Decenes Group - information sheet

1-Decene, dimer, hydrogenated (hydrogenated didecene)
CAS Registry Number 68649-11-6

1-Decene, tetramer, mixed with 1-decene trimer, hydrogenated (HTTD)
CAS Registry Number 68649-12-7

Overview

The Government of Canada conducted a science-based screening assessment under the Canadian Environmental Protection Act, 1999 (CEPA 1999) to address the potential for harm to Canadians and to the environment from 2 substances referred to collectively as the Decenes Group.
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.
The ecological hazard and exposure potentials of these 2 substances were classified using the Ecological Risk Classification of Organic Substances (ERC) Approach.
As a result of the draft screening assessment, the Government is proposing that these 2 substances are harmful to human health, but not to the environment, at levels of exposure considered in the assessment.
Also, the Government has published a risk management scope document for the Decenes Group to initiate discussions with stakeholders on the development of risk management options.

The screening assessment summarized here focuses on 2 substances, hydrogenated didecene and HTTD, referred to collectively as the Decenes Group under the Chemicals Management Plan (CMP).
The substances in the Decenes Group do not occur naturally.
According to information gathered by the Government, these substances are used in lubricants and greases (such as gear oil, transmission oil and firearm maintenance sprays).
Hydrogenated didecene is also used in self-care products (including lipsticks, moisturizers, cleansers and skin creams), and in mining applications.

Canadians may be exposed to hydrogenated didecene and HTTD mainly through the use of certain products available to consumers. Contact with these substances may occur through the following routes:
- oral ingestion from the use of lipsticks
- dermal (skin contact) from the use of self-care and automotive products
- inhalation (breathing in) from the use of cleaner, lubricant, and preservation spray products for firearm maintenance
According to the information considered under the ERC Approach, hydrogenated didecene was identified as having a low ecological exposure potential. HTTD, however, was identified as having a moderate ecological exposure potential based on its overall persistence and quantities reported in recent surveys.

The critical health effects identified for hydrogenated didecene and HTTD are effects on tissue in the nasal cavity and lungs through inhalation exposure.
No critical effects on human health have been identified for hydrogenated didecene and HTTD through the oral or dermal routes of exposure, based upon available information on these substances, and on similar chemicals.
According to information considered under the ERC Approach, hydrogenated didecene and HTTD were identified as having low ecological hazard potentials.

It was determined that hydrogenated didecene and HTTD may pose a risk to human health from potential inhalation exposure through their use in cleaner, lubricant, and preservative spray products used for firearm maintenance, based upon a comparison of levels to which Canadians may be exposed to these substances, and the levels associated with critical health effects.
Based upon the outcome of the ERC Approach, these 2 substances are considered unlikely to be causing ecological harm.
The Government of Canada published the Draft Screening Assessment for the Decenes Group on January 9, 2021. The public is invited to comment on the assessment during the 60-day public comment period ending on March 10, 2021.

The Government is proposing that hydrogenated didecene and HTTD may be harmful to human health.
The Government is also proposing that these substances are not entering the environment at levels that may be harmful to the environment.
It is also proposed that HTTD meets the persistence criteria but not the bioaccumulation criteria and that hydrogenated didecene does not meet the persistence and bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations of CEPA 1999.

The Government of Canada published the Proposed Risk Management Scope for the Decenes Group on January 9, 2021. The public are invited to comment on this document during the 60-day public comment period ending on March 10, 2021.
If the proposed conclusion is confirmed in the final screening assessment, the Government will consider adding hydrogenated didecene and HTTD to Schedule 1 of CEPA 1999, also called the List of Toxic Substances and will consider the following actions to address human health concerns:
- Regulatory and/or non-regulatory actions to reduce inhalation exposure of the general population to hydrogenated didecene and HTTD in cleaner, lubricant, and preservative spray products used for firearm maintenance that are available to consumers, and to prevent inhalation exposure from other types of spray cleaner/lubricant/preservation products available to consumers.
Information is being sought by the Government to inform risk management decision-making. Details can be found in the risk management scope, including where to send information during the public comment period, ending March 10, 2021.

Hydrogenated didecene and HTTD are found in products available to consumers. Canadians should follow any safety warnings and directions related to the product and dispose of products responsibly.
The screening assessment for the Decenes Group focused on potential risks of exposure to the general population of Canada, rather than occupational exposure. 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, Canadians should consult their employer for information on what steps to take in the workplace and/or the Occupational Health and Safety Regulator in their jurisdiction.