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Summary of public comments received on the draft screening assessment for Epoxides and Glycidyl Ethers Group

Comments on the draft Screening Assessment for the Epoxides and Glycidyl Ethers Group, assessed under the Chemicals Management Plan (CMP), were submitted by the Canadian Consumer Specialty Products Association and KAND EHS Services Inc.

Summarized public comments and responses are provided below, organized by topic:

Overarching

Summarized commentSummarized response
The draft screening assessment is a fair and reasonable representation of the potential conditions that exist in Canada for these substances. There is support for the findings and recommendations.  Noted.
The opportunity to provide input into the dSAR is appreciated. Additional information is offered to assist the assessment process. Noted.
It is encouraging to see that additional information submitted by stakeholders was valuable and utilized in the assessment. Noted.
In Section 6.5.2, there is a typographical error. This error has been corrected. 

Sources, uses, & exposure

Summarized commentSummarized response
It is appreciated that the assessment recognizes that these substances are mainly used in industrial settings, are consumed/ used up in reactions, and in the cured form, are not readily available for exposure to the general population.   Noted.
The stakeholder questions why the volumes reported are specific values as opposed to ranges, as seen in previous assessment reports. This would also address any confidentiality concerns. As no confidentiality requests were received, the reported value is presented in the SAR. 

Ecological assessment

Summarized commentSummarized response
The use of the Ecological Risk Classification of Organic Substances to support an ecological conclusion is appropriate. The addition of a summary would be encouraged for greater transparency of the information as it pertains to the substances of the assessment.Detailed information on the application of the ecological risk classification (ERC) approach for organic substances, and information used to support ERC results are available in ECCC (2016a,b). 
A robust rationale to support the conclusion of not CEPA toxic based on moderate hazard and high exposure for TGIC should be presented; similar concern could be raised for o-CGE. The ecological risk classification of organic substances (ERC) approach uses empirical and modelled data and multiple lines of evidence to determine substances’ hazard and exposure profiles, and risk classification. Substances of low ecological concern and some substances of moderate ecological concern are not expected to pose an ecological risk based on current information. The departments consider the level of ecological information provided for the ERC assessments sufficient to support assessment conclusions. The published science approach document on ERC provides additional detailed information on the approach. 

Human health assessment

Summarized commentSummarized response
The use of styrene oxide for read-across is questioned as the structure and physical-chemical properties vary greatly. Three analogues (cresyl glycidyl ether (CGE), phenyl glycidyl ether (PGE), and styrene oxide (SO)) were identified for read-across on the basis of similarities in structure, metabolic pathways, physical-chemical properties, and reactivity. According to the OECD QSAR Toolbox modelling software, SO is predicted to undergo similar metabolic pathways as o-CGE. Furthermore, the health effect of concern for SO is similar to the other analogues (e.g., carcinogenicity). Appendix A of the assessment discusses the relative similarity of the analogues to o-CGE. 
In Section 6.3.1, the ConsExpo model does not account for physical transformation; therefore, this estimate is a very conservative value. It is suggested the assessment recognize this and reduce the margins of exposure. Due to the absence of data on transformation of this substance during use, it was assumed no transformation takes place and all of the substance is available for exposure. Using this conservative assumption, the resultant margins of exposure were considered adequate to account for uncertainties in the health effects and exposure databases. Therefore, refinements were not considered necessary. 
In the do-it-yourself (DIY) arts and crafts/hobby resins scenario for o-CGE, the assumption of use once per week is questioned. A frequency of once per month would be more representative of general use.  In the absence of Canadian data, use frequency values based on a European population were used in the assessment. These values are found in the ConsExpo Fact Sheet for “DIY/hobby products”.
The exclusion of studies with insufficient data is supported. Noted.
Is there a citation to support the statement “available information indicates that any site-of-contact non-cancer effects would be expected to be reversible” in Section 6.3.3?The original statement has been revised to reference data supporting this statement.
It is suggested to improve accuracy by using a weighted average of the constituents of C12-C13 AGE, given the distribution and significant constituent concentrations is known or exist.   As substance-specific information for C12-C13 AGE was available for risk characterization purposes, no adjustment in values was required.   
In Appendix C, all scenarios had a dermal uptake of 100%.  This is unrealistic and very conservative. A default of 50% could be considered.In the absence of substance specific data, a default dermal absorption value of 100% was applied. In route to route extrapolations of oral toxicity studies to the dermal route of exposure, the assumption is that dermal absorption is equivalent to oral absorption; accordingly, that is reflected in the risk characterization tables, as appropriate.
Using this conservative assumption, the margins of exposure were adequate to account for uncertainties in the health effects and exposure databases; therefore, refinements were not considered necessary.
Were estimates for potential exposure to the lifetime average daily dose for the arts and crafts/hobby scenario calculated for teens?The assumption that adults will be exposed to the product for 50 years is considered to be protective of exposures that may occur in individuals under 20.
Information in the Appendix of the SAR has been updated to note this. 

Risk management

Summarized commentSummarized response
The need for enhanced tracking of AGE and o-CGE is questioned.  It is suggested that occasional monitoring through an action such as a non-routine Domestic Substances List Update or a (future) one time omnibus Canadian Environmental Protection Act s.71(1)(b) notice would be appropriate.Noted. 

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2020-08-07