Summary of Public Comments received on the Challenge substance
Nitromethane (CAS 75-52-5)
Draft Screening Assessment Report and Risk Management Scopes for
Batch 8
Comments on the draft screening assessment report for Nitromethane to be addressed as part of the Chemicals Management Plan Challenge were submitted by Inuit Tapiriit Kanatami (ITK).
A summary of comments and responses is included below, organized by topic:
- Data gaps and deficiencies
- Exposure
| Topic | Comment | Response |
|---|---|---|
| Data gaps and deficiencies | There are data gaps in vulnerable population exposure, including workers, exposure via consumer products, concentrations in Canadian environmental media, and long term inhalation exposure, and these gaps need to be addressed by conducting studies. | All available sources of information are taken into consideration in evaluating exposure of the population in Canada , including through use of consumer products. The various conservative exposure scenarios used are considered to be protective of vulnerable populations in Canada. However, if information is available which suggests that a specific sub-population would be particularly vulnerable, this information would be considered in the assessment. Hazard information obtained from occupational settings, in particular data from epidemiological investigations, are considered in the screening assessment. The information developed through the Chemicals Management Plan process may be used to inform decisions concerning additional actions to minimize exposure to workers. The Government of Canada is working to communicate results to appropriate occupational health and safety groups. |
| There are data gaps in the toxicokinetics and metabolism effects of the substance in addition to low-dose carcinogenic and non-carcinogenic effects particularly for vulnerable populations. | At this time adequate margins of exposure for both threshold carcinogenic and non-carcinogenic effects have been achieved. Consequently nitromethane at these exposure levels is not considered to be harmful to human health. | |
| Exposure | Comment received indicating that persistence in air, long-range transport potential and deposition pattern need to be considered. | Further assessment indicates that nitromethane undergoes rapid photolysis and therefore is not expected to be persistent in air. Consequently, long-range transport and deposition are not likely to be a concern for nitromethane. |
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