- Email: [email protected]
Status of commercial food irradiation in the United States
Radiation Physics Chemistry Vol, 22 No. 1/2, pp. 215-224, 1983
0146-5724/83/07215-10503.00/0 © 1983 Pergamon Press Ltd.
Printed in Great Britain
STATUS OF COMMERCIAL
FOOD IRRADIATION
IN THE UNITED STATES
Martin A. Welt, Ph.D. Radiation Technology, P.O. Box 185 Rockaway, New Jersey
Inc. 07866
ABSTRACT It may be difficult for some to realize, but the United States is now starting its fourth decade in food irradiation research. This vast storehouse of research data now makes the ultimate task of bringing the technology to the consumer marketplace that much easier. Radiation Technology, Inc. of Rockaway, New Jersey has pioneered the use of radiation processing for the commercial preservation of food and has established the first food irradiation facility in the United States in West Memphis, Arkansas. The facility, designed by Radiation Technology, Inc., provides the necessary versatility to meet the needs of the food industry. KEYWORDS Radiation Technology, Inc.; food irradiation; zation; food irradiator design; Cobalt-60.
radiation
sterilization;
radiation pasteuri-
INTRODUCTION The initial effort in the quest for commercialization began with research funded by the U.S. Army Quartermaster Corps and directed by the late Professor Bernard Proctor and his colleagues at the Massachusetts Institute of Technology. This 1943 study (Proctor et al., 1943) concerned with the sterilization of ground meat with X-rays, demonstrated the potential for the radiation preservation of food to become the first really new food preservation technique since canning was introduced early in the nineteenth century. Following continuing promising work which began at MIT in the late forties, including studies for the U.S. Navy on preserving meat, fish and other rations (Proctor et al., 1954) and for the U.S. Army on insect disinfestation of cereal bars (Proctor et al., 1954), a concerted national R&D effort was initiated in 1950 under the auspices of the Atomic Energy Commission (U.S. Department of Commerce, 1965). Early investigations also included short-term animal toxicity studies by the Army Medical Nutrition Laboratories involving 45 irradiated foods. The initial interest kindled by the U.S. Army Quartermaster Corps was kept active at the Department of Army, U.S. Army Material Command, when in 1953 Dr. Ralph G.H. Siu, Scientific Director, Research Division, undertook a detailed appraisal of the prospects for radiation preservation of food. Following a review of the Siu report by a National Academy of Sciences Committee, the Quartermaster General requested, in May 1953, authorization to begin a 5-year research program. In May 1956, the Interdepartmental Committee on Radiation Preservation of Food was formed at the suggestion of the Secretary of Defense to coordinate all government activities and to help in the process of commercialization. From 1955 to 1958 an additional 54 irradiated foods were included in seven short-term human volunteer feeding studies, with no adverse effects noted. Excellent summaries of the early Atomic Energy Commission low dose program and the Army's high dose efforts can be found in a 1963 Department of Commerce report (ibid) and an earlier Quartermaster Corps food irradiation status report (U.S. Army, 1956). The various congressional hearings of the Joint Committee on Atomic Energy dealing with radiation processing of foods are also invaluable reference works (Congress, 1955, '56, '60, '62, '63, '65, '66, '68). 2]5
216
M. A WELT
The euphoria of the early research successes began running into setbacks in 1958 with two events which were probably responsible for much of the ultimate delay in bringing about commercialization of food irradiation. These events were: i°
The Food Additives Amendment of 1958 to the Federal Food, Drug and Cosmetic Act provides that any food subjected intentionally to irradiation would be adulterated unless a food additive petition was submitted and approved, in accordance with Section 402(a) 7 of the Act.
2.
The cancellation of plans to build a major food irradiation facility (Army Ionizing Radiation Center) in Stockton, California which was to have been operated under contract to the U.S. Army.
The former event was, in the eyes of many (Federal Food, Drug and Cosmetic Act, 1975; Diehl, 1981; Brynjolfsson, 1978; Welt, 1980, Schubert, 1978) an unfortunate occurrence since it not only made it virtually impossible to prove the safety of the process since the "additive'remained elusive, but also the early conventional animal feeding studies produced more questions than answers due to the highly unbalanced irradiated food diets that were used. However, if we follow the logic of Voltaire in Candide and look for the good in this "best of all possible worlds", it must be admitted that we probably know more after 25 years of effort about the wholesomeness and utility of irradiated food than any other method of food preservation. This vast storehouse of research data now makes the ultimate task of bringing the technology to the consumer marketplace that much easier. The cancellation of the U.S. Army Stockton irradiator due to "reported" harmful effects of irradiation, proved to be a serious setback with regard to getting commercial food and business interests involved, since a full-sized processing facility for pilot test work was denied them. It is now known from Joint Committee hearings in January and March 1960 that there was little or no basis to support claims that irradiation was responsible for harmful effects in animals (Congress, 1960). Shortly after the hearings in 1960, the Army reinstituted plans to continue irradiated food research with a $5 million program which was centralized at the Natick Laboratories in Massachusetts. The food irradiation laboratory built at Natick then contained the world's largest cobalt-60 irradiator as well as a 24 Mev linear accelerator. There were, of course, other factors which seemed to stymie progress. For example, in 1962 Professor L.E. Brownell et al. submitted the nation's first petition from a non-governmental source to the FDA, and received approval to use ionizing radiation for insect disinfestation of wheat and wheat products (Brownell et al., 1963). Shortly thereafter, approval was granted for the sprout inhibition of white potatoes (U.S. Army, 1964) and of greatest importance, the U.S. Army Natick group obtained FDA approval for the radiation-sterilization of bacon (U.S. Army, 1963). Then in 1968 the roof fell in with the withdrawal without prejudice by the Army of a radiation sterilized ham petition on the basis of incomplete information as was required under a new revised FDA protocol format. Since the same "deficiency" existed in the already approved bacon petition, the Commissioner of the FDA decided to withdraw the bacon approval with an eye towards having the petition quickly satisfy the new, much more involved protocol procedure. I'm certain that the Commissioner did not believe that at a meeting taking place nearly fifteen years later, approval was still being denied. One should remember the words of the Surgeon General regarding his belief in the future of irradiated foods: "Food irradiated up to absorbed doses of 5.6 megarads with a cobalt-60 source of radiation or with electrons with energies up to i0 million electron volts have been found to be wholesome; i.e., safe, and nutritionally adequate." (Congress, 1965) Critics of food irradiation in the United States have continually asked why we should strive to implement this technology when nothing of commercial consequence has been done with our potato and wheat/wheat flour approvals and after all, "something must have been wrong with the concept to have the Stockton irradiator cancelled". They also point out that a U.S. Department of Agriculture Demonstration Grain Irradiator (U.S.D.A., 1963) in Savannah, Georgia was not totally successful in its own utilization, nor did it spawn commercial facilities to replace fumigation.
Status of commercial
food irradiation
in the United States
217
The impact of the 1958 Amendment to the Food & Drug Act on further petitions for irradiated food approvals can be shown by pointing out that with the withdrawal of the bacon petition, only a spice irradiation petition submitted by Radiation Technology, Inc. in 1980 was accepted by the FDA for filing in the Federal Register (Radiation Technology, Inc., 1980). In spite of full compliance with existing regulatory guidelines, a final unequivocal approval awaits issuance of the first of a series of FDA food irradiation regulations which is expected in 1982. The "new era" in food irradiation in the U.S., which many of us have waited patiently also got its' start with several significant events: i.
In 1980 the "National Food Irradiation Program" was transferred from the U.S. Army (Department of Defense) to the U.S. Department of Agriculture (U.S. Army, 1980). This move ended the World's most productive research effort in the high dose radiation preservation of food. Recognition must be given to the Natick researchers individually and as a team. I doubt that anyone in the food irradiation field is not familiar with the work and contributions of Ed Josephson, Ari Brynjolfsson, Charles Merritt, Irwin Taub, Bob Jarrett, Eguen Wierbicki, John Halliday, Abe Anellis, Durwood Rowley, etc.
2.
In March, 1981 the FDA issued its Advance Notice of Proposed Rulemaking (FDA, 1981) concerning irradiated food. This long-awaited position paper by the Bureau of Foods recommended the unconditional use of 100 Krad (I kGy) of ionizing radiation from Cobalt-60, Cesium-137 or 10 Mev electrons for processing any food product. It was also indicated that for doses up to and including 1 Mrad (10 kGy), onlj short-term (90-day) two species (rodent and non-rodent) feeding studies and mutagenicity testing would be required. One of the biggest surprises in the FDA document was their recommendation to approve dose up to 5 Mrad (50 kGy) for processing food components that make up less than 0.01% of a daily diet. The importance of this aspect was not the limited practicality of its use since only spices and like ingredients are intended to be covered; but, rather, that in the context of the "Delaney clause" of the 1958 Food Additives Amendment to the Food, Drug and Cosmetic Act it constitutes de-facto recognition by the FDA that a dose as high as 5 Megarads does not generate any cancer-causing substance(s) in food so treated. For general food applications above i00 Kilorads the FDA proposed to drastically reduce the degree of safety testing rigor in support of pre-marketing approval (i.e., a petition) from what has been and is the case. The Agency's proposed easing of testing requirements is no doubt in recognition of the enormous amount of irradiated foods safety-wholesomeness testing that has been conducted worldwide since the original requirements were established some years ago. Nevertheless, one highly credible testing firm developed a detailed estimate, at our request, which indicates that the minimum battery of mutagenicity and sub-chronic animal feeding studies that the FDA proposes to require in support of a petition for each and every irradiated food item above 100 Krads will cost in excess of U.S. $200K and several months of effort, not including the petition preparation, as shown in Table 1 (Giddings, 1982).
TABLE 1
Cost Estimate
for Completing FDA Short Term Feeding & Mutagenicity
Test Description 1. *+2. 3.
Ames Test (bacterial gene mutation) Mouse lymphoma (cell culture) DNA repair ("sister chromatid exchange", "SCD", employing Chinese hamster ovary "CHO", cells)
Estimated Cost/Sample $
1,375 5,700
3,500
Tests
Duration
for,
218
M.A.
*+4. **5. **6.
Drosophila (recessive lethal mutations) Rat Feeding Study Dog Feeding Study
WELT
test
35,000 70,000 ii0,000
2½ mo. 90 days 90 days
*i and 2 are commonly used as screening tests to determine if it is worth spending more money to conduct further tests. Chromosomal analysis is the most popular and least expensive screening assay. *+If mouse lymphoma is positive, the Drosophila test must be negative, otherwise long-term chronic testing is usually called for.
or
**For 5 and 6, the time to report out the study takes almost as long as the time to conduct. The entire battery can be expected to consume on the order of nine (9) months. Then there is the FDA petitioning process to gain clearance which, experience has shown, is no simple matter, as a rule. 3.
In Fall, 1981, at the height of the California Mediterranean fruit fly crisis, and in the face of an impending EPA ban on the use of ethylene dibromide as a fruit fumigant, FDA Commissioner Hayes granted emergency approval of the use of ionizing radiation for "Medfly" disinfestation of affected California fruit and produce in advance of the rulemaking officially allowing same. This emergency approval could not be implemented before the end of the California harvest because irradiation firms were taken by surprise by the approval and had no plants operating in the affected areas, preferring to hold off construction until the FDA's intentions became clearer through the rulemaking process, thereby creating a more conducive environment for installing such plants in California and other 'quarantine' states. The only use of the FDA emergency approval for insect disinfestation for commercial purposes, as far as it is known, was the use of Radiation Technology's food irradiation facility in West Memphis, Arkansas in February, 1982 for processing truck load quantities of California grapes. The species involved were: white (Calmeria), red (Emperor) and purple (Ribier), and the minimum dose utilized was 25 krad (0.25 kGy). Since product could not be moved out of a quarantined county infested with Medfly, the importance of this FDA move was more in its symbolic gesture of things to come rather than an important immediate alternative to EDB fumigation since no commercial irradiators were available within the quarantine region.
It now appears that a revision to the restrictive 1958 Food & Drug Act Amendment will be issued shortly, and together with the introduction of the nation's first commercial food irradiation facility in West Memphis, Arkansas in 1981, the two conditions that have held back commercialization in the U.S. should be eliminated.
COMMERCIAL FOOD IRRADIATION ACTIVITIES IN THE U.S. During the past decade, aside from the Natick effort (now transferred to the USDA) to obtain a high dose radappertization clearance for poultry, only Radiation Technology persisted in pursuing a commercial activity in food irradiation. A summary of these activities was given by the writer at the 26th Annual European Meat Research Workers Meeting (Welt, 1980) held in Colorado Springs in September 1980 and additional details were presented at an IAEA working committee meeting (Welt and Sage, 1979) dealing with the economic and energy aspects of food irradiation in Vienna in 17-21 Sept., 1979. A summary of the significant milestones are given in Table 2. TABLE 2
A Summary of Food Irradiation Achievements by Radiation Technolosy,
Inc.
Processed multi-ton quantities of frozen froglegs and shrimp starting in 1970 for Salmonellae control. First commercial shipment of radurized cod fish fillets to Holland in 1977. Radappertized Hospital Diets shipped to Fred Hutchinson Memorial Hospital, Seattle, Washington in January 1978.
Status of commercial
food irradiation
in the United States
219
Radappertized diets shipped to Canada for use in a 7-month sailing voyage to Fiji in October 1978. Irradiated Spice Petition submitted to FDA in April 1980 and approved for filing. Radurized strawberries shipped to Holland in December 1980. First specifically-built food irradiation facility in U.S. began operations in June 1981 in West Memphis, Arkansas (Model RT 4101-2852). First commercial U.S. Government contract for radappertized diets for NASA Space Shuttle Program in January 1982. Processed pallet load quantities of California grapes under FDA emergency approval for insect disinfestation in February 1982. The introduction of a new type of gamma irradiation system by Radiation Technology, Inc. was first described at the Rutgers Symposium on Food Irradiation (Rutgers U., 1982) in May 1982. The significance of this system is that it permits highly versatile and economic processing of both low dose bulky food products as well as high dose medical product sterilization work. The basic Model RT-4101 was installed by a subsidiary, Process Technology, Inc. in West Memphis, Arkansas, and began operating in June 1981. This unit, which is referred to as the Series 2852 because it handles special pallet loads whose dimensions are 28 inches x 52 inches (71 cm x 132 em), has characteristics shown in Table 3. TABLE 3
Specifications
Maximum Maximum Maximum Maximum Maximum Maximum
for the RT 4101-2852
number of pallets per hour load per pallet pallet dimensions product loading height curie loading (Co60~ number of processing routines
50 1400# (636 kgm) 28" x 52" (71 cm x 132 cm) 84" (214 cm) 3 MCi 6
An advanced version of the Model RT 4101, a series 4048, is now under construction for sites in North Carolina, Rhode Island and California. The North Carolina facility is located near the city of Burlington in Alamance County, and is expected to start operations early in 1983, with the Providence, Rhode Island plant following by about 2-3 months. The third facility, near Stockton, California is expected on-stream by September 1983. The Series 4048 can accommodate standard U.S. pallets 40 inches x 48 inches (102 cm x 122 cm) and will have features as shown in Table 4. TABLE 4
Specifications
Maximum Maximum Maximum Maximum Maximum Maximum
fnr the RT 4101-4048
number of pallets number of processing routines load per pallet pallet dimensions product loading height curie loading (Co60)
50 6 2500# (1136 kgm) 40" x 48" (102 cm x 122 cm) 96" (244 cm) 3 MCi
The importance of having an irradiation facility with maximum versatility is that it overcomes a major problem in introducing commercial food irradiation, in that: I.
Seasonal crop production may rule out a single purpose facility since it can only be used for several months a year.
2.
For a high dose requirement (medical product sterilization) the conveyor system would typically be too light and the required source strength would typically be too high to permit economical processing of low dose requirements such as for sprout inhibition or insect disinfestation.
Table 5 shows the various processing the RT 4101 irradiator.
routines available
to an operations
staff when using
220
TABLE 5
M.A.
WELT
RT 4101 Processing Routines
Routine
1 2 3 4* 5* 6
Purpose Throughput
Dose
High Moderate-High Moderate-High Low-Moderate Low-Moderate Moderate
High Low High High Low Moderate
Processing Mode Passes - Dwell Stations 4 2 2 2 2 4
12 6 6 2 2 4
*Routines 4 and 5 permit dwell times to be increased over normal setting by a factor of i0 for very high dose irradiation, approaching virtually static irradiation conditions. Figure 1 depicts the path taken by pallet loads being processed under Routine I, while Figures 2 and 3 show the routes taken under Routines 2 and 5 for low dose rate or high dose rate processing respectively. The other routines permit the operator to cater to small loads on a reasonably economical manner. Each pallet load introduced into the maze is controlled by a computer which permits rapid entry of new products requiring a different dose than the preceeding load. "Conventional" medical product sterilization facilities require extensive down time for clearing an irradiator before introducing a new product of a different bulk density and requiring a new dwell time. Further, the "conventional" medical product irradiator system is designed for relatively light packaged products and for doses ranging from about 1.2 to 3.5 Mrad (12-35 kGy). These facilities are usually not applicable for proving economic feasibility of low dose requirement food processing and it is for that reason that the RT 4101 system came into being. Once the processing requirement builds up to a level requiring a captive facility, then the versatility of the RT 4101 is no longer required and a high throughput capacity Model RT 4101 TL would be utilized. This TL system is due to be introduced by Radiation Technology, Inc. in November 1982 (Welt, 1982) and we plan to offer this unit on a competitive basis world-wide. All of the RT 4101 systems are designed to minimize product handling and reduce conveyor system complexity. Fifteen years of operational experience with "conventional" tote-conveyor, shuffle-dwell systems have convinced us of the superiority of the RT 4101 pallet load concept. Figure 4 shows the Model 4101 in West Memphis, Arkansas in actual operation. CONCLUSION f
It may very well be appropriate, in October 1982, to conclude a talk on Food Irradiation with the same words used in 1758 by Voltaire at the conclusion of Candide -- "come let us cultivate our garden" and use radiation preservation to prolong the shelf life, eliminate harmful organisms and reduce spoilage, for the good of all mankind.
Status of commercial
~i~~ iii~iii
food irradiation
in the United States
Figure i Processing Routine i Model RT-4101 Service Irradiator
Figure 2 Processing Routine 2 Model RT-4101 Service Irradiator
RPC 22-I/2-P
221
222
M . A . WELT
Figure 3 Processing Routine 5 Model RT-4101 Service Irradiator
Figure 4 Process Technology, Inc W. Memphis, Arkansas Irradiation Cell Entrance/Exit Maze Model RT-4101-2852
Status of commercial food irradiation in the United States
223
References Agriculture, U.S. Department of (1963). Brookhaven National Labs. Study Report: Cobalt60 Bulk Grain Irradiator, BNL 810 (T-312). Brookhaven National Labs., Upton, N.Y. Army, U°S. Department of (1963).
FAP #890 21 CFR 121.3002.
Army, U.S. Department of (1964).
FAP #890 21 CFR 121.3002.
Army, U.S. Department of (1956). History and Status of the Quartermaster Corps. Radiation Preservation of Food Project. Quartermaster Food and Container Institute for the Armed Forces, Chicago. Army, U.S. Department of (1980). Memorandum of Understanding on the Transfer of the Irradiated Food Research Program from Department of the Army to Science and Education Administration, U.S. Department of Agriculture. July 3rd. Brownell et al. (1963).
FAP #941 CFR 121.3003.
Brynjolfsson, A. (1978). The high dose and the low dose food irradiation program in the United States. Tech Report Natick/TR-78/033. U.S. Army, Natick Research and Development Company, Natick, MA 01760. Congress of the United States (1955, '56, '60, '62, '63, '65, '66, '68). Hearings Before the Joint Committee on Atomic Energy: Review of the Army Food Irradiation Program. U.S. Government Printing Office, Washington, D.C. Congress of the United State (1960). Hearings before the Joint Committee on Atomic Energy (First Session, Jan. 14-15; Second Session, March 31). U.S. Government Printing Office, Wash., D.C. Diehl, J.F. (1981). Irradiated Foods -- are they safe? in, Impact of Toxicology on Food Processing, eds. J.C. Ayres and J.C. Kirschman, IFT Basic Symposium Series, AVI Publishing Co., Westport, Conn. 286-304. Federal Food, Drug and Cosmetic Act as Amended (1975). Title 21, U.S. Code of Federal Regulations 321 Part 121 - Food Additives. U.S. Government Printing Office, Wash., D.C. Federal Food, Drug and Cosmetic Act as Amended (1975). Title 21, U.S. Code of Federal Regulations, Section 409 [348 in the Code] - Food Additives, Action on the Petition to Establish Safety. U.S. Government Printing Office, Wash., D.C. Food & Drug Administration (1980). Radiation Technology, Inc., Filing of Food Additive Petition. Federal Register 45(203): 69044-45. October 17th. Docket No. 80F-0368. Giddings, G.G. (1982).
Private communication.
Joint FAO/IAEA/WHO Expert Committee (1981). Wholesomeness of Irradiated Food: World Health Organization Technical Report Series 659. WHO, Geneva. Joint FAO/WHO Food Standards Programme (1982). Alinorm 83/12 - Draft Report of the 15th Session of the Codex Corm~ittee on Food Additives, The Hague, 16-22 March, 1982. Proctor, B.E., Van de Graff, R.J. and FrOm (1943). Effect of X-ray irradiation on the bacterial count of ground meat. Research Reports of the U.S. Army Quartermaster Contract Projects, July, 1942-June, 1943. Dept. of Food Technology, M.I.T. 217-218. Proctor, B.E., Nickerson, J.T.R., and Goldblith, S.A. (1954). Possibility of utilizing high energy cathode rays for the preservation and/or complete sterilization of whole and sliced fresh fruits and vegetables and meats to increase present storage life of these commodities. Final Report on Contract N-140s-46199B, Bureau of Supplies and Accounts, U.S. Navy.
224
A.M.
WELT
Proctor, B.E., Lockhard, E.E., Goldblith, S.A., Grundy, A.V., Tripp, G.E., Karel, M. and Brogle, R.C. (1954). The use of ionizing radiation in the eradication of insects in packaged military rations. Food Technology, 8:536. Schubert, J. (1978). Toxicological Studies on irradiated food and food constituents, Food Preservation by Irradiation, Vol. II, Wageningen Symposium IAEA. U.S. Department of Commerce (1965). Current Status and Commercial Prospects Preservation of Food. U.S. Government Printing Office, Wash., D.C. 303.
in,
for Radiation
Welt, M.A. (1980). First commercial irradiation of foods in the United States. Proc. 26th European Meeting of Meat Research Workers. International Meat Research Congress, Colorado Springs, Vol. I, American Meat Science Assoc., Chicago, 190-192. Welt, M.A., Sage, G. (1979). The commercial prospects for the radiation preservation of food in the United States of America. Presented at the FAO/IAEA Advisory Group Meeting on Comparative Analysis of the Economics and Energy Requirements of Food Irradiation and Other Food Preservation Methods. IAEA, Vienna, 9/17-21. (Unpublished). Welt, M.A. (1982). A unique and versatile gamma irradiator for radiation preservation of food. Symposium-Food Irradiation Technology: State of the Art, Cook College, Rutgers University, New Brunswick, N.J. May 25. Welt, M.A. (1982). Nuclear technology in food preservation. Nuclear Society Meeting, Wash., D.C., November 15, 1982.
Presented at the American
0146-5724/83/07215-10503.00/0 © 1983 Pergamon Press Ltd.
Printed in Great Britain
STATUS OF COMMERCIAL
FOOD IRRADIATION
IN THE UNITED STATES
Martin A. Welt, Ph.D. Radiation Technology, P.O. Box 185 Rockaway, New Jersey
Inc. 07866
ABSTRACT It may be difficult for some to realize, but the United States is now starting its fourth decade in food irradiation research. This vast storehouse of research data now makes the ultimate task of bringing the technology to the consumer marketplace that much easier. Radiation Technology, Inc. of Rockaway, New Jersey has pioneered the use of radiation processing for the commercial preservation of food and has established the first food irradiation facility in the United States in West Memphis, Arkansas. The facility, designed by Radiation Technology, Inc., provides the necessary versatility to meet the needs of the food industry. KEYWORDS Radiation Technology, Inc.; food irradiation; zation; food irradiator design; Cobalt-60.
radiation
sterilization;
radiation pasteuri-
INTRODUCTION The initial effort in the quest for commercialization began with research funded by the U.S. Army Quartermaster Corps and directed by the late Professor Bernard Proctor and his colleagues at the Massachusetts Institute of Technology. This 1943 study (Proctor et al., 1943) concerned with the sterilization of ground meat with X-rays, demonstrated the potential for the radiation preservation of food to become the first really new food preservation technique since canning was introduced early in the nineteenth century. Following continuing promising work which began at MIT in the late forties, including studies for the U.S. Navy on preserving meat, fish and other rations (Proctor et al., 1954) and for the U.S. Army on insect disinfestation of cereal bars (Proctor et al., 1954), a concerted national R&D effort was initiated in 1950 under the auspices of the Atomic Energy Commission (U.S. Department of Commerce, 1965). Early investigations also included short-term animal toxicity studies by the Army Medical Nutrition Laboratories involving 45 irradiated foods. The initial interest kindled by the U.S. Army Quartermaster Corps was kept active at the Department of Army, U.S. Army Material Command, when in 1953 Dr. Ralph G.H. Siu, Scientific Director, Research Division, undertook a detailed appraisal of the prospects for radiation preservation of food. Following a review of the Siu report by a National Academy of Sciences Committee, the Quartermaster General requested, in May 1953, authorization to begin a 5-year research program. In May 1956, the Interdepartmental Committee on Radiation Preservation of Food was formed at the suggestion of the Secretary of Defense to coordinate all government activities and to help in the process of commercialization. From 1955 to 1958 an additional 54 irradiated foods were included in seven short-term human volunteer feeding studies, with no adverse effects noted. Excellent summaries of the early Atomic Energy Commission low dose program and the Army's high dose efforts can be found in a 1963 Department of Commerce report (ibid) and an earlier Quartermaster Corps food irradiation status report (U.S. Army, 1956). The various congressional hearings of the Joint Committee on Atomic Energy dealing with radiation processing of foods are also invaluable reference works (Congress, 1955, '56, '60, '62, '63, '65, '66, '68). 2]5
216
M. A WELT
The euphoria of the early research successes began running into setbacks in 1958 with two events which were probably responsible for much of the ultimate delay in bringing about commercialization of food irradiation. These events were: i°
The Food Additives Amendment of 1958 to the Federal Food, Drug and Cosmetic Act provides that any food subjected intentionally to irradiation would be adulterated unless a food additive petition was submitted and approved, in accordance with Section 402(a) 7 of the Act.
2.
The cancellation of plans to build a major food irradiation facility (Army Ionizing Radiation Center) in Stockton, California which was to have been operated under contract to the U.S. Army.
The former event was, in the eyes of many (Federal Food, Drug and Cosmetic Act, 1975; Diehl, 1981; Brynjolfsson, 1978; Welt, 1980, Schubert, 1978) an unfortunate occurrence since it not only made it virtually impossible to prove the safety of the process since the "additive'remained elusive, but also the early conventional animal feeding studies produced more questions than answers due to the highly unbalanced irradiated food diets that were used. However, if we follow the logic of Voltaire in Candide and look for the good in this "best of all possible worlds", it must be admitted that we probably know more after 25 years of effort about the wholesomeness and utility of irradiated food than any other method of food preservation. This vast storehouse of research data now makes the ultimate task of bringing the technology to the consumer marketplace that much easier. The cancellation of the U.S. Army Stockton irradiator due to "reported" harmful effects of irradiation, proved to be a serious setback with regard to getting commercial food and business interests involved, since a full-sized processing facility for pilot test work was denied them. It is now known from Joint Committee hearings in January and March 1960 that there was little or no basis to support claims that irradiation was responsible for harmful effects in animals (Congress, 1960). Shortly after the hearings in 1960, the Army reinstituted plans to continue irradiated food research with a $5 million program which was centralized at the Natick Laboratories in Massachusetts. The food irradiation laboratory built at Natick then contained the world's largest cobalt-60 irradiator as well as a 24 Mev linear accelerator. There were, of course, other factors which seemed to stymie progress. For example, in 1962 Professor L.E. Brownell et al. submitted the nation's first petition from a non-governmental source to the FDA, and received approval to use ionizing radiation for insect disinfestation of wheat and wheat products (Brownell et al., 1963). Shortly thereafter, approval was granted for the sprout inhibition of white potatoes (U.S. Army, 1964) and of greatest importance, the U.S. Army Natick group obtained FDA approval for the radiation-sterilization of bacon (U.S. Army, 1963). Then in 1968 the roof fell in with the withdrawal without prejudice by the Army of a radiation sterilized ham petition on the basis of incomplete information as was required under a new revised FDA protocol format. Since the same "deficiency" existed in the already approved bacon petition, the Commissioner of the FDA decided to withdraw the bacon approval with an eye towards having the petition quickly satisfy the new, much more involved protocol procedure. I'm certain that the Commissioner did not believe that at a meeting taking place nearly fifteen years later, approval was still being denied. One should remember the words of the Surgeon General regarding his belief in the future of irradiated foods: "Food irradiated up to absorbed doses of 5.6 megarads with a cobalt-60 source of radiation or with electrons with energies up to i0 million electron volts have been found to be wholesome; i.e., safe, and nutritionally adequate." (Congress, 1965) Critics of food irradiation in the United States have continually asked why we should strive to implement this technology when nothing of commercial consequence has been done with our potato and wheat/wheat flour approvals and after all, "something must have been wrong with the concept to have the Stockton irradiator cancelled". They also point out that a U.S. Department of Agriculture Demonstration Grain Irradiator (U.S.D.A., 1963) in Savannah, Georgia was not totally successful in its own utilization, nor did it spawn commercial facilities to replace fumigation.
Status of commercial
food irradiation
in the United States
217
The impact of the 1958 Amendment to the Food & Drug Act on further petitions for irradiated food approvals can be shown by pointing out that with the withdrawal of the bacon petition, only a spice irradiation petition submitted by Radiation Technology, Inc. in 1980 was accepted by the FDA for filing in the Federal Register (Radiation Technology, Inc., 1980). In spite of full compliance with existing regulatory guidelines, a final unequivocal approval awaits issuance of the first of a series of FDA food irradiation regulations which is expected in 1982. The "new era" in food irradiation in the U.S., which many of us have waited patiently also got its' start with several significant events: i.
In 1980 the "National Food Irradiation Program" was transferred from the U.S. Army (Department of Defense) to the U.S. Department of Agriculture (U.S. Army, 1980). This move ended the World's most productive research effort in the high dose radiation preservation of food. Recognition must be given to the Natick researchers individually and as a team. I doubt that anyone in the food irradiation field is not familiar with the work and contributions of Ed Josephson, Ari Brynjolfsson, Charles Merritt, Irwin Taub, Bob Jarrett, Eguen Wierbicki, John Halliday, Abe Anellis, Durwood Rowley, etc.
2.
In March, 1981 the FDA issued its Advance Notice of Proposed Rulemaking (FDA, 1981) concerning irradiated food. This long-awaited position paper by the Bureau of Foods recommended the unconditional use of 100 Krad (I kGy) of ionizing radiation from Cobalt-60, Cesium-137 or 10 Mev electrons for processing any food product. It was also indicated that for doses up to and including 1 Mrad (10 kGy), onlj short-term (90-day) two species (rodent and non-rodent) feeding studies and mutagenicity testing would be required. One of the biggest surprises in the FDA document was their recommendation to approve dose up to 5 Mrad (50 kGy) for processing food components that make up less than 0.01% of a daily diet. The importance of this aspect was not the limited practicality of its use since only spices and like ingredients are intended to be covered; but, rather, that in the context of the "Delaney clause" of the 1958 Food Additives Amendment to the Food, Drug and Cosmetic Act it constitutes de-facto recognition by the FDA that a dose as high as 5 Megarads does not generate any cancer-causing substance(s) in food so treated. For general food applications above i00 Kilorads the FDA proposed to drastically reduce the degree of safety testing rigor in support of pre-marketing approval (i.e., a petition) from what has been and is the case. The Agency's proposed easing of testing requirements is no doubt in recognition of the enormous amount of irradiated foods safety-wholesomeness testing that has been conducted worldwide since the original requirements were established some years ago. Nevertheless, one highly credible testing firm developed a detailed estimate, at our request, which indicates that the minimum battery of mutagenicity and sub-chronic animal feeding studies that the FDA proposes to require in support of a petition for each and every irradiated food item above 100 Krads will cost in excess of U.S. $200K and several months of effort, not including the petition preparation, as shown in Table 1 (Giddings, 1982).
TABLE 1
Cost Estimate
for Completing FDA Short Term Feeding & Mutagenicity
Test Description 1. *+2. 3.
Ames Test (bacterial gene mutation) Mouse lymphoma (cell culture) DNA repair ("sister chromatid exchange", "SCD", employing Chinese hamster ovary "CHO", cells)
Estimated Cost/Sample $
1,375 5,700
3,500
Tests
Duration
for,
218
M.A.
*+4. **5. **6.
Drosophila (recessive lethal mutations) Rat Feeding Study Dog Feeding Study
WELT
test
35,000 70,000 ii0,000
2½ mo. 90 days 90 days
*i and 2 are commonly used as screening tests to determine if it is worth spending more money to conduct further tests. Chromosomal analysis is the most popular and least expensive screening assay. *+If mouse lymphoma is positive, the Drosophila test must be negative, otherwise long-term chronic testing is usually called for.
or
**For 5 and 6, the time to report out the study takes almost as long as the time to conduct. The entire battery can be expected to consume on the order of nine (9) months. Then there is the FDA petitioning process to gain clearance which, experience has shown, is no simple matter, as a rule. 3.
In Fall, 1981, at the height of the California Mediterranean fruit fly crisis, and in the face of an impending EPA ban on the use of ethylene dibromide as a fruit fumigant, FDA Commissioner Hayes granted emergency approval of the use of ionizing radiation for "Medfly" disinfestation of affected California fruit and produce in advance of the rulemaking officially allowing same. This emergency approval could not be implemented before the end of the California harvest because irradiation firms were taken by surprise by the approval and had no plants operating in the affected areas, preferring to hold off construction until the FDA's intentions became clearer through the rulemaking process, thereby creating a more conducive environment for installing such plants in California and other 'quarantine' states. The only use of the FDA emergency approval for insect disinfestation for commercial purposes, as far as it is known, was the use of Radiation Technology's food irradiation facility in West Memphis, Arkansas in February, 1982 for processing truck load quantities of California grapes. The species involved were: white (Calmeria), red (Emperor) and purple (Ribier), and the minimum dose utilized was 25 krad (0.25 kGy). Since product could not be moved out of a quarantined county infested with Medfly, the importance of this FDA move was more in its symbolic gesture of things to come rather than an important immediate alternative to EDB fumigation since no commercial irradiators were available within the quarantine region.
It now appears that a revision to the restrictive 1958 Food & Drug Act Amendment will be issued shortly, and together with the introduction of the nation's first commercial food irradiation facility in West Memphis, Arkansas in 1981, the two conditions that have held back commercialization in the U.S. should be eliminated.
COMMERCIAL FOOD IRRADIATION ACTIVITIES IN THE U.S. During the past decade, aside from the Natick effort (now transferred to the USDA) to obtain a high dose radappertization clearance for poultry, only Radiation Technology persisted in pursuing a commercial activity in food irradiation. A summary of these activities was given by the writer at the 26th Annual European Meat Research Workers Meeting (Welt, 1980) held in Colorado Springs in September 1980 and additional details were presented at an IAEA working committee meeting (Welt and Sage, 1979) dealing with the economic and energy aspects of food irradiation in Vienna in 17-21 Sept., 1979. A summary of the significant milestones are given in Table 2. TABLE 2
A Summary of Food Irradiation Achievements by Radiation Technolosy,
Inc.
Processed multi-ton quantities of frozen froglegs and shrimp starting in 1970 for Salmonellae control. First commercial shipment of radurized cod fish fillets to Holland in 1977. Radappertized Hospital Diets shipped to Fred Hutchinson Memorial Hospital, Seattle, Washington in January 1978.
Status of commercial
food irradiation
in the United States
219
Radappertized diets shipped to Canada for use in a 7-month sailing voyage to Fiji in October 1978. Irradiated Spice Petition submitted to FDA in April 1980 and approved for filing. Radurized strawberries shipped to Holland in December 1980. First specifically-built food irradiation facility in U.S. began operations in June 1981 in West Memphis, Arkansas (Model RT 4101-2852). First commercial U.S. Government contract for radappertized diets for NASA Space Shuttle Program in January 1982. Processed pallet load quantities of California grapes under FDA emergency approval for insect disinfestation in February 1982. The introduction of a new type of gamma irradiation system by Radiation Technology, Inc. was first described at the Rutgers Symposium on Food Irradiation (Rutgers U., 1982) in May 1982. The significance of this system is that it permits highly versatile and economic processing of both low dose bulky food products as well as high dose medical product sterilization work. The basic Model RT-4101 was installed by a subsidiary, Process Technology, Inc. in West Memphis, Arkansas, and began operating in June 1981. This unit, which is referred to as the Series 2852 because it handles special pallet loads whose dimensions are 28 inches x 52 inches (71 cm x 132 em), has characteristics shown in Table 3. TABLE 3
Specifications
Maximum Maximum Maximum Maximum Maximum Maximum
for the RT 4101-2852
number of pallets per hour load per pallet pallet dimensions product loading height curie loading (Co60~ number of processing routines
50 1400# (636 kgm) 28" x 52" (71 cm x 132 cm) 84" (214 cm) 3 MCi 6
An advanced version of the Model RT 4101, a series 4048, is now under construction for sites in North Carolina, Rhode Island and California. The North Carolina facility is located near the city of Burlington in Alamance County, and is expected to start operations early in 1983, with the Providence, Rhode Island plant following by about 2-3 months. The third facility, near Stockton, California is expected on-stream by September 1983. The Series 4048 can accommodate standard U.S. pallets 40 inches x 48 inches (102 cm x 122 cm) and will have features as shown in Table 4. TABLE 4
Specifications
Maximum Maximum Maximum Maximum Maximum Maximum
fnr the RT 4101-4048
number of pallets number of processing routines load per pallet pallet dimensions product loading height curie loading (Co60)
50 6 2500# (1136 kgm) 40" x 48" (102 cm x 122 cm) 96" (244 cm) 3 MCi
The importance of having an irradiation facility with maximum versatility is that it overcomes a major problem in introducing commercial food irradiation, in that: I.
Seasonal crop production may rule out a single purpose facility since it can only be used for several months a year.
2.
For a high dose requirement (medical product sterilization) the conveyor system would typically be too light and the required source strength would typically be too high to permit economical processing of low dose requirements such as for sprout inhibition or insect disinfestation.
Table 5 shows the various processing the RT 4101 irradiator.
routines available
to an operations
staff when using
220
TABLE 5
M.A.
WELT
RT 4101 Processing Routines
Routine
1 2 3 4* 5* 6
Purpose Throughput
Dose
High Moderate-High Moderate-High Low-Moderate Low-Moderate Moderate
High Low High High Low Moderate
Processing Mode Passes - Dwell Stations 4 2 2 2 2 4
12 6 6 2 2 4
*Routines 4 and 5 permit dwell times to be increased over normal setting by a factor of i0 for very high dose irradiation, approaching virtually static irradiation conditions. Figure 1 depicts the path taken by pallet loads being processed under Routine I, while Figures 2 and 3 show the routes taken under Routines 2 and 5 for low dose rate or high dose rate processing respectively. The other routines permit the operator to cater to small loads on a reasonably economical manner. Each pallet load introduced into the maze is controlled by a computer which permits rapid entry of new products requiring a different dose than the preceeding load. "Conventional" medical product sterilization facilities require extensive down time for clearing an irradiator before introducing a new product of a different bulk density and requiring a new dwell time. Further, the "conventional" medical product irradiator system is designed for relatively light packaged products and for doses ranging from about 1.2 to 3.5 Mrad (12-35 kGy). These facilities are usually not applicable for proving economic feasibility of low dose requirement food processing and it is for that reason that the RT 4101 system came into being. Once the processing requirement builds up to a level requiring a captive facility, then the versatility of the RT 4101 is no longer required and a high throughput capacity Model RT 4101 TL would be utilized. This TL system is due to be introduced by Radiation Technology, Inc. in November 1982 (Welt, 1982) and we plan to offer this unit on a competitive basis world-wide. All of the RT 4101 systems are designed to minimize product handling and reduce conveyor system complexity. Fifteen years of operational experience with "conventional" tote-conveyor, shuffle-dwell systems have convinced us of the superiority of the RT 4101 pallet load concept. Figure 4 shows the Model 4101 in West Memphis, Arkansas in actual operation. CONCLUSION f
It may very well be appropriate, in October 1982, to conclude a talk on Food Irradiation with the same words used in 1758 by Voltaire at the conclusion of Candide -- "come let us cultivate our garden" and use radiation preservation to prolong the shelf life, eliminate harmful organisms and reduce spoilage, for the good of all mankind.
Status of commercial
~i~~ iii~iii
food irradiation
in the United States
Figure i Processing Routine i Model RT-4101 Service Irradiator
Figure 2 Processing Routine 2 Model RT-4101 Service Irradiator
RPC 22-I/2-P
221
222
M . A . WELT
Figure 3 Processing Routine 5 Model RT-4101 Service Irradiator
Figure 4 Process Technology, Inc W. Memphis, Arkansas Irradiation Cell Entrance/Exit Maze Model RT-4101-2852
Status of commercial food irradiation in the United States
223
References Agriculture, U.S. Department of (1963). Brookhaven National Labs. Study Report: Cobalt60 Bulk Grain Irradiator, BNL 810 (T-312). Brookhaven National Labs., Upton, N.Y. Army, U°S. Department of (1963).
FAP #890 21 CFR 121.3002.
Army, U.S. Department of (1964).
FAP #890 21 CFR 121.3002.
Army, U.S. Department of (1956). History and Status of the Quartermaster Corps. Radiation Preservation of Food Project. Quartermaster Food and Container Institute for the Armed Forces, Chicago. Army, U.S. Department of (1980). Memorandum of Understanding on the Transfer of the Irradiated Food Research Program from Department of the Army to Science and Education Administration, U.S. Department of Agriculture. July 3rd. Brownell et al. (1963).
FAP #941 CFR 121.3003.
Brynjolfsson, A. (1978). The high dose and the low dose food irradiation program in the United States. Tech Report Natick/TR-78/033. U.S. Army, Natick Research and Development Company, Natick, MA 01760. Congress of the United States (1955, '56, '60, '62, '63, '65, '66, '68). Hearings Before the Joint Committee on Atomic Energy: Review of the Army Food Irradiation Program. U.S. Government Printing Office, Washington, D.C. Congress of the United State (1960). Hearings before the Joint Committee on Atomic Energy (First Session, Jan. 14-15; Second Session, March 31). U.S. Government Printing Office, Wash., D.C. Diehl, J.F. (1981). Irradiated Foods -- are they safe? in, Impact of Toxicology on Food Processing, eds. J.C. Ayres and J.C. Kirschman, IFT Basic Symposium Series, AVI Publishing Co., Westport, Conn. 286-304. Federal Food, Drug and Cosmetic Act as Amended (1975). Title 21, U.S. Code of Federal Regulations 321 Part 121 - Food Additives. U.S. Government Printing Office, Wash., D.C. Federal Food, Drug and Cosmetic Act as Amended (1975). Title 21, U.S. Code of Federal Regulations, Section 409 [348 in the Code] - Food Additives, Action on the Petition to Establish Safety. U.S. Government Printing Office, Wash., D.C. Food & Drug Administration (1980). Radiation Technology, Inc., Filing of Food Additive Petition. Federal Register 45(203): 69044-45. October 17th. Docket No. 80F-0368. Giddings, G.G. (1982).
Private communication.
Joint FAO/IAEA/WHO Expert Committee (1981). Wholesomeness of Irradiated Food: World Health Organization Technical Report Series 659. WHO, Geneva. Joint FAO/WHO Food Standards Programme (1982). Alinorm 83/12 - Draft Report of the 15th Session of the Codex Corm~ittee on Food Additives, The Hague, 16-22 March, 1982. Proctor, B.E., Van de Graff, R.J. and FrOm (1943). Effect of X-ray irradiation on the bacterial count of ground meat. Research Reports of the U.S. Army Quartermaster Contract Projects, July, 1942-June, 1943. Dept. of Food Technology, M.I.T. 217-218. Proctor, B.E., Nickerson, J.T.R., and Goldblith, S.A. (1954). Possibility of utilizing high energy cathode rays for the preservation and/or complete sterilization of whole and sliced fresh fruits and vegetables and meats to increase present storage life of these commodities. Final Report on Contract N-140s-46199B, Bureau of Supplies and Accounts, U.S. Navy.
224
A.M.
WELT
Proctor, B.E., Lockhard, E.E., Goldblith, S.A., Grundy, A.V., Tripp, G.E., Karel, M. and Brogle, R.C. (1954). The use of ionizing radiation in the eradication of insects in packaged military rations. Food Technology, 8:536. Schubert, J. (1978). Toxicological Studies on irradiated food and food constituents, Food Preservation by Irradiation, Vol. II, Wageningen Symposium IAEA. U.S. Department of Commerce (1965). Current Status and Commercial Prospects Preservation of Food. U.S. Government Printing Office, Wash., D.C. 303.
in,
for Radiation
Welt, M.A. (1980). First commercial irradiation of foods in the United States. Proc. 26th European Meeting of Meat Research Workers. International Meat Research Congress, Colorado Springs, Vol. I, American Meat Science Assoc., Chicago, 190-192. Welt, M.A., Sage, G. (1979). The commercial prospects for the radiation preservation of food in the United States of America. Presented at the FAO/IAEA Advisory Group Meeting on Comparative Analysis of the Economics and Energy Requirements of Food Irradiation and Other Food Preservation Methods. IAEA, Vienna, 9/17-21. (Unpublished). Welt, M.A. (1982). A unique and versatile gamma irradiator for radiation preservation of food. Symposium-Food Irradiation Technology: State of the Art, Cook College, Rutgers University, New Brunswick, N.J. May 25. Welt, M.A. (1982). Nuclear technology in food preservation. Nuclear Society Meeting, Wash., D.C., November 15, 1982.
Presented at the American