Table 2.

Recommended airborne (inhalation, ocular) pre-planning clearance goals for transit passengers as well as various airport employees and personnel for selected CWAs and TICs.^a

	Reasonable maximum clearance goals (mg/m3)	Alternative clearance goals (mg/m3)
CWA or TIC	<8-h durationb exposure	>8 but <24-h duration exposure
Tabun (GA)	< 0.0010c	< 0.0003e
Sarin (GB)	< 0.0010c	< 0.0003e
Soman (GD) and Cyclosarin (GF)	< 0.00050c	< 0.0002e
VX	< 0.000071c	< 0.000024e
Sulfur mustard (H/HD)	< 0.008c	< 0.003e
Hydrogen cyanide (AC)	< 1.1d	< 0.37e
Cyanogen chloride (CK)	< 0.25f	< 0.08f
Phosgene (CG)	< 0.08g	< 0.03g

^aChemical formulae: tabun, C₅H₁₁N₂O₂P (NATO code GA); sarin, C₄H₁₀FO₂P (NATO code GB); soman, C₇H₁₆FO₂P (NATO code GD); cyclosarin, C₇H₁₄FO₂P (NATO code GF); VX, C₁₁H₂₆NO₂PS (NATO code VX); sulfur mustard, C₄H₈Cl₂S (NATO code HD); hydrogen cyanide, HCN (NATO code AC); cyanogen chloride, CNCl (NATO code CK); phosgene, COCl₂ (NATO code CG).

^bMay also be used as appropriately protective and health-based vapor screening criteria for releasing items, equipment, and facilities that have not been exposed to liquid or heavy aerosol forms of the chemical of concern; these screening criteria would also be useful for evaluating non-porous items and surfaces that have undergone decontamination. If these vapor screening criteria are attained, such decontaminated items would not be expected to pose a vapor exposure hazard (DA 2008, Table C-5).

^cNRC/COT (2003).

^dNRC/COT (2002).

^eProposed >8 but ≤24-h protective estimates presented for use in this analysis are derived by straight-line extrapolation from the 8-h AEGL-1 values and follow standard protocols (NRC/COT 2001).

^fIn the absence of a previously derived CK exposure guideline comparable to AEGL-1, these estimates were calculated for use in the current assessment (see text for details of derivation. and Wood 1997). 8-h estimate is derived from experimental data with straight-line extrapolation to 24 h. This derivation is considered a reasonable approach given the absence of published AEGL-1 values for cyanogen chloride.

^gIn the absence of a previously derived phosgene (agent CG) exposure guideline comparable to the AEGL-1, these estimates were calculated for use in the current assessment (see text for details of derivation). 8-h estimate is derived as 50% of 8-h AEGL-2 for phosgene (NRC/COT 2002), with straight-line extrapolation to 24 h. This derivation is considered a reasonable approach given the absence of published AEGL-1 values for phosgene.