Summary of Public Comments for 2-Butoxyethanol PDF or HTML
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The public comment period for 2-Methoxyethanol, 2-Ethoxyethanol, 2-Butoxyethanol began on August 19, 2000 and ended on October 18, 2000. A brief summary of comments received during this period will soon be available from this site.

Prior to the public comment period, each draft Assessment Report has been extensively reviewed internally by senior technical staff, reviewed externally by expert technical peer reviewers and approved by a joint Environment Canada/ Health Canada Management Committee. For a full description of the review process, please consult the introduction of the full draft Assessment Report. Also, please note the cut-off date for consideration of relevant literature taken into account for the report.

For paper copies of the Full Assessment Report, please contact the Inquiry Centre at Environment Canada:

To obtain an electronic version of the Assessment Report in PDF, please request a copy from the following address: ESB.DSE@ec.gc.ca

Synopsis

2-Methoxyethanol

2-Methoxyethanol is not commercially produced in Canada. It is imported for use mainly as a chemical processing aid and as a component of formulated products. The use of 2-methoxyethanol has declined over the past few years because it has been partially replaced in some countries by other substances. All reported environmental releases are to the atmosphere.

2-Methoxyethanol reacts with hydroxyl radicals in the air with a half-life of about 18 hours. Much of the 2-methoxyethanol released to the atmosphere is predicted to remain in air, but a substantial proportion would partition to water and to soil. 2-Methoxyethanol is biodegraded in surface water and aerobic soil with an estimated half-life of 1-4 weeks. It is somewhat more persistent under aerobic conditions. 2-Methoxyethanol has a very low octanol/water partition coefficient and is therefore not expected to bioaccumulate to any significant degree. There are very few available data on concentrations of 2-methoxyethanol in the environment in Canada or elsewhere.

Data on toxicity exist for aquatic organisms, including microorganisms, invertebrates and fish. 2-Methoxyethanol is not very toxic to these organisms; in a number of studies, the LC₅₀ was above the highest concentration tested.

Because of the paucity of environmental monitoring data, exposure values for the environmental assessment were estimated based on modelling. Estimated environmental concentrations of 2-methoxyethanol are several orders of magnitude lower than the adverse effects thresholds calculated for sensitive organisms.

2-Methoxyethanol is not involved in stratospheric ozone depletion and is not an important contributor to climate change or ground-level ozone formation.

Based on a relatively extensive database in experimental animals, 2-methoxyethanol has consistently been associated with a wide range of adverse effects on health, including those considered to be severe and irreversible (e.g., teratogenicity), with some occurring at relatively low levels of exposure. However, although relevant data are limited, exposure of the general population through environmental media is expected to be small, due to reported declining use of the compound in recent years as it is replaced with less hazardous compounds. Margins between worst-case estimates of exposure from environmental media and lowest effect levels for developmental toxicity obtained in toxicological investigations in experimental animals are large. However, available data are insufficient to conclude that margins between worst-case estimates of exposure in consumer products and lowest effect levels are adequate.

Based on these considerations, it is concluded that 2-methoxyethanol is not entering the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity or that constitute or may constitute a danger to the environment on which life depends. On the basis principally of its high health hazard potential, 2-methoxyethanol may be entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health. Therefore, 2-methoxyethanol is considered to be "toxic" under Section 64 of the Canadian Environmental Protection Act, 1999 (CEPA 1999).

It is recommended that additional information be acquired on patterns of use of 2-methoxyethanol in Canada, particularly in relation to its presence in consumer products. It is further recommended that, in view of the profile of toxicity of 2-methoxyethanol, potential for exposure of the general population to this compound be eliminated or reduced to the extent possible.

2-Ethoxyethanol

2-Ethoxyethanol is not commercially produced in Canada. It is imported for use mainly as a component of formulated products. All environmental releases are reported to be to the atmosphere. Some 2-ethoxyethanol is also sent to landfills and other waste disposal sites.

2-Ethoxyethanol reacts with hydroxyl radicals in the air with a half-life of about 0.2-4 days. Much of the 2-ethoxyethanol released to the atmosphere is predicted to remain in air, but a substantial proportion would partition to water and to soil. 2-Ethoxyethanol is biodegraded in surface water and aerobic soil with an estimated half-life of 1-4 weeks. It is somewhat more persistent under anaerobic conditions. 2-Ethoxyethanol has a very low octanol/water partition coefficient and is therefore not expected to bioaccumulate to any significant degree. There are very few available data on concentrations of 2-ethoxyethanol in the environment in Canada or elsewhere.

Data on toxicity exist for aquatic organisms, including microorganims, invertebrates and fish. 2-Ethoxyethanol is not very toxic to these organisms; in a number of studies, the LC₅₀ was above the highest concentration tested.

Exposure values for air were based on limited Canadian monitoring data. Because of the paucity of environmental monitoring data, exposure values for soil and water were estimated based on fugacity modelling. Estimated environmental concentrations of 2-ethoxyethanol are several orders of magnitude lower than the adverse effects thresholds calculated for sensitive organisms.

2-Ethoxyethanol is not involved in stratospheric ozone depletion and is not an important contributor to climate change or ground-level ozone formation.

2-Ethoxyethanol has consistently induced hematological, reproductive (effects on testes and sperm parameters) and developmental effects in multiple species of experimental animals exposed by various routes. In addition, there is some limited evidence of effects on the blood and reduced sperm production in occupationally exposed human populations. Although monitoring data are very limited, the margins between upper-bounding estimates of exposure to 2-ethoxyethanol in the general environment and conservative effect levels for critical effects are large. Limited available data do not indicate that 2-ethoxyethanol is commonly present in consumer products in Canada. However, upper-bounding estimates of exposure to 2-ethoxyethanol through use of some consumer products containing the substance may approach or exceed these conservative effect levels, although the degree of confidence in the estimates of exposure from consumer products is considered to be extremely low.

Based on these considerations, it is concluded that 2-ethoxyethanol is not entering the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity or that constitute or may constitute a danger to the environment on which life depends. Based on comparison of upper-bounding estimates of exposure in the general environment with conservative effect levels, it is concluded that 2-ethoxyethanol is not entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health. Therefore, 2-ethoxyethanol is not considered to be "toxic" as defined in Section 64 of the Canadian Environmental Protection Act, 1999 (CEPA 1999).

Although 2-ethoxyethanol was not detected in emissions from a range of consumer products in Canada, acquisition of additional more representative information on its use in consumer products in Canada is desirable.

2-Butoxyethanol

2-Butoxyethanol is not commercially produced in Canada. It is imported for use mainly as a component of formulations, as part of consumer products or manufactured articles, and as a chemical processing aid. Most reported environmental releases are to the atmosphere, with some minor releases to water.

2-Butoxyethanol reacts with hydroxyl radicals in the air with a half-life of a few hours to about a day. Most of the 2-butoxyethanol released to the atmosphere is predicted to remain in air, with some partitioning to water and soil. 2-Butoxyethanol is biodegraded in water and soil, with an estimated half-life of 1-4 weeks. It has a low octanol/water partition coefficient and is therefore not expected to bioaccumulate to any significant degree. Only limited data are available on concentrations of 2-butoxyethanol in the environment in Canada or elsewhere.

Data on toxicity were identified for aquatic organisms, including microorganisms, invertebrates and fish. The most sensitive species reported, based on acute exposure, is the grass shrimp (Palaemonetes pugio).

Because of the limitations of environmental monitoring data, exposures for environmental compartments other than air were estimated based on modelling. Estimated environmental concentrations of 2-butoxyethanol are a few orders of magnitude less than the adverse effects thresholds calculated for sensitive organisms.

2-Butoxyethanol is not involved in stratospheric ozone depletion and is not an important contributor to climate change or ground-level ozone formation.

Based on the limited data identified, inhalation of 2-butoxyethanol in air is an important route of exposure, with estimated exposure through use of consumer products containing the substance being considerable. No data were identified concerning the contribution of food to overall exposure to 2-butoxyethanol.

Based primarily on investigations in experimental animals, the principal critical health effects associated with exposure to 2-butoxyethanol are alterations in hematological parameters associated with hemolysis. Tolerable Concentrations for these effects and for lesions of the forestomach in mice, for which information on mode of action is inadequate to preclude their relevance to humans, were developed, based on Benchmark Concentrations. A Tolerable Concentration is the level of intake to which it is believed a person may be exposed daily over a lifetime without deleterious effect.

Levels of 2-butoxyethanol in ambient air in Canada are less than the Tolerable Concentrations derived for effects on the blood or forestomach. However, exposure to 2-butoxyethanol during use of products containing the substance could potentially exceed the Tolerable Concentrations, based on limited data on emissions from products currently available in Canada.

Based on available data, it is concluded that 2-butoxyethanol is not entering the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity; or constitute or may constitute a danger to the environment on which life depends. 2-Butoxyethanol is considered to be entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health. Therefore, 2-butoxyethanol is considered to be "toxic" as defined in Section 64 of CEPA 1999.

Additional characterization of the ranges and distributions of concentrations of 2-butoxyethanol in consumer products currently available in Canada and their emissions is considered a clear priority as a basis for risk management.

Disclaimer: Although care has been taken to ensure that the information found on this website accurately reflects the requirements prescribed in the Canadian Environmental Protection Act (1999), you are advised that, should any inconsistencies be found, the legal documents, printed in the Canada Gazette, will prevail.