Canadian Environmental Protection Act: Low Risk of Harm from ETU, a substance used in rubber, plastics, fabric textile and leather

Ethylene thiourea (ETU) is a chemical used as a vulcanization accelerator and plasticizer in rubber and plastic materials, and as a process regulator in fabric, textile and leather articles. It is also found as an impurity in some pest control products and a degradation product of certain fungicides.

Pursuant to section 74 of the Canadian Environmental Protection Act, 1999 (CEPA), the Minister of the Environment and the Minister of Health have conducted a screening assessment of 2-imidazolidinethione, hereinafter referred to as ethylene thiourea (ETU). This assessment was published on Canada Gazette on January 14, 2023.

The ecological risk associated with ETU was characterized using the ecological risk classification of organic substances (ERC) approach. The ERC is a risk-based approach that employs multiple metrics for both hazard and exposure with weighted consideration of multiple lines of evidence for determining risk classification.

Based on the outcome of the ERC analysis, ETU is considered unlikely to be causing ecological harm. Considering all available lines of evidence presented in this screening assessment, there is a low risk of harm to the environment from ETU. It is concluded that ETU does not meet the criteria under paragraph 64(a) or (b) of CEPA as it is not entering the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity or that constitute or may constitute a danger to the environment on which life depends.