Permethrin-treated work clothing,
does it really help with Reduced tick bites in outdoor workers?
research showsThe grade is C. A 159-worker trial estimated 82% protection in year one but only 34% with a wide interval in year two. A separate 82-worker trial recorded 60 bites over 33,121 outdoor-work hours versus 166 over 38,550 hours, protective effectiveness 58% (43-69%).
ads claimTreated clothing supplements, rather than replaces, repellents on exposed skin, tick checks, and prompt removal.
Useful facts when choosing a product
- Factory treatment covered the worker's usual outer garments.
- The paper did not report an exact concentration for the proprietary process.
- Field protection declined with wear and laundering.
Chamgap Semantic Classification Code
Candidate index · review held
UNK.work-clothing-factory-treated-with-long-lasting-permethrin.UNK.tick-bites-in-outdoor-workers.reduce.shamUnknown > Work clothing factory-treated with long-lasting permethrin > Unknown > tick bites in outdoor workers > Reduction claim > Sham procedure or device
An automated migration candidate, not an issued permanent code; exact claim scope remains under review. This machine-generated migration candidate helps retrieval but is not a permanent assignment. The original verdict ID and URL remain authoritative.
What the research actually shows
NCT01454414 covered pants, shorts, shirts, socks, and hats. Sham garments were commercially washed and dried, whereas active garments received a proprietary Insect Shield process. The exact concentration was not reported. Insect Shield LLC provided in-kind garment treatment in both field trials. Bites were attached or embedded ticks recorded weekly; the second trial adjusted for outdoor-work hours.
Why this is classified as C (54)
Large time-adjusted bite reduction with small samples and attrition gives C with 54 points.
Counterpoint. A bite endpoint does not establish prevention of tick-borne disease.
Rejudgment record. Cross-check applied — Time-adjusted bite reduction limited by small studies, attrition, and nonindependent replication
| Endpoint | H | Hard endpoint - actual events such as death |
| Replication | R1 | Single confirmatory trial |
| Independence | I1 | Mixed funding sources |
| Effect size | E+ | Meets the clinically important threshold |
Stored derived and displayed grades match; this is not a current recalculation or validity check (C).
Sub-claim grades by effect
This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.
| Effect (sub-claim) | Grade | Basis |
|---|---|---|
| Reduced tick bites | C | Year-one and two-year pooled bite rates were lower. |
| Prevention of tick-borne infection | ? | Infection was not a powered primary endpoint. |
Cross-check — AI research and Codex final gate
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Vaughn et al. 2014 | Double-blind randomized sham-controlled trial | 159 randomized; 127 completed year one and 101 year two | National Institute for Occupational Safety and Health; in-kind garment treatment supplied by Insect Shield LLC | Work-related tick bites on weekly logs | 1,045 bites/5,251 person-weeks; protection 82% (66-91) in year one and 34% (-67 to 74) in year two | Key field trial |
| Mitchell et al. 2020 | Double-blind randomized sham-controlled trial | 82 workers (40/42), two years | NIOSH R01 OH010791; in-kind garment treatment supplied by Insect Shield LLC | Attached tick bites per 100 outdoor-work hours | 60/33,121 hours (0.18/100 h) vs 166/38,550 hours (0.43/100 h), protection 58% (43-69) | Durability-supporting evidence |
Receipt — 2 References
All 2 cited sources were verified for existence at the original page (as of 2026-08-08).
Final verification and publication gate: Codex · Evidence date: 2026-08-08 · Corrections: none
Cite this verdict
[Chamgap] Permethrin-treated work clothing x fewer tick bites — Evidence Grade C·54. 2 cited sources checked. Source: https://chamgap.com/en/verdicts/immunity/permethrin-treated-work-clothes-tick-bites/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.