News Details

On 21 October 2026, the Government of Canada published a final order in the Canada Gazette, Part II, amending the Domestic Substances List (DSL) to apply the Significant New Activity (SNAc) provisions of the Canadian Environmental Protection Act, 1999 (CEPA) to tetramethylthiuram disulfide, commonly known as TMTD or Thiram (CAS RN 137-26-8). The order (SOR/2026-208) will come into force on 7 April 2027. 

The measure follows Canada's assessment of the Thiocarbamates Group under the third phase of the Chemicals Management Plan (CMP). This group includes TMTD and DPTT (CAS RN 120-54-7). 

Canada Identifies Environmental Concerns Related to TMTD 

The final screening assessment, published in January 2021, concluded that TMTD meets the environmental criteria under paragraph 64(a) of CEPA, while DPTT does not meet any of the criteria under section 64. Canadian authorities identified the release of TMTD into the environment from the manufacture of solid rubber products as a cause for concern. 

Stakeholder follow-up also examined the potential use of TMTD in manufacturing latex products. While there was no evidence that TMTD was being used for this purpose in Canada, such uses were identified in the United States and the European Union, indicating that they could potentially be introduced in Canada in the future. 

SNAc Requirements Apply to Certain New TMTD Activities 

The SNAc provisions are intended to ensure that the Government of Canada is notified before specified new activities involving TMTD begin. These requirements particularly address activities involving the manufacture of TMTD in quantities exceeding 100 kg in a calendar year as well as its use in manufacturing of liquid rubber (latex) products where the total quantity used exceeds 100 kg in a calendar year. 

Companies planning activities that meet the conditions specified in the SNAc order must submit the prescribed information to the Minister of the Environment at least 180 days before beginning them. This enables the government to assess potential environmental and human health risks and determine whether further risk management measures are necessary. 

Canada Also Targets Releases from Rubber Manufacturing 

The SNAc measure complements Canada's broader risk-management approach for the rubber sector. On 4 April 2026, Canada published the Release Guidelines for Chemicals Used in the Rubber Product Manufacturing Sector. The guidelines address the release of substances, including TMTD and BENPAT, and incorporate principles from Canada's Code of Practice for he Environmentally Sound Management of Chemicals in the Chemicals, Plastics, and Rubber Sectors. 

Key Regulatory Information 

TMTD / Thiram 
CAS RN: 137-26-8 
Status: Meets the environmental criterion under paragraph 64(a) of CEPA. 
Latest action: SNAc provisions adopted through an amendment to the DSL. 

Entry into force: 7 April 2027. 

DPTT 
CAS RN: 120-54-7 
Status: It does not meet any of the criteria under section 64 CEPA. 
Further risk management: None planned at this time. 

The October 2026 action means that companies manufacturing, importing, or using TMTD in Canada should review their planned activities in order to determine whether the new CEPA SNAc notification requirements will apply when the order comes into force.