fuel, red phosphorus, and hexachloroethane. Toxicity data and exposure guidance levels for other smokes and obscurants will be presented in subsequent volumes.

The Army requested recommendations for four types of exposure limits: (1) emergency exposure guidance levels (EEGLs) for a rare, emergency situation resulting in exposure of military personnel for less than 24 hr; (2) permissible exposure guidance levels (PEGLs) for repeated exposure of military personnel during training exercises; (3) short-term public emergency guidance levels (SPEGLs) for a rare, emergency situation potentially resulting in an exposure of the public to military-training smoke; and (4) permissible public exposure guidance levels (PPEGLs) for repeated accidental exposures of the public residing or working near military-training facilities.

Using NRC guidelines published in 1986 and 1992 for developing exposure guidance levels, the subcommittee developed EEGLs and PEGLs for the four obscuring smokes as shown in Table S-1 and described below.

Diesel-fuel smoke is formed by injecting diesel fuel into the exhaust manifold of a tactical vehicle. The fuel is vaporized and expelled with the vehicle's exhaust. The vapor condenses when exposed to the atmosphere, producing a visual obscurant composed of respirable particles.

Although extensive data are available on the health effects of combusted diesel-fuel exhaust, little information is available on the health effects of uncombusted diesel-fuel smoke. The mortality of rodents following one-time exposure depends on the product of exposure