Arsenic and inorganic arsenic compounds
Asbestos (all forms, including actinolite, amosite, anthophyllite, chrysotile, crocidolite, tremolite)
Beryllium and beryllium compounds
Bis(chloromethyl) ether and chloromethyl methyl ether (technical-grade)
Cadmium and cadmium compounds
Chromium (VI) compounds
Coal-tar pitch
Engine exhaust, diesel
Nickel compounds
Outdoor air pollution
Particulate matter in outdoor air pollution
Plutonium
Radon-222 and its decay products
Silica dust, crystalline, in the form of quartz or cristobalite
Soot
Sulfur mustard
Tobacco smoke, secondhand
Welding fumes
X-radiation and gamma radiation

Source. Adapted from Loomis et al.¹