Selenium is an element essential to life, and found in trace amounts in humans obtained from dietary sources. In certain forms, however, it is an immediate threat to life. Which form of selenium occurs as a gas with a characteristic horseradish or rotten egg scent, and can be lethal in concentrations as low as 1 ppm?
Hydrogen selenide. Subacute toxicity from hydrogen selenide may include GI distress, garlicky breath, fatigue and general malaise. Acute massive exposure can lead to rapid fatality and multisystem organ failure. Another important consideration for selenium toxicity that can lead to rapid fatality is exposure to selenious acid, a compound used in gun bluing (application of a selenious acid containing product to the steel of weapons to limit rust and oxidation).
Wilber CG. Toxicology of selenium: a review. Clin Toxicol. 1980 Sep;17(2):171-230. doi: 10.3109/15563658008985076. PMID: 6998645. Lillian C. Alderman M.D. & James J. Bergin M.D. (1986) Hydrogen Selenide Poisoning: An Illustrative Case with Review of the Literature, Archives of Environmental Health: An International Journal, 41:6, 354-358, DOI: 10.1080/00039896.1986.9935778. Lillian C. Alderman M.D. & James J. Bergin M.D. (1986) Hydrogen Selenide Poisoning: An Illustrative Case with Review of the Literature, Archives of Environmental Health: An International Journal, 41:6, 354-358, DOI: 10.1080/00039896.1986.9935778
Contributed by Joe Kennedy, MD UVM Toxicology