Hydrogen sulfide (H₂S), sodium sulfide (Na(SH)) and sodium sulfide (Na₂S)

On this page

• Summary of publications
• Updated draft assessment and risk management scope
• Timelines

Summary of publications

CAS RN	Common name	DSL name	Updated draft assessment	Public comments on the original draft screening assessment	Original draft screening assessment	Risk management scope	Proposed conclusion on section 64 criteria	Follow-up activities
1313-82-2	None	Sodium sulfide (Na2S)	HTML	HTML	HTML	None	Does not meet	None planned at this time
7783-06-4	None	Hydrogen sulfide (H2S)				HTML	Meets one or more of the criteria	Refer to risk management scope
16721-80-5	Sodium bisulfide	Sodium sulfide (Na(SH))				None	Does not meet	None planned at this time

Updated draft assessment and risk management scope

In February 2024, the Updated Draft Assessment for Hydrogen Sulfide ((H₂S), Sodium Sulfide (Na(SH)) and Sodium Sulfide (Na₂S) was released and the related notice was published in the Canada Gazette, Part I: Vol. 158, No. 5 – February 3, 2024.

As a result of the updated assessment, the Government is proposing that H₂S may be harmful to human health and to the environment.

A Risk Management Scope for Hydrogen Sulfide (H₂S) was also released in conjunction with this publication. There is a 60-day public comment period associated with these publications.

In September 2017, the Draft Screening Assessment for Hydrogen Sulfide (H₂S), Sodium Sulfide (Na(SH)) and Sodium Sulfide (Na₂S) was released and the related notice was published in the Canada Gazette, Part I: Vol. 151 No. 36 – September 9, 2017. Since this publication, new information on the incidental releases of H₂S and exposure to humans and the environment became available. As such, the draft screening assessment was updated and a risk management scope for H₂S was published.

Timelines

Date	Activity
February 2025	Anticipated publication of the final assessment and proposed risk management approach.
February 3, 2024	Publication and start of a 60-day public comment period on the Updated Draft Assessment for Hydrogen Sulfide (H2S), Sodium Sulfide (Na(SH)) and Sodium Sulfide (Na2S) and the Risk Management Scope for Hydrogen Sulfide (H2S). The related notice was published in the Canada Gazette, Part I.
September 9, 2017	Publication and start of a 60-day public comment period on the draft screening assessment (including follow-up activities). The related notice was published in the Canada Gazette, Part I.