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7 Consideration of Decision (Action) To Be Taken When a Criterion (Limit) Is Exceeded In general, the decision taken when the limit in a microbiological cri- terion is exceeded relates to the purpose for which the criterion was established. Criterion limits are related to the acceptability of a raw ma- terial, the adequacy of sanitation measures, the possibility of environ- mental contamination, microbial buildup on equipment, or the acceptability of finished product. In most cases, knowledge that a limit has been exceeded comes "after the fact." For example, the equipment was dirty at start-up; thermophilic anaerobe levels built up in the starch-holding vat feeding the canning line; lactobacilli that produce hydrogen peroxide reached excessive numbers on a stainless steel table where canned hams were emptied prior to slicing, thus posing the threat of discoloration if growth of these organisms con- tinued in the finished product; or Salmonella was detected in the sifter tailings from a milk dryer. In each instance the facts became known days after the finished product was packaged, and in most cases after it had left the processing plant. If microbiological criteria for monitoring con- ditions such as these have been intelligently established, the retrospective findings are of value and should trigger appropriate action. Certain finished products must be held until their compliance with established limits has been determined, e.g., infant formulas (Codex A1- imentarius Commission, 19791. Embargoing finished product is costly and cumbersome; alternative actions should be sought and used wherever pos- sible. For example, with low-acid canned foods, reliance is placed upon monitoring critical control points to give assurance that the process has been properly applied (FDA, 1973; see also Chapter 9, Part J). Other alternatives must be used with perishable foods. With fluid milk, for 145
146 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA example, further sampling is undertaken when the standard plate count exceeds the limit. If the problem persists and three out of the last five analyses exceed the limit, a specified penalty provision is applied, one of which is permit suspension (USPHS/FDA, 19781. If shucked oysters ex- ceed the fecal coliform MPN limit, the oysters are accepted on the con- dition that the state sanitation authority in the originating state makes immediate investigation of the producer's plant and operations and submits a report to the control agency in the market area. On the basis of this report, the control agency in the market area will accept or reject further shipments (USDHEW, 19651. DECISION CATEGORIES Evidence of Existence of a Direct Health Hazard Whenever a product poses a direct hazard to health (see Chapter 4), an implied standard (see Chapter 1, p. 52, note 3) exists and the product is subject to seizure under the Food, Drug and Cosmetic Act (U. S. Congress, 19801. Examples would be the occurrence of Salmonella in dried milk and botulinal toxin in smoked fish. The products involved are generally voluntarily removed from the market by the processor, with the extent of the recall and the form of publicity being commensurate with the degree of hazard. If the processor or other responsible entity refuses voluntarily to recall the product, then the Food and Drug Administration may take legal action leading to seizure of the product. This is generally not nec- essary when a product poses a direct hazard to health, as the processor usually is willing to undertake a prompt recall. The FDA may request recall of a product even if it does not pose a direct health hazard, i.e., if the food is adulterated under Section 402 (a) (3) and (4) of the Federal Food, Drug and Cosmetic Act (U.S. Congress, 19801. Examples are tree nuts contaminated with Escherichia cold and raw shrimp containing salmonellae. It is held that E. cold in tree nuts is evi- dence of the occurrence of filth (fecal material). Similarly, it is held that salmonellae in raw shrimp constitute an added substance that would not be present were the product prepared, packed, and held under sanitary conditions. In neither case is it claimed that a direct health hazard exists. Nevertheless, if recall is not voluntarily undertaken the FDA may take legal action resulting in seizure. Most states have even broader powers than the FDA. For example, a state regulatory inspector may embargo a product without a court order; most commonly this occurs within a processing plant, but it may extend
CONSIDERATION OF DECISION (ACTION) 147 beyond the processing facility into wholesale or retail channels. A USDA inspector may similarly embargo a product without a court order. The law provides alternatives to destruction, if the product can be rendered safe for sale. Reprocessing of the product is permitted and should be considered if the hazard can be eliminated, e.g., reconstitution and repasteurization of dried milk or eggs containing salmonellae. The material may be diverted into a product where the hazard is eliminated, e.g., dried milk or eggs containing Salmonella used as ingredients in retorted foods or dried egg yolk used as a component of mayonnaise. In the case of products that are recalled or seized due to evidence of filth, as in the case of E. cold in tree nuts, elimination of the indicator of filth, ergo E. coli, by some physical or chemical treatment does not con- stitute a reconditioning process satisfactory to the FDA. The filth as well as. the indicator of its presence must be eliminated. Thus, a washing procedure resulting in the elimination of E. cold would be satisfactory whereas soaking the product in a chlorine solution would not be satisfac- tor,v even if E. cold were eliminated by this treatment. Frequently a product that is considered unfit for human consumption is diverted into animal feeds. It is common for condemned or inedible meat, poultry, dairy, and egg products to be used as ingredients in pet foods. Inedible meat, poultry, and fish are rendered and the resultant high- protein meals are used as components of animal feeds. These procedures are justifiable, but not if the diversion ultimately results in perpetuation of a problem in the human population. Blending of uncontaminated with contaminated products in order to comply with established limits has generally not been tolerated by regulatory authorities. In 1977, however, large amounts of corn produced in the southeastern United States were contaminated with aflatoxin. At that time, blending was permitted to bring the concentration of aflatoxin to levels below the maximum permitted for animal feed (FDA, 19781. A similar situation occurred with respect to the 1980 corn crop (FDA, 19811. It is to be expected, however, that blending will continue in the future. Destruction of the food is frequently the only alternative. Though botulinal toxin is relatively heat labile, nothing short of destruction of ~ product containing this toxin is acceptable. Even though consumption of a food containing Staphylococcus enterotoxin does not produce the dire results associated with consumption of botulinal toxin, total destruction of food containing this enterotoxin is indicated since it is heat stable. In considering decisions concerning the fate of foods posing a direct health hazard, careful consideration should be undertaken when alterna- tives other than total destruction are contemplated.
148 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA Evidence That a Direct Health Hazard Could Develop Though virtually any low-acid perishable food poses a potential health hazard if mishandled, the potential for foodborne illness and the speed with which it will develop are related to the numbers and types of con- taminants present. Though small numbers of Staphylococcus aureus, Clos- tridium pe~ringens and Bacillus cereus may be present in foods, they pose no direct health hazard. If, however, mishandling occurs, growth of any of these three organisms may lead to a direct health hazard. Large numbers of B. cereus or S. aureus may produce enterotoxin in food before it is consumed. Large numbers of C. perfringens, if present in food, may lead to the in vivo production of enterotoxin in the consumer. Since small numbers of S. aureus, C. perfringens, and B. cereus are frequently found in food produced under Good Manufacturing Practices, criteria relating to them usually recognize a tolerance, e.g., a few 100/g. Even if this tolerance is greatly exceeded, e.g., levels between 10,000 and 100,000/ g are reached, a direct health hazard still may not exist. A hazard lies in the possibility that further mishandling or previous growth not reflected in such counts (preformed toxins) would create a direct health hazard (see Chapter 41. If tests for preformed toxins are negative, then under controlled circumstances foods of this type can be diverted to use under conditions where proper food handling is assured, thereby avoiding the risk of de- velopment of a direct hazard. Release to general distribution with all the vagaries inherent therein is not advisable. If tests for preformed toxins are positive, the food should be destroyed. Indications That a Product Was Not Produced Under Conditions Assuring Safety Considerations relating to the above conditions have been discussed previously with respect to the existing standards for fluid milk, water, shellfish, and other commodities. For these products, standards based upon the determination of indicator organisms have been established. The va- lidity of these as measures of safe production practices has stood the test of time. For example, shellfish and shellfish growing waters with excessive numbers of coliforms and/or fecal coliforms pose the threat that pathogenic microorganisms may also be present. Similar relationships between in- dicator organisms and safety have not been widely applicable to other foods. For example, indicator tests cannot be substituted for direct deter- mination of Salmonella in dried foods and feeds (Silliker and Gabis, 19761. Mesophilic anaerobic sporeforming bacteria in low-acid canned foods have been used as indicators of unsafe processing conditions. Since Clos- tridium botulinum is one of the most heat-resistant mesophilic sporeform
CONSIDERATION OF DECISION (ACTION) 149 ing bacteria, the occurrence of mesophilic sporeforming bacteria in low- acid canned foods purported to have received a botulinum cook suggests underprocessing. Such bacterial examinations would be used in the in- vestigation of a spoilage outbreak, but examination for mesophilic an- aerobic sporeformers in sound containers should not be routinely recommended. Indications That a Raw Material May Adversely Affect Shelf-life With perishable raw materials such as raw meats, poultry, fish, and liquid eggs, off-condition may be detected by sensory evaluation. The consignment should be rejected when off-conditions are perceptible. The same raw materials may contain high numbers of microorganisms and be on the verge of spoilage (incipient spoilage) and yet show no overt evidence in a sensory evaluation. Microbiological testing will detect borderline raw materials of this type, but if sensory evaluation has been relied upon as the acceptance criterion, then the information derived from the micro- biological tests is of retrospective value, i.e., it becomes the basis for decisions regarding suitability of suppliers. Frozen perishable raw products may be held pending the determination of their acceptability prior to use, in which case judgements may be made based upon either sensory eval- uation or microbiological testing. Nonperishable ingredients may be examined prior to use and, if they fail to meet the limit in an established criterion, may be rejected as un- suitable for their intended use. For example, sugar and starch destined to be components of retorted canned foods may be rejected if they contain excessive levels of thermophilic anaerobic sporeforming bacteria; spices destined to be used in cooked sausages may be rejected if they contain excessive levels of aerobic sporeforming bacteria (Silliker, 19631. Many such criteria exist as components of purchase specifications. As a rule, a raw material that is judged unsatisfactory for one purpose, based upon failure to meet purchase specification limitations, may be quite useful for another purpose. The presence of excessive levels of anaerobic sporeforming bacteria in sugar may render it unsatisfactory as a raw in- gredient for retorted canned products. This attribute is of no relevance, however, if the same sugar is to be used as a sweetening agent in coffee or baked goods. Evidence That a Critical Control Point Is Not Under Control Evidence that a critical control point is not under control should trigger immediate action. Such evidence may relate to a raw ingredient, to the
150 EVALUATION OF THE ROLE OF MICROBIOLOGICAL CRITERIA microbiological condition of processing equipment, to the effectiveness of a process, to the occurrence of undesirable microorganisms in a pro- cessing environment, or to the microbiological condition of a finished product. If it relates to a raw material, that ingredient should not be used. If the raw material has been used, then its influence on the safety and quality of the finished product must be assessed and appropriate measures based upon the findings must be taken. If the critical control point relates to equipment sanitation, the frequency and adequacy of cleaning proce- dures must be reviewed. If failures in these areas influence finished product safety or quality, appropriate decisions must be made with reference to product distribution. If environmental contamination, as for example with Salmonella, is indicated, then the source of such contamination must be determined; furthermore, more intensive finished product testing may be indicated. If failure of a processing step is indicated, the source of the failure must be determined and eliminated. If the quality or safety of the finished product is affected, appropriate steps must be taken with respect to its distribution. If the problem relates to the microbiological condition of the finished product, decisions must be made with respect to its dis- tribution, and the reasons for the unsatisfactory condition of the finished product must be determined. If the HACCP system has been properly applied, the reasons for finished product failure should be evident from monitoring results on critical control points. Finally, it should be mentioned that where the Food and Drug Admin- istration is responsible for assuring that processing plants operate under Good Manufacturing Practices, failure of processors to control critical points might be grounds for regulatory action, even though the limits for these points were established by the processor. REFERENCES Codex Alimentarius Commission 1979 Microbiological specifications for foods for infants and children. Alinorm 79:13, Appendix V. FDA (Food and Drug Administration) 1973 Thermally processed low-acid foods packaged in hermetically sealed containers. Part 128B (recodified as Part 113). Federal Register 38(16):2398-2410, Jan. 24. 1978 Aflatoxin-contaminated corn. Limited exemption from blending prohibition. Federal Register 43(65): 14122- 14123. Apr. 4. 1981 Aflatoxin-contaminated corn; limited exemptions from prohibition of interstate ship- ment and blending. Federal Register 46(15):7447-7449. Jan. 23. Silliker, J. H. 1963 Total counts as indexes of food quality. Pp. 102-112 in Microbiological Quality of Foods. L. W. Slanetz, C. O. Chichester, A. R. Gaufin, and Z. J. Ordal, eds. New York: Academic Press.
CONSIDERATION OF DECISION (ACTION) 151 Silliker, J. H., and D. A. Gabis 1976 ICMSF Methods Studies. VII. Indicator tests as substitutes for direct testing of dried foods and feeds for Salmonella. Can. J. Microbiol. 22:971-974. USDHEW (U.S. Department of Health, Education and Welfare) 1965 Bacteriological criteria for shucked oysters at the wholesale market level. Appendix A in National Shellfish Sanitation Program. Manual of Operations. PHS Pub. 33 (Re- vised 1965). Washington D.C.: U.S. Government Printing Office. USPHS/FDA (U.S. Public Health Service/Food and Drug Administration) 1978 Grade A Pasteurized Milk Ordinance. 1978 Recommendations. PHS/FDA Publication 229. Washington, D.C.: U.S. Government Printing Office. U.S. Congress 1980 Federal Food, Drug and Cosmetic Act as amended. Washington, D.C.: U.S. Gov- ernment Printing Office. .
