Proposed Registration Decision PRD2024-06, Didecyl Dimethyl Ammonium Chloride (DDAC), Acticide DDQ 50-E

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Pest Management Regulatory Agency
31 May 2024
ISSN: 1925-0886 (PDF version)
Catalogue number: H113-9/2024-6E-PDF (PDF version)

Summary

Table of contents

• Proposed Registration Decision for Didecyl Dimethyl Ammonium Chloride (DDAC)
• What does Health Canada consider when making a registration decision?
• What is Didecyl Dimethyl Ammonium Chloride (DDAC)?
• Health considerations
• Environmental considerations
• Value considerations
• Measures to minimize risk
• Next steps
• Other information

Proposed registration decision for didecyl dimethyl ammonium chloride (DDAC)

Health Canada's Pest Management Regulatory Agency (PMRA), under the authority of the Pest Control Products Act, is proposing registration for the sale and use of the technical, Acticide DDQ 80-F, and the end-use product, Acticide DDQ 50-E, containing the technical grade active ingredient didecyl dimethyl ammonium chloride (DDAC), for use as a material preservative in polymers.

DDAC is currently registered for use in a wide range of applications, including hard surface sanitization, industrial process fluids, and the antisapstain protection of wood. For details, see Proposed Re-evaluation Decision PRVD2008-27, Didecyl Dimethyl Ammonium Chloride Cluster (DDAC) and Re-evaluation Decision RVD2009-07, Didecyl Dimethyl Ammonium Chloride Cluster (DDAC) and also, PRVD2016-24 and RVD2017-09, Antisapstain and Joinery Uses of Didecyl Dimethyl Ammonium Chloride (DDAC).

An evaluation of available scientific information found that, under the approved conditions of use, the health and environmental risks and the value of the pest control products are acceptable.

This Overview describes the key points of the evaluation, while the Science Evaluation of the full version of Proposed Registration Decision PRD2024-06, Didecyl Dimethyl Ammonium Chloride (DDAC), Acticide DDQ 50-E provides detailed technical information on the human health, environmental and value assessments of DDAC and Acticide DDQ 50-E.

What does Health Canada consider when making a registration decision?

The key objective of the Pest Control Products Act is to prevent unacceptable risks to individuals and the environment from the use of pest control products. Health or environmental risk is considered acceptable^{Footnote 1} if there is reasonable certainty that no harm to human health, future generations or the environment will result from use or exposure to the product under its proposed conditions of registration. The Act also requires that products have value^{Footnote 2} when used according to the label directions. Conditions of registration may include precautionary measures on the product label to further reduce risk.

To reach its decisions, the PMRA applies modern, rigorous risk-assessment methods and policies. These methods consider the unique characteristics of sensitive subpopulations in humans (for example, children). They also consider the unique characteristics of organisms in the environment. These methods and policies also consider the nature of the effects observed and the uncertainties when predicting the impact of pesticides. For more information on how Health Canada regulates pesticides, the assessment process and risk-reduction programs, please visit the Pesticides and pest management page on Canada.ca.

Before making a final registration decision on DDAC and Acticide DDQ 50-E, Health Canada's PMRA will consider any written comments received from the public in response to this consultation document.^{Footnote 3} Health Canada will then publish a Registration Decision^{Footnote 4} on DDAC and Acticide DDQ 50-E, which will include the decision, the reasons for it, a summary of comments received on the proposed registration decision and Health Canada's response to these comments.

For more details on the information presented in this Overview, please refer to the Science evaluation of PRD2024-06.

What is didecyl dimethyl ammonium chloride (DDAC)?

DDAC is a biocide registered for the control of algae, bacteria, fungi or molluscs in the following use sites: indoor hard surfaces (for example, floors, walls, countertops), other indoor surfaces (for example, carpet, laundry), industrial process fluids (for example, open cooling water tower system, oil field water flood or salt water disposal systems, recirculating water cooling towers) and the antisapstain protection of wood. DDAC damages microbial cell membranes, leading to their death.

Health considerations

Can approved uses of DDAC affect human health?

Acticide DDQ 50-E, containing DDAC, is unlikely to affect your health when used according to proposed label directions.

Potential exposure to DDAC may occur when handling and applying the end-use product, and when coming into contact with treated surfaces. When assessing health risks, two key factors are considered:

• the levels at which no health effects occur and
• the levels to which people may be exposed.

The dose levels used to assess risks are selected to protect the most sensitive human population (for example, children and nursing mothers). As such, sex and gender are taken into account in the risk assessment. Only uses for which the exposure is well below levels that cause no effects in animal testing are considered acceptable for registration.

Toxicology studies in laboratory animals describe potential health effects from varying levels of exposure to a chemical and identify the dose level at which no effects are observed. The health effects noted in animals occur at dose levels more than 100-times higher (and often much higher) than levels to which humans are normally exposed when pesticide products are used according to label directions.

In laboratory animals, DDAC was of low acute toxicity via the dermal route. It was highly acutely toxic via the oral route, and corrosive to eyes and skin. Based on its corrosive nature, DDAC is also considered highly acutely toxic via inhalation. Evidence from the published literature suggests that DDAC causes an allergic skin reaction. As a result of these findings, the signal word "DANGER" and hazard statements "POISON", "CORROSIVE TO EYES AND SKIN", and "POTENTIAL DERMAL SENSITIZER" are required on the label.

The acute toxicity of the end-use product, Acticide DDQ 50-E, was based on the acute toxicity of the active ingredient DDAC. Therefore, the signal word "DANGER" and hazard statements "POISON", "CORROSIVE TO EYES AND SKIN", and "POTENTIAL DERMAL SENSITIZER" are also required on the end-use product label.

Registrant-supplied short- and long-term (lifetime) animal toxicity tests, as well as information from the published scientific literature, were assessed for the potential for DDAC to cause neurotoxicity, immunotoxicity, chronic toxicity, cancer, reproductive and developmental toxicity, and various other effects. The most sensitive endpoints for risk assessment were effects on the respiratory tract, delayed fetal development, general signs of ill health, and allergic skin reactions. There was no evidence of increased sensitivity of the young compared to adult animals. The risk assessment protects against the effects noted above and other potential effects by helping to ensure that the level of exposure to humans is well below the lowest dose level at which these effects occurred in animal tests.

Occupational risks from handling Acticide DDQ 50-E

Occupational risks are not of health concern when Acticide DDQ 50-E is used according to the proposed label directions, which include protective measures.

A risk assessment conducted for individuals mixing and adding Acticide DDQ 50-E to polymers, dispersions, lattices, solutions, and resins for the manufacturing of household/institutional laundry detergents, and individuals entering these facilities, indicated that risk is not of concern when the product is used according to label directions.

Workers adding Acticide DDQ 50-E to polymers, dispersions, lattices, solutions, and resins, can come in direct contact with Acticide DDQ 50-E on the skin or through inhalation. Therefore, the label will specify that anyone mixing or loading Acticide DDQ 50-E and performing cleaning and repair activities, must wear chemical-resistant coveralls over a long-sleeved shirt, long pants, chemical-resistant gloves, socks, chemical-resistant footwear, protective eyewear (goggles or face shield) and a respirator with a NIOSH-approved organic-vapour-removing cartridge (with a prefilter) approved for pesticides or a NIOSH-approved canister approved for pesticides.

There is potential for dermal exposure to downstream workers in the facilities where polymers treated with Acticide DDQ 50-E are manufactured. Since these workers are expected to be wearing personal protective equipment (PPE) as specified in the regulations regarding worker health and safety, it is likely that this will limit potential exposure when conducting postapplication activities.

In addition, there is potential for exposure to secondary occupational workers handling laundry detergent containing the preserved polymers, in commercial (large or small scale) laundry service facilities (for example, handling laundry from hotels, hospitals, restaurants). The risk assessment conducted indicated that the risk to secondary workers is not of concern when the laundry detergent is manufactured according to label directions.

Risks in residential and other non-occupational environments

Risks in residential and other non-occupational environments are not of health concern when Acticide DDQ 50-E is used according to the proposed label directions.

Adults, youth and children can come into direct contact with DDAC residues when adding laundry detergent to laundry or when wearing clothing laundered with the detergent. Taking into consideration the label statements and the duration of exposure, the risks to individuals handling laundry detergent, and wearing clothing laundered with the detergent are not of health concern.

Risks to bystanders

Bystander risks are not of health concern when Acticide DDQ 50-E is used according to the proposed label directions.

Bystander exposure is expected to be negligible for industrial scenarios where Acticide DDQ 50-E is used in the manufacturing of the laundry detergent. Therefore, health risks to bystanders are not of concern.

Environmental considerations

What happens when DDAC is introduced into the environment?

When used according to label directions, the risks associated with the use of Acticide DDQ 50-E, containing DDAC, are acceptable from the viewpoint of environmental protection.

DDAC is not expected to build-up in the environment, and exposure to non-target organisms is expected to be low. Under the use pattern proposed, DDAC is not expected to present a risk to non-target terrestrial and aquatic organisms. When used as a material preservative in accordance with the label directions and the required precautions, the product Acticide DDQ 50-E is expected to pose acceptable risks to the environment.

Value considerations

What is the value of Acticide DDQ 50-E?

Acticide DDQ 50-E is an effective material preservative, capable of preventing the growth of bacteria, yeast, and mould in polymer emulsions.

Water-based polymer emulsions, when contaminated by bacteria or fungi, provide an excellent environment for microbial life to grow. Acticide DDQ 50-E will help prevent spoilage of natural and synthetic polymer emulsions and dispersions by bacteria and fungi during the manufacturing process, and during bulk storage or transport. There are a number of other active ingredients currently registered as in-can polymer preservatives. DDAC will provide manufacturers an alternative that may help address issues with material compatibility, cost, microbial resistance or active ingredient availability.

Measures to minimize risk

Labels of registered pesticide products include specific instructions for use. Directions include risk-reduction measures to protect human and environmental health. These directions must be followed by law.

The key risk-reduction measures being proposed on the labels of Acticide DDQ 80-F and Acticide DDQ 50-E to address the potential risks identified in this assessment are as follows.

Key risk-reduction measures – Human health

Since there is potential for workers to come into direct contact with DDAC through the dermal or inhalation route, workers mixing and loading Acticide DDQ 50-E and performing cleaning and repair activities are required to wear chemical-resistant coveralls over a long-sleeved shirt, long pants, chemical-resistant gloves, socks, chemical-resistant footwear, protective eyewear (goggles or face shield) and a respirator with a NIOSH-approved organic-vapour-removing cartridge (with a prefilter) approved for pesticides or a NIOSH-approved canister approved for pesticides.

Key risk-reduction measures – Environment

• Precautionary label statements are required to inform users that the DDAC end-use product Acticide DDQ 50-E is toxic to aquatic organisms and to update the proposed label with the new effluent label statement.
• Storage and disposal statements are required.

Next steps

Before making a final registration decision on DDAC and Acticide DDQ 50-E, Health Canada's PMRA will consider any written comments received from the public in response to this consultation document up to 45 days from the date of publication (31 May 2024) of PRD2024-06. Please forward all comments to Publications. Health Canada will then publish a Registration Decision, which will include its decision, the reasons for it, a summary of comments received on the proposed decision and Health Canada's response to these comments.

Other information

When Health Canada makes its registration decision, it will publish a Registration Decision on DDAC and Acticide DDQ 50-E (based on the Science evaluation of PRD2024-06). In addition, the test data referenced in this consultation document will be available for public inspection, upon application, in the PMRA's Reading Room. For more information, please contact the PMRA's Pest Management Information Service.