Health Service Support in a Nuclear, Biological, and Chemical Environment

Chapter XXXI: Appendix: J (1)

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FOOD CONTAMINATION AND DECONTAMINATION

J-1. General

_a. Food Susceptibility._ Stored, transported, and prepared food is susceptible to NBC contamination throughout the TO. Planning for any battle or operation must include food protection from contamination; food contamination detection; and contaminated food disposition (decontaminate or destroy).

_b. Countermeasures._ There are three primary countermeasures to overcome or reduce the NBC hazard to food:

(1) Contamination avoidance.

(2) Nuclear, biological, and chemical agent detection.

(3) Nuclear, biological, and chemical agent decontamination.

_c. Priorities._ The priorities for conducting NBC countermeasures are--

(1) _Contamination avoidance._ Contamination avoidance
includes using natural and fabricated barriers to prevent, or
significantly reduce the spread of contamination. Also, using
specific procedures for entry and exit between contaminated
and uncontaminated areas reduce the potential for spreading
contamination. Use of these barriers and procedures may reduce
the subsequent need for detection and decontamination.

(2) _Detection, measurement, and identification._ These
activities are essential for determining the presence, extent,
and nature of NBC contamination. This information is essential
in identifying the existence of uncontaminated supplies, or
decontamination requirements.

(3) _Decontamination._ Decontamination removes the contaminant
and provides food that is safe for consumption.

_d. Decontamination._ Decontamination efforts require an extensive amount of labor, time, and supplies. The use of hasty decontamination is emphasized. That is, decontaminate just enough to sustain operations and keep fighting, rather than to make a contamination-free environment. Normally, decontamination efforts will be limited to the packaging and packing materials. Food decontamination will only occur in critical situations where other food supplies are not available. Most decontamination is performed in or very near the AO. Before beginning decontamination procedures, divide exposed food items into groups based on protection of item at time of exposure. These groups establish priorities based on ease of decontamination and the ability to monitor the food.

(1) Group I--Canned or packaged items exposed only to a
chemical agent vapor.

(2) Group II--Canned or packaged items that are contaminated on
the outside with a liquid chemical agent, a biological agent,
or radioactive fallout.

(3) Group III--Unpacked or poorly packaged items that have been
exposed to any NBC agent.

(4) Group IV--Food contaminated through the food chain.

J-2. Protection of Food from Contamination

An adequate defensive posture for a chemical attack will also protect food against biological contamination and radiation fallout.

_a. Operational Rations._ Operational rations include, but are not limited to, MREs; unit group ration (UGR), A; unit group ration, heat and serve; and medical diet supplement.

(1) Packaging materials and storage methods normally protect
these rations. The packaging and packing of operational rations
protect the contents from deterioration. As a result, the
contents are protected from moisture, to include chemical
liquids, chemical vapors, and biological agents. Operational
rations delivered to an AO will usually have increased levels
of packaging and/or packing protection. Operational rations are
substantially protected while contained in the shipping cases,
especially if protected with an overlay of fiberboard, shrink
wrap, or film wrap.

(2) Enclosed storage is used whenever possible. Refrigerated
warehouses, cold storage rooms, and even prefabricated
refrigerators and trailers provide excellent protection.
Underground shelters, caves, and tunnels that can be made
airtight provide maximum NBC protection. Buildings provide
protection depending on how well they can be closed and sealed.
The basement of a building is a good storage place. However,
keep in mind that chemical vapors tend to seek out low-lying
areas. Storing rations indoors will protect them from liquid
droplet and fallout contamination unless the building is
damaged by an attack. Complete protection against chemical
vapors is only offered by airtight closed spaces like cold
storage facilities.

(3) Chemical protective measures are to be integrated into
daily logistical operation to avoid the contamination of
operational rations. Maximum use is made of alarm and
detection equipment, overhead shelter, shielding materials,
and protective covers. Back up stocks of operational rations
should be dispersed to minimize the risk of destruction or
contamination.

(4) An NBC Protective Cover or similar equipment will help
greatly. The NBC Protective Cover is discarded and replaced
upon becoming contaminated; it reduces overall decontamination
requirements; and it improves the survivability of supplies and
equipment. The NBC Protective Cover provides 24-hour protection
against liquid chemical contamination. Detection paper used on
the NBC Protective Cover will rapidly identify a contaminated
cover.

_b. Bulk and Fresh Foods._

(1) Field expedient or improvised storage may be the only
choice available under high-risk conditions. Expedient storage
for food supplies may be a natural or man-made depression
lined to protect contents against moisture, and then covered
with earth and sod. The earth gives good protection against
all forms of chemical or biological contamination and nuclear
fallout.

(2) Foods are only stored outdoors or in partially protected
areas when absolutely necessary. Only cases of foods packed in
cans, bottles, or airtight foil or film wraps, and foods packed
in sealed boxes or multilayered wrappings can be subjected to
exposed storage. Partial protection is provided by open sheds,
temporary roofing, or tents. When subsistence must be stored
in the open, give as much protection as possible. Protection
material may include NBC Protective Covers, tarpaulins,
tarpaulin sheds, or any other available covering such as
plastic sheeting. Tarpaulins and other treated or waterproof
coverings do not prevent contamination by chemical vapors,
but they do reduce contamination from liquid agents. Canvas
will keep out more than 95 percent of liquid contamination for
a short period of time after the attack. The canvas must be
removed soon after the attack to prevent the agent from seeping
through onto the subsistence; placement of spacers between the
covering and the food will greatly reduce this problem. Even
the thinnest material will offer some protection and is better
than nothing at all. Therefore, food supplies must be covered
by whatever material is available.

J-3. Nuclear

_a. Contamination._

(1) Following a nuclear detonation, food can become
contaminated in three ways:

· _Direct contamination._ Direct contamination results by
fallout collecting on plants, animals, and stored food (surface
contamination). Fallout has two effects. First, it produces
a gamma radiation field over the fallout area. Second, it
contaminates the surface of anything on which it is deposited.
The whole-body gamma irradiation hazard to an individual far
outweighs any potential hazard from food contamination. The
basic rule is: If you can safely be in the area to salvage the
food, then the food salvaged is safe to use (although slightly
contaminated).

· _Indirect contamination._ This form of contamination can
be spread throughout the food chain. Humans can ingest
contamination by eating plants that have absorbed radioactive
isotopes; products (milk or meat) from animals allowed to graze
on contaminated pastures; or fish from contaminated water.

· _Induced radiation._ It is possible that food will be
exposed to sufficient neutron flux (an increase in the number
of free neutrons) as the result of a nuclear explosion to
produce considerable induced radioactivity in food without
it being destroyed by blast and heat. This is possible with
enhanced radiation weapons in the energy range of 1 KT where
the radiation kill radius exceeds the blast destruction zone.
The elements that are most prominently involved are sodium,
potassium, sulfur, copper, bromine, zinc, and especially
phosphorous. Thus, in an area of induced radiation, foods
requiring the most caution are dairy products, high salt
content foods, dry beans, raisins, and ready-mixed cake and
biscuit flours. The radioactivity has a short half-life;
therefore, the radiation will decay very rapidly. It should be
possible to consume foods containing induced radiation within
a week or two. Cans, particularly those with "C" enamel, may
incur a high level of induced radiation (from zinc in the
enamel, not from iron in the can). Glass, because of its high
salt content, will show very high levels of activity; clear
glass will turn brown. Container radioactivity has no bearing
on the food, it is safe to use. The radioactivity is not
transferred to the contents. No significant toxic by-products
are formed in the exposed canned food.

(2) Consumption of food contaminated with radioactive fallout
may cause a risk of radiation injuries from internal radiation;
that is, radiation from radioactive sources within the body.
Most isotopes will pass through the digestive tract or be
excreted very quickly. However, the intestinal tract may
receive a considerable dose. Some isotopes are more hazardous
because they are absorbed from the digestive tract and enter
the metabolism of man and animals.

· Strontium-89 (Sr-89) and Strontium-90 (Sr-90) are beta
emitters and have half-lives of 51 days and 28 years,
respectively. Therefore, Sr-90 is the greatest radiation hazard
in the long term. These two isotopes are absorbed in the body
and used in the same way as calcium. They accumulate in bone,
where bone marrow with its blood forming cells is vulnerable.
Milk and other dairy products are the primary sources of Sr-89
and Sr-90 in the human diet.

· Iodine-131 (I-131) is a beta and gamma emitter and has
a short physical half-life of approximately 8 days. It is
efficiently absorbed and used by the body. Iodine-131 will
contaminate plants that will be eaten by grazing animals.
Smaller amounts can also be absorbed by breathing contaminated
air. Cattle will excrete a large amount of I-131 in milk. Milk
and other dairy products are the primary sources of I-131
intake. One can also get smaller amounts by eating contaminated
fruits and vegetables. Iodine-131 will be concentrated in the
thyroid gland. The intake of I-131 will have its greatest
impact the first few days to weeks following a nuclear
explosion.

· Cesium-137 (Cs-137) is a beta emitter and has a half-live
of 30 years, but is eliminated relatively quickly from the
body. The biological half-live is 70 to 140 days. Cesium-137
is found in most tissues of the body, but it will concentrate
in muscle tissue. Cesium-137 is absorbed and used the same way
as potassium. Meat and milk are the primary sources of Cs-137.
Much precipitation, lack of minerals in the soil, and extensive
cultivation increase the plants' absorption of Cs-137; thus,
the contamination of plant products.

(3) Operational rations are safe when surface decontamination
is performed before breaking the package. Operational rations
stored close to ground zero may become radioactive from induced
radiation. It is more likely, however, that the food will be
damaged or destroyed by the blast and thermal effects of the
nuclear explosion.

(4) Bulk and fresh food stored in the open without protection
will be contaminated. Decontamination is very difficult and
time-consuming. Efforts should be made to ensure proper packing
to prevent food contamination from radioactive fallout. Packing
made from hard and nonporous materials, such as plastic or
multilayer cardboard with a smooth surface, should be used.
In addition, storage facilities should be enclosed to avoid
the entry of fallout. Any material used as a protective cover
will give some protection against nuclear fallout. Protection
against induced radiation, blast, and thermal effects requires
a hardened shelter or underground storage.

(5) Food supplies require protection throughout the chain of
production or procurement. Protection of the civilian-based
food supply includes countermeasures along the production
chain. Meats and milk are the most vulnerable products because
of the possibility for concentration of radioactive isotopes
(Strontium, Cesium, and Iodine). The primary, and possibly the
only, protection of animal products is to keep the animals
indoors and to avoid contaminated fodder. Immediate slaughter
of food animals is recommended if there is a shortage of
uncontaminated fodder. Also, food animals exposed to fallout
should be considered fit for consumption and slaughtered using
routine procedures. Unharvested crops cannot be protected.

_b. Inspection and Monitoring._

(1) Fallout close to ground zero, especially after a surface
burst, may be visible as dust. The presence of dust is an
immediate indicator of contamination. Fallout on unprotected
food produces a grittiness that is unpleasant and warns against
eating the food. The degree and means of food protection
(packaging and storage faculties) must be considered. Food
in a building that remains intact should not receive enough
contamination to be dangerous when eaten.

(2) Veterinary units have the AN/VDR2 Radiac Set and UDR13
dosimeter to conduct ground or aerial surveys for gamma
radioactive contamination levels in an area. The measurement
of the external gamma radiation in the fallout area is an
indication, but not a quantitative measure, for the degree
of hazard from food contamination. These units also use the
AN/VDR2 Radiac Set for point detection of gamma and beta
radiation sources. Food monitoring is conducted in an area with
low background radiation. If the storage area is contaminated,
the food must be moved to a cleaner area for monitoring. With
the AN/VDR2, the initial food monitoring is performed with
the probe cover in place and the probe passed approximately 6
inches from the surface. If the reading is twice the background
dose rate, the food is considered contaminated. If the reading
is not above the background level but contamination is still
suspected, place the probe closer to the food with the beta
probe cover off. Monitor meat and fish with the probe cover
off; pass the probe approximately one-half inch from the
surface of the food.

(3) Monitoring food contaminated through the food chain is
more complicated; depending on the detection instrument
used, special procedures must be followed. Gamma and beta
emitting radionuclides in small volumes may be detected using
radiac sets such as the AN/VDR2; however, alpha emitting ones
cannot. They are rough instruments and may be used only for
screening surface contaminated food. To evaluate the hazards;
the isotopes contributing to the radioactivity must be
identified. Surface contaminated food will contain a mixture of
isotopes with some more hazardous than others, depending upon
whether they are used by the body. Milk will contain mostly
I-131, Cs-137, Sr-89, and Sr-90. Meat and fish will contain
mostly Cs-137. To verify I-131, Cs-137, Sr-89, and Sr-90
contamination, samples must be sent to laboratories equipped to
analyze the samples.

(4) All newly selected food supplies must be surveyed. Begin
continuous monitoring immediately following receipt of a
fallout warning, or when increased levels of radiation are
detected by periodic monitoring.

(5) Periodic monitoring is needed to establish baseline levels
of background radiation in the environment and various food
products. This monitoring is performed during peacetime, when
possible, and throughout the time US forces are deployed in a
TO.

NOTE

The AN/VDR2 is being replaced by the AN/PDR77 Radiac Set.

_c. Decontamination._ There are two methods for nuclear decontamination: aging and removing. Aging is the process of allowing natural radiation decay to occur. The time necessary for this decay to take place depends upon the isotopes present; each has a different decay rate (half-life). Aging may not be possible when there is a short food supply. In some instances, such as with induced radioactivity, it may be the only way to decontaminate. Removing nuclear contamination from areas, personnel, food, or moving equipment to another location eliminates the immediate hazard. To determine which decontamination method is required, food supplies are divided into groups. See Table J-1 for additional information on food items and decontamination.

(1) Group II--Food in sealed and dust-proof packing such
as cans, jars, fiberboard, and cellophane. These products
are easily decontaminated by removing the radioactive dust
covering the packing; brush, wash with soap and water,
or remove the packing (depending on the type of packing
material). If radiation is still detected after removing
the dust, repeat the brush/wash procedure and remonitor. If
radiation is still present, the food itself is then considered
radioactive (induced radiation) and is unfit for consumption.
Decontamination of induced radiation is possible only through
aging. After aging one to two weeks, the food should be safe
for consumption. After surface decontamination, the contents
are safe to eat unless the food has induced radiation.

(2) Group III--Unprotected food. The method chosen to
decontaminate unprotected food items will depend upon whether
or not the food supply is critical. If the food supply is not
critical, the contaminated items are isolated and allowed to
decontaminate by aging. If the food supply is critical, food
with surface contamination can, in principle, be decontaminated
by removing the contaminated surface, or by washing.

(3) Some products can be decontaminated by washing, peeling,
or trimming the outer skin or leaves. Decontaminate potatoes
and hard-skinned fruits and vegetables by washing or scrubbing
under running water, followed by peeling or scraping, then
washing again. Potatoes, carrots, beets, and turnips can be
washed at the supply depot. However, do not wash beans, rice,
and onions until they are delivered to the field kitchen;
washing reduces their storage quality and shelf life. Citrus
fruits, pineapples, corn, peas, beans, melons, pumpkins,
cabbage, and nuts can be peeled. Decontaminate cucumbers,
tomatoes, cherries, cranberries, grapes, pears, plums, and
thin-skinned squash by soaking in a water or detergent
solution and rinsing with vigorous agitation or brushing.
Apricots, peaches, most berries, asparagus, broccoli, and leafy
vegetables cannot be satisfactorily decontaminated because of
fuzzy surfaces, irregular shapes, or small size, which makes
washing difficult.

· Fresh carcass meat, sausages, and fish can be decontaminated
by several washings with cold water. The exterior layer of the
food item is removed if radioactivity is still present. There
is, however, a risk of contaminating the inner parts of the
foodstuff in the process. Cooking with several changes of water
is the last step in decontamination.

_Table J-1. Decontamination of Food Supplies_

· Decontaminate hard cheeses, margarine, and butter by cutting
off the outer layer to a depth of 2.5 to 3 cm.

· Let cooking oils stand for 3 to 5 days, then pour off the
contaminated layer; use a funnel to control spillage.

· Nonperishable items that are hard to decontaminate, such
as flour, sugar, and salt, can be set aside allowing natural
radioactive decay. When supplies are short, dilute the
contamination by mixing with uncontaminated food. This will
reduce the total amount of radioactive exposure in foods
prepared using these contaminated items.

· Decontaminate air permeable, double-sacked goods by removing
the outer sack. If the inner sack is free of radiation, double
sack the food again to restore protection. However, when
contamination is present on the inside bag, the food in contact
with the bag is likely to be contaminated. Three methods can be
used to handle this type of contaminated product. The easiest
method involves spraying the bag of dry goods (except sugar
or salt) with water. This will wet a layer of the food inside
the bag. The wet layer can be removed when the bag contents
are emptied. The uncontaminated contents are scooped back
into clean packaging. Another method involves using melted
paraffin to uniformly coat the outside of the bag. The paraffin
solidifies after 30 to 40 minutes, and then the bag with the
radioactive contamination can be removed from the contents.
Although this method will seal the radioactive substance in
the wax, it probably will not remove the layer of contaminated
food product inside the bag. For the third method, form a piece
of sheet metal into a cylinder the same height as the bag
and 4 to 6 cm smaller in diameter. Insert the cylinder into
the bag, then remove the top 3 to 4 cm of the contaminated
product. Carefully scoop the remaining product out into a
clean sack. With the cylinder still in place, fold the bag
down catching the contaminated product on plastic sheeting, or
a tarpaulin. When using this method, mixing the contaminated
portion with the uncontaminated portion is a problem. Check for
contamination remaining in the product.

· Boiling or cooking has no effect on radioactive contamination.

(4) Group IV--Food contaminated through the food chain. It is
not practical to decontaminate this food. Meat and milk are the
two most common foodstuffs contaminated in this way.

· Milk may be decontaminated to a safe level by a complicated
ion exchange process. The I-131 activity will decline rapidly
during storage of milk and milk-products, although the Cesium
and Strontium activity will remain almost constant for years.
In an area with high-level fallout, milk is withdrawn from
human consumption. The duration of withdrawal will be dependent
upon the type of fallout and levels.

· Meat may be decontaminated to a safe level by soaking in
water or brine. Cesium is loosely bound in the meat. By
repeated soaking of meat cut in small pieces, most of the
Cesium activity will be removed. Traditional meat preserving,
such as salting with brine, will remove up to 60 to 70 percent
of the Cesium activity. See Table J-2.

· Fruits, vegetables, root crops, and grain products may also
contain hazardous amounts of radioactivity if ingested.

(5) Food animals. Food animals that have been exposed
to fallout should be considered fit for consumption and
slaughtered using routine inspection and slaughter procedures.
In those cases where the animal has been exposed to fallout,
but is not scheduled for immediate slaughter, the radiation
burden can be reduced by moving the animal to an uncontaminated
area (barn if available) and washing it with soap and water.
Mild radiation sickness does not necessarily mean that the
animals cannot be used for food. If the animals have been
exposed to an internal radiation hazard, the meat can be eaten
if the internal organs are discarded. Chickens that have eaten
radioactive material may lay contaminated eggs, but most of the
radioactivity will be concentrated in the shells. The white
and yolk will be free of harmful amounts of radiation and can
be eaten. Chickens will not lay eggs if the radioactive body
burden is large enough that their eggs are unfit to eat.

_Table J-2. Traditional Salt Preserving Brine_

======================================================================
MEAT, WHOLE 4-5 KG

25% NaCl (SALT) BRINE 5-LITER BRINE PER KG.
KEEP MEAT IN BRINE FOR 3 WEEKS, TEMPERATURE BELOW 10°C.
SOAK IN WATER FOR 1-2 DAYS.
65-70% OF CS ACTIVITY WILL BE REMOVED.
----------------------------------------------------------------------
MEAT, CUT 1-2 KG

25% NaCl BRINE 5-LITER BRINE PER KG.
KEEP MEAT IN BRINE FOR 4 DAYS.
SOAK IN WATER FOR 4 HOURS.
65-70% OF CS ACTIVITY WILL BE REMOVED.
----------------------------------------------------------------------
MUTTON/LAMB RIB

PIECE OF RIB 1-5 KG.
25% NaCl BRINE 5-LITER BRINE PER KG.
KEEP IN BRINE FOR 2 DAYS.
SOAK IN WATER FOR 2 HOURS.
AIR-DRYING FOR 10 DAYS.
SOAK IN WATER FOR 2 HOURS.
BOIL IN WATER FOR 3 HOURS.
85-90% CS ACTIVITY WILL BE REMOVED.
----------------------------------------------------------------------

DECONTAMINATION OF COARSELY CHOPPED MEAT

0.9% NaCl SOLUTION. 2-LITER SOLUTION PER KG.
SOAK IN NaCl SOLUTION FOR 10 MIN.
60-70% CS ACTIVITY WILL BE REMOVED.
REPEATED PROCEDURES WILL REMOVE THE SAME PERCENTAGE OF CS ACTIVITY.
SIX TIMES REPEATED TREATMENT WILL REMOVE NEARLY 100% OF CS ACTIVITY.
======================================================================

_d._ _Considerations When Decontamination is Not Possible._ When food cannot be decontaminated, sealing the product in a wrapping material or container may be needed. Sealing the product can reduce or shield the emanation of the contamination and/or fix the contamination in place. The hazard from contaminated food is small compared with that from external gamma radiation. Hungry people or animals should not be denied food because of possible fallout contamination. It is not practicable or desirable to preset maximum permissible limits of gross fallout radioactivity as a basis for judging whether or not food should be used. Common sense must be applied in establishing priorities for distribution of available food. For example, use the least contaminated and the most protected food first; hold milk products for 1 to 2 weeks before use.

J-4. Biological

_a. Contamination._ Biological warfare agents exist in the form of toxins and microorganisms. The normal packaging and packing of food (to protect against moisture, dust, and bacterial or other contamination) provides protection against most biological agents. The exception may be toxins and biologically derived substances. However, the protective methods used for chemical agents will also protect against toxins and derived substances. Food in freezers, refrigerators, and in refrigerated trucks or rail cars will be safe if these containers remain sealed until the outer surfaces are decontaminated.

(1) It is unlikely that a biological agent will affect the
appearance, taste, or smell of the food enough for the change
to be apparent.

(2) Packaging and packing materials are not life supportive to
pathogenic agents and are, therefore, self-decontaminating with
the exception of spore-forming organisms.

(3) Most operational rations are packaged in metal containers,
or encased in heavy aluminum laminated plastics that can
withstand boiling water; also, they are impervious to arthropod
penetration. This food is highly resistant to biological agents.

(4) The use of unpackaged items (unwrapped meats, fresh fruits,
and vegetables) should be restricted; use only operational
rations. Unprotected fresh food stored in the open and close to
the source of dissemination will become contaminated.

_b. Detection._

(1) Rapid identification of agents used is absolutely essential
to implement effective countermeasures. Agent identification
must be achieved quickly; it is the first step in answering
critical management questions. What adjustments must be made
in food preparation and distribution? What are the essential
countermeasures? What is the expected outcome of the incident?

(2) Samples of food that are suspected of being contaminated
are transported to the designated supporting laboratory.
Samples must be accompanied by a description of the samples,
the sample collection procedures, and the circumstances, which
prompted the collection. The designated medical laboratory in
the TO will provide a field confirmation identification of the
agent(s). Designated CONUS laboratories accomplish definitive
identification. See Appendix B for sampling procedures.

NOTE

New biological detection equipment is under development that
will enable units to conduct presumptive identification of
biological warfare agents. However, samples must also be
collected and processed as described in Appendix B.

_c. Decontamination._

(1) Food contaminated with toxins is handled in the same manner
as food contaminated with chemical agents. Food contaminated
with microorganisms is handled in the same manner as when
contaminated with the more common foodborne disease-producing
microorganisms.

(2) Several methods are available to decontaminate food
items contaminated with biological agents. The following
decontamination methods are considered to be the minimum. See
Table J-1.

(3) Group II food that is sealed in containers that are
resistant to the passage of biological agents requires
only that the exterior of the container be decontaminated.
Decontamination of these items is as follows:

(_a_) For containers made of metal, glass, plastic, or
porcelain:

_1._ Thoroughly wash the container in potable water and soap,
or in a disinfectant solution. If the water used for washing is
contaminated, the soap and water wash may increase, not reduce,
the contamination hazard. After which, the food containers are
immersed in a disinfectant solution for 30 minutes (see Table
J-3); then rinsed with potable water, if available and time
permits. Chlorine solutions are not as reactive or corrosive as
DS2.

_2._ Place the containers in boiling soapy water for 15
minutes; then rinse with potable water.

NOTES

1. The chemical field decontamination kits do not meet the
requirements to decontaminate food supplies exposed to
biological agents.

2. The same procedures should be followed even if there is
only suspicion of a biological warfare attack.

(_b_) Thoroughly wipe containers that will not withstand
soaking with a cloth soaked in a chlorine detergent solution.
Remove the food from the container and place it in Group III.

(_c_) Metal or glass containers determined to have
trichothecenes (Yellow Rain) present can be decontaminated
using DS2. Allow a contact time of 5 to 30 minutes for the DS2
to neutralize the toxin. Then rinse the container with potable
water.

(4) Group III food items that are not protected by the
packaging material are decontaminated or disposed of as follows:

(_a_) Decontaminate foods that can be peeled or pared by
immersing them in a disinfectant solution for 30 minutes, and
then rinsing them with potable water (see Table J-3). Peel
or pare the items after decontamination, then wash and, if
appropriate, cook before eating.

(_b_) With the exception of certain heat-stable toxins, heat
is the most practical means of decontaminating food. Several
heating methods may be used, but the method chosen depends upon
the type of food to be decontaminated. The key is to apply as
much heat as possible without rendering the food unfit.

_1._ Cook in a pressure-type cooker with 15 pounds of pressure
at 250°F (121°C) for 15 minutes.

_2._ Cook in a low-pressure cooker at 228°F (109°C) for 1 hour.

_3._ Bake bread or related items at 400°F (204°C) for 40
minutes.

+------------------------------------------------------+
| CAUTION |
| |
| Bread made with toxin-contaminated flour (especially |
| with trichothecenes) is still toxic. |
+------------------------------------------------------+

_4._ Bake or roast meat at 325°F (163°C) for 2 hours.

_5._ Boil for at least 15 minutes when no other method is
available.

(_c_) Although decontamination methods are provided above,
vegetables such as lettuce, broccoli, and cauliflower, or
unwrapped meats that have been exposed to biological agents
should not be eaten.

(_d_) Foods, such as butter, ice cream, and bread that will not
withstand any of the above treatments must be destroyed.

(5) Established meat inspection procedures are followed when
animals exposed to biological agents must be used for food. The
meat must be thoroughly cooked.

_Table J-3. Chlorine Solutions for Decontamination of Biological Warfare Agents_

============================================================
CHLORINE | MIXTURE TO PRODUCE 200 PPM
SOURCE | SOLUTION OF AVAILABLE CHLORINE
-------------------------+----------------------------------
HOUSEHOLD BLEACH | 1/2 GAL/25 GAL WATER
|
HIGH-TEST HYPOCHLORITE | 1/2 LB/25 GAL WATER
(CALCIUM HYPOCHLORITE) |
|
SUPERTROPICAL BLEACH | 1 LB/25 GAL WATER
============================================================

J-5. Chemical

_a. Contamination._

(1) Contamination of foodstuffs by a chemical agent may occur
at any point on the battlefield. This contact may render
the food unpalatable also. In many cases, decontamination
is difficult, thus, emphasis must be placed on protection.
Keep food supplies covered at all times. Take special
precautions to protect food that is not packed in protective
packages. Unprotected food, forage, and grain supplies may
be so contaminated that their consumption will produce
gastrointestinal irritation, or systemic poisoning. Nerve
agents, vesicants, and arsenicals are the most dangerous.
Field concentrations of phosgene, hydrocyanic acid, irritants,
and smokes will seldom be high enough to cause serious food
contamination. The effect of CK on food is not known. As a
precaution, foods exposed to CK should be considered toxic.

(2) The effects of chemical agents on food depend on the nature
of the agent and the type of the food. The extent to which
chemical agents penetrate food also depends on the amount, form
of dispersal (liquid [droplet size], or vapor) and duration of
exposure. Nerve agents and mustard will penetrate deeply into
unprotected fatty foods and will readily penetrate granular
products such as grain and sugar. Liquid food products can
be completely contaminated. Arsenicals readily hydrolyze to
poisonous arsenical oxides in some foods. Foods can be divided
into three categories based on their water content, fat
content, and crystalline structure:

(_a_) Foods having a high water content, a low fat content,
and/or a crystalline structure (fresh vegetables, fruits,
sugar, salt, and eggs) will absorb mustard and nerve agents,
either as a liquid or as a vapor. Nerve agents will be
hydrolyzed slowly.

(_b_) Foods having a low fat content and an irregular
(amorphous) structure (flour, bread, grain, rice, cereals,
dried fruits, dried vegetables, tea, coffee, peas, and beans)
readily absorb mustard and nerve agents in liquid form. As a
vapor, these agents are absorbed to some extent, but are easily
removed by airing.

(_c_) Foods having a low water content and a high fat content,
such as butter, fat, fatty oils, ham, cheese, milk, bacon,
fatty meat, and fish, absorb mustard and nerve agents such that
removal of the agents is virtually impossible.

(3) Chemical agents can be physically and chemically absorbed
into food. In addition to the toxic effect, they often
adversely affect taste, smell, and the appearance of the food.
However, chemical agents can cause the food to become very
toxic without causing any other changes in the food. Table
J-4 shows the effects of a number of chemical agents on food.
Since food can be contaminated without any outward change in
appearance, the possibility of contamination must be assumed
in a chemical agent environment. Treat the food with the same
precautions as established for known contaminated items.

(4) The protective properties of packaging materials are
dependent upon a number of factors. The factors include the
form of the agent (liquid versus vapor); concentration and
exposure time; weather (temperature, wind speed, and humidity);
and packaging material (the type of material, thickness, and
the presence of folds, tears, and small holes). Even the
thinnest material will offer some protection and is better
than nothing at all. Therefore, always cover food supplies
with whatever material is available. Table J-5 summarizes the
protection values of various packaging materials against vapors
and liquids.

(_a_) Operational rations are substantially protected while
contained in the shipping cases and especially if stored in the
original palletized unit load with an overlay of fiberboard,
shrink wrap, or film wrap. The worst case is pallets of
subsistence contaminated by liquid droplets during an attack.
After the attack, high vapor concentrations will exist in the
vicinity of the palletized loads. If the outer barrier is
permeable such as fiberboard, it is possible that a liquid
agent can seep through the overlay fiberboard and contact the
shipping containers in liquid form. Normally, with seepage
resistant materials, such as shrink wrap as the outer barriers,
only the vapors of the agent are found within the pallet.

(_b_) While MREs are stored, the food is protected by up to six
layers of material. Multilayer barriers result in a complex
diffusion process of the agent from the outside towards the
interior. Vapor penetration into nonhermetically sealed spaces
is a simple gaseous diffusion process. Permeation through
packaging is a much more complex process regardless of whether
the challenge is a liquid or a vapor.

_1._ Liquid is adsorbed into permeable materials such as
fiberboard or chipboard. With permeation-resistant materials
(such as shrink wrap), the agent dissolves into, seeps through,
and then desorbs from the barrier material. Shrink wrap
provides adequate protection. Fiberboard sheathing provides
adequate protection against mustard agents, but not against
nerve agents.

_2._ The low-density polyethylene used to construct the menu
bag can absorb chemical agents and possibly toxins. If the menu
bag is removed from the shipping container and is exposed to
liquid contamination, enough agent may pass through the bag to
create a health hazard. Keep MREs in the shipping container
until issued to the soldier. The menu bags should then be kept
under the same degree of protection as the soldier.

_3._ The aluminum-laminated materials used to construct the
MRE (retort and nonretort) pouches protect food from chemical
contamination if hermetically sealed. The only item in the MRE
meal bag that is not adequately protected is the spoon.

(5) Mylar and cellophane are resistant to chemical agents.

_Table J-4. Effects of Chemical Agents on Food_

+ INDICATES THE PRESENCE OF RESIDUAL TOXICITY.
- DENOTES THAT RESIDUAL TOXICITY IS NOT PRESENT.
? THE INFLUENCE HAS NOT BEEN DETERMINED.
=======================================================================

_Table J-5. Protection from Chemical Contamination by Packaging Methods and Materials_

_b. Detection._

(1) Currently, a field method for detecting chemical agent
contamination in food does not exist. Contamination is not
always spread evenly throughout food; this makes it impossible
to take a single sample and determine the presence or
absence of chemical agents in the entire lot. Additionally,
standardized laboratory tests have not been developed for
determining levels of chemical agents in food. Until a specific
method to detect chemical agents in food is available, reliance
will have to be made upon determination of contamination, or
lack thereof, on the packaging material; the integrity of the
packaging material; the protective qualities of the packaging
material; and the penetration characteristics of the suspected
chemical agents.

(2) Food may become toxic without any change in outward
appearance. Never taste or smell food to determine if
contamination is present in food.

(3) Veterinary and subsistence units have the following
equipment available to detect chemical agents in the field:

(_a_) The M8 Automatic Chemical Agent Alarm System consists
of the M43 detector unit and the M42 alarm unit. The detector
unit is a portable, automatic, point-monitoring device that is
designed to be hand carried from point to point. The M8 is used
to provide early warning of a toxic agent position and detects
the presence of chemical vapors and aerosols. The M43 detects
all nerve, blood, and choking agents, and some blister agents.
The M43A1 (the replacement for the M43) only detects nerve
agents.

(_b_) The M256 Chemical Agent Detector Kit detects and
identifies nerve, blood, and blister agents. The M256 is the
most sensitive of the chemical agent vapor detectors available.
However, it is not a continuous, real-time monitoring system.
It requires 15 to 20 minutes for sampling and analysis.

(_c_) The ABC-M8 VGH Chemical Agent Detector Paper can detect
and differentiate between nerve and blister agents by color
change. It is intended to be used by blotting and wiping
surfaces suspected of contamination. The M8 paper will respond
with a visual color change in 10 seconds or less.

(_d_) The M9 Chemical Agent Detector Paper will detect liquid
nerve (G & V) and blister agents (H & L), but will not identify
the specific agent or differentiate between nerve and blister
agents. The M9 tape is sensitive to droplets as small as 100 μ,
and will respond with a visual color change in 10 seconds or
less.

(4) All subsistence in a chemical attack area are considered
contaminated until a survey can be conducted, preferably by
veterinary and chemical personnel. Personnel must be at MOPP
Level 4 while conducting the survey. Concentrate the initial
portion of the survey on the adequacy of the storage facility
and other protective measures in preventing chemical agent
contact with subsistence items. The area surrounding the
storage facility is examined for the presence of animals,
rodents, birds, and arthropods acting unusual, or dead in
unusual numbers. If animals are present and assistance is
required in identifying the NBC agent, specimens can be
collected and submitted to the area medical laboratory. Damage
such as broken windows, holes, or loss of structural integrity
of the storage facility is noted. This information combined
with knowledge of the agent form (liquid or vapor), type of
agent (which will indicate the degree of persistency), and
approximate time of attack will provide a risk assessment.
Liquid agents should not significantly penetrate an intact
facility, but may produce vapor contamination by off-gassing.

(_a_) Upon entering the storage facility, the M8 can be used to
determine the presence of chemical vapors. However, precautions
must be taken. The M42 alarm is not to be used inside shelters,
vehicles, vans, or other interior modes. Therefore, when
checking food storage facilities, the alarm unit must be
left outside, turned off, or disconnected. Do not tilt the
M43 detector more than 45 degrees (because of the liquids it
contains). This is not a problem with the improved M43A1, but
the M43A1 requires attachment of an exit port filter when used
indoors. The M256 Chemical Agent Detector Kit can be used to
sample the air.

(_b_) Pre-position M9 chemical agent detector paper in food
storage areas; especially on the least protected pallets and in
areas where droplets may enter, such as near doors or windows.
Examine the M9 paper for indications of liquid chemical agents.
If the M9 paper is positive, or if the packaging materials show
the presence of liquids or stains, use the M8 detector paper to
determine the type of the agent. If an agent is not indicated
by the detector paper, then the amount of agent present will be
insufficient to cause secondary contamination when the outer
package is removed.

(5) Detection procedures become more complicated if a chemical
agent has penetrated or permeated through the packaging and
packing materials. Unless liquid has seeped through the
cardboard, any agent in the interior of the shipping case will
be in a vapor form. Liquid seeping should be obvious. The
sampler-detectors in the M256 Chemical Agent Detector Kit do
not have an aspirator for sampling the interior of the case.
However, there are several procedures that can be used. One is
to open the case, place the activated sampler-detectors inside
the case, and then reclose the case. Another is to punch holes
in the case, place the activated sampler-detector over the
holes, and cover the sampler-detector with an empty box or can
(open end down) to concentrate the vapors escaping from the
case. Alternatively, remove the food from the case and place
it in a plastic bag with the sampler-detectors to concentrate
the vapors. These procedures require two sampler-detectors; one
for blood agents and one for nerve and blister agents. Neither
method is very sensitive in low concentrations of vapor as is
expected to be present inside shipping containers. A better
method is to modify the M43 detector with a field expedient
probe of Teflon tubing attached to the detector's air inlet.
Insert the open end of the tubing into a hole in the case
or package to sample the interior air. When available, the
improved chemical agent monitor (ICAM) can be used; its design
will allow aspiration of air from inside shipping cases. The
ICAM can also be used to detect and identify liquid agents
on a surface provided the agent is vaporizing in sufficient
quantity. The ICAM gives a visual representation of a hazard
evaluation.

_c. Decontamination._

(1) Decontamination is only required for contamination
remaining 10 minutes or longer. Decontamination efforts on
subsistence items will normally be limited to removal of the
containers and carton overwrap material.

(2) The need for decontamination is primarily dictated by the
type of chemical agent used. The method of decontamination
selected will depend upon the type of packaging material used
and the urgency with which the food is required.

(3) Food supplies in storage are not likely to be seriously
contaminated if reasonable protection precautions are taken.
For this reason, large supplies of food are not to be
condemned as a whole simply because they have been exposed to
possible chemical contamination. A prompt and careful survey
of the supplies may reveal that only a few items have been
contaminated to a level that decontamination is required.
Prompt segregation of the heavily contaminated portions will
prevent, or minimize, contamination of the remainder. Foods
without protective packages constitute the major difficulty.

(4) Individual decontamination is performed by each soldier on
those subsistence items in his possession at the time of the
attack. Individual decontamination is limited to operational
rations that are in original, intact containers. Unit-level
decontamination is performed by unit personnel under the
supervision of unit NBC personnel. Support decontamination
is attempted at major subsistence storage facilities. Again,
decontamination is limited to packing material. Decontamination
of food itself is only attempted in emergency situations when
alternative supplies are not available.

(5) Start decontamination operations with the easiest method
and proceed to the most difficult. This allows for the removal
of a relatively large portion of the contamination in a minimum
of time. The simplest procedure is to allow the materials to
age and air ("weather"). Substantial self-decontamination will
occur with most agents. Exceptions are thickened mustard,
thickened GD, and VX. Table J-6 provides the length of time for
which contaminated subsistence supplies may present a contact
hazard. Weather elements that affect decontamination are--

(_a_) Warm temperatures speed liquid agent off-gassing and
hasten the dispersion of chemical agents into the air.

(_b_) High winds rapidly disperse chemical agent vapors and
speed off-gassing from surfaces.

(_c_) Moisture causes chemical agents to react with water to
form nontoxic or less toxic chemicals. Heavy rain or rain of
long duration can aid decontamination by mechanically removing
chemical agents.

(_d_) Even in cold weather, direct sunrays warm surfaces
above the air temperature and hasten the off-gassing and
decomposition of chemical agents.

_Table J-6. Persistency of Selected Liquid Chemical Agents_

(6) Active decontamination is attempted only when weathering
will not decontaminate the packaging material in sufficient
time. Decontamination procedures can be enhanced by using
heat to vaporize the chemical agent; by reaction with
decontaminants; or by removing with hot soapy water.

(_a_) The simplest (standard) decontamination materials
are water and detergents. An effective decontaminant is
hot water used with the addition of soap or detergent and
scrubbing. Commercial abrasive powdered cleansers are effective
decontaminants for many surfaces (metal, glass, Formica), but
not wood or soft plastics.

(_b_) Water can be used to flush chemical agents from surfaces.
High-pressure application produces a better cleansing action
than low pressure. If the surface has absorbed the agent,
flushing will remove the surface contamination, but will not
affect the agent that is absorbed.

(_c_) Soaking contaminated items in boiling water is an
excellent decontamination method for some agents. Water alone
will not be sufficient to decontaminate all chemical agents.
Soaking in warm or cold water may reduce the contamination
slightly; however, the hazard may not be reduced sufficiently
even after prolonged soaking. If hot water is not available,
or if it might cause damage to the item, other methods of
decontamination should be considered, such as decontaminating
solutions or a caustic solution followed by thorough rinsing.

(_d_) Fibrous materials such as cloth and canvas are best
decontaminated by washing and scrubbing.

(_e_) Glass, metal, porcelain, and plastic surfaces are best
decontaminated by using hot water or hot soapy water. Some
toxic materials are readily removed with no more than slight
abrasion or brushing.

(_f_) Painted, varnished, and waxed surfaces are generally
smooth and nonporous. Dust and liquids are readily removed by
wiping, brushing, or vacuuming. Absorbed materials are removed
by hot water, detergent, or complexing agents. None of these
surfaces stand up well to heavy abrasive techniques. Agents
can be attacked and removed by caustics, acids, and organic
chemicals. Some of these surfaces readily absorb agents, so
weathering following decontamination is advisable.

(_g_) Rubber is a porous material that can absorb agents. It is
not easily decontaminated by abrasive techniques. Warm, soapy
water used with brushing is effective since it removes some
absorbed contamination. Strong acids, alkalies, and organic
solvents may deteriorate and decompose rubber articles.

(7) Operational rations are the primary rations issued;
always issue uncontaminated stocks first. This allows for
decontamination of contaminated stocks without interrupting
supply support. Normally, contaminated stocks are not issued.
The decision to issue contaminated items is based on the
tactical situation, criticality of the items, type and extent
of contamination, and the time and resources available for
decontamination. Decontamination efforts on subsistence items
are limited to the containers and carton overwrap material.

(_a_) The MRE retort and nonretort food pouch may be
decontaminated with soap and water wash. The chemical agents
will be removed by the solutions.

(_b_) Semipermeable materials (polyethylene menu bag, shrink
wrap, and film wrap) may have chemicals deposited not only
on the surface, but also dissolved into the matrix of the
material. The chemicals can be removed from the surface by
washing with hot soapy water, but contaminant dissolved in
the material is not removed. The remaining agent can only be
removed by weathering which can be accelerated through the use
of heat and sweeping the surface with air.

(_c_) Fiberboard is both sorbent and permeable and acts like
a blotter. Liquid decontaminants can force the contaminant
further into the fiberboard. Any attempt to decontaminate
fiberboard would be futile. The only alternatives are to remove
the fiberboard, or to allow it to weather.

(_d_) Palletized unit loads of MRE and UGR outerwraps can be
decontaminated through the aid of a forced clean air sweep in 4
to 5 days, compared to 3 weeks or more under natural conditions
without a forced air sweep.

(8) Contaminated food supplies are only handled by personnel
trained in decontamination methods and in MOPP Level 4.
Contaminated food items are divided into three groups as
described below (see Table J-1 for additional information).

(_a_) Group 1 consists of canned and unopened packaged items
which have been exposed only to agent vapors. Most items in
this group will be safe to issue after a brief period of
outdoor airing to remove clinging vapors. Table J-7 lists the
decontamination procedures for packaging materials contaminated
with nerve agents, mustards, and arsenicals.

_Table J-7. Chemical Decontamination of Packaged Material_

======================================================================
PACKAGING MATERIAL CONTAMINATION DECONTAMINATION PROCEDURES
----------------------------------------------------------------------
AIRTIGHT METAL VAPOR AND AIR FOR 24 HOURS. WASH
CONTAINERS, GLASS LIQUID WITH HOT SOAPY WATER,
BOTTLES, FOIL SODA, OR BLEACH SOLUTION.
ALUMINATED LAMINATED RINSE WITH WATER.
MATERIALS.

POLYESTER, PVF. VAPOR REMOVE CONTAMINATED
WOODEN BOXES, CRATES, PACKAGE. AIR CONTENTS FOR
BOARD, MULTILAYER 24 HOURS.
BAGS.

CARDBOARD, LIQUID CONTAMINATED CONTENTS--TREAT
POLYETHYLENE. AS UNPACKAGED FOOD.
=======================================================================

(_b_) Group II consists of canned and unopened packaged items
which have been contaminated with a liquid chemical agent.

_1._ Attempts to decontaminate porous packaging materials,
such as cardboard or wood, are likely to be unsuccessful and
may result in spreading the contamination. The best procedure
in handling such items is to strip off the outer contaminated
coverings and examine the inner layer to see if penetration
of the agent has occurred. If it has, continue stripping off
layers until an uncontaminated layer is reached and place it in
Group I. If the agent has penetrated to the food, place it in
Group III.

_2._ Food in cans or in other sealed, impermeable containers is
not in danger of chemical contamination. Because contamination
is confined to the outer surface of the sealed container,
decontamination is accomplished by: immersion in boiling, soapy
water for 30 minutes and rinse; immersion in boiling water for
30 minutes; spray with DS2; or to wash in hot soapy water,
rinse, and aerate. Under no conditions should contaminated
containers be opened before they have been decontaminated and
monitored.

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Health Service Support in a Nuclear, Biological, and Chemical EnvironmentChapter XXXI: Appendix: J (1)

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