Commercial Naphthenic Acids Group - information sheet

Naphthenic acids
CAS Registry Number 1338-24-5

Naphthenic acids, calcium salts (calcium naphthenates)
CAS Registry Number 61789-36-4

Publications summarized:

• Final Assessment for the Commercial Naphthenic Acids Group (published on January 27, 2024). Public comments received on the draft screening assessment were considered and a summary of the comments with Government responses was published.
• Associated notice: Canada Gazette, Part I: Vol. 158, No. 4 – January 27, 2024

On this page

• Overview
• About these substances
• Human and ecological exposures
• Key health and ecological effects (hazard)
• Consideration of subpopulations who may have greater susceptibility or greater exposure
• Risk assessment outcomes
  • Assessment conclusions
• Related resources

Overview

• The Government of Canada conducts risk assessments of substances under the Canadian Environmental Protection Act, 1999 (CEPA) to determine whether they present or may present a risk to human health or to the environment.
  • The risks posed by a substance are determined by both its hazardous properties (potential to cause adverse human health or ecological effects) and the amount or extent of exposure to people or the environment.
  • When needed, the Government implements risk management measures under CEPA and other federal acts to help prevent or reduce potential harm.
• The ecological hazard and exposure potentials of the two substances in this group were classified using the Ecological Risk Classification of Organic Substances (ERC) Approach.
• Exposure of the general population to CAS RN 1338-24-5 and calcium naphthenates through environmental media, food, or the use of products available to consumers is expected to be minimal. Critical health effects were not identified. Ecological exposure potential is low. The Government concluded that CAS RN 1338-24-5 and calcium naphthenates are not harmful to human health or to the environment at levels of exposure considered in the assessment.

About these substances

• The assessment focused on 2 commercial naphthenic acids obtained through the extraction of petroleum distillates: CAS RN 1338-24-5 and calcium naphthenates, referred to collectively as the Commercial Naphthenic Acids Group under the third phase of the Chemicals Management Plan (CMP).
• Both substances in this group are UVCBs (unknown or variable composition, complex reaction products, or biological materials).
• Commercial naphthenic acids are obtained during the extraction of petroleum distillates, such as jet fuel, kerosene, and diesel during oil processing. Salts of commercial naphthenic acids, such as calcium naphthenates, do not occur naturally.
• According to information gathered by the Government, in Canada, CAS RN 1338-24-5 is used in industrial lubricants and greases, as well as in paints and coatings. CAS RN 1338-24-5 may also be used in certain food packaging materials in Canada. No use of calcium naphthenates in products available to consumers was identified.
• The assessment focused on the commercial naphthenic acids, which differ from naphthenic acids present as a by-product in oil sands process-affected water (OSPW) generated from oil sands mining, extraction and processing of bitumen. OSPW naphthenic acids differ in source, composition, properties and use compared to commercial naphthenic acids. OSPW naphthenic acids are not included on the Domestic Substances List (DSL); therefore, they were not subject to categorization of the DSL and they are not considered in the assessment. Activities initiated under the Canada-Alberta Oil Sands Monitoring program to better understand the naphthenic acids present in OSPW are being pursued by Environment and Climate Change Canada. More information on these research activities is provided in the addendum to the summary of public comments received on the draft screening assessment for the Commercial Naphthenic Acids Group. Additionally, naphthenic acid fraction compounds (NAFCs) and their salts from OSPW have been added to the National Pollutant Release Inventory (NPRI) and there are plans to develop federal environmental quality guidelines (FEGQs) for water. New information generated with respect to the OSPW naphthenic acids will also be considered as part of the identification of risk assessment priorities (IRAP) under CEPA.

Human and ecological exposures

• The assessment indicated that in Canada, CAS RN 1338-24-5 and calcium naphthenates are mainly found in products that are intended for professional/industrial use, such as lubricants for specialized transportation equipment and paints for automobile refinishing. Therefore, exposure of people in Canada to these substances is not expected.
• Exposure of the general population to CAS RN 1338-24-5 and calcium naphthenates through environmental media, food, or the use of products available to consumers is expected to be minimal.
• According to the information considered under the ERC Approach, CAS RN 1338-24-5 and calcium naphthenates were identified as having low ecological exposure potential.

Key health and ecological effects (hazard)

• Critical effects of concern for human health have not been identified within the limited health effects data available for CAS RN 1338-24-5 and calcium naphthenates.
• According to information considered under the ERC Approach, CAS RN 1338-24-5 was identified as having a moderate ecological hazard potential based on potential to cause adverse effects in terrestrial food webs, while calcium naphthenates were identified as having a low ecological hazard potential.

Consideration of subpopulations who may have greater susceptibility or greater exposure

• There are groups of individuals within the Canadian population who, due to greater susceptibility or greater exposure, may be more vulnerable to experiencing adverse health effects from exposure to substances.
• Certain subpopulations are routinely considered throughout the assessment process, such as people of reproductive age and infants. For the commercial naphthenic acids group, these subpopulations were considered; however exposures were expected to be minimal based on use patterns and therefore were not quantified.

Risk assessment outcomes

• Assessments focus on information critical to determining whether the substances are harmful to human health or the environment under CEPA. This is done by considering scientific information, including information, if available, on subpopulations who may have greater susceptibility or greater exposure, vulnerable environments and cumulative effects and by incorporating a weight of evidence approach and precaution.
• Exposure of people in Canada to CAS RN 1338-24-5 and calcium naphthenates is expected to be minimal; therefore, the risk to human health is considered to be low.
• Based upon the outcome of the ERC Approach, these 2 substances are considered unlikely to be causing ecological harm.

Assessment conclusions

• The Government concluded that CAS RN 1338-24-5 and calcium naphthenates are not harmful to human health at levels of exposure considered in the assessment.
• The Government also concluded that these substances are not entering the environment at levels that are harmful.

Related resources

• The assessment focused on potential risks from exposure of the general population of Canada. Hazards related to chemicals used in the workplace are defined within the Workplace Hazardous Materials Information System (WHMIS). For information concerning workplace health and safety and what steps to take in the workplace, people in Canada should consult their employer or the Occupational Health and Safety Regulator in their jurisdiction.