Table 1. NATA 2002 Hazardous Air Pollutants Posing a Respiratory Risk and their Associated Reference Concentration.
| Chemical Name | RfC ab (µg/m 3) | Chemical Name | RfC ab (µg/m 3) |
|---|---|---|---|
| Acetaldehyde | 9.0 | Hexamethylene-1,6-diisocyanate | 0.01 |
| Acrolein | 0.02 | Hydrochloric acid | 20.0 |
| Acrylic acid | 1.0 | Maleic anhydride | 0.7 |
| Acrylonitrile | 2.0 | Methyl bromide | 5.0 |
| Antimony Compounds | 0.2 | Methyl isocyanate | 1.0 |
| Beryllium Compounds | 0.02 | Methyl methacrylate | 700.0 |
| Bis(2-ethylhexyl) phthalate | 0.01 | Methylene diphenyl diisocyanate | 0.6 |
| Chlorine | 0.15 | Naphthalene | 3.0 |
| 2-Chloroacetophenone | 0.03 | Nickel Compounds | 0.09 |
| Chloroprene | 2.0 | Nitrobenzene | 9.0 |
| Chromium Compounds | 0.1 | Phosgene | 0.3 |
| Cobalt Compounds | 0.02 | Phthalic anhydride | 20.0 |
| 1,3-Dichloropropene | 20.0 | Propylene dichloride | 4.0 |
| Diesel Emissions | 5.0 | Propylene oxide | 30.0 |
| Diethanolamine | 3.0 | Styrene oxide | 6.0 |
| Epichlorohydrin | 1.0 | Titanium tetrachloride | 0.1 |
| 1,2-Epoxybutane | 20.0 | Toluene | 5000.0 |
| Ethylene dibromide | 9.0 | 2,4-Toluene diisocyanate | 0.07 |
| Ethylene glycol | 400.0 | Triethylamine | 7.0 |
| Formaldehyde | 9.8 | Vinyl acetate | 200.0 |
| Hexachlorocyclopentadiene | 0.2 |
a RfC is derived from either IRIS (Integrated Risk Information system), CAL (California Environmental Protection Agency), or ATSDR (Agency for Toxic Substances and Disease Registry)
b RfC is the reference level for which harmful health effects can occur as a results of inhalation exposure.