What Permethrin Does (and Why It’s Different from DEET)
Permethrin is a synthetic version of pyrethrin, the natural insecticide found in chrysanthemum flowers. Unlike DEET and picaridin (which are repellents applied to skin), permethrin is a contact insecticide applied to clothing. When a tick or mosquito lands on permethrin-treated fabric, the chemical disrupts its nervous system within seconds — the insect either falls off or dies before biting through the fabric.
This is why permethrin is the gold standard for hikers, military personnel, and outdoor workers — DEET only works while it’s wet on your skin (a few hours), while permethrin-treated clothing remains active for 6 weeks of wear or 6 wash cycles.
Why Yard-Application Permethrin Is Restricted in Canada
Health Canada’s Pest Management Regulatory Agency (PMRA) classifies pesticides into Domestic, Commercial, and Restricted use categories. Higher-concentration permethrin products intended for yard application — the kind you can buy at a US Home Depot — fall under Commercial or Restricted classification in Canada, requiring a licensed applicator.
This is partly because PMRA is more conservative about residential exposure than the US EPA, and partly because Ontario has additional Cosmetic Pesticides legislation limiting which products can be applied to residential lawns at all. The result: most yard-application permethrin you see online or in US retailers cannot be legally imported and applied to a Canadian residential property.
What You CAN Buy as a Canadian Consumer
1. Sawyer Permethrin Clothing Spray (0.5%)
The standard product. Apply to outdoor clothing — pants, shirts, socks, hat, hiking boots, gear bags. Let dry 24 hours before wearing. Re-apply after 6 wash cycles. Effective against ticks, mosquitoes, blackflies, and chiggers.
2. Insect Shield Factory-Treated Clothing
Pre-treated clothing from outdoor brands (ExOfficio, Orvis, Columbia, etc.) using a proprietary permethrin-bonding process. Lasts 70 wash cycles vs 6 for spray-on. Higher upfront cost ($40–$120 per garment) but far lower long-term cost for frequent hikers.
3. Permethrin-Treated Pet Products (Dogs Only)
Some flea/tick collars and topical treatments for dogs use permethrin-based formulations. Veterinarian prescription typically required. NEVER use on cats — even passive exposure to permethrin is fatal to cats.
The Licensed-Applicator Alternative for Whole-Yard Treatment
If you want yard-wide tick and mosquito protection (not just clothing), the only legal residential option in Ontario is hiring a licensed pesticide operator. Licensed Ontario applicators use Health Canada-approved formulations (typically bifenthrin or deltamethrin-based) that provide 21–30 days of residual yard protection per treatment.
BuzzSkito is licensed under Ontario Pesticide Operator Licence #L-240-2436835197 and provides residential mosquito and tick barrier spray across the GTA. Single treatments start at $99; seasonal programs cover the full May–September season with bi-weekly or weekly applications. Get a free quote for your property →
Permethrin vs Other Repellents — Side-by-Side
| Compound | Application | Duration | Best For |
|---|---|---|---|
| Permethrin | Clothing (NOT skin) | 6 weeks / 6 washes | Hiking, ticks, hardcore outdoors |
| DEET 30% | Skin | 5–8 hours | Active outdoor use |
| Picaridin 20% | Skin | 5–7 hours | DEET alternative, kid-friendly |
| Thermacell | 4.5m radius | 4 hr per mat | Stationary patio use |
| Bifenthrin (Pro) | Whole yard | 21–30 days | Licensed barrier spray |
Stacking Permethrin with Other Strategies
Smart Ontario hikers and homeowners use permethrin as ONE layer of a multi-tool strategy:
- Permethrin clothing spray for hiking, yard work in tick zones, evening walks
- DEET or picaridin on exposed skin for active outdoor use
- Thermacell on the patio for stationary repellent zone
- BTI dunks/bits in any standing water on your property
- Professional barrier spray for whole-yard residual protection