Hydrogen Sulfide (H2S) is a gas frequently found when drilling for and in the production of crude oil and natural gas. H2S is also found in wastewater treatment plants, utility facilities and sewers. The gas is generated as a result of the microbial breakdown of organic materials in lieu of oxygen.
The Basics of Detecting Hydrogen Sulfide
Properties | Exposure | Detection
Hydrogen sulfide is a colorless, flammable and very hazardous gas with a “rotten egg” smell. H2S is also known as “knock down gas,” as inhaling high concentrations of the gas can lead to instant loss of consciousness or even death.
Extended exposure to lower concentrations, such as 10-500 ppm, can cause a number of respiratory symptoms that range from rhinitis to acute respiratory failure.
H2S has numerous names, such as sewer gas, stink damp, swamp gas and manure gas. It is naturally occurring in crude petroleum, natural gas and hot springs. Additionally, hydrogen sulfide is created by the bacterial breakdown of organic materials and human/animal wastes (e.g., sewage).
The Occupational Safety and Health Administration (OSHA) determined the Permissible Exposure Limits (PELs) to H2S gas as follows:
- Construction 8-hour Limit: 10 ppm
- General Industry Ceiling Limit: 20 ppm
- General Industry Peak Limit: 50 ppm (up to 10 minutes if no further exposure on-shift)
- Shipyard 8-hour limit: 10 ppm
Detecting Hydrogen Sulfide in Workplaces
H2S gas is heavier than the air it resides in, and it accumulates in low-lying areas of poorly ventilated spaces. When in the presence of air and moisture, in oil and gas applications, sour gas (products containing H2S gas) may produce sulfuric acid, which has the capacity to corrode metals.
Facility equipment, including the internal surfaces of various components, faces reduced durability and impact strength, possibly leading to premature failure.
Image Credit: Ion Science
Hydrogen sulfide is found in several industries; for instance, it is used in textile manufacturing. Some examples of workers in danger of being exposed to hydrogen sulfide include the following:
- Agricultural workers on farms with manure storage pits or landfills
- Factory workers in plants where rayon textiles are manufactured
- Petroleum and natural gas workers involved in drilling and refining
- Workers in wastewater treatment industries
Amongst these industries, using hydrogen sulfide to fabricate material is also particularly hazardous for workers who work in confined spaces. For example,
- Farmworkers can be exposed when cleaning manure storage tanks or working in manure pits.
- Sanitation workers can be exposed when cleaning or maintaining municipal sewers and septic tanks.
- Workers in oil and natural gas drilling and refining may be exposed because hydrogen sulfide may be present in oil and gas deposits and is a by-product of the desulfurization process of these fuels.
Hydrogen sulfide is a fast-acting poison, affecting several bodily systems. Therefore, wearable VOC gas detectors are critical for early detection and alerting, as the body’s senses are not dependable indicators.
Crucially, gas detectors, like the ION Science Ara H2S detector, should be considered as they warn live monitoring personnel of worker H2S gas exposure with a built-in alert system.
Devices with a rapid response time and rugged construction are vital for use in harsh environments where H2S may occur. Furthermore, as H2S in high concentrations can desensitize and bring about almost instant unconsciousness, connected personal monitoring equipment is essential.
This information has been sourced, reviewed and adapted from materials provided by Ion Science.
For more information on this source, please visit Ion Science.