From 21 CFR 110.35:
Substances used in cleaning and sanitizing; storage of toxic materials.
(1) Cleaning compounds and sanitizing agents used in cleaning and sanitizing procedures shall be free from undesirable microorganisms and shall be safe and adequate under the conditions of use. Compliance with this requirement may be verified by any effective means including purchase of these substances under a supplier's guarantee or certification, or examination of these substances for contamination. Only the following toxic materials may be used or stored in a plant where food is processed or exposed:
(i) Those required to maintain clean and sanitary conditions;
(ii) Those necessary for use in laboratory testing procedures;
(iii) Those necessary for plant and equipment maintenance and operation; and
(iv) Those necessary for use in the plant's operations.
(2) Toxic cleaning compounds, sanitizing agents, and pesticide chemicals shall be identified, held, and stored in a manner that protects against contamination of food, food-contact surfaces, or food-packaging materials. All relevant regulations promulgated by other Federal, State, and local government agencies for the application, use, or holding of these products should be followed.
The regulations are generally open-ended, but it is standard industry practice to store cleaning chemicals in a separate, secure location away from food.
Separate - To avoid incidental contamination of food with chemical (ie drum leaks or splashing of chemical while dosing)
Secure - To prevent adulteration of food with chemical, or prevent misuse of the chemical