6.10       Chemical warfare agents
 

6.10.1         Background
 

After World War II large quantities of war ammunition were dumped in both the North Sea and the Baltic Sea. Some of this ammunition contained various types of weapons for chemical warfare. War gas ammunition was dumped within areas shown in Figure 6 - 59. Amongst these weapons especially mustard gas bombs have proven to be a particular risk for fishermen.
 

Of nearly 300 discarded Danish fish catches during 1968-84 about 90 % were contaminated by mustard gas and the rest by sneezing gas (sternutator) or tear gas (lachrymator). Approximately the same ratios have been reported during 2000-2002 though the total numbers of finds have decreased considerably (cf. Figure 6 - 60).

Source: Bornholms Marinedistrikt

6.10.2        Appearance of chemical warfare bombs
Chemical warfare agents were originally most often contained in two types of aerial bombs (cf. Figure 6 - 61). One of them Type KC 250 (cf. Figure 6 - 62) is 160 centimetres long and has four fins in the rear. The other is 100 centimetres and has no fins. Both types are 34-36 centimetres in diameter and have cone-shaped front parts.

Figure 6 - 64 shows the design of Type KC 250 with explosive (TNT), detonator and liquid mustard gas. Figure 6 - 63 shows a central explosive core and tailcone dismounted from such a bomb.
 

The bomb shells are made of thin material and have now often completely corroded away. Finds of whole bombs as in Figure 6 - 65 and Figure 6 - 66 are nowadays getting more and more rare.

Picture source: Bornholms Marinedistrikt

Fishermen sometimes get yellow or brown lumps of mustard gas in their fish catch. The lumps (cf. Figures below) vary in size up to 100 kgs sometimes with a clay-like consistency. Most often the surfaces of the lumps are oxidized to solid state. Sometimes the inner parts of the lumps are still in liquid state and can pose severe injuries.

6.10.3        Properties of chemical warfare agents

Appearance and behaviour of mustard gas
 

In spite of its name, mustard gas is not a gas. In the mustard gas bombs a more or less viscous fluid or sludge is found which may have the consistency of oil, mush, Vaseline or lumps of jelly. When exposed to the environment mustard gas oxidize and solidify.
 

Yellow to brown or dark-brown (sometimes almost black).
 

Sharp, sweet odour which may resemble cress, garlic, horseradish or mustard. The agent is insidious since sense of smell may be fatigued and fail to give warning of dangerous concentrations.
 

Mustard gas often contains special additives which makes it easily stick to skin, clothing and gear. Mustard gas in liquid state will penetrate rapidly through fabric and leather. Ordinary rubber and many types of plastic provide short-time protection.

Skin

Even minor amounts of mustard gas cause itching and burning red spots, or even shooting pain, a few hours after exposure to the skin. After another few hours large liquid-filled blisters may develop. If the blisters break, slow-healing wounds are formed which can easily be infected. Therefore the blisters should be prevented from breaking in every way.
 

When exposed to vapours of mustard gas, the victim at first feels the eyes itching and smarting. After increasing smarting pain and reddening of the eyes a copious flow of tears will arise as well as sensitivity for light, temporary blindness, and a heavy swelling of the eyelids. If the eyes are exposed to liquid mustard gas they will be injured with a severe risk of blindness.
 

The risk of injuries by mustard gas vapours is highest in warm weather, stationary air and confined spaces. Inhalation of hazardous concentrations of mustard gas vapours gives rise to nasal catarrh (runny nose), hoarseness, sore throat and coughing. The coughing may became painful, the power of speech may be lost and the breathing may be deteriorated. The result may be serious injuries to the windpipe and lungs.
 

Lachrymators (tear gases) are volatile substances which affect the mucous membrane of the eyes and cause watery painful eyes. They may irritate the skin and cause local injuries. The effects do not last very long after the affected person has been removed from the gas.

Sternutators (sneezing gases) affect the mucous membranes of the nose, throat and respiratory passages and causes sneezing, coughing, a runny nose and watery eyes. These effects can last from 15 minutes to a couple of hours after the affected person has moved away from the gas to fresh air.

Nerve agent of the tabun type is, in its pure form, a transparent and odourless glycerine-like substance. However, impurities sometimes make the liquid dark and give it a fruity smell, and any additives to it may al so affect its smell.

Nerve agents are easily absorbed through the skin. respiratory organs, eyes and the gastro-intestinal tract. Nerve agents in liquid and vaporised form easily penetrate all textiles and leather. Ordinary robber and many types of plastic only provide brief protection.

A small dose of nerve agent will cause headaches, painful eyes, blurred vision, pupil contractions, a running nose and a feeling of weight on the chest.

A large dose will cause the above symptoms followed by cramps, difficulty in breathing, a slow pulse, and may be fatal as a result of respiratory or cardiac arrest. If a person is exposed to a large dose, the entire poisoning process is very quick. usually between 5 and 10 minutes, unless the patient is treated.
 

Suffocating agents. A typical suffocating agent is phosgene, which is a colourless gas. Phosgene is a liquid below 8^oC,. In low concentrations it has a rather sweet, not unpleasant smell, which is reminiscent of newly cut hay.

In high concentrations the smell becomes sharper and irritating. The fumes are heavier than air. The substance is very insidious, and harmful quantities can be inhaled without the person noticing anything.

For the first few hours after a person has been exposed to phosgene fumes, the only effect is irritation of the mucous membranes in the respiratory passages. The symptoms of poisoning are difficulty in breathing, coughing, a feeling of suffocation, thirst, vomiting, pain in the chest, lips turning blue, foaming at the mouth, extreme weakness, mental disturbances followed by unconsciousness. The reason for this is that phosgene causes pulmonary oedema and prevents oxygen absorption because of damage to the lung tissue.

The mucous membranes of the eyes are also affected by phosgene, which can result in permanent eye damage, even though there are no symptoms of this at the start.

Smoke-generating agents contain often phosphorous compounds. A mixture of sulphur trioxide and chlorosulphonic acid is another powerful smoke generator. In its liquid form it is extremely corrosive on contact with the skin. In its vaporised form, it consists of small particles of hydrochloric acid and sulphuric acid, which irritate the skin, eyes and respiratory organs.

Phosphorous is found in smoke ammunition where the who le charge or part of it consists of yellow (white) phosphorous. When phosphorous is taken out of the-water and comes into contact with the oxygen in the air, it ignites. Phosphorous sores heal very slowly.

The information above does not deal with the possible chronic adverse effects of the poisons.

6.10.4        Actions in incidents involving
                  finds of chemical warfare agents

First steps

Responsible bodies are alerted according to pre-arranged plans. If the find is suspected to contain explosives it must not be moved until it has been examined by appropriate expertise.
 

A vessel is commissioned for a first action involving transport of personnel, warning of seafarers and necessary assistance to involved fishing vessels.
 

If the affected fishing vessel can run by its own engines it is primarily directed to a suitable decontamination anchorage where environmental response vessels are utilized for decontamination actions.
 

Vessels are commanded for transport of disarming personnel and safety equipment. The vessels carry safety equipment for own personnel.
 

It is very important that contaminated skin and eyes are immediately cleaned before the mustard gas has penetrated into the body. Every minute's delay will increase the risk of injuries. If both the skin and eyes are contaminated, assistance should be received from someone not injured so that the first actions can be taken simultaneously according to the guidance below. Do not touch the face and eyes with contaminated hands. Get medical aid as soon as possible.
 

N.B.!
Stay in the open air on deck if the clothes are contaminated. It is important that not to scatter the mustard gas to clean spaces on the vessel.

Skin
First take off all contaminated garments as well as rings, watches etc. There must be a full certainty that no contaminated garments or objects remain on the body. Act rapidly but cautiously so that the face and eyes do not become contaminated.
 

Remove quickly the (sometimes sticky) mustard gas which can be scraped from the skin with a knife or similar. Act cautiously and avoid rubbing it into the skin or to spread it. Low viscous mustard gas should be "tweaked" away with an absorbent material in order to prevent spreading on the skin. Also this must be done quickly.
 

Use thereafter a special decontamination agent for mustard gas, if available on board. Observe care- fully the instructions which apply for the agent. Wash decontaminated skin areas with usual soap or soft soap and water. Observe that mucous membranes and the lower abdomen are especially sensitive to mustard gas. Finish up by careful washing of all the body with soap and water.

Apply wet bandages on injured skin areas. Blisters should not be broken.
 

Wash immediately contaminated eyes with a soft spray of clean and preferably lukewarm fresh water for at least 15 minutes. Keep the eyelids widely apart during washing. Use an eye wash station if available on board. Then close the eyelids and clean the surrounding skin parts cautiously with soap and water. Do not use any kind of eye ointment, decontamination agent or bandage.

On first hand an area of at least 30 m radius should be cordoned off.
 

Continuously monitor the air outside the cordon. The cordon must be expanded if any instrument indication is obtained or suspected smell is noticed.
 

The following apply for decontamination of vessel and equipment:
 

Indicating equipment is used to judge the need for decontamination as well as to check for any remaining contaminants after decontamination actions.
 

Below are 6 different decontamination methods and agents described that have to be used depending on the properties of the contaminated surface. A reference to a detailed report on destruction methods for chemical weapons is given in Ref. 61.

Mustard gas (and other chemical warfare agents) penetrate rapidly through porous materials like wood, fabrics, rubber, etc. It is therefore difficult to decontaminate such materials and it has to be performed by means of penetrating decontaminants or methods like DS2 or boiling. DS2 is a mixture of diethylenetriamine (70%), sodium hydroxide (2%) and ethylene glycol monomethyl ether (28%).

These decontamination methods can have unwanted effects on the materials’ properties. Hard surfaces are not so difficult to decontaminate as they don’t imbibe mustard gas and other chemical warfare agents. Feasible methods are high-pressure steam or hotwater spraying, or treatment with DS2 or chloride of lime.

DS2 or chloride of lime should be distributed over the contaminated items and should act for 15-30 minutes before flushing with high-pressure water.

Decontamination equipment like deck brushes, buckets, cotton waste, etc. as well as well as equipment that is difficult to decontaminate should be regarded and treated as contaminated waste.
 

Airing
Gaseous mustard gas in the air of closed spaces is remove by violent airing.

Washing
Contaminated items are washed with cotton waste soaked with hot soap or detergent solution, or soaked with light diesel fuel oil, kerosene, etc. Alternatively the items are flushed with hot soap solution during simultaneous working with a brush. Discarded cotton waste etc., soaked with kerosene or diesel fuel oil, used for washing should be collected in tin containers as these solvents might affect plastic containers.
 

Decontamination with chloride of lime
A slurry of chloride of lime (sodium hypochlorite can also be used) in at least 3 parts of water is distributed over the contaminated item’s surface. The slurry is worked into the surface with a brush and should act for 15-30 minutes before careful washing or flushing.

N.B.: Chloride of lime and sodium hypochlorite are corrosive for eyes and skin. Both agents corrode metals and may damage fabrics etc. Dry chloride of lime may ignite upon contact with mustard gas.
 

Decontamination with DS2
DS2 is distributed on the contaminated item’s surface (0.05 – 0.1 litre/m²) and should act for 15-30 minutes before careful washing or flushing.