 160 11 30 179 357
32 225 22 53 228 475
13 90 6 20 110 219
27 164 14 40 179 357
41 228 27 63 228 475
Pre-school children Polyethylene Divider oils Jute batching Temporary skins Grain de-dusting All sources
Sliced meats Bread Chocolate Sausages Cerealsa
19 96 71 47 100 100
1 34 5 7 49 96
6 61 12 23 79 152
12 85 23 39 103 198
7 35 7 16 49 96
14 64 14 31 79 152
22 87 26 47 103 198
a
Consumption of cereal-containing foods.
Table 8 Food consumption figures used in mineral wax intake estimates Source
Food
Food consumption (g/day) Consumers (%)
Adults Waxed paper
Cheese coating Poultry de-feathering Confectionery glazing All sources Pre-school children Waxed paper
Cheese coating Poultry de-feathering Confectionery glazing All sources
Per capita
Consumers only
Mean
90th%ile
97.5th%ile
Mean
90th%ile
97.5th%ile
Sliced cheese Biscuits/crackers Bread Sugar confectionery Wax-coated cheese Duck Sugar confectionery
76 78 100 20 6 1 20 100
14 15 111 1 1 0 1 142
34 36 191 4 0 IC 4 236
55 61 263 15 11 IC 15 312
19 19 111 7 12 14 7 143
38 40 191 18 24 IC 18 236
58 68 263 32 43 IC 32 313
Sliced cheese Biscuits/crackers Bread Sugar confectionery Wax-coated cheese Duck Sugar confectionery
47 79 97 43 4 0 43 100
4 10 38 5 0 0 5 57
13 23 71 15 0 IC 15 95
23 36 95 27 5 IC 27 128
9 12 39 11 9 9 11 57
19 26 71 23 16 IC 23 95
28 37 96 34 24 IC 34 128
IC—Insufficient consumers.
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The ‘bread’ category used for wax intakes from wrapped bread is slightly broader than that used for white mineral oils from divider oils. This is because the wax category includes some speciality breads that might be wrapped in waxed paper but are unlikely to be industrially produced. Intakes were calculated using distributional methods based on raw data from the food consumption surveys. A mineral or naturally occurring hydrocarbon concentration is assigned to each relevant food and then multiplied by the amount of food consumed on each eating occasion to generate an intake figure. The total intake is summed for each individual and then divided by the number of days in the survey and the individuals’ body weight to give the average daily intake for that individual.
5. Results 5.1. White mineral oils Conservative estimates for consumers only, indicate that total potential intakes of white mineral oils range from 0.39 to 0.91 mg/kg bw/day for adults and 0.75– 1.77 mg/kg bw/day for children, at the mean and 97.5th percentiles (Table 9). The principal source of intake appears to be the use of white mineral oils as bakery divider oils, approximately equally divided between oils less that 65 cSt and oils greater than 65 cSt. The use of white mineral oils as dough divider oils is a declining practice limited to older designed industrial bakeries and so higher intakes would be limited to a small minority of
Table 9 White mineral oil intakes—consumers only Source
Food
Oil concn. (mg/kg)
Intake (mg/kg bw/day) Consumers (%)
Adults Polyethylene Divider oils Jute batching Temporary skins Grain de-dusting All sources
Sliced meats Bread Chocolate Sausages Cereals
Pre-school children Polyethylene Divider oils Jute batching Temporary skins Grain de-dusting All sources
Sliced meats Bread Chocolate Sausages Cereals
7 243 7 28 40- 110
7 243 7 28 40–110
<65 cSt
>65 cSt
Mean
90th
97.5th
44 98 59 56 100 100
0.127 0.001 0.008 0.077 0.206
0.226 0.002 0.016 0.127 0.347
0.311 0.003 0.025 0.166 0.459
19 96 71 47 100 100
0.237 0.003 0.030 0.161 0.406
0.430 0.007 0.061 0.258 0.677
0.600 0.013 0.090 0.345 0.908
Total
Mean
90th
97.5th
Mean
90th
97.5th
0.001 0.191
0.003 0.340
0.004 0.468
0.187
0.340
0.467
0.001 0.317 0.001 0.008 0.077 0.393
0.003 0.566 0.002 0.016 0.127 0.683
0.004 0.780 0.003 0.025 0.166 0.911
0.004 0.357
0.007 0.647
0.011 0.898
0.343
0.642
0.873
0.004 0.594 0.003 0.030 0.161 0.749
0.007 1.077 0.007 0.061 0.258 1.352
0.011 1.495 0.013 0.090 0.345 1.772
Table 10 White mineral oil intakes- consumers only, application adjusted Source
Food
Oil conc. (mg/kg)
Intake (mg/kg bw/day) Consumers (%)
Adults Polyethylene Divider oils Jute batching Temporary skins Grain de-dusting All sources Pre-school children Polyethylene Divider oils Jute batching Temporary skins Grain de-dusting All sources
Sliced meats Bread Chocolate Sausages Cereals
Sliced meats Bread Chocolate Sausages Cereals
7 243 7 28 40–110
7 243 7 28 40- 110
< 65 cSt
>65 cSt
Mean
90th
97.5th
44 98 59 56 100 100
0.025 0.001 0.008 0.018 0.044
0.045 0.002 0.016 0.030 0.078
0..62 0.003 0.025 0.042 0.106
19 96 71 47 100 100
0.048 0.003 0.030 0.038 0.100
0.086 0.007 0.061 0.061 0.163
0.119 0.013 0.090 0.087 0.213
Total
Mean
90th
97.5th
Mean
90th
97.5th
0.001 0.038
0.003 0.068
0.004 0.094
0.038
0.068
0.095
0.001 0.068 0.001 0.008 0.018 0.086
0.003 0.113 0.002 0.016 0.030 0.146
0.004 0.156 0.003 0.025 0.042 0.198
0.004 0.071
0.007 0.129
0.011 0.180
0.069
0.129
0.177
0.004 0.119 0.003 0.030 0.038 0.169
0.007 0.215 0.007 0.061 0.061 0.282
0.011 0.299 0.013 0.090 0.087 0.390
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consumers who consistently purchased and consumed bread produced in such plants. For the majority of consumers the most important source of exposure is probably form de-dusting agents in imported cereals. When the proportion of bread that is industrially manufactured, and the proportion of cereals that are imported are taken into account (see Table 6), total white oil intakes are reduced to 0.09–0.20 mg/kg bw/day for adults and to 0.17–0.39 mg/kg bw/day for pre-school children (Table 10). True high level intakes probably lie between those calculated on that basis of all potential foods containing white mineral oils (Table 9) and those calculated using the proportions of industrially manufactured bread and imported cereals (Table 10). This is because consumers could always select industrially produced bread and foods made from imported cereals, but this is unlikely to be sustained in the longer term.
However, when the proportion of foods that are wrapped in waxed paper or to which wax is applied are taken into account (see Table 6), total wax intakes are reduced to 0.01–0.02 mg/kg bw/day for adults and to 0.02 to 0.06 mg/kg bw/day for pre-school children (Table 12). The use of microcrystalline wax as a confectioneryglazing agent (E905) followed by transfer from waxed paper into biscuits/crackers and bread remain the principal sources of exposure. True high level intakes probably lie between those calculated on that basis of all potential foods containing waxes (Table 11) and those calculated using the proportions of food wrapped in wax paper or coated (Table 12). This is because although consumers could always select wax paper wrapped or wax-coated foods, this is unlikely to occur in the longer term.
6. Discussion 5.2. Mineral waxes Total wax potential intakes ranged from 0.08 to 0.19 mg/kg bw/day for adults and 0.23 to 0.64 mg/kg bw/day for pre-school children at the mean and 97.5th percentiles (Table 11). For adults the principal sources of exposure were the use of paraffin waxed paper to wrap bread, biscuits and crackers. For pre-school children the most important source of exposure was the use of microcrystalline wax as a confectionery-glazing agent (E905) followed by the transfer of paraffin wax from waxed paper into biscuits/crackers and bread.
Hydrocarbons occur as natural constituents of many foods, particularly those that are fatty or oily. Reich et al. have reviewed the literature on levels of naturally occurring alkanes (Reich et al., 1997). Total US intake was reported to be 0.189 mg/kg bw/day. Using the same data on levels, average intakes of naturally occurring hydrocarbons by European consumers were estimated to range from 0.33 mg/kg bw/day in the UK to 0.61 mg/ kg bw/day in Germany (European average is 0.47 mg/ kg bw/day). The principal sources of exposure were apples, wheat and dairy fat.
Table 11 Mineral wax intake–consumers only Source
Food
Wax concn. (mg/kg)
Intake (mg/kg bw/day) Consumers (%)
ADULTS Waxed paper
Cheese coating Poultry de-feathering Confectionery glazing All sources Pre-school children Waxed paper
Cheese coating Poultry de-feathering Confectionery glazing All sources
Sliced cheese Biscuits/crackers Bread Sugar confectionery Wax-coated cheese Duck Sugar confectionery All above foods
7 105 29 52 4.4 9 200
Sliced cheese Biscuits/crackers Bread Sugar confectionery Wax-coated cheese Duck Sugar confectionery All above foods
7 105 29 52 4.4 9 200
Paraffin
Microcrystalline
Total
Mean
90th
97.5th
Mean
90th
97.5th
Mean
90th
97.5th
76 78 98 20 6 1 20 100
0.002 0.027 0.042 0.005 0.000 0.001
0.003 0.057 0.071 0.013 0.001 IC
0.005 0.096 0.096 0.025 0.001 IC
0.066
0.111
0.152
0.000 0.003 0.005 0.001 0.000 0.000 0.021 0.012
0.000 0.006 0.008 0.001 0.001 IC 0.054 0.021
0.001 0.011 0.011 0.003 0.001 IC 0.108 0.056
0.002 0.030 0.047 0.006 0.001 0.002 0.021 0.077
0.004 0.064 0.078 0.014 0.002 IC 0.054 0.133
0.006 0.106 0.107 0.028 0.003 IC 0.108 0.192
47 79 96 43 4 0 43 100
0.004 0.082 0.071 0.034 0.001 0.004
0.008 0.166 0.128 0.073 0.002 IC
0.012 0.247 0.166 0.102 0.003 IC
0.150
0.266
0.348
0.000 0.009 0.008 0.004 0.001 0.001 0.145 0.079
0.001 0.018 0.014 0.008 0.002 IC 0.308 0.231
0.001 0.027 0.018 0.011 0.003 IC 0.434 0.402
0.005 0.091 0.079 0.038 0.003 0.005 0.145 0.229
0.009 0.185 0.142 0.081 0.005 IC 0.308 0.444
0.014 0.275 0.184 0.113 0.007 IC 0.434 0.640
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Food
Wax concn. (mg/kg)
Intake (mg/kg bw/day) Application (%)
Adults Waxed paper
Cheese coating Poultry de-feathering Confectionery glazing All sources Pre-school children Waxed paper
Cheese coating Poultry de-feathering Confectionery glazing All sources
Sliced cheese Biscuits/crackers Bread Sugar confectionery Wax-coated cheese Duck Sugar confectionery All above foods
7 105 29 52 4.4 9 52
Sliced cheese Biscuits/crackers Bread Sugar confectionery Wax-coated cheese Duck Sugar confectionery All above foods
7 105 29 52 4.4 9 52
8 8 7 9 100 100 10
8 8 7 9 100 100 10
Estimates of total potential intakes of white mineral oils for EU consumers ranged from 0.09 to 0.91 mg/kg bw/day for adults and 0.17 to 1.77 mg/kg bw/day for children, at the mean and 97.5th percentiles respectively, depending on assumptions made (e.g. manufactured bread, imported cereals). The main source of potential intake appears to be the use of white mineral oils as bakery divider oils although for most consumers the most important source of exposure is probably form de-dusting agents in imported cereals. Potential intakes of total wax for EU consumers ranged from 0.01 to 0.19 mg/kg bw/day for adults and 0.02 to 0.64 mg/kg bw/day for pre-school children at the mean and 97.5th percentiles respectively, depending on assumptions made (e.g. use of packaging). For adults the principal sources of potential exposure was the use of paraffin waxed paper. For pre-school children the most important source of potential exposure was the use of microcrystalline wax as a confectionery-glazing agent (E905). No single figure can adequately represent the intake of any substance. This is because levels of chemicals in food are variable as are the amounts of food consumed by different individuals. Furthermore the accuracy of estimates of intake are affected by three sources of uncertainty: 1. The quality of data on the levels and occurrence of hydrocarbons in food; 2. The quality of data on the consumption of affected foods; and
Paraffin
Microcrystalline
Total
Mean
90th
97.5th
Mean
90th
97.5th
Mean
90th
97.5th
0.000 0.002 0.003 0.000 0.000 0.001
0.000 0.005 0.005 0.001 0.001 IC
0.000 0.008 0.007 0.002 0.001 IC
0.005
0.008
0.012
0.000 0.000 0.000 0.000 0.000 0.000 0.002 0.001
0.000 0.001 0.001 0.000 0.001 IC 0.005 0.002
0.000 0.001 0.001 0.000 0.001 IC 0.011 0.005
0.000 0.002 0.003 0.001 0.001 0.002 0.002 0.006
0.000 0.005 0.005 0.001 0.002 IC 0.005 0.010
0.000 0.009 0.007 0.003 0.003 IC 0.011 0.015
0.000 0.007 0.005 0.003 0.001 0.004
0.001 0.013 0.009 0.007 0.002 IC
0.001 0.020 0.012 0.009 0.003 IC
0.011
0.021
0.027
0.000 0.001 0.000 0.000 0.001 0.001 0.014 0.008
0.000 0.001 0.001 0.001 0.002 IC 0.031 0.023
0.000 0.002 0.001 0.001 0.003 IC 0.043 0.040
0.000 0.007 0.006 0.003 0.003 0.005 0.014 0.019
0.001 0.015 0.010 0.007 0.005 IC 0.031 0.038
0.001 0.022 0.013 0.010 0.007 IC 0.043 0.058
3. Assumptions inherent in the method used for analysis. Data on the levels and occurrence of mineral hydrocarbons in food are generally drawn from analytical studies which are several years old and which have limited numbers of samples. Such samples may have been selected because the analyst is expecting to find traces and thus some bias could be introduced. Nevertheless data have been obtained about all significant uses of mineral hydrocarbons associated with food and used as the basis for intake calculations. Mineral hydrocarbon intake estimates based on the assumption that all foods that might contain traces of mineral hydrocarbons actually do, are likely to over-estimate true intakes in the longer term. Information about the proportion of foods that contain traces of mineral hydrocarbons can be used to make more realistic estimates of chronic intake. However, the possibility that certain consumers could always choose particular foods that contain traces of mineral hydrocarbons means that true intakes probably lie between these extremes. Obtaining precise estimates of mineral hydrocarbon intakes is extremely difficult because of uncertainties in the data. However, intake estimates based on the most conservative assumptions provide no indication that the SCF ADIs for certain white mineral oils (0–4 mg/kg bw/ day) and microcrystalline waxes (0–20 mg/kg bw/day) would be exceeded. Levels of exposure are similar to those experienced with naturally-occurring mineral hydrocarbons in foods.
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Acknowledgements The author wishes to thank the European oil industry environment organisation (CONCAWE) and the European Wax Federation (EWF) for supplying information and financial support for this project.
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