Hydrogen Sulphide gas (H2S) is a byproduct in many different industries and is one of the leading causes of death in the oil and gas sector. Workers can become exposed to H2S on worksites during the drilling and production process. H2S gas is heavier than air and can collect in low areas such as sewers, pits, tunnels, and gullies and can quickly reach lethal concentrations in confined spaces.
Understanding H2S and how to handle exposure is critical to workplace safety.
The Danger of H2S
H2S is a colorless, toxic, flammable, and explosive gas that is heavier than air. It does have a strong odor similar to rotten eggs at low concentrations, but can only be detected by smell at concentrations ranging from 0.01-0.3 parts per million (ppm). Detecting H2S gas by relying solely on its odor is not a good idea because at concentrations above 100 ppm it quickly deadens a person’s sense of smell.
Exposure to even very low concentrations of H2S can produce symptoms including eye irritation, light sensitivity, and vision problems, reduced sense of smell, sore nose and throat, difficulty breathing, headache, confusion, nausea, disorientation, and vomiting. In higher concentrations, H2S can paralyze the muscles that control breathing and cause death within seconds.
H2S in any concentrations should be considered dangerous as it is impossible to determine exactly what level will result in symptoms because everyone’s body processes it differently.
How to Reduce the Risk of H2S
The most effective way to reduce the risk of H2S exposure is to eliminate the source. If that’s not possible, other risk controls should be used:
1. Engineering Controls: These involve making modifications to facilities, equipment, and processes. Some examples include scrubbers, ventilation, air monitoring equipment and alarms, and wind direction indicators.
2. Administrative controls: These involve changing work practices and policies. Some examples include exposure control plans, warning signs, rescue plans, and training.
3. Personal protective equipment (PPE): This involves equipping workers with the proper respirators, eye wear, and protective clothing, and ensuring that PPE is regularly inspected and tested.
H2S Alive Training
H2S training is required for any worker who may potentially be exposed to H2S trade, regardless of occupation. H2S Alive is the standard training course for the oil and gas industry in Canada and combines theory and hands-on learning in a classroom environment. It is a full day course that reviews the physical properties of H2S, how to identify it, locations where it can be found, and its health hazards. Hazard recognition and control is discussed and various detection methods are discussed and demonstrated. The course will also cover approved breathing apparatuses and how to inspect and operate them effectively. The Initial Response Strategy will also be reviewed along with doing various rescue and drag techniques on victims. The goal of the training is to enable workers to save their own life or others in the event of an H2S release.
Upon successful completion of the course, the H2S Alive certification is valid for three years.
H2S is a potential hazard on any oil and gas worksite. Understanding the risk, putting controls in place, and making sure that all workers receive proper training is critical to ensuring workplace safety.