Health Hazards of Gases A review of the toxicities of substances that exist in the gaseous state under normal conditions of use

Asphyxiants Asphyxiants Simple: replace oxygen Simple: replace oxygen Chemical: disrupt transport or use of oxygen Chemical: disrupt transport or use of oxygenHypoxia Anoxia – Symptoms: euphoria, increased respiration & HR, headache, fatigue, unconsciousness, death Symptoms: euphoria, increased respiration & HR, headache, fatigue, unconsciousness, death

Oxygen Deficiency The brain is very sensitive to oxygen deficiency Normal oxygen: % Encountered in tanks, silos, mines, poorly ventilated spaces Man may be able to hold breath for ~ 1minute with normal levels of oxygen in the air, but will collapse in seconds with 5% oxygen.

Carbon Monoxide (CO) Colorless, odorless, toxic gas Produced by incomplete combustion of fossil fuels Response 50 PPM = PEL 50 PPM = PEL 200 PPM = slight headache 200 PPM = slight headache 400 PPM = frontal headache 400 PPM = frontal headache 800 PPM = dizziness, nausea, convulsions, insensible 800 PPM = dizziness, nausea, convulsions, insensible

Hydrogen Sulfide Properties Foul odor Foul odor No industrial use, but formed in many processes and decay of sulfur-containing materials Chronic effects Olfactory fatigue, eye irritation leading to “halo” and “blue fog” effects, no apparent long-term effects Olfactory fatigue, eye irritation leading to “halo” and “blue fog” effects, no apparent long-term effects Acute effects Rapidly oxidized in the blood, acts directly on respiratory control center Rapidly oxidized in the blood, acts directly on respiratory control center

Hydrogen Cyanide Common source of cyanide poisoning Rapid absorption via inhalation and through skin Rapid onset of symptoms Headache, nausea, weakness, confusion, collapse, death Headache, nausea, weakness, confusion, collapse, death Antidotes and chances of recovery

Irritants Irritant – A substance producing an irritating effect when it contacts the skin, eyes, nose, or respiratory system. Solubility Can influence the part of the respiratory tract that is effected Can influence the part of the respiratory tract that is effected

Irritants of the Upper Respiratory Tract Are highly soluble in water Generally have good warning properties Usually do NOT produce chronic effects Examples: Ammonia Ammonia Ammonium hydroxide Ammonium hydroxide Acid gases (HF, HCl, HBr), sulfur oxides Acid gases (HF, HCl, HBr), sulfur oxides

Irritants of the Lower Respiratory Tract Have low but significant water solubility or hydrolyze in moist mucous Usually are not irritating to breathe Almost always produce delayed effects Examples Nitrogen dioxide Nitrogen dioxide Phosgene Phosgene

Irritants of the Whole Respiratory Tract Have intermediate levels of solubility Produce some warning but not sufficiently Can affect the whole respiratory system Examples Halogens (fluorine, chlorine, bromine, iodine) Halogens (fluorine, chlorine, bromine, iodine) Ozone Ozone

Summary Simple asphyxiants Chemical asphyxiants URT irritants LRT irritants WRT irritants Asphyxiating irritants Arsine Arsine Stibine Stibine Germane Germane