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GF

GF is a liquid organophosphate nerve agent with an intermediate persistence (evaporation rate about 1/20th of water). It has a nondescript odor (20 test subjects: 35% smelled an odor at 10.4 mg/m3; 65% at 14.8 mg/m3; odor was variously described as sweet, musty, peaches, and shellac).

Synonyms: CMPF, Cyclosarin, Cyclosin, O-Cyclohexyl methylphosphonofluoridate, Cyclohexyl methylphosphonofluoridate, Methyl cyclohexylfluorophosphonate

Boiling Point 239°; Freezing Point -30°; Flammable; Flash Point 94°

DETECTION: Nerve agent sensitive chemical agent detectors (e.g., CAM, M18A2, M256, etc.) and papers (e.g., M8, M9) may be used for detection.

History: Cyclosarin was probably first synthesized during World War II as part of the systematic study of organophosphates undertaken by the Germans after their potential military utility was identified. It was again looked at in the early 1950's by the United States and Great Britain as both countries undertook a systematic study of potential nerve agents. However, the higher cost of the precursors for GF relative to those for GB along with its lower toxicity prevented it from being chosen for manufacture.

SYMPTOMS AND EFFECTS: Lowered acetylcholinesterase levels are indicators of nerve agent intoxication in victims.

Depending on the degree of intoxication, symptoms may include:

Onset is usually rapid, occurring within minutes of exposure.

MEDICAL COUNTERMEASURES: The immediate treatment for nerve agent intoxication is intravenous injection of 2 mg atropine sulfate (intramuscular injection should be considered if the patient is hypoxic and ventilation can not be initiated, as there is a risk of ventricular fibrillation). This should be followed by additional injections of atropine at 10-15 minute intervals, continuing until bradycardia has been reversed (e.g., until the heart rate is at 90 beats/minute). If breathing has stopped, a mechanical respirator should be used to ventilate the patient. DO NOT ATTEMPT
MOUTH-TO-MOUTH RESUCITATION. If possible, oxygen or oxygen-enriched air should be used for ventilation. If possible, monitor cardiac activity.

Oximes (pralidoxime salts, obidoxime) may be of use in restoring acetylcholinesterase activity. Obidoxime may be used to treat GF intoxication; however, it may cause liver damage. Animal studies indicate that the oxime Hi-6 may be significantly superior to other oximes in the treatment of GF intoxication, but it is not widely available. Therefore pralidoxime salts should be used, with a slow intravenous infusion of 500 mg to 1 g being given initially.

Diazepam should be administered to control convulsions. It also has value in controlling fear on the part of the patient. An initial dose of 5 mg may be followed by additional doses at 15 minute intervals up to a total of 15 mg.


PHYSICAL COUNTERMEASURES: Initial Isolation and Protective Action Distances

Protective equipment (self-contained breathing equipment or gas mask, barrier suit) must be used. Medical personnel treating casualties should avoid direct (skin-to skin) contact; protective gear including breathing protection should be worn when treating casualties prior to decontamination. Latex gloves are not adequate protection. Casualties should be removed from exposure and decontaminated as rapidly as possible. Casualties must not be moved into clean treatment areas where unmasked/ungloved personnel are working until decontamination is complete.

2000 Emergency Response Guidebook (ERG2000) Guide 153.


DECONTAMINATION

People: Decontamination of victims is accomplished by removing the victim from the contaminated area, removal of clothing, and removal or neutralization of agent present on the skin (skin decontamination may be unnecessary if the exposure was only to GF vapor). Any visible droplets should be blotted (not wiped) away using an absorbent material (e.g., paper towels, facial tissues, etc.); if available, towelettes moistened with a neutralizing solution should be used. Adsorbent powders may also be used for removal of droplets (in the absence of standard adsorbents, field expedients such as flour may be useful). A solution of 0.5% hypochlorite bleach may be used for skin decontamination. Hair should be thoroughly cleaned using soap and water, with care being taken to prevent wash water from contacting skin.

Property: Surface decontamination may be accomplished using hypochlorite bleach slurries, dilute alkalis, or DS2 decontaminating solution. Steam and ammonia may be used for the decontamination of confined spaces.

GF is only slightly soluble in water and the liquid, if present in relatively large amounts, can layer out at the bottoms of pools.