New substances: risk assessment summary, new substances notification 18618

Official Title: New Substances Notification No. 18618: 4-Ethenylphenol acetate

Regulatory decisions

Under the provisions for Substances and Activities New to Canada in Part 5 of the Canadian Environmental Protection Act, 1999 (CEPA), and pursuant to section 83 of the Act, the Minister of the Environment and the Minister of Health have assessed information in respect of the substance, and have determined that it is not anticipated to enter 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, constitute or may constitute a danger to the environment on which life depends, or constitute or may constitute a danger in Canada to human life or health.

Substance identity

The chemical, 4-ethenylphenol acetate (Chemical Abstracts Service Registry No. 2628-26-2), can be classified as an acetate ester.

Notified and potential activities

The substance is proposed to be manufactured in and/or imported into Canada in quantities greater than 1 000 kg/yr for use in polymer manufacture. No other activities are anticipated in Canada.

Environmental fate and behaviour

Based on its physical and chemical properties, if released to the environment, the substance will tend to partition to water and air. The substance is not expected to be persistent in water based on its moderate biodegradation rate (30-60%) and very high degradation rates of analogue substances (>85%). The substance is not expected to be persistent in air because it will be rapidly oxidized by hydroxyl radicals. The substance is not expected to bioaccumulate based on its low octanol-water partition coefficient (log Kow 0-3) and low bioaccumulation and bioconcentration factors (<250 L/kg).

Ecological assessment

Based on the available hazard information on the substance and surrogate data on structurally related chemicals, the substance is expected to have moderate acute toxicity in fish, aquatic invertebrates and algae (median lethal concentration (LC50) and median effective concentration (EC50) 1-100 mg/L) and moderate chronic in aquatic invertebrates and algae toxicity (no-observed-effect concentration 0.1-10 mg/L). Using the EC50 from the most sensitive organism (aquatic invertebrate) and by applying an appropriate assessment factor, the predicted no-effect concentration (PNEC) was calculated to be 100-1000 µg/L, which was used to estimate the ecological risk.

The notified and other potential activities in Canada were assessed to estimate the environmental exposure potential of the substance throughout its life cycle. Environmental exposure from the notified activity is expected to be mainly from cleaning transportation drums by release of the substance to water. The predicted environmental concentration (PEC) for notified activities is estimated to be 10-100 µg/L. The PEC for potential manufacturing activities is estimated to be 1-10 µg/L.

Comparing the PEC with the PNEC, the ratio is less than 1. This along with other lines of evidence including environmental fate, hazard, and exposure, indicates that the substance is unlikely to cause ecological harm in Canada.

Human health assessment

Based on the available hazard information, the substance has a moderate potential for acute toxicity by the oral route of exposure (median lethal dose 300-2000 mg/kg body weight), a low potential for acute toxicity by the inhalation route of exposure (LC50 >5 mg/L/4hr), and a low to high potential for acute toxicity by the dermal route of exposure. The substance has a low potential for subchronic toxicity following repeat oral doses in mammalian test animals (28-day no-observed-adverse-effect level (NOAEL) >300 mg/kg-bw/d), and a high potential for subchronic toxicity following repeat dermal doses in mammalian test animals (28-day NOAEL <100 mg/kg-bw/d). It is a strong to extreme skin sensitizer (65-100% response (guinea pig maximization test)). It is not mutagenic in vitro but is considered clastogenic in vitro. Therefore, the substance has the potential to cause genetic damage.

When the notified substance is used in polymer manufacturing, direct exposure of the general population is not expected given that the substance is intended for solely industrial applications. Indirect exposure of the general population from environmental media such as drinking water is not expected given the specialized industrial and commercial use of the substance, which results in little or no release to the environment. No potential uses were identified.

Based on the low potential for direct or indirect exposure, the substance is not likely to pose a significant health risk to the general population, and is therefore unlikely to be harmful to human health.

Assessment conclusion

When the substance is used as notified, it is not suspected to be harmful to human health or the environment according to the criteria under section 64 of CEPA.

A conclusion under CEPA, on this substance, is not relevant to nor does it preclude an assessment against the hazard criteria for Workplace Hazardous Materials Information System that are specified in the Controlled Products Regulations or the Hazardous Products Regulations for products intended for workplace use.

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