An inorganic compound that is colorless, volatile and highly flammable with a characteristic, musty odor that emits toxic carbon monoxide fumes upon heating. Nickel carbonyl is primarily used for nickel coatings and to manufacture high-purity nickel powder. Exposure to this substance can cause severe dermatitis, skin and asthma-like allergies and affects the lungs, kidneys, gastrointestinal tract and neurological system. Nickel carbonyl is a known carcinogen and is associated with an increased risk of developing lung and nasal cancers. [ https://pubchem.ncbi.nlm.nih.gov/compound/Nickel-carbonyl-_hsdb ]