Section 3: Mercury (and its Compounds)

Mercury (and its compounds) have been on the NPRI list of substances since the program's inception, with a 10-tonne manufacture, process and other use reporting threshold. Environment Canada and the NPRI Work Group on Substances recognized the need to lower the reporting threshold for mercury (and its compounds) to better track sources of on-site releases and off-site transfers. Mercury and mercury compounds are micro-pollutants which have significant environmental and human health impacts at relatively low levels. Mercury (and its compounds) occur naturally in the environment, but human activities can concentrate them to levels that are toxic to human health and the environment. Under certain circumstances, exposure to high levels of mercury in the environment has been linked to adverse effects on human health and wildlife, such as sensory or neurological impairments.

The Canada-Wide Standards for Mercury Emissions currently targets reductions in mercury emissions from base metals smelting and waste-incineration activities. Canada has signed a protocol on heavy metals under the United Nations Economic Commission for Europe (UN ECE) Convention on Long-range Transboundary Air Pollution, which has reporting requirements for three heavy metal pollutants - lead, mercury and cadmium. Atmospheric emissions of these metals are transported long distances across national boundaries. Canada has also committed to report on mercury releases as part of the Commission on Environmental Cooperation (CEC) Regional Action Plan on Mercury under the North American Free Trade Agreement (NAFTA).

As mercury and mercury compounds are components of commercial products, the NPRI has retained reporting criteria that are based on the quantity manufactured, processed or otherwise used of the substance. Environment Canada examined the impacts of three alternate NPRI thresholds for mercury - 0.5, 5 and 50 kg. At a threshold level of 5 kg, Environment Canada estimated that about 95% of known facility-based mercury releases will be reported to the NPRI, from more than 160 facilities. This 5-kg threshold level is consistent with the new threshold level of 10 pounds (4.5 kg) introduced for the 2000 reporting year by the United States Environmental Protection Agency (U.S. EPA) Toxics Release Inventory (TRI).

Because minimal releases of mercury (and its compounds) may result in significant adverse effects and can reasonably be expected to significantly contribute to exceeding the lower thresholds, Environment Canada removed the 1% concentration exemption for mercury (and its compounds).

Mercury (and its compounds) are listed in Schedule 1, Part 2, of the 2000 Canada Gazette notice. The pure element and any substance, alloy or mixture must be reported as the equivalent weight of the element. No unique CAS number is provided for this listing.

The reporting criteria for mercury (and its compounds) are outlined in Schedule 2, Part 2, of the 2000 Canada Gazette notice and in Figure 2.

Figure 2: Reporting Criteria for Mercury (and its Compounds)

Reporting Criteria for Mercury

A facility is required to report on-site releases and off-site transfers of mercury (and its compounds) if, during the 2000 calendar year:

AND

The 1% concentration exemption included in the 10-tonne manufacture, process or other use threshold for Schedule 1, Part 1, substances does not apply to mercury (and its compounds).

A Material Safety Data Sheet (MSDS) is an important source of information on the composition of a purchased product. Suppliers of hazardous materials are required, as part of the Workplace Hazardous Materials Information System (WHMIS), to supply MSDSs on request.

An example of estimating releases and transfers of mercury (and its compounds) is provided in Chapter 7. Appendix 7 identifies potential sources of mercury. Appendix 8 lists various materials and products known to contain mercury. The emission factor database discussed in Appendix 9 contains a list of substances known to contain mercury and emission factors for mercury (and its compounds).

The terms "manufacture", "process" and "other use" are defined below, as well as in Schedule 4 of the 2000 Canada Gazette notice.

The term "manufacture" means to produce, prepare or compound an NPRI substance. This also includes the incidental manufacture of an NPRI substance as a by-product resulting from the manufacture, processing or other use of other substances.

The term "process" means the preparation of an NPRI substance, after its manufacture, for distribution in commerce. Processing includes preparation of a substance with or without changes in physical state or chemical form. The term also applies to the processing of a mixture or formulation that contains an NPRI substance as one component, as well as the processing of "articles".

The terms "other use" and "otherwise used" encompass any use of an NPRI substance at a facility that does not fall under the definitions of "manufacture" or "process". This includes the use of the substance as a chemical processing aid, manufacturing aid or some other ancillary use. "Other use" does not include routine janitorial or facility grounds maintenance.

The practice of dentistry was added to the list of activities exempt from reporting to the NPRI for 2000. Environment Canada estimated that a dental facility would need to employ more than 14 dentists to meet the reporting criteria for mercury (and its compounds). As the resources required to inform this sector of the reporting requirements would be great and very few dental offices would be expected to meet the reporting criteria, Environment Canada chose to exempt dentists from reporting until further information becomes available. In an effort to reduce the releases of mercury to the environment, the Canadian Council of Ministers of the Environment (CCME) has developed a Canada-Wide Standard (see Appendix 6) to address the issue of mercury in dental amalgams.

An "article" is defined as a manufactured item that does not release an NPRI substance under normal conditions of processing or use. When articles such as metal sheets and bars are processed (punched, cut or sheared) and there are no releases, or the releases such as metal shearings or pieces are recycled 100% or with due care, the NPRI substances in that article need not be included in the threshold calculation. Exercising "due care" in ensuring 100% recycling means that the facility generated less than 1 kg of a substance listed in Schedule 1, Part 1, of the 2000 Canada Gazette notice as waste during the calendar year. Because of the low reporting threshold, Environment Canada has set no quantitative measure of "due care" in recycling mercury (and its compounds). Therefore, if an "article" containing mercury (and its compounds) is processed and there are releases, the mercury (and its compounds) must be included in the threshold calculation. Materials that are welded lose their "article" status because there are releases from the article during welding.

Example

A fluorescent lamp meets the above definition of an article. The mercury content of a fluorescent lamp is only included in a facility's calculation of the 5-kg reporting threshold if the item loses its article status, i.e., the lamp is broken, thus allowing release of mercury. Therefore, as long as fluorescent lamps remain articles, they are not included in calculating the reporting threshold.

If the reporting criteria are met for mercury (and its compounds), then all on-site releases and off-site transfers of mercury (and its compounds) must be reported regardless of the concentration or amount. The facility is required to submit a substance report even if on-site releases or off-site transfers are zero. You must account for total releases of mercury (and its compounds) from your facility to each environmental medium (air, water, land and underground injection).

Report on-site releases and off-site transfers of mercury (and its compounds) in units of kilograms (kg).

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