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Hydrogen Sulphide (H2S)

Hydrogen sulphide is a colourless gas consisting of atoms of sulphur and hydrogen. H2S has an odour of rotten eggs.

How Is It Generated?

Hydrogen sulphide is generated both naturally and anthropogenically (man-made). Sources include: swamps, sewers, sour gas wells, volcanic eruptions.

What Are The Health Effects?

Provincial Guidelines:

What Can We Do?

You must take the necessary precautions when dealing with H2S.

  1. H2S Alive: This training course deals with the proper ways of ensuring your safety when working around H2S. No individual should be on a site where H2S is present without this training.
  2. Personal Protective Equipment (PPE): When working around H2S it is important to be wearing the correct PPE and ensure you know how to use it effectively.
  3. Monitoring: This is an important step for public safety. It provides assurance that the ambient levels of H2S are within safe limits.

Table of Human Symptoms and Other Effects

Occupational Health and Safety Act (Alberta – AR 393/88 Chemical Hazards Regulation)

Concentration (ppb)Exposure TimeHuman Symptoms and Other Effects
0.0047-50% of the population can detect (smell) H2S.
324 hoursAlberta ambient air quality guideline for 24 hours.
<108 hoursDaily workday exposure limit.
101 hourAlberta ambient air quality guideline for 1 hour.
10-20-Exposure at which eye irritation begins.
50-100-Exposure at which eye damage occurs.
150-250-Exposure concentration causing olfactory nerve paralysis, diminished sense of smell and decrease sense of danger.
320-530-Exposure levels leading to pulmonary edema with the possibility of death.
530-1000-Exposure levels that cause strong stimulus of the central nervous system and rapid breathing, which leads to loss of breathing.
8005 minutesConcentration at which 50% of the population will perish (LC50).
>10001 secondExposure causes immediate collapse with loss of breathing.

National Library of Medicine – Specialized in Information Services



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