Manual of Naval Preventive Medicine
Chapter 1: Food Service Sanitation
Section II: Standards and Sanitation of Food Service Equipment and Utensils

1-11. Sanitizing Agents (Disinfectants).

Department of the Navy
Bureau of Medicine and Surgery

1. Introduction. Food service utensils must be sanitized by either a heat or chemical process. Heat is the preferred method. Chemical sanitizing is recommended for bar-type facilities and other food service facilities in emergency situations when equipment is down and/or is unable to maintain proper water temperatures. Chemical sanitizers are readily adaptable to emergency situations. Hot water or chemical sanitization may be accomplished only when the surfaces of dishware and utensils have been thoroughly cleaned.

a. Hot Water Sanitizing. This is the preferred method of sanitizing food service utensils. Hot water sanitization is accomplished when the surface temperature of clean utensils reaches 161 degrees F. This is attained when all surfaces are completely immersed in water with a minimum temperature of 170 degrees F for at least 30 seconds in manual dishwashing or exposed to hot water spray in a dishwashing operation as prescribed in Table 1-2. Booster heaters must be provided for systems unable to maintain prescribed temperatures. Aboard ships, sink heaters with controls as prescribed in specification MIL-H-43895 must be installed on sinks used for sanitizing purposes. The heater and control will hold water at temperatures of 120 degrees F to 195 degrees F. Proper and accurate installed temperature gauges or hand held bimetallic thermometers must be provided to ensure correct temperatures.

 

b. Chemical Sanitizers

(1) Sanitizers or detergent-sanitizers which are used as sanitizing agents must be of the type which do not require a potable water rinse.

(2) Chemical sanitizers must meet the requirements of 21 CFR 178.1010, Sanitizing Solutions.

(3) Chemicals used for sanitizing must not exceed maximum concentrations permitted in 21 CFR 178.1010, Sanitizing Solutions.

(4) Chemical sanitizers must provide an effective equivalent to a solution containing 50 ppm FAC as a hypochlorite.

(5) In some instances chlorine solutions may have contact time (immersion time) reduced from 1 minute to 10 seconds. See Table 1-1. All other sanitizing agents have a 1 minute contact time.

(6) Iodine solutions must have a minimum concentration of 12.5 ppm and will be used only in water solutions which have a pH of 5.0 or less unless the container label specifies a higher pH limit of effectiveness.

(7) Quaternary ammonium compounds shall be used only in water with 500 ppm or less hardness in concentration or as indicated by the manufacturer's label instructions.

(8) When a detergent-sanitizer is used to wash and rinse, the same detergent-sanitizer must be used in the sanitizing compartment.

(9) Except for chlorine, as specified in Table 1-1, the sanitizing solution must be used at a temperature of at least 75 degrees F.

(10) Chemicals must be automatically dispensed when mechanical sanitizing equipment (warewashers) are used.

(11) When sanitizing with alternate manual methods (swabbing or pressure spraying), the detergent sanitizer or chemical sanitizer must be applied at a level specified in Table 1-3 and Article 1-11.6.

(12) When using sanitizing solutions the concentration of chemical in the sanitizing sink compartment must be determined, using a test kit or other device frequently enough to ensure proper concentrations at all times.

2. Chlorine-Iodine Type Disinfectant (Food Service). This is the preferred agent for use in shipboard food service disinfection. It is more desirable than calcium hypochlorite because it is more stable and creates minimum safety hazards in storage. Specific directions for use are found on the package label.

3. Sodium Hypochlorite. Sodium hypochlorite disinfectants (5 to 10 percent) are acceptable food service disinfectants. Items to be sanitized must be completely immersed in a chlorine solution containing not less than 25 ppm FAC for at least 10 seconds (depending on pH and solution temperature). A recommended procedure to establish the proper FAC concentration is to add sufficient hypochlorite to the final rinse water to achieve an initial concentration of 200 ppm FAC (see Table 1-3), and check the concentration periodically to ensure that the FAC is maintained above 50 ppm (25 ppm when particular provisions listed in Table 1-1 are satisfied). Test kits or devices will be on hand and used to accurately determine the strength of the chlorine solutions. Caution! Calcium hypochlorite is a dangerous material and a potential fire hazard. Calcium hypochlorite is not authorized for use in Navy and Marine Corps food service facilities.

Table 1-3 Quantity (Ounces) of Agent Required for Chemical Sanitizing

Gallons of Water	5.0	10.0	15.0	20.0	25.0
Sodium hypochorite Liquid 5% available chlorine) (200 ppm)	2.5	5.0	7.5	10.0	12.5
Sodium hypochorite Liquid 10% available chlorine) (200 ppm)	1.25	2.5	3.75	5.0	6.25
Disinfectnat, liquid. Iodine-type (25 ppm)	1.0	2.0	3.0	4.0	5.0

Note: Three teaspoons equal 1 tablespoon. Two tablespoons equal 1 ounce. Eight ounces equal 1 cup.

4. Liquid Iodine-Type Disinfectant. A liquid iodine type sanitizer is carried in the supply system. It may be mixed in water without regard to water hardness. When used at recommended dilutions, the solution has a rich amber color which remains during germicidal action. When the color fades, its effectiveness is reduced, thus the user has a visual check on proper solution strength. At sanitizing strengths it has a low toxicity, is nonirritating, nonstaining on dishware and utensils, and has no offensive odor. Immersion shall be for at least 1 minute in a solution of not less than 12.5 ppm having a pH not higher than 5.0 and a temperature of at least 75 degrees F (see Table 1-3). Test kits or devices will be on hand to determine the actual strength of iodine solutions, if used.

5. Precautions. When using chemical compounds for sanitizing, a three compartment sink is necessary unless an additional rinse operation is provided. All sanitizers must be added only to the rinse water except for detergent-sanitizers (see Article 1-9.2.b.(3)). Utensils containing silver should not be sanitized with chlorine solutions. Chlorine will cause heavy oxidation and discoloration. Hot water or any approved food service sanitizing chemical, stating on the label that it is safe for silver, should be used.

6. Strength Determinations. Table 1-3 indicates the amount of chlorine compound and iodine-type disinfectant to use for initial dilution of 100 pm FAC and 25 ppm for the iodine-type disinfectant. The measurements can be made with a measuring cup, a teaspoon or tablespoon. When using a tablespoon, divide the required number of teaspoonfuls by three. Always follow directions on the container label.

7. Figure 1-1 illustrates the temperatures necessary for the proper cleaning and sanitizing of food service equipment and utensils.