Polychlorinated terphenyls (PCTs) are yellow resins with characteristics similar to those of Polychlorinated Biphenyls (PCBs), such as extremely high resistance to thermal breakdown, heat stability and non-flammability, making them useful for industrial purposes. PCTs have been used as PCB substitutes and both in closed systems, such as electric transformers, and open-ended applications, such as lubricating and cutting oils.
PCT production occurred over the same period as PCB production, although production quantities of PCBs were 15-20 times those of PCTs. Between 1955-1980, total global production of PCTs is estimated to have reached 60 000 metric tonnes. PCTs have never been produced in Canada but were imported and used commercially. Total import quantities remain unknown. Documented historical uses of PCTs in Canada were as pressure-sensitive adhesive for weatherstrip backing, as plasticizers for urethanes, and in paints. By 1976, commercial use of more than 1 kg of either PCTs or PCBs was required to be reported under the former Environmental Contaminants Act. Three companies replied to the reporting notice, indicating that all uses of PCTs were terminated in the mid-1970s.
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CAS (Chemical Abstracts Service) registry number: 61788-33-8
Note: There is more than one CAS number that applies to this group of substances.
- CEPA 1999 Schedule 1 - List of Toxic Substances - This substance has been added to the List of Toxic Substances.
- Full life-cycle management of the substance (Track 2) under the Toxic Substances Management Policy
This substance is entering the environment from the following source(s):
Risk Management Tool(s)
Tool(s) developed to manage risks associated with the substance:
Risk Management Supporting Activities
Activities supporting the development or implementation of the risk management tool(s):
Forms related to the Prohibition of Certain Toxic Substances Regulations, 2012:
- Schedule 3: Information Related to the Use of Certain Toxic Substances in a Laboratory for Analysis, in Scientific Research or as a Laboratory Analytical Standard
- Schedule 4: Information Required in an Application for a Permit or an Application for Renewal of a Permit
Consultation (past and present) on the substance:
- Draft of the Proposed Regulations Respecting the Total, Partial and Conditional Prohibition of Certain Toxic Substances, 31-10-2003 (archived consultation document)
- Revised Draft: Prohibition of Certain Toxic Substances Regulations, 2005 (Repealed)
- Prohibition of Certain Toxic Substances Regulations, 2003 (Repealed)
- Prohibition of Certain Toxic Substances Regulations (repealed)
Chemicals Management Division
351 St. Joseph Blvd.
- Date Modified: