Salts of oxometallic or peroxometallic acids:

Sodium dichromate

Other chromates and dichromates; peroxochromates:

Molybdates:

Tungstates (wolframates)

Other:

Fluorine, chlorine, bromine and iodine:

Sulfur, sublimed or precipitated; colloidal sulfur

Carbon (carbon blacks and other forms of carbon not elsewhere specified or included)

Hydrogen, rare gases and other nonmetals:

Alkali or alkaline-earth metals; rare-earth metals, scandium and yttrium, whether or not intermixed or interalloyed; mercury:

Hydrogen chloride (Hydrochloric acid); chlorosulfuric acid:

Sulfuric acid; oleum