Hardened Oil
Hardener
HCFC-141b & 142b
HCFC-22
Hexabromo Cyclodecane [HBCD]
Hexachloro Platinic Acid Hexahydrate
Hexamine
Humic Acid
Hydrazine Hydrate
Hydrofluoric Acid
Hydrogen Peroxide
Hydroquinone
Hydroxyapatite [HAP, or known as Active Calcium Phosphates]
Hydroxylamine Sulfate