Hydrogen sulfide (H2S) is a type of gas that’s heavier than air. The gas sometimes occurs naturally, or it can be a by-product of industrial procedures and activities. The gas is toxic, and thus it comes with many health hazards for industrial workers. Teaching your employees how to remain safety against this deadly gas is critical which is why we created this short H2S Toolbox Talk. You can have a quick safety meeting with your team using this information to educate your staff.
Sadly, several employees have experienced significant health impacts, and even death, after being exposed to hydrogen sulfide so safety should be top of mind for all employees. It is important for employees working in industrial zones where the gas may be produced to be aware of its characteristics, risks, and effects on health. Workers also need to know best safety practices for work zones where they may come into contact with H2S.
In addition to this toolbox talk, we also have a video-based H2S Safety Training program as well.
Table of Contents
Hydrogen Sulfide Features
Hydrogen sulfide is typically a colorless gas, but it can be recognized by its unpleasant “rotten egg” smell in lower concentrations. When the gas concentration is denser, however, it affects one’s sense of smell, and the gas is not so easily detected by smell anymore. This means the sense of smell cannot always be relied on to detect the presence of H2S. If you want a deeper understanding of exactly what this gas is, then please refer to our deeper dive on h2s.
The gas is heavier than oxygen or air. This means it tends to sink to lower industrial or factory zone areas. It may be present in greater quantities in low-lying zones, confined spaces, and poorly ventilated areas like pits, basements, or underground vaults.
The gas has several features or characteristics that make it hazardous to workers’ health. When the gas is burned, it releases other toxic fumes like sulfur dioxide.
Even at very low concentrations, the gas can impact one’s health. Concentrations as low as two to five parts per million (ppm) will pose a health risk, especially if workers are exposed to the gas for a long period of time.
H2S is Flammable
The gas is also extremely flammable, which poses a serious fire risk, especially in low-lying areas where the gas occurs in higher concentrations. The gas is known to react with steel to create iron sulfide. This can then ignite if it is exposed to the air.
This fire hazard can impact people as well as expensive industrial equipment and buildings.
How Hydrogen Sulfide Gas is Produced
There are several ways H2S can be released. Other than being a natural gas, hydrogen sulfide occurs in crude petroleum and other industrial processes.
Hydrogen sulfide gas can also be produced when old metals begin to corrode and break down. These processes are known as metal fatigue, sulfide stress cracking, or hydrogen embrittlement. H2S can be released when metals go through these break-down processes.
H2S can also be produced during the breakdown process of organic matter waste from animals and humans. Thus, it may be present in sewer gas, sewer lines, and manure pits.
Types of Hydrogen Sulfide Exposure
There are two main kinds of exposure we talk about when it comes to hydrogen sulfide. The first is acute exposure. This means that a person was exposed to a large amount of H2S in a short span of time.
The second type is chronic exposure. This term refers to when a person is exposed to lesser amounts of this gas over a long period of time.
The Health Reactions to Concentrations of Hydrogen Sulfide
Hydrogen sulfide is highly toxic and heavier than air, making it common and condensed in low-lying places that aren’t well-ventilated. People exposed to H2S, even in low concentrations, can experience a range of health issues. The level of exposure also impacts the kinds of reactions a person may experience. These reactions to the gas include:
- Severe eye, nose, and throat irritation, especially when exposed to low concentrations.
- Headaches and coughing may occur.
- Respiratory system reactions may occur. It interferes with the natural, effective oxygen utilization in a person’s central nervous system. This may cause difficulty breathing for a person exposed to the gas.
- Irrational behavior may be noted at low to moderate exposure levels.
- Exposure to moderate concentrations of H2S may cause feelings of dizziness, as well as nausea and vomiting.
- Exposure to high concentrations of hydrogen sulfide may cause loss of consciousness very quickly, which can worsen to coma, and even death.
How to Keep Safe from Hydrogen Sulfide Hazards in the Workplace
All employees should undergo company training about hydrogen sulfide to keep workers in industrial zones safe from this extremely hazardous gas. This training should include what processes of the company produce the gas, how to test for it, how to respond to its possible and actual presence, and its range of hazards. You can also refer to this OSHA guide to give you additional talking points and information.
Workplace practices to ensure safety from hydrogen sulfide hazards should also be followed conscientiously and consistently. These practices include:
- Initially checking any prospective work area for the smell of rotten eggs, which can indicate the presence of hydrogen sulfide gas.
- Clearly marking off any areas where H2S gas may possibly be present.
- Testing all low-lying zones, poorly ventilated areas, and confined spaces for H2S, and any other dangerous gases, before any work is undertaken there.
- Should concentrations of the gas be found when testing, it should be removed before work can take place. The area may need to have continuous ventilation systems established if the gas is frequently produced by the company’s industrial procedures.
- If H2S concentrations are found to be less than 100ppm, workers may be given full-face respiratory masks equipped with air-purifying cartridges to protect them while they work.
- In higher concentrations, that is, over 100ppm, the concentration of H2S gas is considered immediately dangerous and thus too risky to health and life to work in. These zones must be avoided until the gas has been professionally removed.
- High-tech masking systems or self-contained breathing apparatus must be provided if, for any reason, entry into these zones cannot be avoided, i.e., in the case of rescue operations.
- Facilities in which the production of H2S is a frequent occurrence should have alarm systems set up to make workers aware of the presence of hydrogen sulfide.
Other H2S Protocols
Other company protocols such as the following should be in place to manage circumstances where H2S may be present:
- There should be an emergency plan in place should an incident concerning H2S occur. Employees should be made aware of and follow this company emergency plan in the event of a safety risk.
- Workers needing to work in H2S zones should be “fit tested” to do so.
- Any employees who have been exposed to H2S should be thoroughly examined by a doctor before coming back to work.
H2S Safety Save Lives
As this section shows, safety practices regarding toxic gases like H2S are essential. Fewer accidents reduce costs for a company, but more importantly, it keeps workers healthy. If a worker experiences health issues due to exposure to high concentrations of H2S, it can cost many hours of treatment and rehabilitation without a guarantee of a full recovery.
While following procedures isn’t always convenient, cutting corners could mean the end of a life as someone knows it or life altogether.
H2S Toolbox Talk
Hydrogen sulfide safety in the workplace is a serious matter. Exposure to H2S gas can cause severe health issues and even death. Thus, it is essential for all employees in industries where the presence of gas can occur to be made aware of the risks and how to deal with them.
All industrial enterprises where hydrogen sulfide may be released should have industry-approved protocols, processes, and equipment to deal with H2S risks. Hopefully this hydrogen sulfide toolbox talk will help you and your employee stay safe if you work around this dangerous gas.
- How Long Can Truck Drivers Drive Before a Break is Required? - October 3, 2022
- What Are the DOT Hours of Service Rules? – [Updated for 2022] - September 26, 2022
- 19+ Aerial Lift Safety Tips – [Updated for 2022] - September 23, 2022