Hydrogen sulfide and your health
Learn about hydrogen sulfide, its health risks and how to reduce your exposure.
On this page
- About hydrogen sulfide
- Safety of hydrogen sulfide
- What we're doing to reduce your exposure to hydrogen sulfide
- What you can do to reduce your exposure to hydrogen sulfide
About hydrogen sulfide
Hydrogen sulfide is a colourless gas that has a characteristic rotten egg smell. It's commonly found in soil, air and water.
It can be produced as part of normal body functions, or when plants and animals die and decompose. The gas is part of the natural sulfur cycle and has many natural sources, including:
- volcanoes
- hot springs
- petroleum crude oil deposits
It can also be released from industrial activities, such as:
- mining production
- oil and gas facilities
- kraft pulp and paper mills
- intensive livestock operations
- wastewater treatment systems
Hydrogen sulfide can also be released from inactive oil and gas wells as a result of former activity.
Safety of hydrogen sulfide
At high levels of exposure, hydrogen sulfide can damage your nervous system or other organs and tissues in your body.
Under Canada's Chemicals Management Plan, we review and manage the potential risks that chemical substances can pose to people in Canada and the environment. The first stage of the review process is a draft chemical risk assessment.
In 2017, we published a draft assessment of hydrogen sulfide.
Since then, we have become aware of new information about the incidental releases of hydrogen sulfide from inactive oil and gas wells, and potential harms to human health and the environment. As a result, we have updated the draft assessment.
We've completed the updated draft assessment. We're proposing that hydrogen sulfide may pose a risk to your health when it's released at high levels from inactive oil and gas wells. We're also proposing that these releases are harmful to the environment.
Our updated draft assessment found that exposures to hydrogen sulfide from other sources aren't high enough to pose a risk to human health.
What we're doing to reduce your exposure to hydrogen sulfide
Our assessment is not yet final. We're continuing to evaluate the potential risk posed by hydrogen sulfide before we publish our final conclusion. This includes:
- tracking new information on exposures or hazards
- asking the public to comment on our draft assessment
- reviewing and using this information to help shape our final assessment
All provinces, and several territories, have requirements in place for oil and gas well management. We will review current regulatory actions and programs across jurisdictions that may reduce incidental releases of hydrogen sulfide from inactive oil and gas wells. This will inform potential actions that can reduce the exposure of people in Canada and the environment to these releases.
If the proposed findings for hydrogen sulfide are confirmed in the final assessment, we will consider:
- adding hydrogen sulfide to Schedule 1 of the Canadian Environmental Protection Act, 1999
- this would allow Canada to implement preventive or control actions to help reduce the exposure of people living in Canada and the environment to hydrogen sulfide from inactive oil and gas wells
What you can do to reduce your exposure to hydrogen sulfide
You can provide any comments on our draft assessment during the 60-day public comment period.
If you have concerns about exposure to hydrogen sulfide, contact your provincial or territorial government about potential oil and gas well locations in your area.
If you have concerns about having been exposed to hydrogen sulfide, talk to a health care provider.
If you're exposed to hydrogen sulfide at work, talk to your employer and occupational health and safety (OHS) official about:
- relevant laws
- safe handling and storage practices
- requirements under OHS legislation and the Workplace Hazardous Materials Information System (WHMIS)
Related links
- Measuring your exposure to chemicals
- Canada's systems for addressing chemicals
- Overview of the Chemicals Management Plan