Zinc and its compounds - information sheet

Update June 25, 2021

The Government of Canada published the Draft Screening Assessment for Zinc and its Compounds on June 29, 2019. The draft screening assessment is summarized on this page and has not changed. New information pertaining to zinc in the pulp and paper sector was identified after the publication of the draft and is described in the Additional Risk Characterization Document in Support of the Draft Screening Assessment for Zinc and its Compounds: Pulp and paper sector exposure and risk characterization. This document was published on June 25, 2021 and indicates that:

• new exposure data were identified or derived from measured zinc concentrations in water or effluent
• a potential for ecological harm from zinc was identified from a limited number of facilities in the pulp and paper sector.

The overall proposed conclusion in the draft screening assessment has not changed as a result of the new information. Interested parties are invited to comment on the additional risk characterization document during the 60-day public comment period ending on August 24, 2021 prior to the information being considered in the final screening assessment. Public comments received on the draft screening assessment, the risk management scope and the additional risk characterization document will be considered in the development of the final screening assessment and if appropriate, the risk management approach.  

On this page

• Overview
• About these substances
• Human and ecological exposures
• Key health and ecological effects (hazard)
• Risk assessment outcomes
  • Proposed screening assessment conclusions
• Preventive actions and reducing risk
• Related information

Overview

• The Government of Canada conducted a science-based evaluation, called a screening assessment, to address the potential for harm to Canadians and to the environment from zinc and its compounds.
• Under the Canadian Environmental Protection Act, 1999 (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. A substance may have hazardous properties; however, the risk to human health or to the environment may be low depending upon the level of exposure.
  • More information on assessing risk can be found in the Overview of Risk Assessment and related fact sheets, particularly on Types of Risk Assessment Documents and the Risk Assessment Toolbox.
• As a result of the draft screening assessment, zinc and soluble zinc compounds are proposed to be harmful to the environment, but not to human health at current levels of exposure.

About these substances

• The screening assessment focuses on the zinc moiety, and therefore, includes all forms of zinc found in commerce and those found in the environment, which are referred to collectively as zinc and its compounds. Included are 64 substances on the Domestic Substances List and 11 substances on the Revised In Commerce List under the Chemicals Management Plan (CMP).
• Zinc occurs naturally in zinc-enriched rocks and from human activities such as zinc metal production.
• According to information gathered by the Government, zinc is primarily used for galvanizing iron and steel products to prevent corrosion and rust. Other activities and uses of zinc and its compounds in Canada include metal mining, as a component in metallic element and alloy processes, non-ferrous metal smelting and refining processes, fertilizers, hard material tools, paints and coatings, plastic, and rubber.
• Zinc may be used in certain foods as a food additive or mineral nutrient.
• Zinc may also be present in certain food packaging materials, as well as products available to consumers including drugs, cosmetics, natural health products (for example, multi-vitamin/mineral supplements), pesticides, sealants, cleaning products, automotive products, and plant fertilizers.

Human and ecological exposures

• Food is the primary source of exposure of Canadians to zinc and its compounds. People may also be exposed to zinc and its compounds from environmental sources (for example, drinking water, soil, air, and house dust), and products available to consumers.
• The assessment took into consideration the results of human biomonitoring studies. Measuring substances in blood, urine or breast milk is called biomonitoring and is done on an ongoing basis through health studies or surveys, such as the Canadian Health Measures Survey. Finding the substance in the body does not necessarily mean that it is causing harm. Harmful effects will depend on the levels and the properties of the substances. The information on measured levels in humans is important to estimating exposure to Canadians.
• Zinc and its compounds have the potential to be released to the environment during industrial activities such as metal mining, base metals smelting (BMS) and refining, iron and steel manufacturing, and wastewater treatment systems.

 Key health and ecological effects (hazard)

• Although zinc is an essential element for human health, elevated intake may result in adverse health effects such as headaches, nausea, vomiting, loss of appetite, and abdominal cramps.
• Zinc is also an essential element in plants and animals for a variety of biological functions but may be harmful at elevated concentrations. In excess, it may produce adverse effects on behavior, reproduction, and biochemical and physiochemical reactions.  
• The ecological hazard characterization for zinc took into account factors that affect toxicity such as hardness, pH and dissolved organic carbon.   

Risk assessment outcomes

• Based upon a comparison of levels of total zinc in urine of Canadians and levels associated with adverse health effects, it was determined that the risk to human health from zinc and its compounds is low.
• Based upon the information presented in the screening assessment, it was determined that there is risk of harm to the environment from zinc and soluble zinc compounds. These substances may pose a risk to aquatic organisms through releases of zinc to water from metal mining effluent.
• Zinc and soluble zinc compounds are proposed to meet the persistence criteria but not the bioaccumulation criteria as set out in the Persistence and Bioaccumulation Regulations of CEPA 1999.
• The Government of Canada published the Draft Screening Assessment for Zinc and its Compounds on June 29, 2019. The public are invited to comment on this assessment, during the 60-day public comment period ending on August 28, 2019.

Proposed screening assessment conclusions

• As a result of the assessment, the Government is proposing that zinc and its compounds are not harmful to human health at current levels of exposure.
• However, the Government is proposing that zinc and soluble zinc compounds are entering the environment at levels that are harmful to the environment.

Preventive actions and reducing risk

• The Government of Canada published the Risk Management Scope for Zinc and Soluble Zinc Compounds under the Zinc and its compounds grouping on June 29, 2019. The public are invited to comment on the scope during the 60-day public comment period ending on August 28, 2019. If the proposed conclusion is confirmed in the final screening assessment, the Government will consider adding zinc and soluble zinc compounds to Schedule 1 of CEPA, 1999, also called the List of Toxic Substances. Adding a substance to the list does not restrict its use, manufacture or import. Rather, it enables the Government to take risk management actions under CEPA 1999.
• The Government will also consider the following actions to address ecological concerns:
  • Reducing release of zinc to water from metal mining activities by applying the updated zinc effluent limits in the Metal and Diamond Mining Effluent Regulations (MDMER). Information received from regulated mines in response to environmental effects monitoring requirements under these regulations will be reviewed to determine if additional regulatory or non-regulatory risk management is appropriate.
  • Reducing release of zinc to water from base metals smelting and refining by addressing facilities that are subject to the MDMER through the action proposed above for metal mining. Base metals smelting and refining facilities that are not subject to the MDMER are not proposed for risk management action.
  • Interested stakeholders are invited to provide information regarding dissolved concentrations of zinc in effluents, receiving environments, and reference areas for surface waters. Information on dissolved organic carbon, pH, and hardness related to these dissolved concentration of zinc in surface waters would be also be helpful.
• Additional information on the risk management of substances addressed under the CMP is available.

Related information

• Canadians are reminded to only take multi-vitamin/mineral supplements that have a Natural Product Number (NPN) on the label. Ingredient information can be found on the product label.
• Zinc and its compounds may be found in products available to consumers. Canadians should follow any safety warnings and directions on product labels 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.