Significant new activity notification: phenol, methylstyrenated

Significant New Activity Notification: Phenol, Methylstyrenated, Chemical Abstracts Service Registry Number 68512-30-1

Health Canada & Environment and Climate Change Canada

September 2016


Phenol, methylstyrenated, Chemical Abstracts Service Registry Number (CAS RN) 68512-30-1, was identified during the categorization of the Domestic Substances List (DSL) as a high priority for assessment. It underwent a screening assessment in April 2008 (Canada 2008a) and it was concluded that phenol, methylstyrenated did not meet the criteria of section 64 of the Canadian Environmental Protection Act, 1999 (CEPA), because it was not entering the environment at levels that could have posed a risk to human health or to the environment (Canada 1999). The conclusion was based on the fact that no industrial activities (import or manufacture) in relation to the substance were identified in Canada above the reporting threshold of 100 kg for the specified reporting year and, therefore, there was no exposure to humans or to the environment (Canada 2008). However, given the persistent, bioaccumulative, and inherently toxic (PBiT) properties of this substance, there was concern that new activities, which had not been identified or assessed, could lead to the substance meeting the criteria of section 64 of CEPA. Therefore, this substance has been subject to the Significant New Activity provisions specified under subsection 81(3) of CEPA as one of 145 substances of similar profile and which are not in commerce (Canada 2008b).  The SNAc provisions for this substance require notification, for the purpose of assessment, of all manufacture, import, or use in Canada in quantities at or above 100 kg.

Substance Identity

The notified substance is an organic Unknown or Variable Composition, Complex Reaction Products and Biological Material (UVCB), consisting of a number of phenolic components (mono, di, and trimethylstyrenated phenol) and non-phenolic components (dimers and trimers of methylstyrene). Key physical-chemical properties (i.e., water solubility and log Kow) vary among these components.

Significant New Activity Notification

In August 2015, the Government of Canada received a Significant New Activity Notification (SNAN) from a stakeholder for a new activity involving phenol, methylstyrenated. The notifier proposed to import this substance as an ingredient in an epoxy-based primer coating that is applied in a dry spray booth, with all waste captured and incinerated.

Environmental Fate and Behaviour

If released to the environment, partitioning of components of the notified substance in environmental media vary, due to their different physical-chemical properties. A review of available information on the substance confirmed the results that were generated during the categorization of the DSL, namely that the substance is inherently toxic and that it meets the criteria for persistence and for bioaccumulation, as defined by the Persistence and Bioaccumulation Regulations (Canada 2000).

Ecological Assessment

Considering the water soluble components in the notified substance (i.e., mono and dimethylstyrenated phenol and dimers of methylstyrene), the available empirical data suggest that these components elicit moderate-to-high toxicity to aquatic organisms from short term exposure. Data from a structural analogue indicates moderate-to-high chronic toxicity to aquatic organisms. In addition, a major component of the UVCB, monomethylstyrenated phenol, has shown positive results in certain estrogenicity assays (ECHA 2015).

Critical toxicity values (CTVs)for structural components demonstrating effects below their water solubilities
Structural constituent CTV Assessment Factor Predicted No Effect Concentration
Monomethyl styrenated phenol 96h LC50 = 0.9 mg/L 100Footnoteb 9 ug/L
Dimethyl styrenated phenol 21d NOEC = 0.115 mg/LFootnotea
10Footnotec 11.5 ug/L
Dimers of methylstyrene 48h EC50 = 0.057 mg/L 100 0.57 ug/L

Based on the information provided in the SNAN, there is no anticipated release of the substance to the environment that would occur as a result of this notified use. Consequently, it has been concluded that the substance, when used as notified, is not likely to present a risk to the environment in Canada.

However, considering the substance‚Äôs hazard profile and persistent and bioaccumulative properties, there is concern that releases of the substance to the environment resulting from potential future activities (including the manufacture of the substance) and from differences in waste management practices compared to those notified, could result in releases to the environment that would pose a risk to the environment.  

Human Health Assessment

Based on the information provided in the SNAN, there is no anticipated exposure to the general population that would occur as a result of this notified use. Consequently, it has been concluded that the substance, when used as notified, is not likely to present a risk to the health of the general population.

Assessment Conclusion

Considering the notified use and stewardship of wastes reported in this SNAN, no releases of the notified substance to the environment would be expected. The use of the substance for the notified activity is not likely to present a risk to human health or to the environment. The prior determination that the substance does not meet the criteria set out under section 64 of CEPA is therefore maintained.

However, concern remains for any potential future activities involving phenol, methystyrenated, given its hazard profile and its persistent and bioaccumulative properties.

Risk Management

Based on the information provided in the notification and the risk assessment analysis, the substance, when used as specifically notified, does not present a risk to human health or to the environment. Therefore, no risk management relating to the notified use is recommended for phenol, methylstyrenated at this time.

As no specific concerns have been identified for this activity, and since the SNAN provided the government with new chemical and toxicological data on the notified substance, the government is considering amending the existing SNAc definition and data requirements for any future SNANs in relation to the phenol, methylstyrenated. However, the current SNAc Order remains in force until an amended Order is registered and published in the Canada Gazette, Part II.


Canada. 1999. Canadian Environmental Protection Act, 1999. S.C. 1999, c.33 Canada Gazette, Part III, vol. 22, no. 3.

Canada. 2000. Canadian Environmental Protection Act, 1999: Persistence and Bioaccumulation Regulations. P.C. 2000-348, 29 March, 2000, SOR/2000-107.

Canada. 2008. Final screening assessment report for 145 PBiT substances. Environment Canada and Health Canada.

Canada. 2008b. Order 2007-66-11-01 Amending the Domestic Substances List, Canadian Environmental Protectection Act, 1999. SOR/2008-184. Canada Gazette, Part II, vol. 142, no. 13, June 25, 2008 (portable document format, 5.85 megabytes).

[ECHA] European Chemicals Agency. 2015. Online database for chemicals registered in EU.

[UK EA] United Kingdom Environment Agency. 2009. Environmental risk evaluation report: Styrenated phenol.

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