加拿大发布国内物质清单中乙二胺四乙酸（EDTA）及其三种盐类的评估结果

Whereas EDTA and tetrasodium EDTA identified in the annex below are substances identified under subsection 73(1) of the Canadian Environmental Protection Act, 1999;

Whereas a summary of the screening assessment conducted on ferric monosodium EDTA and ferric ammonium EDTA pursuant to paragraphs 68(b) and (c) and on EDTA and tetrasodium EDTA pursuant to section 74 of the Act is annexed hereby;

And whereas it is concluded that the substances do not meet any of the criteria set out in section 64 of the Act,

Notice therefore is hereby given that the Minister of the Environment and the Minister of Health propose to take no further action on these substances at this time.

Catherine McKenna
Minister of the Environment

Ginette Petitpas Taylor
Minister of Health

ANNEX

Summary of the screening assessment of EDTA and its salts group

Pursuant to section 68 or 74 of the Canadian Environmental Protection Act, 1999 (CEPA), the Minister of the Environment and the Minister of Health have conducted a screening assessment of four substances referred to collectively as the EDTA and its salts group. Although there are other EDTA salts, substances in this group were identified as priorities for assessment as they met categorization criteria under subsection 73(1) of CEPA or were considered a priority on the basis of other human health concerns. The Chemical Abstracts Service Registry Numbers (CAS RNfootnote1), their Domestic Substances List (DSL) names and their common names are listed in the table below.

Substances in the EDTA and its salts group

Notes

Note a

This substance was not identified under subsection 73(1) of CEPA, but was included in this assessment as it was considered a priority based on other human health concerns.

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The four substances in this group do not occur naturally in the environment. Some of them are primarily used as chelating agents or preservatives in cleaning products, cosmetics, prescription and non-prescription drugs, natural health products, and products used by consumers. Other uses include manufacture of products for printing inks, paints and coatings, ion exchange agents, automotive care, water treatment, food packaging, and pest control. In 2011, only EDTA and tetrasodium EDTA were manufactured in Canada in quantities ranging from 100 to 10 000 kg. In the same year, all four substances were imported into Canada in quantities ranging from 1 000 to 10 000 000 kg.

The ecological risks of the substances in the EDTA and its salts group were characterized using the ecological risk classification of organic substances (ERC). The ERC is a risk-based approach that employs multiple metrics for both hazard and exposure based on weighted consideration of multiple lines of evidence for determining risk classification. Hazard profiles are established based principally on metrics regarding mode of toxic action, chemical reactivity, food web-derived internal toxicity thresholds, bioavailability, and chemical and biological activity. Metrics considered in the exposure profiles include potential emission rate, overall persistence, and long-range transport potential. A risk matrix is used to assign a low, moderate or high level of potential concern for substances on the basis of their hazard and exposure profiles. The ERC identified the four substances in the EDTA and its salts group as having low potential to cause ecological harm.

Considering all available lines of evidence presented in the screening assessment, there is a low risk of harm to organisms and the broader integrity of the environment from EDTA, tetrasodium EDTA, ferric monosodium EDTA, and ferric ammonium EDTA. It is concluded that EDTA, tetrasodium EDTA, ferric monosodium EDTA, and ferric ammonium EDTA do not meet the criteria under paragraph 64(a) or (b) of CEPA, as they are not entering the environment in a quantity or concentration or under conditions that have or may have an immediate or long-term harmful effect on the environment or its biological diversity or that constitute or may constitute a danger to the environment on which life depends.

Owing to their structural similarity and ability to chelate metals, EDTA, tetrasodium EDTA, ferric monosodium EDTA, and ferric ammonium EDTA were grouped together for characterization of risk to human health. A read-across approach was used in the absence of substance-specific data for the assessment of human health effects. EDTA salts also dissociate in solution and, accordingly, data from other EDTA salts (e.g. Na2EDTA) were also taken into consideration in characterizing the hazard of the four substances in this group.

The four substances within this group are not considered to be carcinogenic or genotoxic. In laboratory studies, systemic effects were observed only at high doses equal to or exceeding the limit dose of 1 000 mg/kg bw/day and were considered secondary to the chelating properties of substances in this group. In conjunction with the low oral and dermal absorption of substances in the group, health effects from exposure to the EDTA and its salts group are not expected. Inhalation risks to the EDTA and its salts group were not considered to be of concern due to their low to negligible volatility, as well as their potential uses. As hazard is low, risk is also considered to be low and quantitative estimates of exposure and risk were not derived.

On the basis of the information presented in the screening assessment, it is concluded that EDTA, tetrasodium EDTA, ferric monosodium EDTA, and ferric ammonium EDTA do not meet the criteria under paragraph 64(c) of CEPA, as they are not entering the environment in a quantity or concentration or under conditions that constitute or may constitute a danger in Canada to human life or health.

Overall conclusion

It is concluded that EDTA, tetrasodium EDTA, ferric monosodium EDTA, and ferric ammonium EDTA do not meet any of the criteria set out under section 64 of CEPA.

The screening assessment for these substances is available on the Canada.ca (Chemical Substances) website.