The challenge of working by H2S is that it is a toxic product with few warning signs. Since its physical state is usually in a gaseous state, it is easy to inhale it before one realizes that it is too late. It is colorless so it is difficult to see. It is highly poisonous and many provinces vary in their occupational exposure limit from 1 to 10 ppm. Federally, it is currently an exposure of only 1 ppm, due to its ease in knocking people down after one breath. To complicate matters, it has a rotten egg smell due to its sulphur content, but peoples olfactory senses get overloaded easily… Then, people stop smelling the odor and assume it has dissipated. In fact, it is often increasing in intensity, but by that time, the person has inhaled enough to shut down their respiratory system.
It is a nerve gas that affects the cytophase inhibitor in the bloodstream. This makes it difficult for the body to absorb oxygen, leading to respiratory and cardiac arrest in a few minutes.
This gas is also very corrosive, and can eat through metal containment rapidly. Since it is soluble in fluids, those that agitate, heat or depressurize systems with H2S in it will find that it will rise. Its vapour density is heavier than air (about 19% heavier). So in a cold day with no wind, it may settle in low spots. However, in hot conditions that are windy, it may rise , making it difficult to protect oneself, particularly if downwind of the source.
We recommend thorough H2S training to understand the physical properties and challenges related to hydrogen sulphide gas.
Contact Allstar Enviro Safety today to book a program. 403-214-1558
www.safetymom.ca [email protected]