1,1,1-Trichloroethane
1,1,1-Trichloroethane has not been assessed under the PSL1 assessment program.
The following information is an extract from the Notice published on January 22, 1994, in the Canada Gazette, Part I.
The priority substance 1,1,1-trichloroethane (herein referred to as methyl chloroform) was added to the Priority Substances List because of concerns about its use in high volumes as a solvent and the human health and environmental effects that may result from exposure to this substance. Also of concern was the contribution that methyl chloroform makes to the depletion of the ozone layer.
The increasing global concerns over the appearance of ozone "holes" over the north and south poles as well as the general thinning of the global ozone layer resulted in the signing of an international agreement in 1987 to reduce chlorofluorocarbons (CFCs) and other halocarbon emissions to the atmosphere. This agreement, known as the Montreal Protocol on Substances that Deplete the Ozone Layer, is a control treaty to the Vienna Convention for the Protection of the Ozone Layer which established a framework to protect the Earth's upper atmosphere. To date, 107 countries have signed the Protocol and have agreed to specified limits on the consumption and the eventual phase-out of ozone-depleting substances from commerce.
In 1990, international recognition of the contribution that methyl chloroform makes to the depletion of the ozone layer led to an agreement to amend the Montreal Protocol to include methyl chloroform on its list of ozone-depleting substances, and to propose a very specific reduction schedule leading to complete phase-out of this substance by 2005. This amendment was ratified by a sufficient number of signatory countries, including Canada, by March 10, 1992, and subsequently entered into force on August 10, 1992.
In support of these actions under the Montreal Protocol, the Governor in Council, on the recommendation of the Ministers of the Environment and of National Health and Welfare, has, through an Order in Council, added methyl chloroform to the List of Toxic Substances in Schedule 1 of the Canadian Environmental Protection Act (Canada Gazette, Part II, May 9, 1993, pg. 2242). Through a second Order in Council (Canada Gazette, Part II, May 19, 1993, pg. 2243-2296), the Governor in Council, on the recommendation of the Ministers of the Environment and of National Health and Welfare has also made a regulation applying to Canadian consumption of methyl chloroform that implements an immediate freeze at 1989 levels beginning in 1993, and schedules an 85% reduction by the end of 1994 and a total phase-out by the year 2000.
At their fourth meeting held in Copenhagen, Denmark from November 23 through 25, 1992, the Parties to the Montreal Protocol agreed to accelerate the phase-out of methyl chloroform. Parties, including Canada, will now phase out consumption of methyl chloroform by January 1, 1996, subject to possible exemptions for essential uses. The Canadian regulations will be amended to reflect this new agreement. In so doing, the Minister of the Environment will be ensuring that consumption of methyl chloroform for virtually all non-feedstock uses in Canada will cease by the end of 1995. As a result, releases to the environment from non-feedstock uses will also be eliminated.
In view of the actions described above, the Ministers of the Environment and of Health do not believe that further effort to assess methyl chloroform as a priority substance is warranted. Such an effort would not add in a meaningful way to the international consensus that has emerged on the contribution that this substance makes to depletion of the ozone layer, nor will it alter the actions that Canada has proposed to control methyl chloroform.
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