Protecting Yourself from Hydrogen Sulfide
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Tip written by: Infraspection Institute
Petrochemical refineries provide many opportunities for the application thermography. At the same time, they also provide unique safety challenges. In this Tip we discuss safety issues when working around hydrogen sulfide.
Hydrogen sulfide is a colorless, flammable, extremely hazardous gas with a “rotten egg” smell. It occurs naturally in crude petroleum and natural gas, and can be produced by the breakdown of organic matter and human/animal wastes such as sewage. Large quantities of hydrogen sulfide are often produced in refineries. Unintended leaks can allow hydrogen sulfide to collect in low-lying and poorly ventilated areas such as basements, manholes, sewer lines and underground telephone/electrical vaults.
Hydrogen sulfide can be smelled at low levels, but with continuous low level exposure or at higher concentrations you lose your ability to smell the gas even though it is still present. At high concentrations one’s ability to smell the gas can be lost instantly. NEVER depend on your sense of smell for indicating the continuing presence of this gas or for warning of hazardous concentrations.
The health effects associated with exposures to hydrogen sulfide vary with how long, and at what level, you are exposed. Asthmatics may be at greater risk. At low concentrations, hydrogen sulfide can cause irritation of eyes, nose, throat, or respiratory system. At high concentrations, shock, convulsions, coma, and death are possible; in some cases the effects can occur within a few breaths.
Before entering areas with possible hydrogen sulfide, the air should be tested for the presence and concentration of hydrogen sulfide by a qualified person using appropriate test equipment. Testing should also be performed to determine if fire/explosion precautions are necessary. If hydrogen sulfide or hazardous gasses are present, the space should be ventilated until acceptable limits are achieved. In some cases, continuous monitoring of the work area may be required.
Thermographer safety is one of the many topics covered in the Infraspection Institute Level I Certified Infrared Thermographer® training course. For more information including course locations and dates, visit Infraspection Institute online at www.infraspection.com or call us at 609-239-4788.
For more complete information on workplace safety, visit the OSHA Website.
