Proposed Risk Management Approach for Chlorinated Paraffins

Environment Canada
Health Canada


August 2008


Ecological and human health follow-up assessments were recently undertaken on chlorinated paraffins (CPs) under the provisions of the Canadian Environmental Protection Act, 1999 (CEPA 1999). The assessments were undertaken as a follow-up to the work done on chlorinated paraffins under the first Priority Substances List (PSL1) program.

CPs were included on the PSL1 program under the 1988 Canadian Environmental Protection Act (CEPA 1988) for assessment of potential risks to the environment and human health. In 1993, Environment Canada and Health Canada published a proposed assessment report that concluded short chain chlorinated paraffins constitute or may constitute a danger to human health or life as set out in the CEPA. However, data identified at that time were considered insufficient to conclude whether short, medium or long chain chlorinated paraffins were harmful to the environment or whether medium or long chain chlorinated paraffins were considered a danger to human health.

Following the publication of the proposed assessment report, research to address data gaps relevant to the assessment of impacts of CPs on the environment was undertaken and an industry survey on the Canadian manufacture, import and uses of chlorinated paraffins was conducted for the years 2000 and 2001 through a Canada Gazette Notice issued pursuant to section 71 of CEPA 1999. Literature was also reviewed for new exposure and toxicological data on chlorinated paraffins on human and non-human organisms in Canada and elsewhere.

On June 11, 2005, the Ministers of the Environment and of Health published, for a 60-day public comment period, in the Canada Gazette Part I, the summary of the scientific results of the follow-up assessment on CPs and a statement indicating the measures they propose to take on the basis of scientific considerations. Comments were received from industry and industry associations on the follow-up assessment. Stakeholder input was carefully reviewed by Environment Canada and Health Canada. The final follow-up assessment report was revised based on these comments.

A Notice summarizing the scientific considerations of a final follow-up assessment report was published by Environment Canada and Health Canada in the Canada Gazette Part I for chlorinated paraffins that have the molecular formula CnHxCl(2n+2-x) in which 10 ≤ n ≤ 38, on August 30, 2008, under paragraph 68(b) of CEPA 1999. The final follow-up assessment report concluded that:

Based on conclusions of the assessment, it is therefore recommended that all CPs be added to Schedule 1 of CEPA 1999.

Furthermore, CPs containing up to 20 carbon atoms are predominantly anthropogenic, and the available data regarding their persistence and bioaccumulation potential indicate that they satisfy the criteria outlined in the Persistence and Bioaccumulation Regulations, made under CEPA 1999. CPs containing up to 20 carbon atoms will be recommended for addition to the Virtual Elimination List.

The full assessment report may be obtained from the Chemical Substances website at https://www.canada.ca/en/health-canada/services/chemical-substances.html or from the Existing Substances Division, Environment Canada, Gatineau QC K1A 0H3; 819-953-4936 (fax); or by email at Existing.Substances.Existantes@ec.gc.ca.

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 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 to add the substances to the Virtual Elimination List.

In this case, the Ministers proposed to recommend the addition of all CPs to the List of Toxic Substances in Schedule 1 of CEPA 1999 and recommend CPs containing up to 20 carbon atoms for virtual elimination. As a result, the Ministers will develop an instrument respecting preventive or control actions to protect the health of Canadians and the environment from the potential effects of exposure to these CPs.

The final follow-up assessment report concluded that CPs containing up to 20 carbon atoms meet the virtual elimination criteria set out in subsection 77(4) of CEPA 1999 because:

As a result, for CPs containing up to 20 carbon atoms, the Government of Canada will follow the process specified in CEPA 1999 for substances that meet the criteria for virtual elimination.

CPs are chlorinated hydrocarbons (n-alkanes) that can have carbon (C) chain lengths ranging from 10 to 38. They are grouped by chain length: short chain chlorinated paraffins (SCCPs) (CPs with 10-13 carbon atoms), medium chain chlorinated paraffins (MCCPs) (CPs with 14-17 carbon atoms) and long chain chlorinated paraffins (LCCPs) (CPs with ≥18 carbon atoms). For the ecological assessment, the long group was divided into three sub-groups: liquid LCCPs with 18-20 carbon atoms (C18-20 - liquid), liquid LCCPs with carbon atoms greater than 20 (C>20 - liquid) and solid LCCPs with carbon atoms greater than 20 (C>20 - solid).

Molecular Formula: CnHxCl(2n+2-x), 10 ≤ n ≤ 38

SCCPs, MCCPs and the lower chlorinated LCCPs are mixtures that are viscous, colourless or yellowish dense oils. Highly chlorinated alkanes, with carbon chain length greater than 20, are waxy solids at ambient temperatures. The average chlorine content by weight is 30-52% for C18-20 liquid products, 40-54% for C>20 liquid products, and 70-72% for C>20 solid products. The difference in chlorine content results in differing physical/chemical properties. Various stabilizers are often added to commercial CPs products in order to improve their thermal stability.

Environmental Risks

SCCPs have been detected in sewage treatment plant effluents from southern Ontario, surface water, sediments, plankton, invertebrates and fish from Lake Ontario and marine mammals from the St. Lawrence River.

SCCPs have also been detected in Arctic air, sediments from remote northern lakes and marine mammals from the Canadian Arctic. SCCPs detected in Arctic biota and lake sediments, in the absence of significant sources of SCCPs in the region, suggest that long-range atmospheric transport of SCCPs is occurring.

There are no data available for LCCPs in Canadian lake sediments; however, based on their physical/chemical properties, which are similar to those of MCCPs, LCCPs are expected to be persistent in sediments. The available toxicity data indicate that SCCPs and MCCPs, as well as C18-20 LCCPs, may be harmful to certain aquatic species (e.g., Daphnia magna) at low concentrations.

SCCPs and MCCPs, as well as C18-20 LCCPs, are also considered to be both highly persistent and bioaccumulative. Substances that are persistent remain in the environment for a long time, increasing the magnitude and duration of exposure. Releases of small amounts of bioaccumulative substances may lead to high internal concentrations in exposed organisms. Highly bioaccumulative and persistent substances are of special concern, since they may biomagnify in food webs, resulting in very high internal exposures, especially for top predators. All CPs have been found to meet the criteria under paragraph 64(c) of CEPA 1999.

Human Health Risks

A comprehensive literature search was conducted (SCCP, up to February 2001; MCCP and LCCP, up to September 2000) to identify critical new data for the assessment of human health risk under paragraph 64(c) of CEPA 1999.

For all CPs (SCCP, MCCP and LCCP), there was insufficient information to characterize the effects of exposure upon humans. Reports of health effects were limited to studies with laboratory animals.

There is low confidence in the upper-bounding estimates of exposure to all CPs. The estimates of intake for most age groups in the general Canadian population are based almost entirely upon limited sampling of foodstuffs in the United Kingdom, which were published in 1980. Methodology for analysis in this study is considered inadequate by present-day standards, and, as such, the data can be regarded at best as semi-quantitative. Reported concentrations represented both SCCP and MCCP, and, as a result, intake of the individual groups of chlorinated paraffins (SCCP, MCCP and LCCP) from these sources has been overestimated.

Lifetime exposure of SCCP to mice resulted in cancer of the liver and thyroid. In a similar study with rats, there were tumours in liver, thyroid and kidney. Although there are uncertainties, it could not be concluded that these effects were not relevant to humans, i.e., there is some probability of harm at any level of exposure.

In other studies, non-cancer effects (on liver, kidney and thyroid) were observed in rats. The World Health Organization has derived a tolerable daily intake for SCCP. A tolerable daily intake is the level of intake to which it is believed that a person may be exposed daily over a lifetime without deleterious effects.

SCCP has been identified in Canada in ambient air, river water and fish. Estimates of total daily intake by Canadians were calculated by supplementing these data with concentrations of SCCP reported in foods in an older British study. The highest intake of SCCP calculated for the population of Canada is within the range of the tolerable daily intake of SCCP derived by the World Health Organization.

No studies were identified which had investigated carcinogenicity of MCCP in laboratory animals. Non-cancer effects (decrease in body weight) were observed in the offspring of rats exposed to MCCP. Effects upon liver and thyroid were reported elsewhere. A tolerable daily intake was derived on the basis of non-cancer effects.

Concentrations of MCCP were identified in fish in Canada. However, the estimates of total daily intake of MCCP by Canadians were based almost entirely upon older data from Britain. The estimated intake of MCCP by several age groups in the Canadian population exceeded the value of the tolerable daily intake.

In a study with laboratory animals, LCCP was carcinogenic to male mice but not to male rats. Non-cancer effects were observed in the liver, pancreas and lymph nodes of female rats. Based upon these effects, a tolerable daily intake was derived.

Concentrations of LCCP were not identified in any medium in Canada (food, drinking water, air, soil). The estimates of total daily intake for the Canadian population were based entirely upon older data from Britain. The highest estimate of total daily intake for Canadians was within the same order of magnitude as the tolerable daily intake.

Total reported annual usage of chlorinated paraffins in Canada (production + imports - exports) was approximately 2.8 kilotonnes in 2000 and 2001. As production of CPs in Canada has stopped, CPs are now imported into Canada as chemical formulations from foreign producers or as formulations in products such as paints, sealants, plastics and metalworking fluids.

The vast majority of CP consumption in Canada is MCCPs, while much smaller quantities of SCCPs and LCCPs are also being consumed in specific applications. The two dominant end-use applications for CPs in Canada are in the formulation of metalworking fluids such as cutting oils and high pressure lubricating oils used in the metalworking industry and as a plasticizer in polyvinyl chloride (PVC) applications. CPs are also used as flame retardants in various plastics or formulated chemical products (e.g., adhesives, paints, sealants). The use profile information provided in Figure 1 was developed based upon information collected from an Environment Canada survey of CP producers and end-users in Canada.

Figure 1: 2001 Approximate Uses of CPs in Canada

Metalworking Fluids

Approximately 15 metalworking fluid formulators in Canada consumed an estimated 1.2 kilotonnes of CPs in 2001. CPs are used as extreme pressure additives across a wide temperature range to enhance lubrication and surface finish in demanding metalworking and forming applications where hydrodynamic lubrication cannot be maintained.

Polyvinyl Chloride

Approximately 15-25 companies in the polyvinyl chloride (PVC) processing sector in Canada consumed an estimated 1.2 kilotonnes of CPs in 2001. CPs are used in the PVC processing industry as secondary plasticizers, and in some cases as flame retardants. While there are several different sub-sectors within the PVC processing industry, the use of CPs (on a volume basis) has historically been restricted to three specific sub-sectors where they have been used as secondary plasticizers and flame retardants, namely: (i) flooring manufacturing; (ii) wire and cable sheathing and insulation; and (iii) wall coverings and emulsions. MCCPs are the dominant CPs used in the PVC processing industry, with only minor amounts of SCCPs or LCCPs used.

Paints and Coatings, Adhesives and Sealants, and Rubber and Elastomers

Approximately 0.4 kilotonnes of CPs were used in the Canadian paints and coatings, adhesives and sealants, and rubber and elastomer sectors in 2001. CPs are used in other end-use segments in Canada, in addition to metalworking fluids and PVC, although in much smaller quantities. These specific applications are: (i) paints and coatings; (ii) adhesives and sealants; and (iii) rubber and elastomers. The majority of CPs consumed in these applications are MCCPs along with small amounts of LCCPs. CPs are used in these applications because of their ability to: (i) improve the flexibility (and therefore the durability) of the coating; and (ii) reduce the amount of time needed to achieve "tack-free" conditions.

There are no known natural sources of CPs. The major sources of release of CPs into the Canadian environment are likely the formulation and manufacturing of products containing CPs. The possible sources of releases to water from manufacturing include spills, facility wash-down and drum rinsing/disposal. CPs in metalworking/metal cutting fluids may also be released to aquatic environments from carry-off and spent bath. These releases are collected in sewer systems and often ultimately end up in the effluents of sewage treatment plants.

Landfilling is also a major disposal route for CP-containing products in Canada. CPs would be expected to remain stabilized in these products, with minor losses to washoff from percolating water. Leaching from landfill sites is likely to be negligible owing to strong binding of CPs to soils. Outlined, in Table 1, below are estimates of CP releases in Canada, which are based upon the demand profile for CPs in Canada and the release factors for CPs that were contained in European risk assessment reports.

Table 1: 2001 Estimated Releases of CPs in Canada
(kilotonnes)
Production/End-use Area Estimated
Annual
Releases
Metalworking fluids formulation and end-use 0.3
Plastics production and end-use <0.1
Rubber production and end-use <<0.1
Sealants, adhesives and caulks formulation and end-use <<0.1
Paint formulation and end-use <<0.1
Other <<0.1

As there are no known natural sources of CPs, the release of CPs to the environment is primarily from formulation and use. The release of CPs as a result of leaching or volatilization from products containing the substances is thought to be negligible, as was the leaching of CPs from products that are landfilled. The primary source of release of CPs is predicted to occur from the metalworking sector through the disposal of metalworking fluid. SCCPs have been found in the Arctic food web. The higher volatility of certain SCCPs suggests their presence resulted from long-range atmospheric transportation.

Though there are at present no restrictions on uses of CPs in Canada, there are two categories of CPs that are listed on the National Pollutant Release Inventory (NPRI). CPs are reported to the NPRI as "alkanes, C10-13, chloro" (SCCPs) and "alkanes, C6-18, chloro", a category that includes SCCPs, MCCPs and some LCCPs.

Existing European Initiatives

A Marketing and Use Directive in the European Union (EU), (Directive 2002/45/EC), restricts the concentration of short chain CPs in metalworking and leather fat liquoring preparations to 1% or less. These restrictions took effect on January 6, 2004.

Also, SCCPs are on the initial list of 16 substances identified as substances of very high concern under REACH3 (Registration, Evaluation, Authorization and Restriction of Chemical substances).

U.S. Initiatives

The U.S. EPA added the category of polychlorinated alkanes to its list of toxic chemicals subject to Toxics Release Inventory reporting under EPCRA section 313 (see 40 CFR 372.65) based on available carcinogenicity and ecotoxicity data for short chain species (59 Federal Register 61432, November 30, 1994).

International Agreements

In May 2006, the Parties to UNECELRTAP Convention's Protocol on Persistent Organic Pollutants agreed that SCCPs meet the UNECE criteria for long term transboundary transport, persistence and bioaccumulation. Discussions regarding addition of SCCPs to the POPs Protocol are ongoing under the Convention. The United Nations Environment Program is also considering adding SCCPs as a POP to the Stockholm Convention on Persistent Organic Pollutants.

In October 2001, Canada offered to prepare an information dossier for the ad hoc Expert Group on Persistent Organic Pollutants (POPs) under the United Nations Economic Commission for Europe (UNECE) Convention on Long-range Transboundary Air Pollution (LRTAP) relating to the possible addition of short chain CPs to the LRTAPPOPs Protocol. A draft dossier incorporating the new information generated by the National Water Research Institute (NWRI) was submitted to the LRTAP Convention in the spring of 2002.

In determining risk management options, there is a need to consider the risks and costs of potential alternative substances and technologies.

Metalworking Fluids

There are two approaches to minimizing the releases of CPs within the metalworking industry, specifically to: (i) increase the adoption rate of substitutes to CPs among metalworking fluid formulators and end-users; and (ii) increase the adoption of best management practices by end-users of metalworking fluids.

Although substitutes to CPs are available to metalworking fluid formulators, several issues need to be considered in their implementation, as some potential alternatives are:

Polyvinyl Chloride

In PVC manufacturing, CPs are used primarily in applications where moderate plasticizing and flame retardant properties are required at low cost. Moreover, it is not anticipated that there would be many technical obstacles if CPs had to be replaced with alternative plasticizers and/or flame retardants. Analysis of CP alternatives suggests that, in many cases, the overall technical characteristics of the PVC product such as flexibility and stability would improve with the use of alternatives. Although technically feasible, the use of these alternatives would likely increase the raw material costs for manufacturers and they may also pose environmental and health risks.

Paints and Coatings, Adhesives and Sealants, and Rubber and Elastomers

Very small quantities of CPs are used annually in Canada in the formulation of paints and coatings, adhesives and sealants, and rubber and elastomers relative to metalworking fluids and PVC. Less than 100 tonnes of both MCCPs and LCCPs were reported to Environment Canada for the year 2001. The favorable characteristics provided by CPs include good compatibility with the resin systems where they are used; they are colourless; they are non-volatile and do not add to volatile organic compounds (VOC) content of a coating system; and they have low viscosity.

The use of CPs in the rubber industry has historically involved the utilization of SCCPs to manufacture rubberized conveyor belts for the underground mining industry as well as other technical products such as hoses and gaskets. They are used in these applications because of their superior flame retardant properties, which are often required in order to meet fire standard codes for products.

Technical barriers have been reported for adhesives and sealants substitutes as well; the primary technical issue is that they are more prone to bleeding from the sealant product, thus directly affecting the durability of the sealant and the substrate.

Socio-economic factors have been considered in the selection process for an instrument respecting preventive or control actions, and in the development of the risk management and human health objectives. Socio-economic factors will also be considered in the development of 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.

Socio-economic considerations for CPs included a qualitative analysis of costs to industry in terms of switching to alternatives and benefits to the public.

It was determined that the cost of using alternative substances would have a minimal economic effect for most uses. However, where the costs of alternatives are significant there would be an increase in the raw material costs for manufacturers that are currently using CPs in their products. This increase, along with other re-formulation costs, could hinder the competitiveness of these products in domestic and foreign markets.

The proposed human health objective for SCCPs, MCCPs and LCCPs is to minimize human exposure to the extent practicable.

The environmental objective for CPs with up to 20 carbon atoms is virtual elimination (VE) as specified under subsection 77(4) of CEPA 1999.

The proposed risk management objective is to reduce releases of CPs, to the lowest level possible, from all sources and prevent the re-introduction of their manufacture in Canada.

As recommended by the Government of Canada's Cabinet Directive on Streamlining Regulation4 and criteria identified in the Treasury Board document entitled Assessing, Selecting, and Implementing Instruments for Government Action, the proposed risk management instrument was selected using a consistent approach taking into consideration information received from industry and other information available at the time.

In order to achieve the risk management objective and to work towards achieving the environmental or human health objective, the risk management being considered for CPs is a prohibition regulation. The prohibition regulation would prohibit the manufacture, use, import, sale and offer for sale of CPs.

Specific use exemptions for some CP uses may be allowed where it can be demonstrated that alternatives are not technically or economically feasible. If specific use exemptions are granted, complementary tools will be considered as a means to ensure that releases of CPs are reduced to the lowest level possible.

CPs will be recommended for addition to Schedule 1 of CEPA 1999. Furthermore, consistent with the provisions of CEPA 1999, it will be recommended that CPs containing up to 20 carbon atoms be subject to Virtual Elimination. A proposed instrument will be published in the Canada Gazette Part I following consultations with stakeholders.

Monitoring for CPs in the environment will be considered under a more comprehensive monitoring and surveillance strategy for all substances in the Chemicals Management Plan. Monitoring has been identified as a key pillar in the Chemicals Management Plan to: collect and generate human health and environmental data to inform decision-making; provide an adaptive management framework to support intervention; and measure the efficacy of preventive and mitigation actions. Monitoring may include the analysis of landfill leachate to confirm that it is not being released from landfill, and monitoring to measure the efficacy of preventive and mitigation actions.

The Risk Management Approach (RMA) for CPs will be posted on Environment Canada’s website for comments:

https://pollution-waste.canada.ca/environmental-protection-registry/completed-consultations

Consultation document on chlorinated paraffins

Environment and Health Canada will seek advice on the proposed risk management objectives and risk management instruments. The design of further stakeholder consultations will be assessed following the publication of the proposed RMA and receipt of comments. These consultations could cover the risk management process, the proposed instruments and alternatives to CPs.

Stakeholders in the consultation process will include associations representing formulators and manufacturers of CPs and products containing CPs. As one proposed instrument is the regulation of CPs, users of products containing CP would also be included in the consultation. Other stakeholders will include various levels of government and environmental non-government organizations (ENGOs).

Actions Date
Consult on Risk Management Approach Fall 2008
Initiate Development of Proposed Instrument(s) Fall 2008
Consult on Proposed Instrument(s) Winter 2009
Publication on Proposed Instruments in Canada Gazette I Summer 2010
Publication on Proposed Instruments in Canada Gazette II Winter 2012

Industry and other interested stakeholders are invited to submit comments on the content of this proposed risk management approach or other information that would help to inform decision making. Please submit comments prior to October 29, 2008, since the Government of Canada will be moving forward with the risk management of CPs after this date. Pursuant to section 313 of CEPA 1999, any person who provides information to the Minister under CEPA 1999 may submit with the information a request that it be treated as confidential. During the development of the risk management instrument(s) and/or tool(s), there will be opportunity for consultation on the proposed instrument. Comments and information submissions on the proposed risk management approach should be submitted to the address provided below:

Chemicals Management Division
351 St. Joseph Blvd.
Gatineau QC
K1A 0H3
Tel.: 819-934-6449
Fax: 819-953-8963
Email: RiskManagementPrograms@ec.gc.ca

Canada, 1999. Canadian Environmental Protection Act, 1999 = Loi Canadienne sur la Protection de l'Environnement, 1999. Statutes of Canada = Statuts du Canada. Ottawa: Queen's Printer. Ch. 33. Available at Canada Gazette (Part III) 22(3):chapter 33 http://www.gazette.gc.ca/archives/p3/1999/g3-02203.pdf (PDF 1.6 MB)

Treasury Board of Canada Secretariat. 2007. Cabinet Directive on Streamlining Regulation, section 4.4. www.regulation.gc.ca/directive/directive01-eng.asp

PSL1 Assessment Report - Chlorinated Paraffins (1993) ISBN 0-662-205154
https://www.canada.ca/en/health-canada/services/environmental-workplace-health/reports-publications/environmental-contaminants/canadian-environmental-protection-act-priority-substances-list-assessment-report-chlorinated-paraffins.html

Canada Gazette Part I; Vol. 139, No. 24 - June 11, 2005; Publication of results of investigations and recommendations for the substances short chain chlorinated paraffins, medium chain chlorinated paraffins and long chain chlorinated paraffins (paragraphs 68(b) and 68(c) of the Canadian Environmental Protection Act, 1999) https://www.canadagazette.gc.ca/rp-pr/p1/2005/2005-06-11/pdf/g1-13924.pdf (PDF 1.3 MB)

Follow-up Report on a PSL1 Assessment for Which Data Were Insufficient to Conclude Whether the Substances Were "Toxic" to the Environment and to the Human Health; Environment Canada/Health Canada February 2008. https://www.canada.ca/en/environment-climate-change/services/canadian-environmental-protection-act-registry/publications/chlorinated-paraffins.html

Analysis of Options to Mitigate Chlorinated Paraffin Releases in Canada; Environment Canada, January 2005

Survey on the Canadian manufacture, import and uses of chlorinated paraffins for the years 2000 and 2001 through a Canada Gazette Notice issued pursuant to section 71 of the Canadian Environmental Protection Act, 1999




Footnotes

1 Paragraph 64(c) of CEPA 1999 defines a substance as "toxic" if it is entering or may enter the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health.
2 Paragraph 64(a) of CEPA 1999 defines a substance as "toxic" if it is entering or may enter 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.
3 REACH is a European Community Regulation on chemicals and their safe use (EC 1907/2006).
4 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".

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