Proposed Plan of Priorities: substances prioritized for assessment under CEPA

Substances identified as priorities for assessment

Specific substances:

• 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta[g]-2-benzopyran (HHCB; CAS RN 1222-05-5)
• Apigenin (CAS RN 520-36-5)
• Dichloromethane (DCM; CAS RN 75-09-2)
• Methylene blue (CAS RN 61-73-4)
• Nanoscale silver (nAg; CAS RN 7440-22-4)
• Nanoscale zinc oxide (nZnO; CAS RN 1314-13-2)
• N,N-Dimethyl-p-toluidine (DMPT; CAS RN 99-97-8)
• Octocrylene (CAS RN 6197-30-4)
• Phosphine oxide, diphenyl(2,4,6-trimethylbenzoyl)- (PODP; CAS RN 75980-60)
• Quercetin (CAS RN 117-39-5)
• Styrene (CAS RNs 98-83-9 and 100-42-5)
• Tetrachloroethene (PERC; CAS RN 127-18-4)
• Trichloroethylene (TCE; CAS RN 79-01-6)
• Trimethylolpropane triacrylate (TMPTA; CAS RN 15625-89-5)

Certain substances within the following groups:

• 1,4-Benzenedimamine, N-(1,3-dimethylbutyl)-N'-phenyl- (6PPD)*, its transformation products, and related p-phenylenediamines (PPDs)
• Alkylbenzene sulfonates (ABS) and derivatives
• Alkylphenols
• Bisphenol A structural analogs and functional alternatives (BPA SAFA)
• Coumarins
• Fluoropolymers
• Hydroxybenzophenones
• Nanoscale forms of nickel oxide (nNiO)
• Nanoscale forms of titanium dioxide (nTiO₂)
• Oil sands process water naphthenic acids (OSPW NAs)*
• Organic flame retardants (OFRs)
• Pharmaceutical substances
• Quaternary ammonium compounds (QACs)
• Salicylates
• Terpenes of concern (TOC)
• Very hazardous substances capable of long-range transport (VH-LRT)
• Vetiver oils
• Xylenes

Rationales for priorities for assessment

1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethyl-cyclopenta[g]-2-benzopyran (HHCB) is a synthetic polycyclic musk fragrance used in personal care products, air fresheners, cleaners, pest control, and automotive care. Based on reported activity in a 2017 information gathering initiative and wastewater monitoring in Canada, aquatic organisms may be exposed to HHCB through wastewater from both manufacturers and the use of products available to consumers. HHCB has been classified and labelled internationally as having acute and chronic hazards to aquatic organisms and has been included on the NORMAN List of Emerging Substances. Additionally, the European Union has indicated that further evaluation of its persistence, bioaccumulation, toxicity and endocrine disrupting properties is needed; the US Environmental Protection Agency has designated it as a high priority for further assessment.

Apigenin and quercetin were identified based on their potential impact on the endocrine system. There is evidence of potential exposure in Canada from consumer use of personal care products based on reported activity in a 2017 information gathering initiative. The proposed approach is to consider quercetin and apigenin together.

1,4-Benzenediamine, N-(1,3-dimethylbutyl)-N'-phenyl-) (6PPD) is used globally in the manufacture of tires and other rubber products as an antiozonant and antioxidant (i.e., used to prevent or slow damage). In 2018, 6PPD was assessed as part of Substances identified as being of low concern using the ecological risk classification of organic substances (ERC) and the threshold of toxicological concern (TTC)-based approach for certain substances and found not to be a risk to the environment or human health under CEPA. The 2018 assessment however did not address the transformation product 6PPD-quinone, which was identified in December 2020 as a result of advances in analytical methods and efforts to understand urban runoff mortality syndrome, a phenomenon which has affected U.S. Pacific Northwest coho salmon for decades. This research linked 6PPD-quinone to the death of U.S. Pacific Northwest coho salmon in urbanized watersheds. The substances 6PPD-quinone may be a threat for this vulnerable species in Canada. Recent monitoring has also detected 6PPD-quinone in the Canadian aquatic environment at concentrations that may be of concern for coho salmon. 6PPD was included in a June 2023 information gathering initiative to collect updated information on its commercial status. A public request for the assessment of 6PPD was received and accepted for addition to the proposed Plan of Priorities under section 76 of CEPA. 6PPD and its transformation products, including 6PPD-quinone, are proposed to be considered together for assessment. Related p-phenylenediamine (PPD) substances may also be considered due to similarities with 6PPD in terms of commercial use, chemical structure, and potential to form harmful transformation products.

Alkylbenzene sulfonates (ABS) and derivatives are a large class of surfactant substances with common uses including cleaners, cosmetics, paints, coatings, lubricants and several other industrial applications. A subset of this group was prioritized during the 2006 Categorization of the Domestic Substances List; however, it was determined that assessment of a broader class would be more effective to discourage the selection of harmful substitutes. In addition, the Ecological risk classification of organic substances approach (version 2) has identified some of these substances as having a high risk potential. To more clearly inform next steps, these substances were included in a June 2023 information gathering initiative to collect information on the commercial status of the broad group of substances. These substances may be assessed in structurally similar subgroups.

People in Canada are exposed to alkylphenols through products used by consumers, including disinfectant products, food packaging, incidental food additives, plastic and rubber materials, fuels and additives, and craft paints. Medium and long chain alkylphenols (5 to 12 carbons long) have been associated with endocrine-related effects, in particular estrogen-binding affinity, and reproductive toxicity. The proposed approach is to subgroup substances by chain length for assessment, starting with dodecylphenol and its ethoxylates, which were included in the 2023 information gathering initiative.

Bisphenols are used in a variety of ways, including in plastics, thermal paper and other paper products, paint additives, adhesives and sealants, and in various automotive parts. This group contains a variety of substances that are structural analogs or functional alternatives for Bisphenol A (BPA), a chemical with endocrine disrupting properties that was in 2008 and concluded to be a risk to the environment and human health under CEPA. Regulatory action for BPA, as well as consumer and market shifts toward “BPA-free” products, has led to a rise in the use of BPA alternatives (e.g., Bisphenol S) that have not been assessed. A technical consultation document for a group of Bisphenol A structural analogues and functional alternatives (BPA SAFAs) was published in December of 2020, followed by an information gathering initiative on these substances in November 2021.

Coumarin-1 (7-(diethylamino)-4-methyl-2-benzopyrone, CAS RN 91-44-1) was assessed in 2023 and was concluded to be a risk to human health under CEPA. Additional scoping has identified a group of similar coumarin substances that are used in Canada in products available to consumers, such as fragrances, hair care, deodorants and tobacco products. Other jurisdictions have identified hazards with coumarins, including liver toxicity, skin sensitization, and developmental toxicity. There is also some evidence that people assigned male at birth may be at heightened risk for carcinogenic outcomes.

Dichloromethane (DCM) is used as a solvent in paint and furniture stripping products, a blowing agent in foam production, a component in aerosol products, and in other industrial process applications. DCM was assessed in 1993 and added to Schedule 1 of CEPA due to the risk to the environment and human health. The assessment indicated that there were adverse effects on aquatic organisms and that it was possibly carcinogenic to humans from its use as a paint remover, a blowing agent for foam production, and as a component of aerosols. Since that time, DCM has been found in a number of products available to consumers for which direct exposure was not explicitly considered as part of the human health component of the 1993 assessment. International work has been undertaken, including the proposed prohibition by the US Environmental Protection Agency of certain uses, and the European Chemicals Agency identifying DCM as a reproductive/developmental toxicant and potential endocrine disrupting compound. Canada’s 2022 performance measurement evaluation of DCM has recommended a re-examination, indicating that although the risk management goals were met for the risks previously identified (or exposures of concern), more work needs to be done to characterize the possible risk from the use of products available to consumers not specifically addressed in the 1993 assessment and to consider potential recommendations for occupational settings. Additionally, new scientific information suggests that the ozone depletion potential of DCM was likely underestimated in the 1993 assessment. Given the above, DCM has been included in a June 2023 information gathering initiative to collect updated information on its commercial status. Due to the new information available, additional risk characterization of this substance is proposed to determine whether there is need for further risk management measures.

Fluoropolymers have been defined in the Updated Draft State of Per- and Polyfluoroalkyl Substances (PFAS) Report as “polymers made by the polymerization or copolymerization of olefinic monomers (at least 1 of which contains fluorine bonded to 1 or both of the olefinic carbon atoms), which forms a carbon-only polymer backbone with fluorine atoms directly bonded to it”. Fluoropolymers are used in many sectors, e.g., aerospace, automotive, electronics, food, pharmaceutical, medical equipment and devices, textile, architecture, renewable energy, oil and gas, water and semiconductor industries. In Europe, fluoropolymers are included in the proposed universal restriction of PFAS, currently under evaluation by ECHA’s scientific committees. There is evidence to suggest that fluoropolymers may have different exposure and hazard profiles compared with other PFAS in the class. In order to further examine these differences, additional work is warranted. PFAS meeting the definition of fluoropolymers were therefore not addressed within the Updated Draft State of PFAS Report and are proposed for consideration in a separate assessment.

Benzophenone (CAS RN 119-61-9) was assessed in 2021 and concluded to be a risk to human health under CEPA. Following this, a list of structurally similar hydroxybenzophenones were identified that are also used as ultraviolet light filters in sunscreens, plastics, paints and coatings, and cosmetics, similar to benzophenone. They have been associated with adverse human health effects, including reproductive and endocrine effects. These substances were also associated with high or moderate hazard and moderate risk potential within the Ecological risk classification of organic substances approach (version 2). Hydroxybenzophenones were included in a June 2023 information gathering initiative to gather current information on their commercial status.

Methylene blue was identified based on its potential impact on the endocrine system. There is evidence of potential exposure in Canada from consumer use of personal care products based on reported activity in a 2017 information gathering initiative.

Nanoscale nickel oxide was identified under the Government of Canada initiative to ensure that nanomaterials currently in commerce in Canada undergo ecological and human health risk assessment. Nanoscale forms of nickel oxide have not been explicitly considered in the assessments of existing substances conducted under CEPA. Nanoscale nickel oxide (n-iO) is used in commercial and consumer products for energy storage, in magnetic materials, and in thermoelectric, catalytic and photocatalytic applications to name a few. nNiO is known to cause oxidative stress and toxicity to organisms in the environment. Non-nanoscale NiO was assessed in 1994 and added to Schedule 1 of CEPA alongside other nickel compounds due to its potential for human carcinogenicity. nNiO was found to be in commerce in Canada based on a 2015 information gathering initiative to determine the commercial status of nanomaterials. In addition, the increasing use of nNiO means that there may be greater potential for environmental and human exposure. The proposed approach is to conduct risk characterization of nNiO to determine whether there is need for specific risk management measures for the nanoscale forms.

Nanoscale titanium dioxide (nTiO₂) was identified under the Government of Canada initiative to ensure that nanomaterials currently in commerce in Canada undergo ecological and human health risk assessment. Nanoscale forms of titanium dioxide have not been explicitly considered in the assessments of existing substances conducted under CEPA. Based on a 2015 information gathering initiative and an additional 2020 follow-up to determine the commercial status of certain nanomaterials, nTiO₂ was found to be imported into Canada at a high volume in 2014 (>600,000 kg), and was reported to be used in various consumer products including self-care products, paints and coatings, adhesives and sealants, etc. nTiO₂ can be photoactive in the aquatic environment causing oxidative stress and potential toxicity to aquatic organisms. Titanium dioxide is a Group 2B carcinogen ''possibly carcinogen to humans'' according to the International Agency for Research on Cancer. nTiO₂ may have negative genotoxic neurotoxicological, cardiovascular, and reproductive effects. It has also been shown to cause pulmonary damage/inflammation following inhalation exposure.

Nanoscale zinc oxide (nZnO) was identified under the Government of Canada initiative to ensure that nanomaterials currently in commerce in Canada undergo ecological and human health risk assessment. Nanoscale forms of zinc oxide have not been explicitly considered in the assessments of existing substances conducted under CEPA. Based on a 2015 information gathering initiative and an additional 2020 follow-up to determine the commercial status of certain nanomaterials, nZnO was imported annually into Canada at volume of 79,000 kg, and was reported to be used in various consumer products, including some intended for use by or for children (e.g., toys, sunscreen lotions), food packaging, drugs and personal care and cosmetics. There is evidence that nanoscale zinc oxide can be harmful to human health and the environment. There is evidence that nZnO can affect aquatic organisms due to nanoparticle effects and release of the zinc ion. There is a concern for reproductive/developmental toxicity following exposure to nanoscale zinc oxide, and potential hazard resulting from repeated dose oral and inhalation exposure is moderate. Zinc oxide nanoparticles may exert genotoxic effects in mammalian cells.

Nanoscale silver was identified under the Government of Canada initiative to ensure that nanomaterials currently in commerce in Canada undergo ecological and human health risk assessment. Nanoscale forms of silver have not been explicitly considered in the assessments of existing substances conducted under CEPA. Nanoscale silver (nAg) is used in a wide variety of commercial and consumer products. Advances in the ability to synthesize nAg has allowed for innovation for the impregnation of nAg into common consumer products such as athletic clothing, bedding, cosmetics, and medical equipment, often leveraging the antimicrobial properties of the substance. Additionally, nAg is useful in electrical and optical applications. There is evidence that nanoscale silver can be harmful to human health and the environment. There is high potential for human health hazard as several studies have reported associations between exposure to silver nanoparticles and reproductive/developmental effects, and there is also evidence of neurotoxicity. In addition, preliminary findings for nAg suggest high aquatic toxicity, particularly to planktonic and bacteria species. nAg was found to be in commerce in Canada based on a 2015 information gathering initiative to determine the commercial status of nanomaterials.

DMPT is used in artificial nail products and adhesives as identified in a 2017 information gathering initiative. It was identified as a concern based on potential consumer uses and evidence of high hazard to human health. It is classified as a Group 2B carcinogen (i.e., possibly carcinogenic to humans) by the International Agency for Research on Cancer (IARC).

Octocrylene is mainly used in Canada as a UV filter/absorber in personal care products as identified in a 2017 information gathering initiative. It was identified as a priority due to inherent toxicity, persistence and bioaccumulation, as well as increasing quantities in commerce in Canada. The Ecological risk classification of organics substances approach (version 2) has identified this substance as having a high risk potential. This substance has also been identified for work internationally on the basis of ecological concerns. Numerous studies have identified octocrylene as being highly bioaccumulative and as a potential endocrine disruptor. Octocrylene has been shown to degrade to another chemical of concern, benzophenone, and may co-occur in consumer products with other organic UV filters.

Oil sands process-affected water (OSPW) is a waste product generated from oil sands mining, extraction and processing of bitumen. Stakeholders have raised concerns that the potential risks of naphthenic acids (NAs) in OSPW have not been evaluated. While large quantities of naphthenic acids may be found in tailing ponds, the degree of exposures to the environment and humans are not known. The extent of available hazard and exposure data is uncertain. Activities to better understand OSPW NAs are occurring under the Canada-Alberta Oil Sands Monitoring program. There are plans to develop federal environmental quality guidelines (FEQGs) for naphthenic acids in aquatic systems. Naphthenic acid fraction compounds and their salts have been added to CEPA’s National Pollutant Release Inventory, beginning with the 2020 reporting year. The addition includes OSPW NAs. A public request for the assessment of OSPW NAs was received and accepted for addition to the proposed Plan of Priorities under section 76 of CEPA.

People in Canada are exposed to organic flame retardants (OFRs) through products used in daily life including furniture, clothing, electronics and other materials. Firefighters have also raised concerns regarding their exposure to flame retardants released during household fires (see the Firefighters Action Plan). Some OFRs have shown evidence of genotoxicity, carcinogenicity, or adverse effects on reproductive and developmental systems. The ecological risk of flame retardants may also be of concern due to the persistence, bioaccumulation and hazardous properties of many flame retardants in the environment.

The list of OFRs currently proposed for assessment includes a variety of chemicals that could be used as flame retardants, many of which are structurally related to OFRs that were previously assessed and concluded to be a risk to the environment and human health under CEPA. The list includes both organophosphate (OPFRs) and brominated (BFRs) flame retardants.

Tetrabromobisphenol A (TBBPA) and 2 of its derivative substances, which were previously assessed under CEPA in 2013 and concluded to not be posing a risk to the environment or human health, were also included. New scientific information related to these substances indicate potential carcinogenicity, endocrine disrupting characteristics, and increased industrial activity, which warrants renewed attention on TBBPA and its derivatives. An information gathering initiative was published in June 2023 to collect information on the commercial status of TBBPA and 2 of its derivatives, which will inform the next steps. It is proposed that OFR substances be considered in structurally similar subgroups.

Pharmaceuticals contain ingredients that are designed to be biologically active in humans, livestock and companion animals, or farmed aquatic organisms (aquaculture). When pharmaceuticals are released into the environment, for example, during manufacture, use or disposal, even very small concentrations have the potential to affect organisms inhabiting the receiving environment. People may also be exposed to pharmaceuticals indirectly through contact with the environment, such as ingestion of drinking water. Some pharmaceutical substances have been identified as being persistent or bioaccumulative and inherently toxic to organisms. Some have endocrine disrupting properties. Some have common environmental exposure scenarios. For example, municipal wastewater may contain mixtures of pharmaceuticals from multiple sources, many which are released on a continual basis but poorly removed during wastewater treatment, and therefore may have the potential to cause cumulative effects.

Similar substances may be considered together for assessment, such as pharmaceutical substances with the same mode of action that are likely to co-occur. Some pharmaceuticals may also be proposed for assessment, for example, based on a review of substances on the Revised In Commerce List (R-ICL), or in the context of the development of a broader approach for addressing pharmaceuticals in the environment.

Phosphine oxide, diphenyl(2,4,6-trimethylbenzoyl)- (PODP) is a photopolymerization initiator that has a variety of uses, including in inks, toners, and colourants, as well as being used for the manufacture of plastic products. The Ecological Risk Classification of organic substances approach (version 2) has identified this substance as having a high risk potential and endocrine disrupting properties. It is also internationally classified as a reproductive toxicant. This substance was included in a June 2023 information gathering initiative to gather current information on its commercial status.

Quaternary ammonium compounds (QACs) are a large chemical class with many common uses including in disinfectants, pesticides, detergents, and personal care products. Most QACs are hazardous to aquatic organisms (many are biocidal by nature/design). Secondly, their total usage in Canada has historically been high, and an information gathering initiative conducted in 2018 on this broader group confirmed that many of these substances are used in very high quantities in Canada (millions kg/year). Furthermore, the COVID-19 pandemic resulted in a rise in the use of disinfectants worldwide, which included QACs. These substances may also be alternatives for triclosan, which was determined to pose a risk to the environment under CEPA in 2016. Thirdly, international jurisdictions have identified hazards with respect to QACs as part of their regulatory activities (for example California EPA biomonitoring priority chemicals, etc.). The proposed approach is to consider this class of substances by subgroups of structurally similar QACs.

The draft screening assessment of a select group of salicylates was published in March 2020 and it proposes to conclude that salicylic acid is a risk to human health under CEPA. Salicylic acid is associated with effects on the liver and kidney, as well as developmental effects. An additional group of salicylates on the Domestic Substances List (with various uses) have been identified that could potentially breakdown to salicylic acid and contribute to total exposure.

Styrene is a key monomer used globally for the production of polystyrene and as a co-polymer with other monomers (e.g., acrylates). Widely used in plastics, it is found in many commercial and consumer products, and in the environment. Styrene was assessed in 1993 and concluded not to be posing a risk to the environment or human health under CEPA; however, the previous assessment did not address exposure from products used by consumers as identified in a 2017 information gathering initiative. More recent international assessments have identified human health hazards, including being classified as possibly carcinogenic. This substance was also measured in the Canadian Health Measures Survey (CHMS) and detected in both blood samples (cycles 3, 4, and 5) and indoor air samples (cycle 2, 3, and 4).

Plant-derived “essential oils” have many components that can be extracted from different parts of a plant (e.g., leaves, seed, stem, flower, root, fruits, woods, barks, grass, gum, tree blossoms, bulbs, flower buds). These oils are complex substances, made of up many components, including Terpenes, but there is high variability in the concentration of the components, depending on source, extraction methods, and other variables, which can impact the safety of the oil itself. In the draft screening assessment of Terpenes and Terpenoids Acyclic, Monocyclic, and Bicyclic Monoterpenes Group, published in March 2020, a number of oils were assessed using hazard data from the primary Terpene of concern (TOC). However, most of these TOCs were not assessed under CEPA, yet are present in multiple oils which could result in combined exposures. People in Canada may be exposed to the TOCs in these oils through the use of personal care products, cleaning products, air fresheners, and solvents. These TOCs have shown a variety of hazardous effects including kidney, liver and bladder effects, reproductive and developmental effects, and changes in serum biochemistry. It is proposed that a number of common TOCs, including isomers, be assessed to better reflect the exposure to and hazard from a non-exhaustive number of oils.

Tetrachloroethene, also known as perchloroethylene (PERC), was assessed in 1993 and added to Schedule 1 of CEPA due to its risk to the environment. At the time, it was used principally as a dry-cleaning solvent, for cleaning and degreasing of metals, and for production of chlorofluorocarbons. Since then, risk management action has been taken to control releases of PERC to the environment. However, more recent international assessments have identified human health hazards, including being classified as possibly carcinogenic, and have implemented risk management measures based on those concerns. Additionally, data collected through an information gathering initiative in 2017 identified additional uses, such as in products for vehicles (e.g., brake cleaner, lubricant, polishing agent, tire sealant) and textiles (e.g., finishing agent, spot removers, water repellent), that could result in potential exposure for consumers. PERC was also included in the Canadian Health Measures Survey (CHMS) and detected in both blood samples (cycle 3) and indoor air samples (cycle 2). Additional risk characterization is being proposed to determine the need for further risk management measures.

Trichloroethene (TCE) was assessed in 1993 and added to Schedule 1 of CEPA due to the risk to the environment and human health. Since that time, new evidence of use in products available to consumers has been identified (e.g., lubricants and greases, adhesives and sealants, cleaning and furnishing care), which was not considered in the 1993 assessment and is not covered by existing risk management actions. There is also potential for exposure from environmental media, including drinking water and air. TCE is internationally classified as a carcinogen and has adverse effects on the liver, kidney, nervous system, immune system and reproductive/developmental systems. The US Environmental Protection Agency is proposing to prohibit the manufacture, processing and distribution of this substance based on unreasonable health risk. TCE has been included in a June 2023 information gathering initiative to collect information on the commercial status of this substance. Additional risk characterization of this substance is proposed to determine the potential need for further risk management measures.

Trimethylolpropane triacrylate (TMPTA) was identified based on its classification by IARC as a Group 2B carcinogen (i.e., possibly carcinogenic to humans), as well as its widespread use in cosmetics and personal care products in Canada and globally. TMPTA is also used as a photosensitive substance in the formulation of paints and coatings, inks, toners and colourants, and is used as an intermediate. Additionally, it is used as an adhesive and sealant substance in resin and synthetic rubber manufacturing, and as a paint additive used in motor vehicle manufacturing. Between 100,000 and 1,000,000 kg were reported to be imported in 2015 in Canada as identified in a 2017 information gathering initiative. TMPTA has been classified and labelled internationally as very hazardous to the aquatic compartment with acute and chronic effects. Available ecotoxicity data from the European Chemicals Agency (ECHA) indicate a potential for adverse effects to organisms in the aquatic compartment, such as mortality and growth inhibition, from exposure to this substance. TMPTA was also evaluated as part of the European Commission’s CoRAP substance evaluation process, which identified concerns including carcinogenicity, genotoxicity, and toxicity and risks for the environment. In addition, the Ecological risk classification of organic substances approach (version 2) has identified these substances as having a moderate risk potential based in part on the substance having a high hazard severity.

Substances that are very hazardous and can travel long distances (e.g., undergo long-range transport) in water and/or air may be harmful to human health or the environment at low concentrations. Unassessed substances on the Domestic Substances List that potentially have these characteristics were identified using the Ecological risk classification of organic substances approach (version 2). In this approach, VH-LRT substances were defined as having the potential for wide and rapid distribution of a poorly reversible or non-reversible effect over very long distances via air or water. Identified substances were included in a June 2023 information gathering initiative to gather information on their commercial status which will be used to refine their exposure profile. Given the properties of these substances, it is proposed to assess a subset of those found to be used in high quantities in Canada.

People in Canada are exposed to vetiver oils and their derivatives via products used by consumers. Vetiver oils are complex chemical mixtures and have shown adverse effects on the thymus and thyroid hormones in rats. 2 vetiver oil substances were initially prioritized with the Terpenes and Terpenoids: Tricyclic Sesquiterpenes and Triterpenoids group; however, they were removed from this group due to a lack of composition and toxicological data. Additional scoping and data generation were conducted to help fill data gaps and to identify similar substances to form an expanded group for assessment.

Xylenes are used in a variety of industrial and consumer applications, including as an octane booster in gasoline blending, paints and coatings, pesticide formulations, printing inks, adhesives and sealants, cleaning agents. Xylenes are also naturally present as a mixture of isomers in gasoline. Xylenes were assessed in 1993 and concluded not to be posing a risk to the environment or human health under CEPA. Since then, xylenes have been identified in uses not previously considered in the 1993 assessment, including in consumer uses, and large quantities in Canada have been identified from a 2017 information gathering initiative. Of note, the total quantity consumed in Canada was approximately 3.5 times the quantity identified in the 1993 assessment, and the quantity used in gasoline blending as an octane booster was approximately 8 times the quantity in the 1993 assessment. There were also indications from biomonitoring data that Canadians may be exposed to these chemicals. Xylenes are also part of an ongoing Community Rolling Action Plan (CoRAP) evaluation under the European Chemicals Agency (ECHA), in particular for neurotoxicity concerns. In addition, the Ecological risk classification of organic substances approach (version 2) has identified these substances as having a high-risk potential, and there is updated hazard data (e.g., from recent assessments or reviews) available since the 1993 assessment.

Work plan