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Comparing REACH Chemical Safety Assessment information with practice—a case-study of polymethylmethacrylate (PMMA) in floor coating in The Netherlands
G Model
ARTICLE IN PRESS
IJHEH-13091; No. of Pages 5
International Journal of Hygiene and Environmental Health xxx (2017) xxx–xxx
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International Journal of Hygiene and Environmental Health journal homepage: www.elsevier.com/locate/ijheh
Short communication
Comparing REACH Chemical Safety Assessment information with practice—a case-study of polymethylmethacrylate (PMMA) in floor coating in The Netherlands Ton Spee a,b,1 , Daan Huizer c,∗ a
Arbouw, Harderwijk, the Netherlands Institute for Risk Assessment Sciences (IRAS), Utrecht University, the Netherlands c Caesar Consult, Nijmegen, the Netherlands b
a r t i c l e
i n f o
Article history: Received 31 January 2017 Received in revised form 12 April 2017 Accepted 29 May 2017 Keywords: Occupational exposure Exposure modelling Risk management measures Exposure measurement Methyl methacrylate
a b s t r a c t On June 1st, 2007 the European regulation on Registration, Evaluation and Restriction of Chemical substances (REACH) came into force. Aim of the regulation is safe use of chemicals for humans and for the environment. The core element of REACH is chemical safety assessment of chemicals and communication of health and safety hazards and risk management measures throughout the supply chain. Extended Safety Data Sheets (Ext-SDS) are the primary carriers of health and safety information. The aim of our project was to find out whether the actual exposure to methyl methacrylate (MMA) during the application of polymethylmethacrylate (PMMA) in floor coatings as assessed in the chemical safety assessment, reflect the exposure situations as observed in the Dutch building practice. Use of PMMA flooring and typical exposure situations during application were discussed with twelve representatives of floor laying companies. Representative situations for exposure measurements were designated on the basis of this inventory. Exposure to MMA was measured in the breathing zone of the workers at four construction sites, 14 full shift samples and 14 task based samples were taken by personal air sampling. The task-based samples were compared with estimates from the Targeted Risk Assessment Tool (v3.1) of the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOCTRA) as supplied in the safety assessment from the manufacturer. For task-based measurements, in 12 out of 14 (86%) air samples measured exposure was higher than estimated exposure. Recalculation with a lower ventilation rate (50% instead of 80%) together with a higher temperature during mixing (40 ◦ C instead of 20 ◦ C) in comparison with the CSR, reduced the number of underestimated exposures to 10 (71%) samples. Estimation with the EMKG-EXPO-Tool resulted in unsafe exposure situations for all scenarios, which is in accordance with the measurement outcomes. In indoor situations, 5 out of 8 full shift exposures (62%) to MMA were higher than the Dutch occupational exposure limit of 205 mg/m3 (8 h TWA), which equals the DNEL. For semi-enclosed situations this was 1 out of 6 (17%). Exposures varied from 31 to 367 mg/m3 . The results emphasize that ECETOC-TRA exposure estimates in poorly controlled situations need better underpinning. © 2017 Elsevier GmbH. All rights reserved.
1. Introduction On June 1st, 2007 the European Regulation on Registration, Evaluation and Restriction of Chemical substances (REACH) came
∗ Corresponding author at: Caesar Consult, Nijmegen, the Netherlands. E-mail address: [email protected] (D. Huizer). 1 Present position: retired
into force (EC, 2006). This regulation will be fully implemented in 2018. Aim of the regulation is safe use of chemicals for humans (workers and consumers) and for the environment. The core element of REACH is communication of health and safety information throughout the supply chain, from the manufacturer or importer via formulators to downstream users of the product. Health and safety information must be documented in a Chemical Safety Report (CSR), authorized by the European Chemicals Agency (ECHA). Extended Safety Data Sheets (Ext-SDS), which are based on
http://dx.doi.org/10.1016/j.ijheh.2017.05.012 1438-4639/© 2017 Elsevier GmbH. All rights reserved.
Please cite this article in press as: Spee, T., Huizer, D., Comparing REACH Chemical Safety Assessment information with practice—a case-study of polymethylmethacrylate (PMMA) in floor coating in The Netherlands. Int. J. Hyg. Environ. Health (2017), http://dx.doi.org/10.1016/j.ijheh.2017.05.012
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the CSR, are the primary carriers of information on intended use, described by process categories (PROC) operational conditions (OC) and risk management measures (RMM) for occupational use. In the context of REACH, risk assessment takes place by a tiered approach. The first tier is a conservative estimation using a risk assessment model. The manufacturer in this study used the Targeted Risk Assessment Tool from the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC-TRA) (ECETOC, 2012). This model is considered to produce conservative exposure estimates (Money et al., 2007, 2014). When the first tier assessment does not show an adequately controlled exposure, a more advanced model must be applied in tier 2, or safe use must be confirmed with measurement data. Several authors have reported about the accuracy of the ECETOC-TRA tool. Exposure to ethylbenzene during paint manufacturing and painting (Ishii et al., 2017), TDI and MDI during polyurethane foam production (Kupczezewska-Dobecka et al., 2012) and toluene, ethyl benzene and acetone during paints and lacquers production, shoe making and refining (KupzewskaDobecka et al., 2011) were measured and compared to the outcomes of the model. In most cases, ECETOC-TRA appeared to be conservative indeed. However, exposure during shoe manufacturing was underestimated and also during painting several measurement outcomes were higher than predicted by the model (Ichii et al., 2017). Angelini et al. (2016) propose site specific reduction coefficients to make ECETOC-TRA adequately conservative. Lamb et al. (2015) evaluated tier 1 exposure models under REACH. They consider the conservatism of an instrument low when >25% of the measured values exceed the tool estimate, and found for ECETOC-TRA V3 that this was the case for 32% of the measurements. No information was found in the literature about the accuracy of ECETOC-TRA exposure estimates for application of floor coating. This study aimed to find out whether the exposure to methyl methacrylate (MMA) during the application of polymethylmethacrylate (PMMA) in floor coatings as calculated in the CSR (the Ext-SDS was not available) reflect the exposures situations as observed in the Dutch construction practice.
Esmated vs. measured exposure, CSR data 10000
Measured exposure (mg/m3)
2
1000
100
10
1 1
10 100 1000 Esmated exposure (mg/m3)
10000
Fig. 1. Scatter plot of measured versus estimated exposures to methyl methacrylate, data as described in the CSR. + = mixing and transfer (Proc 19, n = 5), x = pouring and rolling (Proc 10, n = 9).
Task-based measured exposures were compared with the ECETOC-TRA (v.3) estimations as presented in the CSR. To check the sensitivity of these estimations, the effects of a lower ventilation efficiency (50% instead of 80%) and a higher process temperature for mixing and rolling (>40 ◦ C instead of 20 ◦ C) were also calculated. For comparison, exposures were also assessed with the EMKG-EXPO assessment tool (BAuA, 2008). Full-shift exposures were evaluated against the Dutch occupational exposure limit (OEL) of 205 mg/m3 eight hours TWA, which is based on irritation of the respiratory epithelial nose tissue as the critical health effect (Health Council of the Netherlands, 2011). This is the legally binding OEL in the Netherlands, and is equal to the long term inhalation DNEL for workers. In other European countries OELs vary from 10 to 208 mg/m3 (GESTIS, 2016). 3. Results
2. Materials and methods First, the use of PMMA flooring and typical exposure situations during application were discussed in two meetings with representatives of floor laying companies in The Netherlands. The Dutch Association of Finishing Enterprises (the employers association in the Netherlands), Section Flooring has 30 members who work with MMA (Dutch Association of Finishing Enterprises, personal communication). All members were invited for a discussion on work practices during floor coating, twelve of which participated. The PROCs, OCs and RMMs, as described in Chapter 9 of the CSR of MMA were presented and the company representatives were asked whether or not these occurred in their practice, and if there were any scenarios not corresponding to the PROCs and OCs as listed. The resulting list of exposure scenarios was used to select representative situations for exposure measurements. Measurements were performed on four days in June and July 2013 at four different construction sites. Full-shift (6.5–8 h) and tasked-based measurements in the breathing zone of the workers were executed simultaneously by personal air sampling. MMA was sampled on 3M-3500 Organic Vapour Passive Air Monitoring badges and every task was sampled on a separate badge. The collected amount of MMA was analysed according to MDHS no 96 (HSE, 2000) by the Laboratory for Occupational and Environmental Hygiene, University of Leuven (Belgium). Outdoor temperatures varied from 18 to 25 ◦ C.
Based on the list of exposure scenarios, all relevant exposure situations were divided into three situations: indoors in rooms smaller than 30 m2 (small rooms), indoors in rooms well over 30 m2 (large rooms) and semi-enclosed spaces (five out of six sides enclosed). The results of the task-based exposure measurements are summarized in Table 1. In 12 out of 14 cases (86%) the measured exposure was higher than the exposure estimate in the CSR. The results of the sensitivity analysis are presented in Figs. 1–4. For 12 out of 14 measurements (86%) the actual exposure appeared to be higher than the ECETOC TRA exposure estimate (Fig. 1). Recalculated estimations for a more realistic ventilation efficiency (50% instead of 80%, Fig. 2) did not change the results. Considering an elevated process temperature (>40 ◦ C during mixing and transfer and during pouring and rolling), underestimation of the exposure decreased from 12 to 10 out of 14 samples (71%) for an elevated temperature during mixing and transfer alone (Fig. 3) and 1 out of 14 (7%) for an elevated temperature during mixing/transfer and rolling/pouring (Fig. 4). Calculations with EMKG-EXPO indicated an exposure range of 200–2000 mg/m3 for preparation and mixing and >2000 mg/m3 for pouring and rolling. The results of the full-shift measurements are presented in Table 2. 5 out of 8 full shift exposures (62%) exceed the limit value in indoor situations. For semi-enclosed situations this is 1 out of 6 (17%).
Please cite this article in press as: Spee, T., Huizer, D., Comparing REACH Chemical Safety Assessment information with practice—a case-study of polymethylmethacrylate (PMMA) in floor coating in The Netherlands. Int. J. Hyg. Environ. Health (2017), http://dx.doi.org/10.1016/j.ijheh.2017.05.012
PROCs (from CSR of MMA)
OCs
RMMs
Exposure estimate (ECETOC- TRA) in CSR (mg/m3 )
Exposure estimate (EKMG-EXPO) (mg/m3 )
Exposure measurement from CSR (mg/m3 )
Preparation and mixing of batches of raw materials and mixtures by hand and transfer to the work location
1. indoors, with ventilator
PROC 5: Mixing or blending in batch process for formulation of preparations and articles (multistage and/or significant contact) PROC 19: Hand mixing with intimate contact and only PPE available
Concentration 25–100%; duration 4 h to 8h
LEV with 80% efficiency; gloves basic training
82
200–2000
50 (n = 1)
Concentration 25–100%; duration 15 min to 1h
Indoors without LEV. Gloves basic training
82
200–2000
Outdoors; gloves basic training Indoors without LEV. Gloves basic training
58
200–2000
123
2. indoors, no ventilator
3. outdoors Pouring on the floor followed by rolling, sweeping or troweling
4a. Indoors, no ventilation 4b. indoors, with ventilation 5. outdoors
PROC 10: roller application or brushing Not described
Concentration 25–100%; duration 4 h to 8h
PROC 10: roller application or brushing
Concentration 25–100%; duration 1 h to 4h
Outdoors without LEV. Gloves basic training
Remarks
Task-based measurements (mg/m3 )
GM
P95
range
N
...
...
...
...
232
940
40–834
4
50 (n = 1)
83
...
...
1
>2000
–
777
1966
530–1734
4
–
>2000
56 (n = 1)
537
...
...
1
172
>2000
–
300
784
139–670
4
Not used during exposure measurements
Measurement in semi-enclosed space (boarding kennels and balconies)
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Please cite this article in press as: Spee, T., Huizer, D., Comparing REACH Chemical Safety Assessment information with practice—a case-study of polymethylmethacrylate (PMMA) in floor coating in The Netherlands. Int. J. Hyg. Environ. Health (2017), http://dx.doi.org/10.1016/j.ijheh.2017.05.012
Table 1 Task based exposure measurements to methyl methacrylate (MMA) compared to estimation with the ECETOC-TRA and EKMG-EXPO exposure assessment tools and measurements as described in the Chemical Safety Report (CSR) of MMA.
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Table 2 Measurements of personal full shift exposure to methyl methacrylate for polymethylmethacrylate floor layers. Exposure situation
Type of area
N
Indoors, small (<30 m2 ) Indoors, large (»30 m2 )
No data Automatic car wash facility (95 m2 ) Bakery (130 m2 ) Boarding kennels (40 m2 ) Walled-in balconies (30 m2 )
– 2 6 2 4
Semi-enclosed
1000
100
10
AM (SD)
GM (GSD)
Range
– 253 (68) 235 (200) 222 (90) 40 (8)
– 244 (1.3) 165 (2.2) 220 (1.5) 39 (1.2)
– 204–301 105–367 80–364 31–50
Esmated vs measured exposure, all temperatures > 40oC 10000
Measured exposure (mg/m3)
Measured exposure (mg/m3)
10000
Esmated vs. measured exposure, venlaon efficiency 50%
MMA concentration in air (mg/m3 )
1000
100
10
1 1
100 10000 Esmated exposure (mg/m3)
Fig. 2. Scatter plot of measured versus estimated exposures to ethyl methacrylate, ventilation efficiency 50% instead of 80%. + = mixing and transfer (Proc 19, n = 5), x = pouring and rolling (Proc 10, n = 9).
Measured exposure (mg/m3)
Esmated vs. measured exposure, mixing temperature > 40OC 10000
1000
100
10
1 1
10 100 1000 10000 Esmated exposure (mg/m3)
Fig. 3. Scatter plot of measured versus estimated exposures to ethyl methacrylate, ventilation efficiency 50% instead of 80% and mixing temperature >40 ◦ C. + = mixing and transfer (Proc 19, n = 5), x = pouring and rolling (Proc 10, n = 9).
4. Discussion The aim of this study was to compare measured exposures to MMA during PMMA floor coating with ECETOC- TRA estimates. Measured concentrations exceeded the estimated concentrations for 12 out of 14 task-based measurements. Full-shift exposure measurements showed that 43% of all outcomes exceeded the Dutch occupational exposure limit. Only coating in the semi-enclosed sit-
1 1
10
100
1000
10000
Esmated exposure (mg/m3) Fig. 4. Scatter plot of measured versus estimated exposures to ethyl methacrylate, ventilation efficiency 50% instead of 80% and mixing and pouring/rolling temperature > 40 ◦ C. + = mixing and transfer (Proc 19, n = 5), x = pouring and rolling (Proc 10, n = 9).
uation (walled-in balconies, with five out of six sides enclosed), resulted in exposures mostly below the Dutch occupational exposure limit. This may be due to more natural ventilation, but also to lower production due to rainy weather during part of the day. An explanation for the poor agreement between measured and estimated results may be due to the use of incorrect input parameters for several ECETOC-TRA estimations as presented in the CSR. A ventilation efficiency of 80% using a mobile ventilator is unrealistic and in practice it will be closer to 50%. This assumption may have led to underestimation of air concentrations of MMA, although Fig. 2 shows that a lower ventilation efficiency does not change the number of underestimated exposure situations in this study. Another determinant which may have influenced the ECETOCTRA estimation is the process temperature. As polymerisation of MMA is an exothermic process, the process temperature may rise to over 40 ◦ C. Figs. 3 and 4 show that correction for this higher temperature has a strong effect on the outcomes of the estimates indeed. A higher process temperature is plausible during mixing and transfer, but pouring the mass on a cold surface will rapidly lower the temperature of the mixture. When the higher temperature applies only to mixing and transfer, the effect on the outcomes is limited. Therefore, inadequate input is not likely to have caused the poor agreement between the ECETOC TRA calculations and the measured exposures. Other authors have shown that calculations with ECETOC TRA in well-controlled production processes are sufficiently conservative compared to the actual measured concentration (Ishii et al., 2017; Kupczewska-Dobecka et al., 2011, 2012). However, in less controlled exposure situations the exposure is underestimated by the ECETOC TRA tool. Kupczewska-Dobecka et al. (2011) has found an
Please cite this article in press as: Spee, T., Huizer, D., Comparing REACH Chemical Safety Assessment information with practice—a case-study of polymethylmethacrylate (PMMA) in floor coating in The Netherlands. Int. J. Hyg. Environ. Health (2017), http://dx.doi.org/10.1016/j.ijheh.2017.05.012
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underestimation during shoe manufacturing and Ishii et al. (2017) revealed that the estimation during paint manufacturing is better than during painting. Our study showed a similar pattern. A conservative estimate for mixing of components especially when a higher temperature is taken into account, but an underestimation for the poorly controlled exposure situation which is the case during pouring and rolling. It seems that the poorer controlled the situation, the larger the underestimation from ECETOC TRA. This can be considered a plea to further underpin the ECETOC TRA estimation with measurements in poorly controlled exposure situations. Besides ECETOC-TRA, ECHA (2016) describes two other Tier 1 models for inhalation exposure assessment: EMKG-EXPO-Tool and Mease. The latter focuses on metals and inorganic substances and is therefore not applicable. Estimations with the EMKG-EXPO-Tool result in unsafe exposure situations for all scenarios, which is in accordance with the measurement outcomes. The relatively small number of measurements is a limitation of our study. However, it is clearly shown that several exposure situations are not adequately controlled. Performing more measurements will not very likely change our findings. One other limitation of our study is that one of the relevant exposure situations, indoors application in rooms smaller than 30 m2 , could not be evaluated. However, this is the most unfavourable situation of the three, which means that the underestimation by ECETOC-TRA would still be greater if we could have taken this situation into account. 5. Conclusions ECETOC TRA underestimated hazardous exposures for several scenarios, even when applying more reasonable scenarios than as described in the CSR. Better underpinning of ECETOC-TRA exposure estimates in poorly controlled exposure situations is urgently needed. Full shift exposures to methyl methacrylate during polymethylmethacrylate floor coating were up to 8.4 times higher than the Dutch exposure limit. Conflicts of interest The authors have no conflicts of interests to disclose. Acknowledgements Arbouw has funded the study. From 1st July 2016, Arbouw is discontinued and its activities are continued by Volandis. The authors thank Gert van der Meulen for convening the discussion sessions with flooring companies, flooring companies and personnel for facilitating the measurements and Prof. Dr. Hans Kromhout for critically reading the manuscript.
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References Angelini, E., Camerini, G., Diop, M., Roche, P., Rodi, T., Schippa, C., et al., 2016. Respiratory Health–Exposure measurements and modelling in the fragrance and flavour industry. PLoS One 11 (2), e0148769, 10.1371/journal.pone.0148769. BAuA, Federal Institute for Occupational Safety and Health, 2008. Exposure estimate at the workplace; EMKG-EXPO tool. http://www.reach-clp-biozidhelpdesk.de/en/Exposure/Exposure.html (accessed 20th March, 2017). European Community, 2006. REGULATION (EC) No 1907/2006 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 18 December 2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH). http://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:02006R190720140410&qid=1471703745603&from=en (accessed 13 July, 2016). ECETOC, European Centre for Ecotoxicology and Toxicology of Chemicals, 2012. Technical Report 114: ECETOC TRA Version 3:Background and Rationale for Improvements. Brussels, ISSN-2079-1526-114 (online) http://www.ecetoc.org/wp-content/uploads/2014/08/ECETOC-TR-114ECETOC-TRA-v3-Background-rationale-for-the-improvements.pdf (accessed 13th March, 2017). ECHA, European Chemicals Agency, 2016. Guidance on Information Requirements and Chemical Safety Assessment Chapter R.14: Occupational exposure assessment version 3.0. https://echa.europa.eu/documents/10162/13632/information requirements r14 en.pdf (accessed 15th March, 2017). GESTIS, Gefahrstoffinformationssystem der Deutschen Gesetzlichen Unfallversicherung, 2016. International limit values for chemical agents (Occupational exposure limits, OELs). Latest update of the database: June 2016. http://www.dguv.de/ifa/gestis/gestis-internationale-grenzwerte-fuerchemische-substanzen-limit-values-for-chemical-agents/index-2. jsp (accessed: 10th March, 2017). HSE, 2000. MDHS 96, Methods for the Determination of Hazardous Substances in air, Volatile organic compounds in air 4. Health and Safety Executive, Sudbury, Suffolk http://www.hse.gov.uk/pubns/mdhs/pdfs/mdhs96. pdf (accessed 13 July, 2016). Health Council of the Netherlands, 2011. Methyl methacrylate, Health-based recommended occupational exposure limit. Report No. 2011/38, The Hague, December 16, 2011. https://www.gezondheidsraad.nl/sites/default/files/201138. pdf (accessed: 10th March, 2017). Ishii, S., Katagiri, R., Kitamura, K., Shimojima, M., Wada, T., 2017. Evaluation of the ECETOC TRA model for workplace inhalation exposure to ethylbenzene in Japan. Japan J. Chem. Health Safety 24, 8–20. Kupczewska-Dobecka, M., Czerczak, S., Jakubowski, M., 2011. Evaluation of the TRA ECETOC model for inhalation workplace exposure to different organic solvents for selected process categories. Int. J. Occup. Med. Environ. Health 24, 208–217. Kupczewska-Dobecka, M., Czerczak, S., Brzeznicki, S., 2012. Assessment of exposure to TDI and MDI during polyurethane foam production in Poland using integrated theoretical and experimental data. Environ. Toxicol. Pharmacol. 34, 512–518. Lamb, J., Hesse, S., Miller, B.G., MacCalman, L., Schroeder, K., Cherrie, J., van Tongeren, M., 2015. Evaluation of Tier 1 Exposure Assessment Models under REACH (ETEAM) Project. Final Overall Project Summary Report, p150. Bundesanstalt für Arbeitsschutz, Dortmund, Berlin, Dresden. http://www.baua.de/en/Publications/Expert-Papers/F2303-D26-D28. html (accessed 13 July, 2016). Money, C.D., Jacobi, S., Penman, M.G., Rodriguez, C., De Rooij, C., Veenstra, G., 2007. The ECETOC approach to targeted risk assessment; lessons and experiences relevant to REACH. J. Expo. Sci. Environ. Epidemiol. 17 (Suppl 1), S67–71. Money, C., Schnoeder, F., Noij, D., Chang, H.Y., Urbanus, J., 2014. ECETOC TRA version 3: capturing and consolidating the experiences of REACH. Environ. Sci. Process Impacts 16, 970–977.
Please cite this article in press as: Spee, T., Huizer, D., Comparing REACH Chemical Safety Assessment information with practice—a case-study of polymethylmethacrylate (PMMA) in floor coating in The Netherlands. Int. J. Hyg. Environ. Health (2017), http://dx.doi.org/10.1016/j.ijheh.2017.05.012
ARTICLE IN PRESS
IJHEH-13091; No. of Pages 5
International Journal of Hygiene and Environmental Health xxx (2017) xxx–xxx
Contents lists available at ScienceDirect
International Journal of Hygiene and Environmental Health journal homepage: www.elsevier.com/locate/ijheh
Short communication
Comparing REACH Chemical Safety Assessment information with practice—a case-study of polymethylmethacrylate (PMMA) in floor coating in The Netherlands Ton Spee a,b,1 , Daan Huizer c,∗ a
Arbouw, Harderwijk, the Netherlands Institute for Risk Assessment Sciences (IRAS), Utrecht University, the Netherlands c Caesar Consult, Nijmegen, the Netherlands b
a r t i c l e
i n f o
Article history: Received 31 January 2017 Received in revised form 12 April 2017 Accepted 29 May 2017 Keywords: Occupational exposure Exposure modelling Risk management measures Exposure measurement Methyl methacrylate
a b s t r a c t On June 1st, 2007 the European regulation on Registration, Evaluation and Restriction of Chemical substances (REACH) came into force. Aim of the regulation is safe use of chemicals for humans and for the environment. The core element of REACH is chemical safety assessment of chemicals and communication of health and safety hazards and risk management measures throughout the supply chain. Extended Safety Data Sheets (Ext-SDS) are the primary carriers of health and safety information. The aim of our project was to find out whether the actual exposure to methyl methacrylate (MMA) during the application of polymethylmethacrylate (PMMA) in floor coatings as assessed in the chemical safety assessment, reflect the exposure situations as observed in the Dutch building practice. Use of PMMA flooring and typical exposure situations during application were discussed with twelve representatives of floor laying companies. Representative situations for exposure measurements were designated on the basis of this inventory. Exposure to MMA was measured in the breathing zone of the workers at four construction sites, 14 full shift samples and 14 task based samples were taken by personal air sampling. The task-based samples were compared with estimates from the Targeted Risk Assessment Tool (v3.1) of the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOCTRA) as supplied in the safety assessment from the manufacturer. For task-based measurements, in 12 out of 14 (86%) air samples measured exposure was higher than estimated exposure. Recalculation with a lower ventilation rate (50% instead of 80%) together with a higher temperature during mixing (40 ◦ C instead of 20 ◦ C) in comparison with the CSR, reduced the number of underestimated exposures to 10 (71%) samples. Estimation with the EMKG-EXPO-Tool resulted in unsafe exposure situations for all scenarios, which is in accordance with the measurement outcomes. In indoor situations, 5 out of 8 full shift exposures (62%) to MMA were higher than the Dutch occupational exposure limit of 205 mg/m3 (8 h TWA), which equals the DNEL. For semi-enclosed situations this was 1 out of 6 (17%). Exposures varied from 31 to 367 mg/m3 . The results emphasize that ECETOC-TRA exposure estimates in poorly controlled situations need better underpinning. © 2017 Elsevier GmbH. All rights reserved.
1. Introduction On June 1st, 2007 the European Regulation on Registration, Evaluation and Restriction of Chemical substances (REACH) came
∗ Corresponding author at: Caesar Consult, Nijmegen, the Netherlands. E-mail address: [email protected] (D. Huizer). 1 Present position: retired
into force (EC, 2006). This regulation will be fully implemented in 2018. Aim of the regulation is safe use of chemicals for humans (workers and consumers) and for the environment. The core element of REACH is communication of health and safety information throughout the supply chain, from the manufacturer or importer via formulators to downstream users of the product. Health and safety information must be documented in a Chemical Safety Report (CSR), authorized by the European Chemicals Agency (ECHA). Extended Safety Data Sheets (Ext-SDS), which are based on
http://dx.doi.org/10.1016/j.ijheh.2017.05.012 1438-4639/© 2017 Elsevier GmbH. All rights reserved.
Please cite this article in press as: Spee, T., Huizer, D., Comparing REACH Chemical Safety Assessment information with practice—a case-study of polymethylmethacrylate (PMMA) in floor coating in The Netherlands. Int. J. Hyg. Environ. Health (2017), http://dx.doi.org/10.1016/j.ijheh.2017.05.012
G Model IJHEH-13091; No. of Pages 5
ARTICLE IN PRESS T. Spee, D. Huizer / International Journal of Hygiene and Environmental Health xxx (2017) xxx–xxx
the CSR, are the primary carriers of information on intended use, described by process categories (PROC) operational conditions (OC) and risk management measures (RMM) for occupational use. In the context of REACH, risk assessment takes place by a tiered approach. The first tier is a conservative estimation using a risk assessment model. The manufacturer in this study used the Targeted Risk Assessment Tool from the European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC-TRA) (ECETOC, 2012). This model is considered to produce conservative exposure estimates (Money et al., 2007, 2014). When the first tier assessment does not show an adequately controlled exposure, a more advanced model must be applied in tier 2, or safe use must be confirmed with measurement data. Several authors have reported about the accuracy of the ECETOC-TRA tool. Exposure to ethylbenzene during paint manufacturing and painting (Ishii et al., 2017), TDI and MDI during polyurethane foam production (Kupczezewska-Dobecka et al., 2012) and toluene, ethyl benzene and acetone during paints and lacquers production, shoe making and refining (KupzewskaDobecka et al., 2011) were measured and compared to the outcomes of the model. In most cases, ECETOC-TRA appeared to be conservative indeed. However, exposure during shoe manufacturing was underestimated and also during painting several measurement outcomes were higher than predicted by the model (Ichii et al., 2017). Angelini et al. (2016) propose site specific reduction coefficients to make ECETOC-TRA adequately conservative. Lamb et al. (2015) evaluated tier 1 exposure models under REACH. They consider the conservatism of an instrument low when >25% of the measured values exceed the tool estimate, and found for ECETOC-TRA V3 that this was the case for 32% of the measurements. No information was found in the literature about the accuracy of ECETOC-TRA exposure estimates for application of floor coating. This study aimed to find out whether the exposure to methyl methacrylate (MMA) during the application of polymethylmethacrylate (PMMA) in floor coatings as calculated in the CSR (the Ext-SDS was not available) reflect the exposures situations as observed in the Dutch construction practice.
Esmated vs. measured exposure, CSR data 10000
Measured exposure (mg/m3)
2
1000
100
10
1 1
10 100 1000 Esmated exposure (mg/m3)
10000
Fig. 1. Scatter plot of measured versus estimated exposures to methyl methacrylate, data as described in the CSR. + = mixing and transfer (Proc 19, n = 5), x = pouring and rolling (Proc 10, n = 9).
Task-based measured exposures were compared with the ECETOC-TRA (v.3) estimations as presented in the CSR. To check the sensitivity of these estimations, the effects of a lower ventilation efficiency (50% instead of 80%) and a higher process temperature for mixing and rolling (>40 ◦ C instead of 20 ◦ C) were also calculated. For comparison, exposures were also assessed with the EMKG-EXPO assessment tool (BAuA, 2008). Full-shift exposures were evaluated against the Dutch occupational exposure limit (OEL) of 205 mg/m3 eight hours TWA, which is based on irritation of the respiratory epithelial nose tissue as the critical health effect (Health Council of the Netherlands, 2011). This is the legally binding OEL in the Netherlands, and is equal to the long term inhalation DNEL for workers. In other European countries OELs vary from 10 to 208 mg/m3 (GESTIS, 2016). 3. Results
2. Materials and methods First, the use of PMMA flooring and typical exposure situations during application were discussed in two meetings with representatives of floor laying companies in The Netherlands. The Dutch Association of Finishing Enterprises (the employers association in the Netherlands), Section Flooring has 30 members who work with MMA (Dutch Association of Finishing Enterprises, personal communication). All members were invited for a discussion on work practices during floor coating, twelve of which participated. The PROCs, OCs and RMMs, as described in Chapter 9 of the CSR of MMA were presented and the company representatives were asked whether or not these occurred in their practice, and if there were any scenarios not corresponding to the PROCs and OCs as listed. The resulting list of exposure scenarios was used to select representative situations for exposure measurements. Measurements were performed on four days in June and July 2013 at four different construction sites. Full-shift (6.5–8 h) and tasked-based measurements in the breathing zone of the workers were executed simultaneously by personal air sampling. MMA was sampled on 3M-3500 Organic Vapour Passive Air Monitoring badges and every task was sampled on a separate badge. The collected amount of MMA was analysed according to MDHS no 96 (HSE, 2000) by the Laboratory for Occupational and Environmental Hygiene, University of Leuven (Belgium). Outdoor temperatures varied from 18 to 25 ◦ C.
Based on the list of exposure scenarios, all relevant exposure situations were divided into three situations: indoors in rooms smaller than 30 m2 (small rooms), indoors in rooms well over 30 m2 (large rooms) and semi-enclosed spaces (five out of six sides enclosed). The results of the task-based exposure measurements are summarized in Table 1. In 12 out of 14 cases (86%) the measured exposure was higher than the exposure estimate in the CSR. The results of the sensitivity analysis are presented in Figs. 1–4. For 12 out of 14 measurements (86%) the actual exposure appeared to be higher than the ECETOC TRA exposure estimate (Fig. 1). Recalculated estimations for a more realistic ventilation efficiency (50% instead of 80%, Fig. 2) did not change the results. Considering an elevated process temperature (>40 ◦ C during mixing and transfer and during pouring and rolling), underestimation of the exposure decreased from 12 to 10 out of 14 samples (71%) for an elevated temperature during mixing and transfer alone (Fig. 3) and 1 out of 14 (7%) for an elevated temperature during mixing/transfer and rolling/pouring (Fig. 4). Calculations with EMKG-EXPO indicated an exposure range of 200–2000 mg/m3 for preparation and mixing and >2000 mg/m3 for pouring and rolling. The results of the full-shift measurements are presented in Table 2. 5 out of 8 full shift exposures (62%) exceed the limit value in indoor situations. For semi-enclosed situations this is 1 out of 6 (17%).
Please cite this article in press as: Spee, T., Huizer, D., Comparing REACH Chemical Safety Assessment information with practice—a case-study of polymethylmethacrylate (PMMA) in floor coating in The Netherlands. Int. J. Hyg. Environ. Health (2017), http://dx.doi.org/10.1016/j.ijheh.2017.05.012
PROCs (from CSR of MMA)
OCs
RMMs
Exposure estimate (ECETOC- TRA) in CSR (mg/m3 )
Exposure estimate (EKMG-EXPO) (mg/m3 )
Exposure measurement from CSR (mg/m3 )
Preparation and mixing of batches of raw materials and mixtures by hand and transfer to the work location
1. indoors, with ventilator
PROC 5: Mixing or blending in batch process for formulation of preparations and articles (multistage and/or significant contact) PROC 19: Hand mixing with intimate contact and only PPE available
Concentration 25–100%; duration 4 h to 8h
LEV with 80% efficiency; gloves basic training
82
200–2000
50 (n = 1)
Concentration 25–100%; duration 15 min to 1h
Indoors without LEV. Gloves basic training
82
200–2000
Outdoors; gloves basic training Indoors without LEV. Gloves basic training
58
200–2000
123
2. indoors, no ventilator
3. outdoors Pouring on the floor followed by rolling, sweeping or troweling
4a. Indoors, no ventilation 4b. indoors, with ventilation 5. outdoors
PROC 10: roller application or brushing Not described
Concentration 25–100%; duration 4 h to 8h
PROC 10: roller application or brushing
Concentration 25–100%; duration 1 h to 4h
Outdoors without LEV. Gloves basic training
Remarks
Task-based measurements (mg/m3 )
GM
P95
range
N
...
...
...
...
232
940
40–834
4
50 (n = 1)
83
...
...
1
>2000
–
777
1966
530–1734
4
–
>2000
56 (n = 1)
537
...
...
1
172
>2000
–
300
784
139–670
4
Not used during exposure measurements
Measurement in semi-enclosed space (boarding kennels and balconies)
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Table 1 Task based exposure measurements to methyl methacrylate (MMA) compared to estimation with the ECETOC-TRA and EKMG-EXPO exposure assessment tools and measurements as described in the Chemical Safety Report (CSR) of MMA.
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Table 2 Measurements of personal full shift exposure to methyl methacrylate for polymethylmethacrylate floor layers. Exposure situation
Type of area
N
Indoors, small (<30 m2 ) Indoors, large (»30 m2 )
No data Automatic car wash facility (95 m2 ) Bakery (130 m2 ) Boarding kennels (40 m2 ) Walled-in balconies (30 m2 )
– 2 6 2 4
Semi-enclosed
1000
100
10
AM (SD)
GM (GSD)
Range
– 253 (68) 235 (200) 222 (90) 40 (8)
– 244 (1.3) 165 (2.2) 220 (1.5) 39 (1.2)
– 204–301 105–367 80–364 31–50
Esmated vs measured exposure, all temperatures > 40oC 10000
Measured exposure (mg/m3)
Measured exposure (mg/m3)
10000
Esmated vs. measured exposure, venlaon efficiency 50%
MMA concentration in air (mg/m3 )
1000
100
10
1 1
100 10000 Esmated exposure (mg/m3)
Fig. 2. Scatter plot of measured versus estimated exposures to ethyl methacrylate, ventilation efficiency 50% instead of 80%. + = mixing and transfer (Proc 19, n = 5), x = pouring and rolling (Proc 10, n = 9).
Measured exposure (mg/m3)
Esmated vs. measured exposure, mixing temperature > 40OC 10000
1000
100
10
1 1
10 100 1000 10000 Esmated exposure (mg/m3)
Fig. 3. Scatter plot of measured versus estimated exposures to ethyl methacrylate, ventilation efficiency 50% instead of 80% and mixing temperature >40 ◦ C. + = mixing and transfer (Proc 19, n = 5), x = pouring and rolling (Proc 10, n = 9).
4. Discussion The aim of this study was to compare measured exposures to MMA during PMMA floor coating with ECETOC- TRA estimates. Measured concentrations exceeded the estimated concentrations for 12 out of 14 task-based measurements. Full-shift exposure measurements showed that 43% of all outcomes exceeded the Dutch occupational exposure limit. Only coating in the semi-enclosed sit-
1 1
10
100
1000
10000
Esmated exposure (mg/m3) Fig. 4. Scatter plot of measured versus estimated exposures to ethyl methacrylate, ventilation efficiency 50% instead of 80% and mixing and pouring/rolling temperature > 40 ◦ C. + = mixing and transfer (Proc 19, n = 5), x = pouring and rolling (Proc 10, n = 9).
uation (walled-in balconies, with five out of six sides enclosed), resulted in exposures mostly below the Dutch occupational exposure limit. This may be due to more natural ventilation, but also to lower production due to rainy weather during part of the day. An explanation for the poor agreement between measured and estimated results may be due to the use of incorrect input parameters for several ECETOC-TRA estimations as presented in the CSR. A ventilation efficiency of 80% using a mobile ventilator is unrealistic and in practice it will be closer to 50%. This assumption may have led to underestimation of air concentrations of MMA, although Fig. 2 shows that a lower ventilation efficiency does not change the number of underestimated exposure situations in this study. Another determinant which may have influenced the ECETOCTRA estimation is the process temperature. As polymerisation of MMA is an exothermic process, the process temperature may rise to over 40 ◦ C. Figs. 3 and 4 show that correction for this higher temperature has a strong effect on the outcomes of the estimates indeed. A higher process temperature is plausible during mixing and transfer, but pouring the mass on a cold surface will rapidly lower the temperature of the mixture. When the higher temperature applies only to mixing and transfer, the effect on the outcomes is limited. Therefore, inadequate input is not likely to have caused the poor agreement between the ECETOC TRA calculations and the measured exposures. Other authors have shown that calculations with ECETOC TRA in well-controlled production processes are sufficiently conservative compared to the actual measured concentration (Ishii et al., 2017; Kupczewska-Dobecka et al., 2011, 2012). However, in less controlled exposure situations the exposure is underestimated by the ECETOC TRA tool. Kupczewska-Dobecka et al. (2011) has found an
Please cite this article in press as: Spee, T., Huizer, D., Comparing REACH Chemical Safety Assessment information with practice—a case-study of polymethylmethacrylate (PMMA) in floor coating in The Netherlands. Int. J. Hyg. Environ. Health (2017), http://dx.doi.org/10.1016/j.ijheh.2017.05.012
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underestimation during shoe manufacturing and Ishii et al. (2017) revealed that the estimation during paint manufacturing is better than during painting. Our study showed a similar pattern. A conservative estimate for mixing of components especially when a higher temperature is taken into account, but an underestimation for the poorly controlled exposure situation which is the case during pouring and rolling. It seems that the poorer controlled the situation, the larger the underestimation from ECETOC TRA. This can be considered a plea to further underpin the ECETOC TRA estimation with measurements in poorly controlled exposure situations. Besides ECETOC-TRA, ECHA (2016) describes two other Tier 1 models for inhalation exposure assessment: EMKG-EXPO-Tool and Mease. The latter focuses on metals and inorganic substances and is therefore not applicable. Estimations with the EMKG-EXPO-Tool result in unsafe exposure situations for all scenarios, which is in accordance with the measurement outcomes. The relatively small number of measurements is a limitation of our study. However, it is clearly shown that several exposure situations are not adequately controlled. Performing more measurements will not very likely change our findings. One other limitation of our study is that one of the relevant exposure situations, indoors application in rooms smaller than 30 m2 , could not be evaluated. However, this is the most unfavourable situation of the three, which means that the underestimation by ECETOC-TRA would still be greater if we could have taken this situation into account. 5. Conclusions ECETOC TRA underestimated hazardous exposures for several scenarios, even when applying more reasonable scenarios than as described in the CSR. Better underpinning of ECETOC-TRA exposure estimates in poorly controlled exposure situations is urgently needed. Full shift exposures to methyl methacrylate during polymethylmethacrylate floor coating were up to 8.4 times higher than the Dutch exposure limit. Conflicts of interest The authors have no conflicts of interests to disclose. Acknowledgements Arbouw has funded the study. From 1st July 2016, Arbouw is discontinued and its activities are continued by Volandis. The authors thank Gert van der Meulen for convening the discussion sessions with flooring companies, flooring companies and personnel for facilitating the measurements and Prof. Dr. Hans Kromhout for critically reading the manuscript.
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Please cite this article in press as: Spee, T., Huizer, D., Comparing REACH Chemical Safety Assessment information with practice—a case-study of polymethylmethacrylate (PMMA) in floor coating in The Netherlands. Int. J. Hyg. Environ. Health (2017), http://dx.doi.org/10.1016/j.ijheh.2017.05.012