The United States has renounced all use of biological agents in warfare, but the need still exists to be prepared to defend ourselves against these agents if other countries should use them. The following section, therefore, discusses the nature of biological agents and the measures you should use to decontaminate the galley, messing areas, and food storage spaces in the event of enemy biological attack.

A biological agent is defined as a microorganism that either causes disease in man, plants, and animals or causes the deterioration of material.

The chief objective of biological agents is mass infection that results in the incapacitation or death of large numbers of individuals or in the destruction of their sources of food, both animal and plant. The biological agents, unlike most other weapons, act on living matter only and are limited in use to these objectives.

In case of a biological attack there are certain instructions that should be carried out for the protection and decontamination of eating, drinking, and galley utensils; galley and foodservice equipment; and messing areas contaminated by biological agents. Good sanitary and hygienic practices are the best defense against many aspects of biological warfare. A close examination of the cleanliness of the mess and strict adherence to the applicable instructions will improve biological defense greatly.

The problems of biological agents differ from ordinary military hygiene problems only in that hardier types of organisms may be present in other than their normal environment and in higher levels of contamination.

BIOLOGICAL CONTAMINATION

In treating the problem of biological attack, it is assumed that there could be contamination of personnel, of all exposed surfaces, and of circulating air. Because of the current difficulties in rapidly detecting biological agents, knowledge of contamination might (although not necessarily) be based on the occurrence of widespread or unusual sickness. This sickness could be caused by contamination that had occurred several days or weeks before. A situation could exist also whereby extensive use of biological agents would require additional precautions in the operation of all messes. These instructions are intended for use in the event of suspected or known biological attack. The problem is to decontaminate and prevent recontamination.

BIOLOGICAL DECONTAMINATION METHODS

Use calcium hypochlorite (bleach) solutions for biological decontamination. Scrub the interior surfaces of contaminated spaces with 200-ppm chlorine solution to remove dust and grease. Then, hose spaces with fresh, safe water and repeat the process. You may also use iodine solutions prepared by the medical department.

Large equipment (those items too large to be immersed in sinks or run through dishwashing machines) should be washed, rinsed, and decontaminated in the same manner as prescribed for interior surfaces of messes. Small items of equipment that will not suffer damage by immersion should be washed, rinsed, and sanitized in the dishwashing machine or by hand dishwashing as described earlier in this chapter.

Before eating and drinking utensils are brought to the scullery for decontamination, the interior bulkheads, all working surfaces (tables, dish carts, and sinks), the interior and exterior of the dishwashing machine, and all other equipment used in the washing and sanitizing of eating and drinking utensils should be thoroughly washed, rinsed, and decontaminated as appropriate.

Eating and drinking utensils should be decontaminated by machine or hand washing. A person who has handled contaminated utensils should not handle decontaminated utensils until the person has been decontaminated. Decontaminated articles should not be placed in contact with any surface that has been exposed to contamination. If possible, use baskets or containers designed to hold silverware in a vertical position, handles down, during the washing and sanitizing processes, and additional containers of similar construction into which the silverware may be inverted without being handled by workers. If such containers are not available, lay the silverware flat in the racks, not exceeding two utensils, with the handles extending in the same direction. Do not exceed a depth of two utensils. Take care when removing utensils from the racks after decontamination to prevent recontamination.

Sterilization by hypochlorite solution should be used only when dishwashing machines do not operate correctly. The utensils should be soaked, while still in the washrack, for 1 full minute at 100F to 140F in a solution of 1 part hypchlorite and 50 parts water in a single-tank machine, or 1 part hypochlorite and 500 parts water in a double-tank machine; one-fifth of 1 percent of a detergent must be added to either solution.

This solution may be mixed from nonionic detergent and any one of several chlorine containing compounds such as calcium hypochlorite, or laundry bleach.

In storage, compounds containing chlorine have been known to deteriorate. It will be necessary, therefore, to have a qualified person from the ship's company analyze the soaking solution for chlorine content to make sure the proper concentration of available chlorine is attained and continued at sufficient strength.

After the sterilization, soak and water rinse, cover the washracks containing the utensils with a cloth that has been sterilized by boiling. Do not transfer utensils to another rack. Make sure personnel in the serving line pick up utensils from the washracks by touching only the handles.

Large equipment may be decontaminated by the use of hypochlorite. Hypochlorite is corrosive to all metals that will rust and should not be allowed to come in contact with motors and other electrical equipment from which hypochlorite could not be thoroughly wiped off. After decontamination, cover as much of the equipment as possible with clean cloths to prevent recontamination. Avoidance of Recontamination

Recontamination may be caused by secondary aerosols that resettle organisms on surfaces or contaminate the air that is breathed. Secondary aerosols are clouds formed from particles (bacteria or other organisms) that, having been deposited on a surface, are stirred up into the air again by scuffing, shaking, or other mechanical action. Secondary aerosols may be suppressed by wetting surfaces with oil or water. If oil is used as a suppressant, it must not generate harmful vapors and it must not be applied to walking surfaces which may create slippery conditions.

It is important to make sure, before entering the messing area, MS personnel and all personnel eating in the messing areas are as free as possible from contamination. The medical officer should be consulted on the decontamination of foodservice personnel. In cold weather, personnel in the serving line should be required to remove outer garments and leave them outside the messing area before entering the mess. It has been found that removing clothing will shake off organisms that have come in contact with the surfaces, thereby setting up secondary aerosols. Do not permit unauthorized personnel in foodservice spaces.

Hypochlorite is a strong oxidizer and, in powdered form, reacts violently with oils and greases. Use hypochlorite in a well-ventilated area. Always wear goggles and protective gloves, and consult the MSDS for additional precautions.

Decontaminating Food Items

The advice of the medical officer must be sought before any attempt is made to decontaminate food suspected of biological contamination.

Semiperishable Food Items

Food packed in containers that are resistant to the passage of biological agents (sealed containers made of metal, plastic, glass, or porcelain) requires only proper exterior decontamination be performed. Paper labels and paper covers must be removed from the container and one of the following methods of decontamination should be used:

1. Immerse the containers for 15 minutes in a solution of water to which 200-ppm available chlorine has been added and then rinse them with potable water.

2. Soak the containers for a minimum of 15 minutes in effective detergent solution as a quick method to reduce contamination to a safe level (see formula 1 discussed under the heading Radiological Decontamination); then rinse them with potable water.

3. The exterior surfaces of stacks of food packed in impermeable packages can be sterilized using any of the standard chemical methods such as bleach solution, sodium carbonate, or DS2 followed by rinsing in potable water.

Food packages that will not stand immersion must be wiped off with a solution of water to which 200-ppm available chlorine has been added and the food thoroughly cooked before it is eaten.

Fresh or Chill Items

Food that can be peeled or pared may be decontaminated by soaking for 15 minutes in water to which 200-ppm available chlorine has been added before it is peeled. The food must then be thoroughly rinsed in potable water. It can then be peeled or pared and should be rinsed again with potable water. This method has been applied satisfactorily to apples, potatoes, and eggs.

For other fresh or chill items, the use of heat is the most practical means of decontaminating foods.

Thorough cooking will reduce contamination to a safe level so that food can be consumed.

Frozen Items

Food items stored in the freeze space in impermeable containers (tamed frozen strawberries, for example) may be decontaminated by immersing the containers for 15 minutes in a solution of water to which 200-ppm available chlorine has been added; the containers are then rinsed with potable water.

Food items stored in the freeze space in permeable containers (frozen vegetables, for example) may be decontaminated as outlined earlier for food packaged in sacks or other permeable containers.

Food items stored in the freeze space, but not contained in outer packaging (meat, for example), must be completely thawed and thoroughly cooked before they are eaten.

Additional Precautions

Hands should be free of contamination during the opening operations to make sure the contents are not contaminated. Opened cans of fruit jam, jelly, or similar foods must be destroyed. Opened cans of vegetables may be decontaminated by boiling the vegetables for a minimum of 15 minutes in a steam-jacketed kettle. Biological Decontamination in Food

Preparation

The use of heat is the most practical means of decontaminating biologically contaminated foods. In no case should decontaminated food be consumed until it is pronounced safe by a medical officer.  It is recommended that, insofar as possible, only foods contained in impermeable packages (cans, bottles, jars) be decontaminated and used for meal preparation.

Food items that are not packaged or that are packaged in permeable containers may be cooked by either cooking in a pressure-type cooker at 15 pounds of pressure at 250F (or 121C) for 15 minutes or boiling for a minimum of 15 minutes.

Certain contaminated items may be decontaminated by baking. Only those recipes listed in the Armed Forces Recipe Service (AFRS) that specify an oven temperature of 400F and above, for a cooking period of 30 minutes or longer, should be used to prepare baked items from contaminated ingredients.

All meats except those contained in decontaminated impermeable containers (canned meat items) must be cooked to the well-done stage. Guidance cards in the AFRS include information on internal temperatures indicating the well-done state.

Biological Decontamination of Water

The detection of water contamination and requisite laboratory analysis are responsibilities of the medical department. Biological decontamination of water is not difficult when regular water treatment facilities exist. However, more chlorine probably will need to be added during the ordinary processing of the water. If no water treatment facilities are available, water can be decontaminated by any of the following methods:

1. By boiling for 20 minutes

2. By using iodine tablets coupled with boiling

A medical officer should approve the method of decontaminating; after the decontamination process, the officer should determine whether or not the water is fit to be used. Water that has been decontaminated must be protected against further contamination.