Re-evaluation Decision RVD2022-13, Ziram and Its Associated End-use Products, Used as a Preservative in Adhesives, Final Decision

Pest Management Regulatory Agency
8 December 2022
ISSN: 1925-1025 (PDF version)
Catalogue number: H113-28/2022-13E-PDF (PDF version)

Summary

To obtain a full copy of Re-evaluation Decision RVD2022-13, Ziram and Its Associated End-use Products, Used as a Preservative in Adhesives please contact our publications office.

Should you require further information please contact the Pest Management Information Service.

Table of contents

Re-evaluation decision for ziram and associated end-use products

Under the authority of the Pest Control Products Act, all registered pesticides must be re-evaluated by Health Canada's Pest Management Regulatory Agency (PMRA), on behalf of the Minister of Health, to ensure that they continue to have acceptable risk to human health and the environment, and have acceptable value. The re-evaluation considers available data and informationFootnote 1 from pesticide registrants, published scientific reports, existing assessments, other governments, and international regulatory authorities, as well as comments received during public consultations. Health Canada applies internationally accepted current risk assessment methods as well as risk management approaches and policies. More details, on the legislative framework, risk assessment and risk management approach, are provided under the section of Evaluation Approach.

This document forms part of a re-evaluation assessment of several active ingredients used as preservatives in paints, coatings and related uses. As per Re-evaluation Note REV2018-02, Approach for the Re-Evaluation of Pesticides Used as Preservatives in Paints, Coatings and Related Uses, the paint-related uses of sodium omadine, chlorothalonil, dazomet, folpet and ziram were evaluated separately from other uses and relied on data provided by the registrants and the Antimicrobial Exposure Assessment Task Force II (AEATF II). This approach was adopted in order to obtain and review paint-related studies, have risk assessments more reflective of current and realistic exposure scenarios and to allow for a consistent approach to the risk assessment and risk management for these uses. In the absence of scenario-specific data, paint studies/data were used as surrogates for the assessment of building materials and adhesives.

Ziram is an "in-can" material preservative used to control bacterial and fungal degradation of dry starch and synthetic latex adhesives. The only other use of ziram, as a protectant fungicide in agriculture, was evaluated separately (Re-evaluation Decision RVD 2018-39, Ziram and Its Associated End-use Products for Agricultural Uses); all agricultural uses in Canada have been cancelled as a result of the re-evaluation. Therefore, all remaining registered products in Canada are solely for use as material preservatives in adhesives; refer to the Pesticide Product Information Database and Appendix I for a list of products.

The Proposed Re-evaluation Decision PRVD2020-04, Ziram and Its Associated End-use Products, Used as a Preservative in AdhesivesFootnote 2 containing the evaluation of the material preservative uses of ziram and proposed decision, was published on 9 July 2020 for a 90-day consultation period. An additional 60 days for consultation was provided in response to requests from stakeholders to accommodate time constraints imposed by pandemic measures; the 150-day consultation period ended on 6 December 2020.

PRVD2020-04 proposed the cancellation of material preservative uses of ziram due to risks of concern for occupational workers (mixing/loading the end-use product and handling the impregnated dry starch and latex adhesives) and residential handlers.

Health Canada received comments relating to the health and value assessments during the public consultation period conducted in accordance with section 28 of the Pest Control Products Act. Commenters are listed in Appendix II of RVD2022-13. These comments are summarized in Appendix III of RVD2022-13 along with the responses by Health Canada. These comments did not result in revisions to the health or value assessments, and therefore, did not result in changes to the proposed re-evaluation decision as described in PRVD2020-04.

A reference list of information used as the basis for the proposed re-evaluation decision is included in PRVD2020-04; no further information was used in the final re-evaluation decision. Therefore, the complete reference list of all information used in this final re-evaluation decision is set out in PRVD2020-04.

This document (Re-evaluation Decision RVD2022-13, Ziram and Its Associated End-use Products, Used as a Preservative in Adhesives) presents the final re-evaluation decisionFootnote 3 for ziram, including the required risk mitigation measures to protect human health. Environmental exposure from this use is expected to be minimal. All material preservative products containing ziram that are registered in Canada are subject to this re-evaluation decision.

Re-evaluation decision for ziram

Health Canada has completed the re-evaluation of ziram for use as a material preservative. Under the authority of the Pest Control Products Act, Health Canada is cancelling the registration of all ziram products in Canada. An evaluation of available scientific information found that risks to human health were not shown to be acceptable when ziram is used according to the current conditions of registration, or when additional mitigation is considered.

Next steps

To comply with this decision, all ziram products are cancelled (as of the date of publication) pursuant to paragraph 20(1)(b) of the Pest Control Products Act. Where risks of concern are not considered imminent and serious, existing stocks of the cancelled products are phased out in Canada following a general timeline of three (3) years from the publication date of the decision and following a sequential timeline provided for each level of the supply chain (in other words, at registrant, retail/distribution, and user levels). Health Canada has determined that the identified risks from the use of ziram in adhesives under the current conditions of use are not expected to be serious or imminent over the three-year phase-out period, as risks of concern were from long-term exposure durations.

Therefore, continued possession, handling, storage, and use of existing stock in Canada of these products will be authorized under paragraph 21(5)(a) of the Pest Control Products Act during the phase-out period as per the schedule below:

During the phase-out period, importing or manufacturing pest control products containing ziram in Canada is prohibited. In addition, registrants are required to continue to comply with sales and incident reporting obligations (relating to all pest control products containing ziram) during the phase-out period.

Ziram-Treated Articles

Information Note – Treated ArticlesFootnote 4 (September 2022) provides regulatory requirements for articles that have been treated with pesticides.

During the three-year phase-out period, the import of adhesive treated with ziram into Canada is permitted. After 3 years from the publication date of the decision document, the import of ziram-treated articles will be prohibited.

Other information

Any person may file a notice of objectionFootnote 5 regarding this decision on ziram and its associated end-use products, used as a preservative in adhesives within 60 days from the date of publication of this Re-evaluation Decision. For more information regarding the basis for objecting (which must be based on scientific grounds), please refer to the Pesticides section of the Canada.ca website (Request a Reconsideration of Decision) or contact Health Canada's Pest Management Information Service.

The relevant confidential test data on which the decision is based (as referenced in PRVD2020-04) are available for public inspection, upon application, in PMRA's Reading Room. For more information, please contact Health Canada's Pest Management Information Service.

Evaluation Approach

Legislative framework

The Minister of Health's primary objective under the Pest Control Products Act (or the Act) subsection 4(1) is to prevent unacceptable risks to individuals and the environment from the use of pest control products.

As noted in the preamble of the Act, it is in the national interest that the attainment of the objectives of the federal regulatory system continue to be pursued through a scientifically-based national registration system that addresses risks to human health, the environment and value both before and after registration and applies to the regulation of pest control products throughout Canada; and that pest control products with acceptable risk and value be registered for use only if it is shown that their use would be efficacious and if conditions of registration can be established to prevent unacceptable risks to human health and the environment.

For the purposes of the Act, the health or environmental risks of a pest control product are acceptable if there is reasonable certainty that no harm to human health, future generations or the environment will result from exposure to or use of the product, taking into account its conditions of registration as per subsection 2(2) of the Pest Control Products Act.

Risk for the human health and environment, and value are defined under the Act subsection 2(1) as follows:

When evaluating the health and environmental risks of a pesticide and determining whether those risks are acceptable, subsection 19(2) of the Pest Control Products Act requires Health Canada to apply a scientifically-based approach. The science-based approach to assessing pesticides considers both the toxicity and the level of exposure of a pesticide in order to fully characterize risk.

Risk and value assessment framework

Health Canada uses a comprehensive body of modern scientific methods and evidence to determine the nature as well as the magnitude of potential risks posed by pesticides. This approach allows for the protection of human health and the environment through the application of appropriate and effective risk management strategies, consistent with the purpose described in the preambular text set out above.

Health Canada's approach to risk and value assessment is outlined in A Framework for Risk Assessment and Risk Management of Pest Control Products.Footnote 6 A high-level overview is provided below.

i. Assessing Potential Health Risks

With respect to the evaluation and management of potential health risks, Health Canada's risk assessments follow a structured, predictable process that is consistent with international approaches and the Health Canada Decision-Making Framework for Identifying, Assessing, and Managing Health Risks.Footnote 7

The evaluation of potential health risks begins with a consideration of the toxicological profile of a pesticide to establish reference doses at which no adverse effect is expected and against which the expected exposure is assessed. This includes, where appropriate, the use of uncertainty (protection) factors to provide additional protection that accounts for the variation in sensitivity among members of human population and the uncertainty in extrapolating animal test data to humans. Under certain conditions, the Pest Control Products Act requires the use of another factor to provide additional protection to pregnant women, infants, and children. Other uncertainty factors, such as a database deficiency factor, are considered in specific cases. More details related to the application of the uncertainty factors are provided in SPN2008-01.Footnote 8

Assessments estimate potential health risks to defined populationsFootnote 9 under specific exposure conditions. They are conducted in the context of the registered conditions of use, such as the use of a pesticide on a particular field crop using specified application rates, methods and equipment. Potential exposure scenarios consider exposures during and after application of the pesticide in occupational or residential settings, food and drinking water exposure, or exposure when interacting with treated pets. Also considered are the anticipated durations (short-, intermediate- or long-term) and routes of exposure (oral, inhalation, or skin contact). In addition, an assessment of health risks must consider available information on aggregate exposure and cumulative effects.

ii. Assessing risks to the environment

With respect to the evaluation of environmental risks, Health Canada's environmental risk assessments follow a structured, tiered approach to determine the likelihood that exposure to a pesticide can cause adverse effects on individual organisms, populations, or ecological systems. This involves screening assessments starting with simple methods, conservative exposure scenarios and sensitive toxicity effects metrics, then moving on, where required, to more refined assessments that can include exposure modelling, monitoring data, results from field or mesocosm studies, and probabilistic risk assessment methods.

The environmental assessment considers both the exposure (environmental fate, chemistry, and behaviour, along with the application rates and methods) and hazard (toxic effects on organisms) of a pesticide. The exposure assessment examines the movement of the pesticide in soil, water, sediments and air, as well as the potential for uptake by plants or animals and transfer through the food web. The possibility for the pesticide to move into sensitive environmental compartments such as groundwater or lakes and rivers, as well as the potential for atmospheric transport, is also examined. The hazard assessment examines effects on a large number of internationally recognized indicator species of plants and animals (terrestrial organisms include invertebrates such as bees, beneficial arthropods, and earthworms, birds, mammals, plants; aquatic organisms include invertebrates, amphibians, fish, plants and algae), and includes considering effects on biodiversity and the food chain. Acute and chronic effects endpoints are derived from laboratory and field studies that characterize the toxic response and the dose–effect relationship of the pesticide.

The characterization of environmental risk requires the integration of information on environmental exposure and effects to identify which, if any, organisms or environmental compartments may be at risk, as well as any uncertainties in characterizing the risk.

iii. Value assessment

Value assessments consist of two components: an assessment of the performance of a pest control product and its benefits.

During re-evaluation, value is examined under current conditions and in light of alternative pest control methods (both chemical and nonchemical) that may have been developed since the pesticide was first registered. An assessment of the benefits associated with the pesticide may also be conducted to demonstrate its value in the current context, and to identify potential alternatives.

Risk management

The outcomes of the assessments of risks to human health and the environment, and the assessment of value, form the basis for identifying risk management strategies. These include appropriate risk mitigation measures and are a key part of decision-making on whether health and environmental risks are acceptable. The development of risk management strategies take place within the context of the pesticide's conditions of registration. Conditions can relate to, among other things, the specific use (for example, application rates, timing, frequency and method of application), personal protective equipment, pre-harvest intervals, restricted entry intervals, buffer zones, spray drift and runoff mitigation measures, handling, manufacture, storage or distribution of a pesticide. If feasible conditions of use that have acceptable risk and value cannot be identified, the pesticide use will not be eligible for registration.

The selected risk management strategy is then implemented as part of the re-evaluation decision. The pesticide registration conditions include legally-binding use directions on the label. Any use in contravention of the label or other specified conditions is illegal under the Pest Control Products Act. Implementation of post-market decisions follow the framework articulated in the Policy on Cancellations and Amendments Following Re-evaluation and Special Review.Footnote 10

Following a decision, continuous oversight activities such as post-market review, monitoring and surveillance, including incident reporting, all play an essential role to help ensure the continued acceptability of risks and value of registered pesticides.

Appendix I Registered products containing ziram in Canada as of 6 September 2022

Table 1 Registered products containing ziram in Canada that are cancelled as a result of re-evaluation
Registrant Registration number Product name Marketing classTable 1 Footnote 1 Formulation type Active ingredient
Taminco US LLC. 28426 Ziram Technical (98.4%) T Dust or Powder 98.4%
30858 Vancide MZ-98 C Dust or Powder 98.4%
Table 1 - Footnote 1

T = technical grade active ingredient; C = commercial

Return to Table 1 Footnote 1 referrer

Note: Discontinued products and products with submissions for discontinuation not included. Technical products where the registrant indicated that they did not support paint-related uses are not included.

Footnotes

Footnote 1

Canada. Health Canada. Information Note – Determining Study Acceptability for use in Pesticide Risk Assessments. Ottawa, 2019. (Internet: https://www.canada.ca/en/health-canada/services/consumer-product-safety/reports-publications/pesticides-pest-management/fact-sheets-other-resources/determining-study-acceptability-pesticide-risk-assessments.html; cited October 2022.)

Return to footnote 1 referrer

Footnote 2

"Consultation statement" as required by subsection 28(2) of the Pest Control Products Act.

Return to footnote 2 referrer

Footnote 3

"Decision statement" as required by subsection 28(5) of the Pest Control Products Act.

Return to footnote 3 referrer

Footnote 4

Canada. Health Canada. Information Note – Treated Articles. Ottawa, 2022. (Internet: https://www.canada.ca/en/health-canada/services/consumer-product-safety/reports-publications/pesticides-pest-management/fact-sheets-other-resources/treated-articles.html; cited October 2022.)

Return to footnote 4 referrer

Footnote 5

As per subsection 35(1) of the Pest Control Products Act.

Return to footnote 5 referrer

Footnote 6

Canada. Health Canada. PMRA Guidance Document, A Framework for Risk Assessment and Risk Management of Pest Control Products, 2021 (Internet: https://www.canada.ca/en/health-canada/services/consumer-product-safety/reports-publications/pesticides-pest-management/policies-guidelines/risk-management-pest-control-products.html, cited October 2022).

Return to footnote 6 referrer

Footnote 7

Canada. Health Canada Decision-Making Framework for Identifying, Assessing, and Managing Health Risks, 2000 (Internet: https://www.canada.ca/en/health-canada/corporate/about-health-canada/reports-publications/health-products-food-branch/health-canada-decision-making-framework-identifying-assessing-managing-health-risks.html, cited October 2022)

Return to footnote 7 referrer

Footnote 8

Canada. Health Canada. Science Policy Note: The Application of Uncertainty Factors and the Pest Control Products Act Factor in the Human Health Risk Assessment of Pesticides, 2008 (Internet: https://www.canada.ca/en/health-canada/services/consumer-product-safety/reports-publications/pesticides-pest-management/policies-guidelines/science-policy-notes/2008/application-uncertainty-factors-pest-control-products-act-factor-human-health-risk-assessment-pesticides-spn2008-01.html, cited October 2022).

Return to footnote 8 referrer

Footnote 9

Consideration of Sex and Gender in Pesticide Risk Assessment, 2020 (https://www.canada.ca/en/health-canada/services/consumer-product-safety/reports-publications/pesticides-pest-management/fact-sheets-other-resources/consideration-sex-gender-pesticide-risk-assessment-infographic.html, cited October 2022).

Return to footnote 9 referrer

Footnote 10

PMRA Regulatory Directive DIR2018-01 Policy on Cancellations and Amendments Following Re-evaluation and Special Review (https://www.canada.ca/en/health-canada/services/consumer-product-safety/reports-publications/pesticides-pest-management/policies-guidelines/regulatory-directive/2018/dir2018-01-policy-cancellations-amendments.html).

Return to footnote 10 referrer

Page details

Date modified: