Summary of public comments received on the draft screening assessment for TMSS

Comments on the draft Screening Assessment for TMSS (Silanamine, 1,1,1-trimethyl-N-(trimethylsilyl)-, hydrolysis products with silica), assessed under the Chemicals Management Plan (CMP), were submitted by Canadian Consumer Specialty Products Association, IBM Canada and Dr. D. Mukerjee.

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


Summarized comment Summarized response
The submitter is in agreement with the conclusion of this risk assessment; however, further studies could be beneficial. Specifically, children below 5 years of age, and people who are asthmatic or prone to a dust allergy may be particularly vulnerable to inhalation health effects from the use of cosmetics containing TMSS. Additional labelling for cosmetics containing TMSS is suggested to protect vulnerable subpopulations.     The screening assessment concludes that current levels of exposure to TMSS do not pose a risk to the general population. Screening assessments are based on consideration of the available data and include various conservative exposure scenarios that account for both the general population and for vulnerable populations in Canada. If information is available that suggests a specific sub-population would be particularly vulnerable, it is considered in the assessment. Additionally, the Government is currently considering how to evolve and better communicate its approach on the identification and assessment of exposures to vulnerable populations in Canada.
Stakeholders support the conclusion of the assessment. Noted.

Environmental fate and ecological assessment

Summarized comment Summarized response
Physical and chemical properties of synthetic amorphous silica (a TMSS precursor) were provided to show low bioaccumulation potential. The stakeholder notes that there is potential exposure to animals and plants from TMSS in pesticides and feed products. They also request further data and studies on soil accumulation and release from surface coatings.     Information submitted regarding bioaccumulation is consistent with the TMSS data used in the Ecological Risk Classification of organic substances (ERC) approach. The particle size information is important to inhalation studies, determining how deep the particles can get into the respiratory system, but not for the oral studies. So, the particle size was not mentioned for all non-inhalation studies in the current SAR. Data considered in the approach can be found in the supporting document available from Based on the information considered under the ERC approach, TMSS was classified as having a high ecological exposure potential. This characterization took some aspects of environmental fate into consideration (e.g., chemical half-lives in various media and biota, partition coefficients, and fish bioconcentration data). TMSS was classified as having a low hazard potential and as having a low potential for ecological risk. Despite its high exposure potential, TMSS is unlikely to be resulting in concerns for the environment in Canada considering its low hazard potential.
Further ecological research studies were provided for consideration.   The additional ecotoxicolgical studies that were provided are consistent with the low hazard classification of TMSS according to the ERC approach. No changes were made to the ecological assessment in response to this comment.

New information and data

Summarized comment Summarized response
Additional toxicity information, use patterns, and quantity information were provided for consideration.   The additional information submitted was compared to existing information in the assessment, and no changes were made.  

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