Aliphatic Diesters Group – information sheet

Hexanedioic acid, diisodecyl ester (DIDA)
CAS Registry Number 27178-16-1

Overview

The Government of Canada conducted a science-based evaluation, called a screening assessment, to address the potential for harm to Canadians and to the environment from substances in the Aliphatic Diesters Group.
Under the Canadian Environmental Protection Act, 1999 (CEPA 1999), the risk posed by a substance is determined by considering both its hazardous properties (its potential to cause adverse human health or ecological effects) and the amount of exposure there is to people and the environment. A substance may have hazardous properties; however, the risk to human health or to the environment may be low depending upon the level of exposure.
- More information on assessing risk can be found in the Overview of Risk Assessment and related fact sheets, particularly on Types of Risk Assessment Documents and the Risk Assessment Toolbox.
The ecological hazard and exposure potentials of both substances were classified using the Ecological Risk Classification of Organic Substances Approach.
DIDA may have hazardous properties; however, the risk to Canadians is low. It was concluded that DIDA is not harmful to human health or to the environment at current levels of exposure.

This screening assessment focused on the substance hexanedioic acid, diisodecyl ester, also referred to as DIDA. It is 1 of 2 substances referred to collectively as the Aliphatic Diesters Group under the Chemicals Management Plan (CMP).
The other substance, called nonanedioic acid, bis(2-ethylhexyl) ester (CAS RN 103-24-2), was determined to be of low concern to both human health and the environment through other approaches. Conclusions for that substance are provided in the Screening Assessment for Substances Identified as Being of Low Concern based on the Ecological Risk Classification of Organic Substances and the Threshold of Toxicological Concern (TTC)-based Approach for Certain Substances.
According to information gathered by the Government, DIDA is used as a plasticizer in electrical cables, as a processing aid, and as an ingredient in lubricants and greases in Canada.
Lubricant-type products available to consumers in Canada containing DIDA were identified as motor oils, power steering fluids, aerosol lubricants, and lubricant products designed to stop oil leaks.
DIDA is also used as a non-medicinal ingredient in natural health products.

Canadians may be exposed to DIDA from the use of products available to consumers, such as motor oil, aerosol lubricant, and limited natural health products.
According to information considered under the Ecological Risk Classification of Organic Substances Approach, DIDA was identified as having a high ecological exposure potential due to its overall persistence (ability to stay in the environment over time) and large use quantities.

There were limited health effects (hazard) data for DIDA, therefore, a comparative approach using similar chemicals, called read-across, was used for assessing potential health effects.
Using data available on a similar substance, developmental effects were identified as the important or “critical” effects for characterizing the risk to human health from DIDA exposure.
According to information considered under the Ecological Risk Classification of Organic Substances Approach, DIDA was identified as having a moderate level of ecotoxicity.

Based upon a comparison of levels to which Canadians can be exposed to DIDA and levels associated with health effects, the risk to human health from this substance is low.
Also, based upon the outcome of the Ecological Risk Classification of Organic Substances Approach, DIDA is considered unlikely to cause ecological harm.
The Government of Canada published the Final Screening Assessment for the Aliphatic Diesters Group on February 9, 2019.

As a result of the assessment, the Government concluded that DIDA is not harmful to human health at current levels of exposure.
The Government also concluded that DIDA is not entering the environment at levels that are harmful to the environment.

Although DIDA is not considered to be harmful to human health at current levels of exposure, this substance is considered to have a health effect of concern due to its potential to cause developmental effects. There may be a concern for human health if exposures to this substance were to increase.
Therefore, the Government published a notice of intent to apply Significant New Activity (SNAc) provisions of CEPA 1999 to DIDA. The SNAc provisions would require that the Government be notified of proposed new activities related to DIDA, and that the new activity be assessed before being undertaken. This publication has a 60-day public comment period ending on April 10, 2019.

DIDA may be found in products available to consumers. Canadians should follow any safety warnings and directions on product labels and dispose of products responsibly.
Canadians who may be exposed to DIDA in the workplace should consult with their employer and an occupational health and safety (OHS) representative about safe handling practices, applicable laws, and requirements under OHS legislation and the Workplace Hazardous Materials Information System (WHMIS).