Substances identified as being of low concern using the ecological risk classification of inorganic substances and 3 human health science approaches - information sheet

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 21 substances identified as being of low concern.
Under 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.
As a result of the screening assessment, the Government concluded that these 21 substances are not harmful to human health or to the environment at current levels of exposure. Three of the substances (silicon carbide CAS RN 409-21-2, molybdenum oxide CAS RN 1313-27-5, and beryllium CAS RN 7440-41-7) are associated with human health effects of concern; however, the risk to Canadians was determined to be low at current levels of exposure.

The screening assessment summarized here focuses on 21 substances that were identified under the Chemicals Management Plan (CMP) as being of low concern to both human health and the environment, using 4 different streamlined science approaches, as noted below.
The human health risks of these 21 substances were characterized and published in one of the following human health science approach documents:

The biomonitoring-based approach 1 considers substances to be of low concern for human health when biomonitoring data indicates that exposure to Canadians from the substance is limited or unlikely.

The biomonitoring-based approach 2 considers substances to be of low concern for human health when biomonitoring data indicates that exposure to Canadians is below the biomonitoring guidance values (health effects) that are protective of human health.
The low human health hazard potential approach considers substances to be of low concern when there is sufficient hazard data to indicate that human health effects are limited or unlikely.

The ecological hazard and exposure potentials of these 21 substances were characterized using the Ecological Risk Classification of Inorganic Substances (ERC-I) Approach.

The human health exposure and risks were characterized using 2 science approaches based upon biomonitoring data. Human biomonitoring is the measurement of substances in blood, urine or breast milk through health studies or surveys. The information on measured levels in humans is important to estimating exposure to Canadians.

Three substances were characterized in the biomonitoring-based approach 1, and they are considered to have limited or unlikely exposure to Canadians.
Thirteen substances were characterized in the biomonitoring-based approach 2, and the exposure to Canadians is considered to be below the biomonitoring guidance values.

For these 21 substances, ecological exposure was characterized in the ERC-I Approach, using information from the Domestic Substances List (DSL) inventory updates, Canada Border Services Agency, National Pollutant Release Inventory (NPRI) , and data collected by federal and provincial water quality monitoring programs.

The general principles outlined in the Science Approach Document for Substances with Low Human Health Hazard Potential were taken into consideration for the human health effects assessment. Five substances are considered to have low health hazard potentials, based upon their limited or unlikely health effects.
Biomonitoring guidance values (health effects) were determined for 13 substances, as outlined in the Science Approach Document for the Biomonitoring-based Approach 2 .
The International Agency for Research on Cancer (IARC) has classified 3 of the 21 substances:

Silicon carbide (CAS RN 409-21-2) as being possibly carcinogenic to humans
Molybdenum oxide (CAS RN 1313-27-5) as being possibly carcinogenic to humans, based upon occupational exposure to the substance through steel production
Beryllium (CAS RN 7440-41-7) as being carcinogenic to humans, based upon occupational exposure to beryllium or beryllium compounds

IARC has classified fibrous silicon carbide as possibly carcinogenic to humans; however, at the time of the screening assessment, only non-fibrous sources were used in Canada. Non-fibrous silicon carbide was determined to be of low concern for human health based upon the low human health hazard potential approach.
For these 21 substances, ecological hazard was characterized in the ERC-I Approach, using information from past domestic and international assessments and water quality guidelines. When no suitable hazard data were available, multiple sources of information were consulted to derive predicted no-effect concentrations.

Using the 3 human health science approaches, these 21 substances were characterized as being of low concern for human health.
Using the ERC-I Approach, these 21 substances were characterized as having low ecological concern.
The Government of Canada published the Final Screening Assessment for Substances Identified as Being of Low Concern Using the Ecological Risk Classification of Inorganic Substances and Three Human Health Science Approaches on November 14, 2020.

The Government concluded that these 21 substances are not harmful to human health, and are not entering the environment at levels that are harmful to the environment.

Although these substances are not considered to be harmful to human health at current levels of exposure, 3 of the substances (silicon carbide, molybdenum oxide, and beryllium) are considered to have health effects of concern based upon their potential carcinogenicity. Therefore, there may be a potential risk for human health if exposures were to increase.
For this reason, the Government will undertake information gathering activities to track changes in exposure and use patterns for silicon carbide.
Available information on current and potential future uses of molybdenum oxide and beryllium does not suggest a likelihood that exposures will increase to levels of concern to human health. For this reason, specific follow-up activities to track changes in exposure and/or commercial use patterns for these substances are not being considered at this time.

These substances 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 for these substances 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 . 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.