Canada Gazette, Part I, September 9, 2017 — Draft Screening Assessment re Hydrogen Sulfide (H2S), Sodium Sulfide (Na(SH)) and Sodium Sulfide (Na2S)

The document outlines opposition to a Draft Screening Assessment regarding hydrogen sulfide (H2S), sodium bisulfide (Na(SH)), and sodium sulfide (Na2S). The authors argue that H2S poses significant risks to human health, particularly for communities near oil and gas operations, and that the government's assessment fails to apply a precautionary approach or account for olfactory nuisance as an adverse effect.

• The authors contend that the Draft Screening Assessment is flawed because it ignores the health risks H2S releases pose to Canadians living or working near oil and gas infrastructure or those impacted by geological fracturing.
• Evidence is provided of severe H2S leaks in Saskatchewan, including reports of concentrations reaching 150,000 ppm, which is 150 times the level that causes instant death.
• The document argues that olfactory nuisance should be considered an adverse health effect, citing legal precedents in Ontario and British Columbia where odours caused nausea, headaches, and stress.
• The authors criticize the Draft Screening Assessment for using a neurological no observable adverse effect concentration (NOAEC) of 30 ppm based on rat studies, whereas the California OEHHA uses a much lower acute reference exposure level of 0.03 ppm.
• The authors claim the government failed to apply uncertainty factors to the chronic inhalation NOAEC of 10 ppm, which they argue would result in a reference exposure level well within measured ambient air concentrations in Canada.
• The document asserts that the Margins of Exposure (MOEs) for acute respiratory effects (60 to 200) and chronic inhalation (320 to 10,000) fall below the 1,000 threshold that Health Canada policy generally requires for 'no further action'.

APA

Canadian Association of Physicians for the Environment (2017). Canada Gazette, Part I, September 9, 2017 — Draft Screening Assessment re Hydrogen Sulfide (H2S), Sodium Sulfide (Na(SH)) and Sodium Sulfide (Na2S). https://cape.ca/wp-content/uploads/2018/04/1.Re-Hydrogen-sulphide-Nov.-8-2017.pdf

Chicago

Canadian Association of Physicians for the Environment. Canada Gazette, Part I, September 9, 2017 — Draft Screening Assessment re Hydrogen Sulfide (H2S), Sodium Sulfide (Na(SH)) and Sodium Sulfide (Na2S). 2017. https://cape.ca/wp-content/uploads/2018/04/1.Re-Hydrogen-sulphide-Nov.-8-2017.pdf.

Wikipedia

{{cite press release |author=Canadian Association of Physicians for the Environment |title=Canada Gazette, Part I, September 9, 2017 — Draft Screening Assessment re Hydrogen Sulfide (H2S), Sodium Sulfide (Na(SH)) and Sodium Sulfide (Na2S) |date=8 November 2017 |url=https://cape.ca/wp-content/uploads/2018/04/1.Re-Hydrogen-sulphide-Nov.-8-2017.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@misc{canadianassociationofphysiciansfortheenvironment2017canada, author = {{Canadian Association of Physicians for the Environment}}, title = {{Canada Gazette, Part I, September 9, 2017 — Draft Screening Assessment re Hydrogen Sulfide (H2S), Sodium Sulfide (Na(SH)) and Sodium Sulfide (Na2S)}}, publisher = {Canadian Association of Physicians for the Environment}, year = {2017}, month = nov, url = {https://cape.ca/wp-content/uploads/2018/04/1.Re-Hydrogen-sulphide-Nov.-8-2017.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }