 Nickel tetracarbonyl is considered as one of the strongest inhalation poisons.Inhalation of nickel tetracarbonyl causes acute non-specific symptoms similar to a carbon monoxide poisoning as nausea, cough, headache, fever, and dizziness.After some time, severe pulmonary symptoms such as cough, tachycardia, and cyanosis, or problems in the gastrointestinal tract occur.