OFF!
OFF! Backyard Mosquito Coil
Coil · EPA-registered pesticide
Pros
- Meaningful landing/bite reduction (30–60%)
- EPA-registered device
- Active ingredient concentration disclosed
Cons
- Protects only the treated zone, and effectiveness drops sharply in wind or open air
- You have to sit in the smoke, which carries fine particulates (PM2.5) and combustion byproducts
- Highly toxic to fish and aquatic life — keep well away from water
- Pyrethroid smoke — keep cats away and never run it in an enclosed space
The full review
Smoldering spiral coil from SC Johnson that burns slowly to release a d-trans allethrin smoke, meant to repel mosquitoes across a small patch of still outdoor air rather than protect your skin. The label pairs one coil with an area of roughly 10 by 10 feet and about 4 hours of burn time. Like all coils it works best in calm, sheltered air and does little once a breeze pushes the smoke away, and burning it produces smoke you should avoid breathing directly.
Scorecard
Expand any pillar to see exactly why it scored what it did.
Effectiveness45%24This is an area device, not applied to skin: published field trials report roughly 30–60% fewer mosquito landings or bites, over about a 5 ft zone. Scored 60% on that reduction and 40% on how much space it protects, so a larger zone counts for real. Reduction figures come from controlled or semi-field trials, not backyard conditions. Real-world protection drops sharply in wind and open air, so this is scored with lower confidence.
This is an area device, not applied to skin: published field trials report roughly 30–60% fewer mosquito landings or bites, over about a 5 ft zone. Scored 60% on that reduction and 40% on how much space it protects, so a larger zone counts for real. Reduction figures come from controlled or semi-field trials, not backyard conditions. Real-world protection drops sharply in wind and open air, so this is scored with lower confidence.
Evidence & honest claims25%54d-trans-Allethrin is well-supported by published evidence, weighted by how close its concentration is to the studied effective dose (base 56). Of 3 marketing claims audited: 0 strong, 2 moderate, 1 weak, 0 unsupported (-2).
d-trans-Allethrin is well-supported by published evidence, weighted by how close its concentration is to the studied effective dose (base 56). Of 3 marketing claims audited: 0 strong, 2 moderate, 1 weak, 0 unsupported (-2).
Safety15%46This is an area device, not applied to skin, so dermal risk does not apply. Scored on moderate inhalation risk from the smoke (−18); burning it releases fine-particle smoke (PM2.5) and combustion byproducts you breathe (−14); high toxicity to fish and aquatic life (−22). Burn it outdoors in the open air only and stay out of the smoke stream, keep cats away. Keep it well away from ponds, aquariums, and water features.
This is an area device, not applied to skin, so dermal risk does not apply. Scored on moderate inhalation risk from the smoke (−18); burning it releases fine-particle smoke (PM2.5) and combustion byproducts you breathe (−14); high toxicity to fish and aquatic life (−22). Burn it outdoors in the open air only and stay out of the smoke stream, keep cats away. Keep it well away from ponds, aquariums, and water features.
Transparency15%75This product publishes an ingredient list (+20); discloses 100% of active concentrations (+40); discloses 100% of all ingredient concentrations (+15); inert ingredients are not fully accounted for (0).
This product publishes an ingredient list (+20); discloses 100% of active concentrations (+40); discloses 100% of all ingredient concentrations (+15); inert ingredients are not fully accounted for (0).
Every pillar is scored from published rules. Read how we score.
Coverage & effectiveness
This is an area device: it protects a zone around it rather than your skin. Effectiveness is the published reduction in mosquito landings or bites. Real-world protection is best in still air and drops in wind or open space.
Mosquitoes
EstimatedModerate- Protected zone
- ~5 ft zone
- Fewer bites
- 30–60%
Allethrin coils cut mosquito biting only in calm, sheltered air, where published mortality figures for coils run roughly 24 to 64 percent. The marketed 10-by-10-foot zone is a best case; the effective area is smaller and protection drops sharply in any breeze. Burning the coil emits smoke containing fine particulate (PM2.5), carbon monoxide, and other combustion byproducts, so keep it away from where you are breathing.
Ingredient disclosure
This product publishes an ingredient list (+20); discloses 100% of active concentrations (+40); discloses 100% of all ingredient concentrations (+15); inert ingredients are not fully accounted for (0).
Only active ingredients are disclosed. The full ingredient list (inerts/carriers) is not published, so this may not be the complete formula.
- d-trans-AllethrinActive
Active repellent · 0.15%
Claims audit
What the marketing says, versus what the evidence supports.
“Protects an area up to 10 ft by 10 ft”
EfficacyWeakA still-air best case. The effective zone is smaller in practice and collapses in any breeze; coil studies show only about 24 to 64 percent mosquito mortality.
“Each coil lasts up to 4 hours”
DurationModerateBurn time is generally accurate, though realized protection depends on wind and placement.
“DEET-free outdoor mosquito protection”
OtherModerateActive is d-trans allethrin, not DEET. True as stated, but the tradeoff is combustion smoke you should not breathe.
Safe around dogs & cats?
Worst case from this product’s active ingredients. Do not apply this or any human repellent to your pet.
Mainly from d-trans-Allethrin.
Not veterinary advice. Full guide to repellents around pets →