TMTD proposed for addition to Schedule 1

Summary#

On October 8, 2022, the Government of Canada published a proposal to add thioperoxydicarbonic diamide, tetramethyl (TMTD) to Schedule 1 of the Canadian Environmental Protection Act, 1999. That addition would let the government create specific rules later to reduce environmental releases because TMTD was found to be toxic to the environment, especially aquatic life.

What it does#

• Adds TMTD to Schedule 1 of the Canadian Environmental Protection Act, 1999, which is the list of substances the government can manage under that law.
• Gives the ministers (the Department of the Environment and the Department of Health) the authority to propose risk-management actions for TMTD (for example, limits or controls on uses or releases).
• The proposed Order itself would not immediately create new rules or costs for businesses. Any actual regulations or measures would be developed later and come with separate consultations.
• The public was invited to comment for 60 days after publication (about December 7, 2022).
• If a final Order is made, it would come into force on the day it is registered.

Who's affected#

• Manufacturers that use TMTD, especially companies that do solid rubber compounding (rubber products and parts makers).
• Automotive and other manufacturers that use rubber compounds, adhesives, sealants, or latex products that may contain TMTD.
• Producers and registrants of pesticides where TMTD (also known as thiram) is an active ingredient — the Pest Management Regulatory Agency (PMRA) already regulates some pesticide uses.
• Cosmetic producers that use latex products (the chemical is already restricted in cosmetics to a maximum of 14% in some products).
• Communities and ecosystems near wastewater discharges from facilities that handle raw TMTD powders, because aquatic life is the main ecological concern.
• If you are unsure whether your industry uses TMTD, the departments asked for information from industry in earlier surveys; the exact list of affected products and firms will depend on follow-up actions.

Why it matters#

• The screening assessment found TMTD is highly toxic to aquatic organisms even at low exposures. That raises concern where the chemical can enter waterways from factory wastewater.
• Adding TMTD to Schedule 1 is the step that allows the government to design and enforce targeted measures (for example, limits on releases, codes of practice, or new conditions on products). That can lead to changes in how some factories operate, especially handling, cleaning, and wastewater controls.
• The change does not itself create immediate costs or bans. It starts a process that could result in rules after further consultation.
• There are also health concerns noted for thiram/TMTD (developmental neurotoxicity and possible carcinogenicity), but current non-pesticidal uses were judged to pose low exposure to the general public. If exposure rises, the government said it could reassess human health risks.