GF (cyclohexyl methylphosphonofluoridate) is an organophosphate nerve agent. The physical and chemical properties, toxicokinetics, and toxicity of GF are discussed in detail by CDEPAT(1994), Marrs et al. (1996), and Somani (1994). Human-toxicity estimates have been derived for percutaneous vapor exposures, vapor inhalation exposures, and for percutaneous liquid exposures. Only a few toxicity end points were considered; they include lethality and cholinesterase (ChE) inhibition in humans and animals. The subcommittee's assessment of the scientific validity of CDEPAT's proposed human-toxicity estimates for GF is discussed below.
CDEPAT's proposed LCt50 estimate for percutaneous exposure to GF vapor is 2,500 mg-min/m3, assuming exposure durations of 30 to 50 min and