Existing Substances Evaluation: Risk Management Approach 541-02-6

Proposed Risk Management Approach
for
Cyclotetrasiloxane, octamethyl-
(D4)
Chemical Abstracts Service Registry Number (CAS RN):
556-67-2
Cyclopentasiloxane, decamethyl-
(D5)
Chemical Abstracts Service Registry Number (CAS RN):
541-02-6

This proposed risk management approach document builds on the previously released risk management scope document for Cyclotetrasiloxane, octamethyl- and Cyclopentasiloxane, decamethyl-, and outlines the proposed control actions for these substances. Stakeholders are invited to submit comments on the content of this proposed risk management approach or provide other information that would help to inform decision making. Following this consultation period, the Government of Canada will initiate the development of the specific risk management instrument(s) where necessary. Comments received on the proposed risk management approach will be taken into consideration in developing the instrument(s). Consultation will also take place as instrument(s) are developed.

1. ISSUE

1.1 Categorization and the Challenge to Industry and Other Interested Stakeholders

The Canadian Environmental Protection Act, 1999 (CEPA 1999) (Canada 1999) requires the Minister of the Environment and the Minister of Health (the Ministers) to categorize substances on the Domestic Substances List (DSL). Categorization involves identifying those substances on the DSL that a) are considered to be persistent (P) and/or bioaccumulative (B), based on the criteria set out in the Persistence and Bioaccumulation Regulations, and “inherently toxic” (iT) to humans or other organisms; or b) present, to individuals in Canada, the greatest potential for exposure (GPE). In addition, the Act requires the Ministers to conduct screening assessments of substances that meet the categorization criteria. The assessment further determines whether the substance meets the definition of “toxic” set out in section 64 of CEPA 1999.

In December 2006, the Challenge identified 193 chemical substances through categorization which became high priorities for assessment due to their hazardous properties and their potential to pose risks to human health and the environment. In February 2007, the Ministers began publishing, for industry and stakeholder comment, profiles of batches containing 15 to 30 high-priority substances.

In addition, the information-gathering provisions under section 71 of CEPA 1999 are being used under the Challenge to gather specific information where it is required. The information that is collected through the Challenge will be used to make informed decisions and appropriately manage any risks that may be associated with these substances.

The substances Cyclotetrasiloxane, octamethyl-, Chemical Abstracts Service Registry Number (CAS RN)¹ 556-67-2 and Cyclopentasiloxane, decamethyl-, CAS RN 541-02-6, referred to throughout this document as "D4" and "D5", respectively, were included in Batch 2 of the Challenge under the Chemicals Management Plan.

1.2 Final Screening Assessment Reports Conclusions for D4 and D5

Notices summarizing the scientific considerations of the final screening assessment reports were published by Environment Canada and Health Canada in the Canada Gazette, Part I, for D4 and D5 on January 31, 2009, under subsection 77(6) of CEPA 1999. The final screening assessment reports (Canada 2008a, 2008b) concluded that D4 and D5 are entering or may be entering the environment in a quantity or a concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity, but are not entering the environment in a quantity or a concentration or under conditions that constitute or may constitute a danger in Canada to human life or health.

The final screening assessment reports concluded that D4 and D5 meet the criteria for persistence as defined by the Persistence and Bioaccumulation Regulations made under CEPA 1999 in air (D4 and D5), water (D5) and sediment (D4 and D5). The final screening assessment reports also indicated that while D4 and D5 have bioaccumulation potential in biota, it is not possible to conclude at this time that they meet the criterion for bioaccumulation as defined by the Persistence and Bioaccumulation Regulations made under CEPA 1999. The presence of D4 and D5 in the environment results primarily from human activity.

1.3 Proposed Measure

Following a screening assessment of a substance under section 74 of CEPA 1999, a substance may be found to meet the criteria under section 64 of CEPA 1999. The Ministers can propose to take no further action with respect to the substance, add the substance to the Priority Substances List (PSL) for further assessment, or recommend the addition of the substance to the List of Toxic Substances in Schedule 1 of CEPA 1999. Under certain circumstances, the Ministers must make a specific proposal either to recommend addition to the List of Toxic Substances or to recommend the implementation of virtual elimination (or both). In this case, the Ministers proposed to recommend the addition of D4 and D5 to the List of Toxic Substances in Schedule 1 of CEPA 1999. As a result, the Ministers will develop a regulation or instrument respecting preventive or control actions to protect the health of Canadians and the environment from the potential effects of exposure to this substance.

The final screening assessment report did not conclude that D4 and D5 meet the conditions set out in subsection 77(4) of CEPA 1999. As a result, D4 and D5 will not be subject to the virtual elimination provisions under CEPA 1999 and will be managed using a life-cycle approach, to prevent or minimize their release into the environment.

2. BACKGROUND

2.1 Substance Information

D4 and D5 are part of the chemical grouping organosilicon compounds and the chemical sub grouping cyclic volatile methyl-siloxanes (cVMS).

It should be noted that D4 and D5 are also contained under another Chemical Abstracts Service Registry Number. This registry number, CAS RN 69430-24-6, refers to a mixture of dimethyl-substituted cyclosiloxanes in a cyclic configuration (SEHSC 2007). This CAS number is associated with the following names: cyclopolydimethylsiloxane, cyclopolydimethylsiloxane (DX), cyclosiloxanes di-Me, dimethylcyclopolysiloxane, polydimethyl siloxy cyclics, polydimethylcyclosiloxane, cyclomethicone and mixed cyclosiloxane.

Tables 1 and 2 present other names, trade names, chemical classes, the chemical formulae, the chemical structures and the molecular masses for D4 and D5.

3. WHY WE NEED ACTION

3.1 Characterization of Ecological Risk

The approach taken in the ecological screening assessment was to examine various supporting information and develop conclusions based on a weight-of-evidence approach and using the precautionary principle as required under subsection 76(1) of CEPA 1999. Particular consideration was given to risk quotient analysis, persistence, bioaccumulation, toxicity, sources and fate in the environment.

D4 and D5 are both persistent in air and have the potential to be transported over long-distances in the atmosphere. However, these substances lack the potential to be deposited in water or soil in remote regions. In addition, D4 is persistent in sediment and D5 is persistent in sediment and water. As indicated in the final screening assessment reports, it was not possible to conclude on the bioaccumulation potential for D4 and D5. A quantitative evaluation of exposure and of ecological effects was therefore conducted as part of the weight-of-evidence evaluation of D4 and D5's potential to cause harm to aquatic organisms.

The risk quotient (RQ) analysis for D4 and D5 was performed with combined consumer and industrial releases. Under conservative scenarios, it was shown that there is a risk to aquatic organisms with RQs exceeding 1. The problematic sites, with RQ>1, are 23.4% and 6.8% of all evaluated municipal wastewater and industrial sites across Canada for D4 and D5 respectively. Given the high toxicity of D4 to sensitive aquatic organisms and organisms at their sensitive early-life stage, long-term environmental exposure to D4 is expected to potentially cause adverse effects to aquatic organisms in certain Canadian environments. For D5, given the persistence of these substances in the water compartment, long-term environmental exposure to D5 is expected to potentially cause adverse effects to aquatic organisms in certain Canadian environments.

4. CURRENT USES AND INDUSTRIAL SECTORS

According to information submitted under a section 71 notice published on May 12, 2007, the Challenge questionnaire submissions and other data voluntarily submitted, D4 and D5 were not manufactured in Canada in 2006 in a quantity meeting the 100 kg reporting threshold.

All silicone polymers contain trace residual amounts of volatile cyclosiloxanes, including D4 and D5. D4 and D5 are also constituents of polydimethylcyclosiloxane (CAS RN 69430-24-6), termed cyclomethicone in the cosmetics industry, which is a mixture of low molecular weight volatile cyclic siloxanes, the principal ingredients of which are D4 and D5 in varying proportions.

Silicone polymers in fluid/gel form are used in the production of personal care products for hair and skin care, antiperspirants and deodorants; pharmaceuticals; processing aids such as defoamers used in various industrial processes, surfactants (in certain pesticide products), leveling agents (in paint, lacquers and varnishes) and mould release agents; lubricants; cleaners; sealants; architectural coatings; mechanical, heat transfer and dielectric fluids; plastic products and films; polishes and coatings on a range of substrates including textiles, carpeting and paper; and reprography. Silicone polymers in fluid/gel mixtures can also be used to make medical devices (both implantable and non-implantable); as active or non-active ingredients in pharmaceuticals; in blood handling equipment; as protective barriers and lubricants; and for surface treatment of wound dressings. Silicone polymers in gum form are used in the production of elastomers which are used as sealants and adhesives; molded silicone rubber; coatings and encapsulation. Silicone polymers in resin form are primarily used in specialty coatings and in the production of silicone-modified polymers. Concentrations of D4 and D5 in silicone polymers are reported to range between 0.05% and 3%.

4.1 D4 (CAS RN 556-67-2)

D4 was imported into Canada in quantities between 1 000 000 kg and 10 000 000 kg in 2006.

D4 is used mainly as a raw material or intermediate in the production of silicone polymers and copolymers.

4.2 D5 (CAS RN 541-02-6)

D5 was imported into Canada in quantities between 1 000 000 kg and 10 000 000 kg in 2006.

In Canada, the most important use of D5 is in personal care products. Concentrations of D5 in these products are reported to range from less than 0.001% to 100%, although most are well under 5%. D5 is used as a raw material or intermediate in the production of silicone polymers. A small number of commercial dry cleaners in Canada use a dry cleaning fluid that contains D5.

5. PRESENCE IN THE CANADIAN ENVIRONMENT AND EXPOSURE SOURCES

5.1 Releases to the Environment

D4 and D5 are not reported to occur naturally, nor are their releases reported as part of Environment Canada's National Pollutant Release Inventory (NPRI). These substances are released to the environment in a dispersive manner due to their widespread use. Releases of D4 and D5 are mainly to air, due to their high volatility, and water (via effluents from wastewater treatment systems) during personal care and consumer product use, but they can also be released to the environment during their use in industrial processes. When they are discharged to wastewater collection and treatment systems, some of these substances will partition to the residual sludge produced from the treatment processes. Wastewater sludge may then be sent to landfills, incinerated or applied to agricultural soils as fertilizer. Since they are found in landfill gas, these substances are released to air from the disposal of personal care, consumer and industrial products containing D4 and D5 in landfills.

A Mass Flow Tool, in which various assumptions were made, was used to estimate the quantities of these substances released and the proportions of those releases to the various environmental media. The tool is based on a life-cycle analysis and on emission scenario documents published by the Organisation for Economic Co-operation and Development (OECD 2004, 2006). The goal of this tool is to quantify the mass of a substance released to the environment during its life cycle.

5.1.1 D4 (CAS RN 556-67-2)

The Mass Flow Tool predicted that more than 80% of the quantity of D4 imported into Canada is used as a chemical intermediate in the production of silicone polymers, and is considered to be chemically transformed during the manufacturing process. For the remaining quantity of D4 imported, the main compartments of release are to air (~ 12%) and wastewater (~ 5%). Releases to air and water happen mainly during product use, but some releases occur during product processing.

5.1.2 D5 (CAS RN 541-02-6)

The Mass Flow Tool predicted that of the quantity of D5 imported, approximately 80% is released to air and approximately 10% is released to wastewater. Releases to air and water happen mainly during product use, but some releases occur during product processing.

5.2 Exposure Sources

D4 and D5 may be emitted to the environment from industrial processes in which they are reacted to form silicone polymers and co-polymers, and from blending, formulating and packaging operations. Industrial releases of D4 and D5 may also occur when silicone polymers are used in process industries as foam control agents, mould release agents, lubricants and in other applications. The releases from industrial processes are expected to be to the atmosphere and wastewater.

D4 and D5 may be released to the air and to wastewater during the use of personal care products such as hair and skin care products, antiperspirants and others. When personal care, consumer and industrial products are disposed of at landfill sites, D4 and D5 are released to air through landfill gas.

The results of environmental fate modeling of D4 and D5, giving a characteristic travel distance of more than 2000 km, strongly suggests the possibility that long-range atmospheric transport of D4 and D5 to Canada from the United States, Europe or from other foreign countries where siloxanes are produced and used, will occur. Similarly, atmospheric transport may occur from industrialized areas of high population density to remote and sparsely populated areas. Although it was concluded that D4 and D5 have the potential to be transported over long distances in the atmosphere, they lack the potential to be deposited in water or soil in remote regions. It is expected that airborne D4 and D5 will be eventually degraded by hydroxyl radicals in air.

6. OVERVIEW OF EXISTING ACTIONS

6.1 Existing Canadian Risk Management

6.2 Existing International Risk Management

There are no known existing international risk management measures for D4 or D5.

7. CONSIDERATIONS

7.1 Alternative Chemicals or Substitutes

A report initiated by the Danish Environmental Protection Agency (Lassen et al. 2005) identified alternatives to D5 and cyclomethicone in personal care products. A report prepared by the Institute for Research and Technical Assistance for the California Department of Health Services and the United States Environmental Protection Agency (Wolf et al. 2006) listed alternatives to D5 in the dry-cleaning process, as well as in repair and maintenance cleaning operations.

D4 and D5 have a number of properties, such as emulsification and defoaming, which are not easily substituted. It is unknown whether there are suitable alternatives for all applications.

It is important to note that the effectiveness of these alternatives has not been evaluated by the Government of Canada, nor have they undergone an assessment to determine whether they meet the criteria under section 64 of CEPA 1999.

7.2 Alternative Technologies and/or Techniques

7.3 Socio-economic Considerations

Socio-economic factors have been considered in the selection process for a regulation and/or instrument respecting preventive or control actions, and in the development of the risk management objective(s). Socio-economic factors will also be considered in the development of regulations, instrument(s) and/or tool(s) as identified in the Cabinet Directive on Streamlining Regulation (Treasury Board of Canada Secretariat 2007) and the guidance provided in the Treasury Board document Assessing, Selecting, and Implementing Instruments for Government Action.

D4 is primarily used in the production of silicone polymers and copolymers, which are then used in the production of sealants, architectural coatings and personal care products (such as hair and skin care products, antiperspirants, etc.). The main use of D5 is in personal care products. There is no domestic manufacture of D4 or D5; therefore, imports of these substances satisfy Canadian demand. In 2006, between 1 000 000 kg and 10 000 000 kg each of D4 and D5 were imported into Canada.

In Canada, the overall revenue of the toilet preparation manufacturing sub-sector was $1.3 billion in 2005, with approximately 196 establishments employing 5608 employees. This sector has a trade deficit of $460 million. The toilet preparation manufacturing sub-sector (industry) includes shampoo and conditioner manufacturing, face and body cream manufacturing, make-up manufacturing, etc.

According to the Danish EPA study (Lassen et al. 2005), the cost of cyclomethicone is approximately $10 per kg. The incremental cost difference between cyclomethicone and one alternative is an estimated $11–13 per kg, although it should be noted that for some applications lower-cost alternatives may be available. In addition to the costs for alternatives, the industry may also incur reformulation costs for some products.

7.4 Children's Exposure

The Government of Canada considered, where available, risk assessment information relevant to children's exposure to these substances. As part of the Challenge, the Government asked industry and interested stakeholders to submit any information on the substances that may be used to inform risk assessment, risk management and product stewardship. In particular, stakeholders were asked through a questionnaire if any of the products containing the substances were intended for use by children. Given the information received, and no other data considered, it is proposed that no risk management actions to specifically protect children are required for these substances at this time.

8. PROPOSED OBJECTIVES

8.1 Environmental Objective

An environmental objective is a quantitative or qualitative statement of what should be achieved to address environmental concerns identified during a risk assessment.

The proposed environmental objective for D4 and D5 is to prevent or minimize releases of D4 and D5 to the aquatic environment.

8.2 Risk Management Objective

A risk management objective is a target expected to be achieved for a given substance by the implementation of risk management regulations, instrument(s) and/or tool(s). In order to prevent or minimize releases of D4 and D5 to the aquatic environment, the proposed risk management objective is to achieve the lowest level of release of D4 and D5 to water that is technically and economically feasible.

9. PROPOSED RISK MANAGEMENT

9.1 Proposed Risk Management Regulation, Instrument(s) and/or Tool(s)

As required by the Government of Canada's Cabinet Directive on Streamlining Regulation,³ and criteria identified in the Treasury Board document entitled Assessing, Selecting, and Implementing Instruments for Government Action, the proposed risk management regulations, instrument(s) and/or tool(s) were selected using a consistent approach, and took into consideration the information that has been received through the Challenge and other information available at the time.

In addition, the proposed risk management instruments will be developed in accordance with the principles of public participation as outlined in the Guidelines for Effective Regulatory Consultations developed under the Cabinet Directive on Streamlining Regulation.

In order to achieve the risk management objective and to work towards achieving the environmental objective, the Government of Canada will consider imposing regulations to:

During the regulatory development period for these instruments, further analysis will be completed on the use pattern and release estimate assumptions used to develop this risk management approach. Additional regulations, instruments and/or tools in other sectors may be considered as appropriate.

The use patterns or pathways which are not being considered for additional investigation at this time are critical uses that are anticipated to result in low contribution to environmental exposures, including medical device applications regulated under the Food and Drugs Act.

The regulatory proposal will be published in the Canada Gazette, Part I, within approximately 24 months.

9.1.1 Releases from Products

In Canada, the most significant use of D5 is in personal care products. D4 is also used in personal care products. D4 and D5 are also used in various consumer products including cleaners, caulkings, putties and polishes. The risk management being considered for D4 and D5 is a regulation that limits the quantity or concentration of these substances in certain personal care products and, where appropriate, in consumer products that are manufactured in and imported into Canada. This risk management action would focus on those products that have the potential to result in releases to the aquatic environment.

Certain personal care products such as those with a recognized therapeutic purpose will be given due consideration during instrument development to ensure continued effectiveness and access.

9.1.2 Industrial Releases

In Canada, D4 is used mainly as a raw material or intermediate in the production of silicone polymers and copolymers. D5 is also used as raw material or intermediate in the production of silicone polymers and copolymers but to a lesser extent than D4. According to information submitted under a section 71 notice published on May 12, 2007, the Challenge questionnaire submissions and other data voluntarily submitted, the majority of D4 and D5 releases that occur during the manufacturing of silicone polymers are emissions to air. However, mass flow models also predict some releases to water.

The Government of Canada will consider imposing a regulation to prevent or minimize releases to the aquatic environment. The regulation would:

In accordance with the Government of Canada's regulatory framework for wastewater, it is the intent that the regulation be applied as a risk management action to manage pollutants at their source. For more information on the framework, please consult www.ec.gc.ca/eu-ww.

9.1.3 Pest Control Products Sector

Pest control products are regulated by the Pest Management Regulatory Agency (PMRA) of Health Canada, under the Pest Control Products Act (PCPA) and Regulations. D4 and D5 are used as formulants in approximately 150 pest control products registered under the PCPA. With the exception of one product, the concentrations of these substances in pest control products are less than 1.0%. As a result of their categorization as Challenge substances, D4 and D5 have been reclassified as List 2 formulants by the PMRA, which elevates their priority for reassessment within the Agency. When the formulant reassessment program begins, the PMRA will utilize information from the screening assessments conducted for the Challenge substances under the Chemicals Management Plan as well as additional information available on bioaccumulation potential, in order to determine whether reduction of concentrations of D4 and D5 in pest control products beyond current levels is required.

9.2 Other Information Gathering/Research

Monitoring for D4 and D5 in the environment will be conducted under a more comprehensive monitoring and surveillance strategy for all substances that come under the Chemicals Management Plan. Monitoring has been identified as a key pillar in the Chemicals Management Plan, and will serve the following functions: collecting and generating human health and environmental data to inform decision making; providing an adaptive management framework to support intervention; and measuring the efficiency of preventive and mitigation actions.

As part of the Chemicals Management Plan monitoring, it is planned that D4 and D5 will be monitored in air starting in 2008. This monitoring will be used to inform the Government on ambient levels of D4 and D5 in the environment. Monitoring of D4 and D5 will be expanded to additional media in 2009-2010 as analytical methodologies become available.

9.3 Implementation Plan

It is the intent of the Government to publish a proposed risk management measure in the Canada Gazette, Part I, by winter 2011.

10. CONSULTATION APPROACH

The risk management scope for D4 and D5, which summarized the proposed risk management under consideration at that time, was published on May 17, 2008, and is available at www.ec.gc.ca/TOXICS/EN/detail.cfm?par_substanceID=236&par_actn=s1. Industry and other interested stakeholders were invited to submit comments on the risk management scope during a 60-day comment period. Comments received on the risk management scope document were taken into consideration in the development of this proposed risk management approach document.

Consultation for the risk management approach will involve publication on January 31, 2009, and a 60-day public comment period.

11. NEXT STEPS / PROPOSED TIMELINE

Industry and other interested stakeholders are invited to submit comments on the content of this proposed risk management approach or to provide other information that would help to inform decision making. Please submit comments prior to April 1, 2009, since the Government of Canada will be moving forward with the risk management of D4 and D5 after this date. Pursuant to section 313 of CEPA 1999, any person who provides information to the Minister of the Environment under CEPA 1999 may submit with the information a request that it be treated as confidential. During the development of regulations, instrument(s) and/or tool(s), there will be opportunity for consultation. Comments and information submissions on the proposed risk management approach should be submitted to the address provided below:

Existing Substances Division
Gatineau QC K1A 0H3
Tel.: 1-888-228-0530 / 819-956-9313
Fax: 1-800-410-4314 / 819-953-4936
Email: Existing.Substances.Existantes@ec.gc.ca

12. REFERENCES

Canada. 2000. Canadian Environmental Protection Act: Persistence and Bioaccumulation Regulations, P.C. 2000-348, 23 March, 2000, SOR/2000-107. Canada Gazette. Part II, vol. 134, no. 7, p. 607-612. Ottawa: Queen's Printer. Available from: http://canadagazette.gc.ca/partII/2000/20000329/pdf/g2-13407.pdf

Lassen C, Hansen CL, Mikkelson SJ, Maag J. 2005. Siloxanes - Consumption, Toxicity and Alternatives. Danish Ministry of the Environment, Environmental Protection Agency (Danish EPA). Environmental Project No. 1031.

[NCI] National Chemical Inventories [database on a CD-ROM]. 2006. Issue 1. Columbus (OH): American Chemical Society, Chemical Abstracts Service. [cited 2008 Aug 08]. Available from: www.cas.org/products/cd/nci/require.html

[OECD] Organisation for Economic Co-operation and Development. 2004. Emission scenario document on plastics additives [Internet]. Paris (FR): OECD Environmental Directorate, Environmental Health and Safety Division. [cited September, 2004]. Available from: http://www.oecd.org/ehs/

[OECD] Organisation for Economic Co-operation and Development. 2006. Draft emission scenario document on transport and storage of chemicals. Prepared by the Environment Agency (UK). Available on request from: Environment Canada, Existing Substances Division, Ottawa, K1A 0H3.

[PMRA] Pest Management Regulatory Agency. 2007. PMRA List of Formulants. Ottawa (ON): Health Canada, Pest Management Regulatory Agency. Regulatory Note REG2007-04. [cited 2008 Jan]. Available from: www.pmra-arla.gc.ca/english/pubs/reg-e.html

[SEHSC] Silicones Environmental, Health and Safety Council. 2007. SEHSC communication to EC/HC on CAS No. 69430-24-6, 2007.

Transport Canada. 2006. Transportation of Dangerous Goods Regulations. [cited 2008 Jan]. Available from: www.tc.gc.ca/tdg

Wolf K, Morris M. 2006. Assessment, development and demonstration of alternatives for five emerging solvents. Institute for Research and Technical Assistance. Available from: www.irta.us/Five%20Emerging%20Chemicals.pdf

¹ CAS RN: Chemical Abstracts Service Registry Number. The Chemical Abstracts Service information is the property of the American Chemical Society and any use or redistribution, except as required in supporting regulatory requirements and/or for reports to the Government of Canada when the information and the reports are required by law or administrative policy, is not permitted without the prior written permission of the American Chemical Society.

² National Chemical Inventories (NCI). 2006: AICS (Australian Inventory of Chemical Substances); ASIA-PAC (Asia-Pacific Substances Lists); ECL (Korean Existing Chemicals List); EINECS (European Inventory of Existing Commercial Chemical Substances); ENCS (Japanese Existing and New Chemical Substances); NZIoC (New Zealand Inventory of Chemicals); PICCS (Philippine Inventory of Chemicals and Chemical Substances); and TSCA (Toxic Substances Control Act Chemical Substance Inventory).

³ Section 4.4 of the Cabinet Directive on Streamlining Regulation states that "Departments and agencies are to: identify the appropriate instrument or mix of instruments, including regulatory and non-regulatory measures, and justify their application before submitting a regulatory proposal."

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.

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