Triazines and Triazole Group - information sheet

• 1H-1,2,4-Triazol-3-amine
  (Amitrole)
  CAS Registry Number 61-82-5
• 1,3,5-Triazine-2,4,6(1H,3H,5H)-trione, 1,3-dichloro-, sodium salt
  (Sodium dichloroisocyanurate; NaDCC)
  CAS Registry Number 2893-78-9
• 1,3,5-Triazine-2,4,6-triamine, N,N,N',N',N'',N''-hexakis(methoxymethyl)-
  (Hexa(methoxymethyl)melamine)
  CAS Registry Number 3089-11-0

Publications summarized:

• Final Screening Assessment for Triazines and Triazole Group (published on July 3, 2021).
• Associated notice: Canada Gazette, Part I: Vol. 155, No. 27 – July 3, 2021

On this page

• Overview
• About these substances
• Human and ecological exposures
• Key health and ecological effects (hazard)
• Risk assessment outcomes
  • Screening assessment conclusions
• Preventive actions and risk reduction
  • Where to find updates
• Related resources

Overview

• The Government of Canada conducts risk assessments of substances under the Canadian Environmental Protection Act, 1999 (CEPA 1999) 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 both by its hazardous properties (potential to cause adverse human health or ecological effects) and the amount or extent of exposure to people and the environment.
  • When needed, the Government implements risk management measures under CEPA 1999 and other federal acts to help prevent or reduce potential harm.
• The ecological hazard and exposure potentials of these 3 substances were classified using the Ecological Risk Classification of Organic Substances (ERC) Approach.
• Amitrole, NaDCC, and hexa(methoxymethyl)melamine may be associated with health effects; however, at levels of exposure considered in the assessment, the Government concluded that they are not harmful to human health or the environment at levels of exposure considered in the assessment.

About these substances

• The screening assessment focused on 3 substances referred to as the Triazines and Triazole Group, under the third phase of the Chemicals Management Plan (CMP). The 3 substances are amitrole, NaDCC, and hexa(methoxymethyl)melamine.
• Two other substances (CAS RNs 101-37-1 and 288-88-0) were determined to be of low concern to both human health and the environment through another approach. Conclusions for these 2 substances are provided in the Final Screening Assessment for Substances Identified as Being of Low Concern using the Ecological Risk Classification of Organic Substances and the Threshold of Toxicological Concern (TTC)-based Approach for Certain Substances.
• Another substance (CAS RN 121-82-4) will be assessed in another screening assessment.
• The 3 substances in this group are not expected to occur naturally in the environment. According to information gathered by the Government, amitrole is registered in Canada as a herbicide; however, these products are in the process of being discontinued.
• NaDCC may be used in a variety of products, such as water treatment products, cleaning products, and disinfectants. It is also an active ingredient in pest control products.
• Hexa(methoxymethyl)melamine may be used in the manufacture of food packaging materials. It may be used in commercial products, such as paints and coatings as well as in automotive, aircraft and transportation applications.

Human and ecological exposures

• Exposure of Canadians to amitrole is not expected, based upon the uses of the substance identified in the screening assessment.
• Canadians may be exposed to:
  • NaDCC mainly from the use of products available to consumers, such as water treatment tablets and cleaning abrasive powders.
  • Hexa(methoxymethyl)melamine from its potential presence in drinking water. Exposure to this substance from food packaging is expected to be negligible.
• According to information considered under the ERC Approach, amitrole and NaDCC were identified as having low ecological exposure potential; however, hexa(methoxymethyl)melamine was classified as having a high ecological exposure potential due to its overall persistence and use quantities reported to the Government.

Key health and ecological effects (hazard)

• To identify health effects information, national and international reports of data were considered, including assessments by the Joint Food and Agriculture Organization of the United Nations/World Health Organization Expert Committee on Food Additives, the International Agency for Research on Cancer, and Health Canada's Pest Management Regulatory Agency (PMRA).
• Amitrole has been classified as:
  • a substance that is likely to cause cancer in humans, according to the United States National Toxicology Program, and
• a suspected or presumed reproductive toxicant by the European Chemical Agency.
• There were limited health effects (hazard) data for NaDCC and hexa(methoxymethyl)melamine; therefore, a comparative approach using similar chemicals, called read-across, was used for assessing potential health effects. Using data available for similar substances, the critical effects identified for these substances from laboratory studies were:
  • for NaDCC, effects on the urinary tract and heart, and
  • for hexa(methoxymethyl)melamine, effects on the bladder, urinary system and possible carcinogenicity.
• According to information considered under the ERC Approach, amitrole and hexa(methoxymethyl)melamine were identified as having low ecological hazard potential, while NaDCC was identified as having a high ecological hazard potential based on its reactivity and ecotoxicity.

Risk assessment outcomes

• As exposure of Canadians to amitrole is not expected, the potential risk to human health is considered to be low.
• The risk to human health from NaDCC and hexa(methoxymethyl)melamine is also considered to be low, based upon a comparison of levels to which Canadians may be exposed to these substances, and the levels associated with health effects, along with the consideration of international assessments.
• Based upon the outcome of the ERC Approach, these 3 substances are considered unlikely to be causing ecological harm.

Screening assessment conclusions

• The Government concluded that amitrole, NaDCC, and hexa(methoxymethyl)melamine are not harmful to human health at levels of exposure considered in the assessment, and that these 3 substances are not entering the environment at levels that are harmful.

Preventive actions and risk reduction

• Although a risk to human health or the environment has not been identified at current levels of exposure, there may be a concern if exposures to amitrole or to hexa(methoxymethyl)melamine were to increase. As a result, these substances may be considered in future initiatives to track their commercial status or identify new uses.

Where to find updates

• Updates can be found on the timeline for the Triazines and Triazole Group.
• Updates on information gathering initiatives and information on the risk management of substances addressed under the CMP is available.
• Use the Substances Search tool to find substances that are referenced in certain legislative or regulatory instruments or on Government of Canada websites.

Related resources

• In 2018, Health Canada's PMRA initiated a special review of amitrole. All pest control products containing amitrole are now being discontinued, and the special review of amitrole is closed.
• NaDCC may be 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 focused on potential risks from exposure of 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 and what steps to take in the workplace, Canadians should consult their employer and/or the Occupational Health and Safety Regulator in their jurisdiction.