Screening Assessment Petroleum Sector Stream Approach Natural Gas Condensates Environment Canada Health Canada December 2016 - Screening Assessment Natural Gas Condensates Synopsis Pursuant to sections 68 and 74 of the Canadian Environmental Protection Act, 1999 (CEPA), the Ministers of the Environment and of Health have conducted a screening assessment of natural gas condensates (NGCs), a class of substances that share similar sources, properties, and use. In this screening assessment, NGCs are defined as complex combinations of hydrocarbons that condense or are separated from the gaseous phase into the liquid phase: during production at wellheads; in natural gas processing plants; in gas pipelines for production, gathering, transmission and distribution; and/or in straddle plants along the main gas pipelines. NGCs consist of hydrocarbons mostly falling within, but not necessarily spanning, a carbon range of C2 to C30, with predominant hydrocarbons typically falling between C5 and C15. In addition, this definition encompasses all liquids derived from natural gas distillates, except those with predominant hydrocarbon fractions below C5. The largest use of condensates in Canada is as a diluent for bitumen or heavy crude oils. About 23% of the NGCs used for this purpose can be recovered from the diluted materials in petroleum refineries and/or upgraders for reuse; this recovered NGC is also considered within the context of this assessment. Other uses are as industrial feedstocks and as gasoline blending stocks. NGCs were included in the Petroleum Sector Stream Approach (PSSA) because they are related to the petroleum sector and are considered to be of Unknown or Variable composition, Complex reaction products or Biological materials (UVCBs). Following the categorization of the Domestic Substances List, three NGCs (CAS RNs 64741-47-5, 64741-48-6 and 68919-39-1) were identified as priorities for assessment as they met the categorization criteria under subsection 73(1) of CEPA and were identified as priorities based on other human health concerns. Due to their similarity of sources, properties, hazard, and the compositional variability within, and overlap between NGCs that can lead to interchangeable use of CAS RNs, this screening assessment encompasses all NGCs as described in the Substance Identity and Uses sections. Spill data for NGCs for the years 2002-2011 from the province of Alberta were analyzed to provide an indication of the frequency and magnitude of spills to land and freshwater. Spill data for this same period from the Nova Scotia and Newfoundland and Labrador offshore petroleum boards were used for the analyses of spills to marine water. The risk analysis conducted with these data indicates that NGCs may cause harm to soil organisms given the frequency and volume of spills to land (i.e., approximately 50 reported spills per year with a median volume of 500 L). In addition, there are, on average, two reported spills/year of NGCs to freshwater that may cause harm to aquatic organisms. Given the low reported frequency and magnitude of release of NGCs to marine water, there is a low risk of harm to marine organisms. i - Screening Assessment Natural Gas Condensates Considering all available lines of evidence presented in this screening assessment, there is risk of harm to organisms, but not to the broader integrity of the environment from NGCs. It is concluded that NGCs meet the criteria under paragraph 64(a) of CEPA as they are 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. However, it is concluded that NGCs do not meet the criteria under paragraph 64(b) of CEPA as they are not entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger to the environment on which life depends. Exposure and hazard information on the three high-priority NGCs (CAS RNs 64741-47-5, 64741-48-6 and 68919-39-1), as well as information on NGCs in general, were used for the human health portion of this assessment. Due to the absence of relevant toxicological studies on NGCs, health effects information on benzene and low boiling point naphthas (LBPNs) (that are similar to NGCs from a physical-chemical perspective) were considered. Benzene, a component of NGCs, has been identified by Health Canada and several international regulatory agencies as a carcinogen, and was added to the List of Toxic Substances in Schedule 1 of CEPA. Based on an analysis of the major hydrocarbon constituents of NGCs, benzene was selected as a high-hazard component to characterize potential exposure and risk to the general population from evaporative emissions of NGCs. The potential for general population exposure to NGCs was evaluated by considering data on the handling/transportation of CAS RNs 64741-47-5, 64741- 48-6 and 68919-39-1 and on evaporative emissions from NGC storage facilities. For non-cancer endpoints, margins of exposure (MOEs) for short-term inhalation exposures to evaporative emissions of NGCs in the vicinity of rail loading/unloading sites are considered potentially inadequate to address uncertainties related to health effects and exposure. For cancer endpoints, MOEs based on upper-bounding estimates of long-term inhalation exposures to evaporative emissions of NGCs in the vicinity of high-volume rail or truck loading/unloading sites, as well as in the vicinity of NGC storage facilities, are considered potentially inadequate to address uncertainties related to health effects and exposure. Based on the information presented in this screening assessment, it is concluded that NGCs meet the criteria under paragraph 64(c) of CEPA as they are 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. It is concluded that natural gas condensates meet one or more of the criteria set out in section 64 of CEPA. ii - Screening Assessment Natural Gas Condensates Table of Contents Synopsis ............................................................................... i Table of Contents ............................................................... iii List of Tables ....................................................................... v 1. Introduction ..................................................................... 1 2. Substance Identity .......................................................... 3 3. Physical and Chemical Properties ................................ 5 4. Sources .......................................................................... 10 5. Uses ................................................................................ 11 6. Release to the Environment ......................................... 12 6.1 Releases from Petroleum Facilities ........................................................... 12 6.2 Unintentional Releases – Spills to the Environment .............................. 16 6.3 Releases from Transportation ................................................................ 18 7. Environmental Fate and Behaviour ............................. 19 7.1 Environmental Distribution ......................................................................... 19 7.1.1 Fate in Water ...................................................................................... 20 7.1.2 Fate in Soil .......................................................................................... 22 7.2 Persistence and Bioaccumulation Potential ........................................... 24 7.2.1 Environmental Persistence .............................................................. 24 7.2.2 Potential for Bioaccumulation .......................................................... 26 8. Potential to Cause Ecological Harm............................ 27 8.1 Ecological Effects Assessment .................................................................. 27 8.1.1 Aquatic Compartment ......................................................................... 28 8.2 Ecological Exposure Assessment .......................................................... 39 8.2.1 Aquatic Compartment ......................................................................... 39 8.2.2 Terrestrial Compartment ..................................................................... 41 8.3 Characterization of Ecological Risk ....................................................... 41 8.3.1 Conclusion .......................................................................................... 46 iii - Screening Assessment Natural Gas Condensates 8.3.2 Uncertainties in Evaluation of Ecological Risk .................................... 46 9. Potential to Cause Harm to Human Health ................. 47 9.1 Exposure Assessment ........................................................................... 47 9.2 Health Effects Assessment ........................................................................ 58 9.3 Characterization of Risk to Human Health ................................................. 62 9.4 Uncertainties in Evaluation of Risk to Human Health ................................ 65 10 Conclusion .................................................................... 66 11. References ................................................................... 67 Appendix A: Petroleum substance grouping ................................................... 95 Appendix B: Other terms