The composition of this stream may vary, but typically contains hydrogen sulphide together with carbon dioxide and traces of other sulphur compounds. Class D, Division 2 - Materials Causing Other Toxic Effects. Hydrogen Sulphide 4. Exposure to levels above 500 ppm will lead to immediate respiratory failure. Exposure to sub-lethal levels may lead to varying degrees of eye irritation.
Inhalation represents by far the most significant route of entry for hydrogen sulphide.
Exposure to levels of hydrogen sulphide above 500 ppm even for short periods will generally result in rapid or immediate respiratory failure or collapse. Death will result unless the victim is rescued immediately and given pulmonary resuscitation. Exposure to levels below 500 ppm may result in serious consequences including unconsciousness and death. 15 ppm Ceiling is 20 ppm 5. Hydrogen Sulphide mixes readily with air to form an explosive mixture.