Petroleum and Refinery Gases
Chemical Abstracts Service Registry Numbers (CAS RN):
1.1 Draft Screening Assessment Report Conclusion
Section 74 of the Canadian Environmental Protection Act, 1999 (CEPA 1999) (Canada 1999) requires the Minister of the Environment and the Minister of Health to conduct screening assessments of substances that have met the categorization criteria set out in the Act to determine whether these substances present or may present a risk to the environment or human health. Pursuant to this section of the Act, the Ministers of the Environment and of Health have conducted a screening assessment of the following petroleum and refinery gases, which are included in Stream 2 of the Petroleum Sector Stream Approach under the Government of Canada’s Chemicals Management Plan:
|CAS RN||DSL name|
|68131-75-9||Gases (petroleum), C3–C4|
|68477-33-8||Gases (petroleum), C3–C4, isobutane-rich|
|68477-85-0||Gases (petroleum), C4-rich|
|68527-19-5||Hydrocarbons, C1–C4, debutanizer fraction|
A notice summarizing the scientific considerations of the draft screening assessment report was published for these petroleum and refinery gases by Environment Canada and Health Canada in the Canada Gazette, Part I, April 28, 2012, under subsection 77(1) of the CEPA1999.
Based on the information available, the draft screening assessment report proposes that these 4 petroleum and refinery gases are or 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.
The draft screening assessment report also proposes that these 4 petroleum and refinery gases are 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.
In addition, the draft screening assessment report proposes that many components of these petroleum and refinery gases meet or exceed the atmospheric persistence criteria, but that no components were identified that meet the bioaccumulation criteria as defined in the Persistence and Bioaccumulation Regulations made under CEPA 1999.
Further information on the proposed conclusion for these 4 substances is included in the draft screening assessment report, available on the Stream 2 (Industry-Restricted) page of the Chemical Substances website. Conclusions described in this document and in the draft screening assessment report are preliminary and are subject to change.
1.2 Current Uses and Exposure Sources/Pathways of Concern
Industry-restricted petroleum and refinery gases are produced in Canadian refineries, upgraders and natural gas processing facilities. According to information submitted through mandatory data gathering conducted under section 71 of CEPA 1999, and other sources of information, these substances can be transported to another petroleum facility or other industry sector, but they are not sold directly to consumers.
It is recognized that there are potential unintentional releases (including fugitive releases) of these gases into the atmosphere from equipment, valves or fittings. In general, the common sources of fugitive releases from a petroleum sector facility are compressor seals, processing valves, flanges, pressure-relief valves, seals, storage tanks, loading operations, sample lines and open-ended lines (CCME 1993, CPPI 2005). When compared to liquids, gases usually have a higher potential for fugitive releases due to their high vapour pressure and mobility and disperse more readily into larger volumes. Therefore, there is the potential for general population and environment exposure in the vicinity of refinery, upgrader and natural gas processing facility sites. However, the potential for exposure of the general population to the regular releases of these industry-restricted petroleum and refinery gases during loading, transit and unloading is not expected.
A critical effect for characterization of risk to human health for petroleum and refinery gases is carcinogenicity, as other jurisdictions (European Union) have identified petroleum and refinery gases containing greater than 0.1 wt% 1,3-butadiene as carcinogens. Additionally, 1,3-butadiene has been identified by Health Canada and several international regulatory agencies as a carcinogen, and is listed in Schedule 1 of CEPA 1999. 1,3-Butadiene was found to be a multi-site carcinogen in rodents, increasing the incidence of tumours at all inhalation concentrations tested. 1,3-Butadiene also exhibits genotoxicity in vitro and in vivo, and a plausible mode of action for induction of tumours involves direct interaction with genetic material. Consistent with the approach used to assess the site-restricted (Stream 1) petroleum and refinery gases, (refer to: Site-Restricted Petroleum and Refinery Gases) 1,3-butadiene was selected as a high-hazard gas component to characterize potential exposure to the general population as it is considered, based on available information, to be present in these 4 CAS RNs.
The air dispersion modelling and calculations based on the application of emission factors indicate that unintentional releases of these four petroleum and refinery gases contribute to the overall 1,3-butadiene concentration in ambient air in the vicinity of refineries, upgraders and/or natural gas processing facilities. Margins of exposure are considered potentially inadequate to address uncertainties in the health effects and exposure databases.
Use of a single high-hazard component to characterize hazard may not reflect all hazards associated with the mixture. Uncertainties with respect to health effects include limitations of a component approach, as other hazardous components in the petroleum and refinery gases are not considered in the hazard and risk characterization.
2. Overview of Existing Risk Management
2.1 Existing Canadian Risk Management
While Canadian regulations exist which manage hydrocarbons generally, none specifically name any of these 4 petroleum and refinery gases. Provincial or territorial requirements typically exist to prevent or manage the unintentional releases of substances and streams within a petroleum facility through the use of permits. For example, provincial operational permits may reference the Environmental Code of Practice for Measurement and Control of Fugitive VOC Emissions and Equipment Leaks (CCME 1993). Additionally, existing provincial/territorial occupational health and safety legislation may specify measures to minimize occupational exposures to employees and some of these measures also serve to reduce general population exposures.
Non-regulatory measures (e.g., guidelines, best practices) are also in place at many petroleum sector facilities to reduce releases. Examples include the Canadian Association of Petroleum Producer (CAPP)’s Best Management Practice for Fugitive Emissions Management and the Canadian Petroleum Products Institute (CPPI)’s participation in the National Framework for Petroleum Refinery Emissions Reductions (NFPRER). Such control measures include appropriate material selection during the setup and design process, regular inspection and maintenance of storage tanks, piping and other process equipment, the implementation of leak detection and repair or other equivalent programs, the use of floating roofs in aboveground storage tanks to reduce the internal gaseous zone and the minimal use of underground tanks, which can lead to undetected leaks (SENES 2009). Similar measures have been applied to natural gas processing facilities as well as of 2007 (CAPP 2007).
The shipment of pressurized petroleum gaseous substances requires stringent safety considerations due to their physical–chemical properties. Under the Transportation of Dangerous Goods Regulations of the Transportation of Dangerous Goods Act 1992, Transport Canada requires that a series of standards, developed by the Canadian Standards Association or the Canadian General Standards Board, be followed for design, manufacture, use of safety devices, inspection and operation involved in the transportation of petroleum-related gases by rail, road and marine. As well, equipment for handling the substances must meet design standards for appropriate pressures and temperatures. These regulations are modeled on the UN Recommendations on the Transport of Dangerous Goods.
Furthermore, requirements are in place at the federal and provincial levels for handling gaseous hydrocarbons. These requirements are intended to minimize or prevent releases from these operations. Some of the measures outlined in these provisions set specified design and safety standards and apply to the means of containment (i.e., transportation vessel), means of transportation (i.e., transportation vehicle) and equipment handling for transportation of pressurized gases. As stated in the regulations, these measures also include a requirement for certificates and licences for handling compressed gases; regular inspections by professional personnel on pressurized vessels and pressurized piping systems; the development of Emergency Response Assistance Plans and, in case of any foreseen or actual accidental occurrence, reporting by designated personnel. An inspector may also inspect any matters related to the handling or transportation of these substances at any reasonable time.
2.2 Existing International Risk Management
In the United States, several regulations have been developed under National Emission Standards for Hazardous Air Pollutants (NESHAP) of the Clean Air Act that pertain to refineries, however the 4 petroleum and refinery gases referred to in this document have not been assessed under the NESHAP program, which primarily deals with discrete substances (National Archives and Records Administration, 1999, Federal Register - 40 CFR Part 63 – National Emission Standards for Hazardous Air Pollutants: Oil and Natural Gas Production and Natural Gas Transmission and Storage; Final Rule, June, 1999).
Transportation of pressurized gases that may pose a flammability or explosion hazard is covered under the Federal Hazardous Materials Regulations by the US Department of Transportation. Similar to the Canadian requirements, the US regulations are modeled on the UN Recommendations on the Transport of Dangerous Goods.
In Europe, the Directive for Integrated Pollution Prevention and Control (IPPC) sets out guidelines that must be followed to minimize pollution from various point sources, including petroleum refining. Best Available Techniques reference documents have been produced for the oil and gas refining sector and address reducing VOC emissions, particularly fugitive emissions; the Best Available Techniques reference document (BREF) on Mineral Oil and Gas Refineries was adopted in 2003. However a revised draft is currently in development.
Transportation of these substances in Europe is addressed by the European Agreement concerning the International Carriage of Dangerous Goods by Road, and is similarly covered for rail (under the regulations concerning the International Carriage of Dangerous Goods by Rail), and other modes of transportation. The European requirements are also compliant with the UN Recommendations on the Transport of Dangerous Goods.
3. Proposed Risk Management
As a result of a screening assessment of a substance under section 74 of CEPA 1999, the substance may be found to meet one or more of the criteria under section 64 of CEPA 1999. The Ministers can propose to take no further action with respect to the substance, to add the substance to the Priority Substances List (PSL) for further assessment, or to recommend the addition of the substance to the List of Toxic Substances in Schedule 1 of the Act. 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).
If the final screening assessment report does not conclude that these petroleum and refinery gases meet the conditions set out in subsection 77(4) of CEPA 1999, these substances will not be subject to the virtual elimination provisions under CEPA 1999. As a result, these petroleum and refinery gases would be managed using a life-cycle approach to prevent or minimize their release into the environment.
In accordance with the Government of Canada’s Cabinet Directive on Streamlining Regulation, the proposed risk management regulation(s), instrument(s) or tool(s) would be selected using a thorough, consistent and efficient approach and take into consideration the information received through the Chemicals Management Plan and other available information.
In the case of these petroleum and refinery gases, if the final screening assessment report concludes that these four substances meet one or more of the criteria under section 64 of CEPA 1999, options for risk management would focus on additional practices and technologies available for reducing fugitive emissions from petroleum facilities (which include refineries, upgraders and natural gas processing facilities). Where possible, efficiencies will be achieved by using a single instrument to address risks associated with several substances, such as the site-restricted (Stream 1) petroleum and refinery gases, if required.
The application of the Significant New Activity provisions under CEPA 1999 to these substances will also be recommended. These provisions would require that any proposed new manufacture, import, transport, or use be subject to further assessment to determine if the new activity requires further risk management consideration.
4. Next Steps
Industry and other interested stakeholders are invited to submit comments on the content of this risk management scope or other information that could inform decision making. Comments should be submitted prior to June 27, 2012 since the risk management for these petroleum and refinery gases will be moving forward after this date. A proposed Risk Management Approach is expected to be released at the time of the publication of the final screening assessment report for these substances. Another opportunity for consultation on the proposed risk management strategy will be provided at that time.
Comments and information submissions on this risk management scope should be submitted to the address provided below:
Program Development and Engagement Division
Gatineau QC K1A 0H3
Tel: 1-888-228-0530 / 819-956-9313
Canada. 1999. Canadian Environmental Protection Act, 1999. S.C., 1999, ch. 33 as amended from time to time. Canada Gazette. Part III. vol. 22, no. 3.
Canada. 2000. 1,3-Butadiene. Ottawa (ON): Environment Canada; Health Canada. (Priority substances list assessment report).
[CAPP] Canadian Association of Petroleum Producers. 2007. Best Management Practice for Fugitive Emissions Management.
[CCME] Canadian Council of Ministers of the Environment, 1993. Environmental Code of Practice for Measurement and Control of Fugitive VOC Emissions from Equipment Leaks.
[CPPI] Canadian Petroleum Products Institute. 2005 National Framework for Petroleum Refinery Emission Reductions (NFPRER).
Environment Canada. 2008. Data for industry-restricted petroleum and refinery gases collected under the Canadian Environmental Protection Act, 1999, Section 71 Notice with respect to certain high priority petroleum substances.
Environment Canada. 2009. Data for industry-restricted petroleum and refinery gases collected under the Canadian Environmental Protection Act, 1999, Section 71 Notice with respect to potentially industry-limited high priority petroleum substances.
[ESIS] European Chemical Substances Information System. 2008. Database developed by the European Chemicals Bureau (ECB). [cited 2008 Sep 11].
European Commission. 2004. Commission Directive 2004/73/EC of 29 April 2004 adapting to technical progress for the 29th time Council Directive 67/548/EEC on the approximation of the laws, regulations and administrative provisions relating to the classification, packaging and labelling of dangerous substances. Annex 1B. Official Journal of the European Union. 16.6.2004. L 216/72-L 216/86. 29th ATP. [cited 2008 Sep 17].
[EURAR] European Union risk assessment report: CAS: 106-99-0: 1,3-butadiene. 2002. Luxembourg: Office for Official Publications of the European Communities. Report No.: EUR 20420. On the cover, European Commission Joint Research Centre.
[SENES] SENES Consultants Limited. 2009. Review of current and proposed regulatory and non-regulatory management tools pertaining to selected petroleum substances under the Chemical Management Plan. Ottawa (ON): SENES Consultants Limited.
Treasury Board of Canada Secretariat. 2007. Cabinet Directive on Streamlining Regulation, section 4.4.
[US EPA] US Environmental Protection Agency. 2002. Health assessment of 1,3-butadiene. Washington (DC): US Environmental Protection Agency, National Center for Environmental Assessment. Report No.: EPA/600/P-98/001F.
 DSL = Domestic Substances List
 For more information on the assessment of 1,3 butadiene and additional risk management measures related to this substance, refer to 1,3-Butadiene - Ongoing risk management activities.
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