Special Review Decision SRD2021-01, Special Review of Tetrachlorvinphos and Its Associated End-use Products

Pest Management Regulatory Agency
3 March 2021
ISSN: 2561-6269 (PDF version)
Catalogue number: H113-17/2021-1E-PDF (PDF version)

Summary

Table of contents

• Special Review Decision
• Next steps
• Other information
• Appendix I - Registered products containing tetrachlorvinphos as of 17 December 2020

Special Review Decision

Pursuant to subsection 17(1) of the Pest Control Products Act, Health Canada’s Pest Management Regulatory Agency (PMRA) conducted a special review of tetrachlorvinphos, based on the toxicology information submitted under section 12 of the Pest Control Products Act, following the re-evaluation of tetrachlorvinphos (Canada, 2003; and Canada, 2004). The aspects of concern identified for the special review are potential occupational and residential risks. Health Canada evaluated the aspects of concern that prompted the special review in accordance with subsection 18(4) of the Pest Control Products Act. Please refer to the PMRA Guidance Document, Approach to Special Reviews of Pesticides for additional information on special review triggers and the processes.

The document (Special Review Decision SRD2021-01, Special Review of Tetrachlorvinphos and Its Associated End-use Products) presents the final regulatory decision^{Footnote 1} for the special review of tetrachlorvinphos. All pest control products containing tetrachlorvinphos that are registered in Canada are subject to this special review decision (Appendix I). Prior to finalizing this decision, Health Canada published the Proposed Special Review Decision, PSRD2019-04, Special Review of Tetrachlorvinphos and Its Associated End-use Products ^{Footnote 2} for 45-day consultation.

Comments and additional information were received during consultation period. Comments are summarized in Appendix II of SRD2021-01 with the responses from Health Canada. The final special review decision considered the comments and information received during the consultation of PSRD2019-04. The outcome of the revised assessment of the aspects of concern based on additional information received is outlined below:

• The received information did not result in a change to the toxicology reference values established for the human health risk assessment in PSRD2019-04.
• Additional information resulted in revisions to the occupational and residential risk assessments of certain uses (see Science evaluation update and Appendix III of SRD2021-01 for more details) and did result in changes to the proposed special review decision as described in PSRD2019-04:
  • The non-cancer and cancer handler risks for applications of the wettable powder formulation to poultry dust boxes are shown to be acceptable and the use will be retained. An additional statement will be added to labels to prevent handlers from mixing the product with their hands, as the exposure assessment does not account for hand mixing.
  • The non-cancer and cancer handler risks for mechanically-pressurized handgun application to poultry facilities for fowl tick treatment are shown to be acceptable with additional mitigation measures (limiting the amount handled per day and reducing the spray volume) and the use will be retained.
  • The non-cancer handler risks for rotary or mechanical dust application of the wettable powder formulation to floors of poultry facilities are not shown to be acceptable even with additional personal protective equipment (PPE). Therefore, the use will be cancelled.
  • Residential postapplication dermal non-cancer and cancer risks resulting from exposure to pet collars are not shown to be acceptable when using data from the new pet collar study. In addition, risks were not shown to be acceptable for exposure when applying pet collars (PSRD2019-04). Pet collar products will be cancelled due to application and postapplication risks.

Following an evaluation of the aspects of concern, Health Canada has determined that continued registration of certain uses/products containing tetrachlorvinphos is acceptable with additional mitigation measures (Appendix IV of SRD2021-01). On this basis, Health Canada is confirming the registration for the following products containing tetrachlorvinphos for sale and use in Canada with additional risk mitigation measures, pursuant to subsection 21(1) of the Pest Control Product Act:

Commercial-class

• Ear tag product
• Wettable power product
  • Roost paint application to treat lice, mites, and lesser mealworms.
  • Handheld spray application to poultry to treat lice and mites.
  • Handheld spray application to poultry house floor management to treat lice, mites, and lesser meal-worms.
  • Handheld spray application to poultry droppings, manure piles, garbage piles, and under feed troughs to treat maggots.
  • Handheld spray application to livestock premises (1% and 2% dilution) to treat flies.
  • Application of the wettable powder formulation to poultry dust boxes to treat lice and mites.
  • Handheld spray application to poultry housing walls, ceilings, floor cracks and crevices to treat fowl ticks.

Domestic-class

• Flea and tick liquid (trigger spray) products

The assessment indicated that the potential risk to human health for the following uses of tetrachlorvinphos is not considered to be acceptable, and these uses are cancelled, pursuant to subsection 21(2)(b) of the Pest Control Product Act:

Commercial-class

• Wettable powder product.
  • Rotary or mechanical dust application of the wettable powder formulation to floors of poultry facilities

Domestic-class

• All flea and tick powder/dust products.
• All flea and tick pet collar products.

Next steps

To comply with this decision, the required amendments (mitigation measures and label updates) must be implemented on all product labels sold by registrants no later than 24 months after the publication date of SRD2021-01. Accordingly, both registrants and retailers will have up to 24 months from the date of this decision document to transition to selling the product with the newly amended labels. Similarly, users will also have the same 24-month period from the date of this decision document to transition to using the newly amended labels, which will be available on the Public Registry.

Certain tetrachlorvinphos products are to be cancelled since these product labels have no uses that are acceptable for continued registration as a result of this special review. Products that are cancelled will be phased out following the implementation timeline outlined below:

• One (1) year of sale by registrant from the publication date of this decision document, followed by;
• One (1) year of sale by retailer from the last date of sale by registrant, followed by;
• One (1) year of permitted use from the last date of sale by retailer.

Other Information

Any person may file a notice of objection^Footnote 3 regarding this decision on tetrachlorvinphos within 60 days from the date of publication of this special review decision. For more information regarding the basis for objecting (which must be based on scientific grounds), please refer to the Pesticides section of Canada.ca (Request a Reconsideration of Decision) or contact the PMRA's Pest Management Information Service.

Appendix I Registered products containing tetrachlorvinphos as of 17 December 2020

Table 1: Products requiring label amendments

Registration Number	Marketing Class	Registrant	Product Name	Formulation Type	GuaranteeFootnote 1
23019	Technical Grade Active Ingredient	The Hartz Mountain Corporation	Hartz Rabon Technical Insecticide (Tetrachlorvinphos)	Solid	98.7%
25338	Technical Grade Active Ingredient	Elanco Canada Limited	Technical Rabon Insecticide	Dust or powder	98.7%
17415	Commercial	Elanco Canada Limited	Debantic 50 WP Insecticide Poultry and Livestock Premises Spray	Wettable powder	50%
22880	Commercial	Bayer Inc.	Ectogard Insecticide Cattle Ear Tag	Solid	14.0%
25654	Domestic	Hartz Canada Inc.	Hartz Ultraguard Flea & Tick Spray For Dogs	Solution	1.08%
25655	Domestic	Hartz Canada Inc.	Hartz Ultraguard Flea & Tick Spray For Cats	Solution	1.08%
30181	Domestic	Hartz Canada Inc.	Hartz Ultraguard Plus Flea & Tick Spray For Dogs With Aloe	Solution	Tetrachlorvinphos 1.08% s-methoprene 0.07%

Table 2: Products cancelled as a result of this special review

Registration Number	Marketing Class	Registrant	Product Name	Formulation Type	GuaranteeTable 2 footnote 1
13266	Domestic	Hartz Canada Inc.	Hartz Incontrol Flea & Tick Collar For Cats	Slow release generator	14.55%
16673	Domestic	Hartz Canada Inc.	Hartz Ultraguard Flea & Tick Powder For Dogs	Dust or powder	3.3%
17959	Domestic	Hartz Canada Inc.	Hartz Ultraguard Flea & Tick Powder For Cats	Dust or powder	3.3%
18108	Domestic	Hartz Canada Inc.	Hartz Incontrol Flea & Tick Collar For Dogs	Slow release generator	14.55%
25381	Domestic	Hartz Canada Inc.	Hartz Ultraguard Plus Flea & Tick Collar For Cats & Kittens	Slow release generator	Tetrachlorvinphos 14.55% s-methoprene 1.02%
25382	Domestic	Hartz Canada Inc.	Hartz Ultraguard Plus Flea & Tick Collar For Dogs & Puppies	Slow release generator	Tetrachlorvinphos 14.55% s-methoprene 1.02%
25620	Domestic	Hartz Canada Inc.	Hartz Ultraguard Flea & Tick Collar For Dogs	Slow release generator	14.55%
25621	Domestic	Hartz Canada Inc.	Hartz Ultraguard Flea & Tick Collar For Cats & Kittens	Slow release generator	14.55%
28355	Domestic	Hartz Canada Inc.	Hartz Ultraguard Reflective Flea & Tick Collar For Dogs & Puppies	Slow release generator	14.55%
28356	Domestic	Hartz Canada Inc.	Hartz Ultraguard Reflective Flea & Tick Collar For Cats & Kittens	Slow release generator	14.55%
29475	Domestic	Hartz Canada Inc.	Hartz Ultraguard Flea & Tick Collar For Large Dogs	Slow release generator	14.55%
29476	Domestic	Hartz Canada Inc.	Hartz Ultraguard Flea And Tick Collar For Puppies	Slow release generator	14.55%
29720	Domestic	Hartz Canada Inc.	Hartz Ultraguard Plus Flea & Tick Collar For Dogs And Puppies With Reflect-X Shield	Slow release generator	Tetrachlorvinphos 14.55% s-methoprene 1.02%
29721	Domestic	Hartz Canada Inc.	Hartz Ultraguard Plus Flea & Tick Collar For Cats And Kittens With Reflect-X Shield	Slow release generator	Tetrachlorvinphos 14.55% s-methoprene 1.02%
31439	Domestic	Wellmark International	Vet-Kem Breakaway Flea & Tick Collar For Cats & Kittens	Slow release generator	14.55%
31440	Domestic	Wellmark International	Vet-Kem Flea & Tick Collar For Dogs	Slow release generator	14.55%
31441	Domestic	Wellmark International	Vet-Kem Ovitrol Breakaway Dual Action Flea & Tick Collar For Cats & Kittens	Slow release generator	Tetrachlorvinphos 14.55% s-methoprene 1.02%
31443	Domestic	Wellmark International	Vet-Kem Ovitrol Dual Action Flea & Tick Collar For Dogs & Puppies	Slow release generator	Tetrachlorvinphos 14.55% s-methoprene 1.02%
31444	Domestic	Wellmark International	Zodiac Breakaway Flea & Tick Collar For Cats & Kittens	Slow release generator	14.55%
31445	Domestic	Wellmark International	Zodiac Flea & Tick Collar For Dogs	Slow release generator	14.55%
31446	Domestic	Wellmark International	Zodiac Power Band Plus Breakaway Dual Action Flea & Tick Collar For Cats & Kittens	Slow release generator	Tetrachlorvinphos 14.55% s-methoprene 1.02%
31473	Domestic	Wellmark International	Zodiac Power Band Plus Ii Dual Action Flea & Tick Collar For Dogs & Puppies	Slow release generator	Tetrachlorvinphos 14.55% s-methoprene 1.02%