What is it

Tabun is classified as a nerve agent that interrupts the transmission of nerve impulses in the body. For example, it binds to nerves in the spine, muscles or central nervous system depending on the manner of ingestion. It was developed in Germany in 1936 as an insecticide. Like a number of widely used insecticides, tabun is an organic compound containing phosphorus (organophosphorus compounds). It is a tasteless liquid that ranges from colorless to brown and has a somewhat fruity odor. It is volatile at room temperature and can be absorbed through the eyes or skin or inhaled as vapor.

Syntoms

The symptoms depend on how tabun is ingested. If inhaled or absorbed through the eyes, the first symptom to appear is usually miosis, or constriction of the pupils, and visual blurriness, combined with shortness of breath, wheezing, runny nose and tightness of the chest. If swallowed or absorbed through skin not near the eyes, pupil constriction may not occur, and nausea is the first symptom to appear. Tabun's effects also include vomiting and diarrhea, urinary and fecal incontinence, loss of muscle control, convulsions, coma, and death. Vomiting and diarrhea are symptoms of a serious exposure that must be treated immediately.

Testing

The level of tabun exposure is determined by testing the activity of the enzyme cholinesterase in the blood. Tabun also causes fluctuations in the levels of gases in the blood. A chest X-ray and EEG monitoring may also help determine the level of exposure.

Recovery Potential

Although skin absorption great enough to cause death may occur in one to two minutes, death may not occur for one to two hours. Respiratory lethal dosages kill in one to 10 minutes, and liquid in the eye kills almost as rapidly. In most cases, by the time the patient arrives at the emergency room, the agent has already taken effect. If the exposure is mild to moderate, recovery is possible if treated immediately.

Prevention/Treatment

Do not induce vomiting. A person exposed to tabun should immediately don a respiratory mask. If eye contact has occurred, the patient should rinse the eyes with water for 10 to 15 minutes before putting on the mask; in the case of skin contact, wash the affected area with lots of water and soap, sodium carbonate or bleach, but not hot water, as this will speed tabun absorption. At the emergency room, medical personnel should administer a nerve agent antidote. The patient may need an IV or to be placed on a ventilator to restore breathing. A person exposed to tabun or other nerve gases should remain in the emergency room for at least 24 hours. Chances of long-term survival are high, but effects such as miosis, blurred vision and balance problems can persist for months.

Environmental Cleanup

It quickly dissipates when mixed with water in any form. Under average weather conditions, it can persist for one to two days. Contaminated clothing should be removed, bagged and sealed. Secondary exposure can occur from contact with contaminated clothing; it can also occur when tabun evaporates from contaminated clothes.

Basic solutions, such as bleach, ammonia and ethanol, also are effective against tabun.