TAC San Diego Acetaldehyde 675 Benzene 2267 "1,3-Butadiene" 400 Carbon tetrachloride 0.02 Chromium (Hexavalent) 0.2184 para-Dichlorobenzene 133 Formaldehyde 1941 Methylene Chloride 372 Perchloroethylene 1631 Diesel PM 1748