Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
The Meaning of Safety as Regards Food Additives R. BLACKWELL SMITH, JR. President, Medical College of Virginia Safety, in relation to food additives, has been defined as the practical certainty that no harm will ensue when a particular material is used in a specified manner. It has also been stated that safety is the practical certainty that a particular use of a given substance is without appreciable hazard. If one examines these statements on the meaning of safety, it is apparent that safety is really a negative quality, the absence of hazard. The concept of safety, then, represents no positive state, but rather is emblematic of an instinctive urge, shared by all organisms having a minimum level of intelligence or environ- mental awareness, to be free from the threat of harm, i.e., danger or hazard. It is not susceptible of complete fulfilment, save pos- sibly in the grave where any further hazards that may exist are certainly not related to food additives. That this concept or idea we call safety is really a manifesta- tion of the basic instinct toward self-preservation, is probably the reason why the idea of adding chemicals to foods stimulates in the minds of the uninformed, to whom any chemical is something unnatural and therefore to be feared, an irrational and emotional, revulsive reaction. Since in technical areas such as this more people are uninformed than otherwise, one can see why this subject has provoked the writing of reams of nonsense during the past ten years. It has provided almost perfect grist for the mills of the professional alarmists, such as the poison pen pushers with literary royalties in mind; those unscrupulous and cynically provocative writers who thrive on sensationalism; those politi- 49
cians who see here an almost perfect chance to appear in the noble role of protectors of the helpless and the weak; those who apparently take positive delight in shivering anticipation of dangers unknown and perhaps non-existent; and some few dedi- cated but legalistically minded bureaucrats who firmly believe the public interest cannot possibly be protected save through ever more complicated and restrictive regulatory enactments. Alarmed and stimulated by such vociferous and formidable threats to the use of chemicals to promote a better food supply, a perfectly legitimate and often necessary practice, many who know better have responded with soothing syrup of the "every- thing is perfectly fine" variety, pointing out that since every- thing is chemical in nature, one need have no fears whatsoever concerning the use of chemicalsâor additives, if you willâin connection with the production, processing, improving, preserva- tion, packaging, and storage of foods. This, too, is nonsense. This fact should be faced. There are potential hazards asso- ciated with the use of food additives, but these can be controlled through the application of knowledge and common sense, just as society controls the adverse potential of other accepted haz- ards incident to everyday living. At the risk of belaboring the obvious, it might be pointed out that every potential social advance presents alternatives imposing value judgments which cannot be avoided except at the risk of stagnation. Almost al- ways when progress is made, a risk of some nature is incurred and means devised to minimize or contain that risk. Soâto cite only one exampleâit has been in the field of transportation, and so it is and must be in the provision of an adequate and whole- some supply of food. Many years ago public policy accepted the risk incident to the necessary or unavoidable presence of limited amounts of poten- tially deleterious substances (pesticides) in food under certain conditions. More recently, as has been pointed out frequently, the growth of the pest population on the one hand and the human population on the other has resulted in a competition for food so intense that a multitude of pesticidal substances of varying nature and properties has become necessary for the production of an adequate food supply. Again, public policy as 50
reflected in statutory enactments has accommodated itself by liberalizing the restrictions of earlier legislation and requiring only that a pesticide be useful, not necessary or unavoidable as demanded earlier, provided data can be adduced to support the establishment of a safe level of use, or tolerance. Essentially similar provisions, so far as demonstration of safety is concerned, have now been enacted with respect to chemicals, other than pesticides, present in foods consequent to technological use or added to confer qualities believed to be desirable. In referring above to the liberalization of the restrictions of early legislation, no decrease in the protection offered the public is implied, nor to the best of my knowledge and belief has there been any such decrease. Liberalization has nevertheless taken place in the sense of statutory recognition of the truth that there is no basis in fact for the idea that any substance either is or is not a poison, or either is or is not innately poisonous or delete- rious. This idea, the so-called "per se" concept, had served to create confusion and to delay recognition of and attention to the real issue, i.e., whether a particular use of a chemical additive is safe (relatively free from harmful potential). For many years pharmacologists, toxicologists, and other scien- tists concerned with such matters sought without success to develop a generally satisfactory definition of a poison. The truth, belatedly recognized, is that substantially every substance, in- cluding pure water and table salt, may be harmful if a sufficient quantity is swallowed or otherwise introduced into the body; and conversely, it is a generally accepted fact that there is no substance sure to kill or harm if swallowed or taken otherwise, provided the amount taken be sufficiently small. That this harmless amount in many cases may be so small as to approach zero doubtless accounts for the popular characterization of sub- stances known to be harmful in relatively small amounts as poisonous. To recapitulate, an additive or other chemical is not and cannot be of itself either poisonous or non-poisonous, haz- ardous or non-hazardous, harmful or safe; but every additive or other chemical may be safe at some level or mode of intake and hazardous at some other level or mode of intake. The question, then, is not one of whether but essentially one of how much. 51
Procedures are available which generally are adequate to the task of answering the question of how much of a food additive can be used safely. These involve, first, the scientific determina- tion of the maximum amount of a given additive which can be administered or fed to animals without the production of injury, and, second, an estimate by extrapolation of the amount which can be safely consumed by man. The applicable technical pro- cedures have been described by the Food Protection Committee of the National Academy of SciencesâNational Research Coun- cil (1), the United Nations WHO-FAO Joint Expert Committee on Food Additives (2), Lehman and his coworkers of the United States Food and Drug Administration (3) and others. These procedures involve long-term animal feeding and other studies leading to a determination of the highest "no-effect" level in the species studied. They are cumbersome, time consuming, and costly; and they stand in need of improvement or replace- ment. Workers in the field are bending every effort toward this end. The interpretation of the data obtained is a complex matter as is their extrapolation to the human, and both require the expert skill which can be acquired only through extensive ex- perience. Nevertheless, for a given additive, the means available permit the identification with practical certainty of safe levels of use. Absolute assurance of safety cannot be provided either by present methods or by those reasonably to be anticipated in the future, but the risk involved can be reduced to a level be- lieved to be negligible. The major exception to this generalization concerns proposed additives found to be carcinogenic when studied by the long- term animal feeding tests now routinely employed in the study of most additives. The cause or causes of spontaneously occur- ring cancer are still unknown, as are the modes of action of chemicals known to produce cancer when fed or otherwise ad- ministered to animals. There is recent evidence that a dose- response relationship may be defined for chemically induced cancer in animals. Thus it may be theoretically possible to cal- culate a non-carcinogenic feeding level in animal species for which oral dose-response curves have been accurately defined for a given carcinogen. However, there presently exists no ac- 52
cepted basis for the extrapolation of such levels to man. Yet it seems doubtful one should conclude at this time that no additive which produces cancer in any species of animal by any route of administration may ever be shown safe for use in the human food supply. Glucose itself has produced malignant disease in mice when administered under certain conditions not paralleled by human food use of this common nutritive substance. Although cancer is probably the most alarming reaction a proposed addi- tive can produce, further studies may develop information which could lead to the safe use in food of other chemicals known to produce cancer in animals under certain special conditions. To return to more general considerations, it seems possible that a relatively simple matter, an understanding of the meaning of safety as regards food additives, has perhaps been impeded by the great acceleration of scientific and technological progress which has taken place in recent years. The development during the last great war, and more recently, of a large number of new and effective pesticidal chemicals, and the demonstrated need for such weapons against insects and other pests, have resulted in a tremendous pressure for their use. The rapid development of new chemicals technologically useful in packaging, in improv- ing the palatability or attractiveness of old food products, or in the development of new food products having great consumer appeal, has created pressure for the early use of many new additives in this category. It is not remarkable that those directly entrusted with the responsibility of maintaining the integrity of the food supply should approach conservatively the problems involved in the almost simultaneous introduction of so many new chemical additives, nor that others of conservative mind should express concern. The understandable tendency of the developers and the agri- cultural and food industrial users of these new pesticides and other additives to press for their early if not immediate use, their often expressed impatience in suffering the checks on their pro- grams imposed by the limitations of the only methods available for the demonstration of safety, and their frequent complaint that technological progress is being placed in grave jeopardy by these checks, to the certain detriment of the national welfare, 53
inevitably have generated defense reactions among those having the statutory obligation of containing such innovations to the extent necessary for the protection of the public health. More heat than light has developed in some instances, and in this atmosphere it has been difficult to attract attention to a few simple and comforting truths. First: Safety in regard to food additives means the scientific establishment of reasonable certainty that a given use of an additive will not be harmful. The goal of safety as here defined is one which can be attained without major difficulty, but not inexpensively or with the celerity which is desirable. Second: Absolute proof of safety of a given use of a food addi- tive cannot be adduced, but the methods used to establish safety are believed to provide data which give far greater assurance of human longevity than do data relative to the safety of riding in automobiles, crossing the street, climbing ladders, standing in the bath, or many of the other common activities in which we routinely engage. Third: This country has the world's most abundant and whole- some food supplyâconvincing evidence that the methods re- quired for assurance of safety have not completely stultified agricultural and food industrial progress and, further, that these methods have served to guard effectively against the introduc- tion of harmful uses of food additives. The American people are deeply indebted for this healthy state of affairs to three groupsâan active corps of scientists expert in the pertinent fields of inquiry; an alert and resourceful agri- cultural and related industrial group which seeks unremittingly to use every applicable scientific advance in behalf of a more wholesome and abundant food supply; and the able and effective people of the U. S. Food and Drug Administration, whose labors have aided sound progress in this area, despite the fact that they must operate under regulatory statutes of necessarily negative import. 54
References 1. Food Protection Committee. Principles and Procedures for Evaluating the Safety of Food Additives. Nat. Acad. Sc.â Nat. Research Council Publ. 750, Washington, 1959. 2. Joint FAO/WHO Expert Committee on Food Additives. Second Report: Procedures for the Testing of Intentional Food Additives to Establish their Safety for Use. WHO Technical Report Series No. 144, Geneva, 1958. (Also, FAO Nutrition Meeting Series, No. 17, Rome, 1958.) 3. Appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics. Association of Food and Drug Officials of the United States, Baltimore, 1959. 55
