Evaluation and Definition of Potentially Hazardous Foods - Appendix A. Development of the Definition of "Potentially Hazardous Foods"
- U.S. Public Health Service. An Ordinance Regulating Food and Drink Establishments (December 1935). This ordinance regulates "perishable food or drink" in eating and drinking establishments. Specifically, Item 13 (Refrigeration) of this document recommends that "perishable food or drink [be] kept at or below 50 °F., except when being prepared or served."
- U.S. Public Health Service. Ordinance and Code Regulating Eating and Drinking Establishments (March 1938). Item 13 (Refrigeration) is retained. A scientific explanation of the "public-health reason" that perishable foods need to be kept cold (because there is a danger of pathogenic bacteria entering food and causing disease) is added along with a "code" for "satisfactory compliance."
- U.S. Public Health Service. Ordinance and Code Regulating Eating and Drinking Establishments (June 1940). Item 13 (Refrigeration) is retained. The regulation to keep perishable food or drink at or below 50 °F (10 °C) now includes heat as a deterrent (that is, keeping food warm) and is specifically includes "cream-filled pastries."
- U.S. Public Health Service. Ordinance and Code Regulating Eating and Drinking Establishments (1943; PHS Publication No. 37). Item 13 (Refrigeration) is retained. This item includes not only microorganisms but also their toxins as public health concerns. The regulation specifically includes custard- and cream-filled pastries, milk and milk products, egg products, meat, fish, shellfish, gravy, poultry stuffing, and sauces, dressings, and salads containing meat, fish, eggs, milk, or milk products.
- U.S. Public Health Service. Food Service Sanitation Manual, Including a Model Food Service Sanitation Ordinance and Code (1962; PHS Publication No. 934). This code includes extensive and detailed additions to the earlier ordinances. "Perishable food," for example, is defined as "any food of such type or in such condition as may spoil." The term "potentially hazardous food" is introduced and defined as: "any perishable food which consists in whole or in part of milk or milk products, eggs, meat, poultry, fish, shellfish, or other ingredients capable of supporting rapid and progressive growth of infectious or toxigenic micro-organisms." Specific recommendations for ensuring the safety of potentially hazardous food are stated along with sanitary practices recommended for the "storage, preparation, display, and service of food."