We all have heard how Hydrogen Sulfide smells like rotten eggs. But remember, that is in small concentrations. If it is in high enough concentration it will simply kill you.
Since H2S is heavier than air and may travel along the ground, it will collect in low-lying and enclosed, poorly-ventilated areas such as manholes, vaults and sewer lines. The primary route of exposure is inhalation and the gas is rapidly absorbed by the lungs. In high enough concentrations, the ability to smell the gas can be lost instantaneously. Therefore, DO NOT RELY on your sense of smell to indicate presence of H2S.
In addition, Hydrogen sulfide is high flammable and gas/air mixtures can be explosive. If ignited the gas burns to produce toxic gases.
Below are solid guidelines to follow when dealing with H2S Systems:
- Engineer and design systems that keep exposure at a minimum
- Areas containing H2S should have adequate Gas detector monitors, Egress pathways and Evacuation procedures in place.
- Personnel should have personal H2S monitors, respirators and SCBA readily available.
- Never enter an area containing Hydrogen Sulfide without proper training and authorization.