The first warm weekend of the year has a feeling all its own. The porch chairs come out, the hiking boots get dusted off, and somewhere in last summer's beach bag you find a half-used bottle of repellent. Before you head out to the trail or settle in for a long evening on the deck, one quick question: is this bottle still good?
Does bug spray expire? The quick answer
Yes, bug spray expires, but slowly. The date is mostly about performance, not safety: an older spray may simply not work quite as well. OFF! and Ranger Ready suggest replacing bug spray after about 3 years, while Sawyer says its products last 10 years when stored correctly. Heat and sun shorten any window.
Many bottles carry no date at all, and that is normal: Michigan State University Extension explains that the EPA only requires an expiration date on a pesticide label in certain circumstances. With no date and proper storage, MSU suggests you "assume a two-year shelf life." A bottle from five summers ago is past most brands' guidance.
How long does bug spray last?
On the shelf
Most brand guidance lands around 2 to 3 years, with Sawyer the long outlier at 10. The two tables below break it down by active and by brand.
On your skin
Hours, set by the active and its concentration. HowStuffWorks cites University of Michigan figures of about five hours for roughly 20% DEET and two to three hours for 7% DEET. The EPA's advice: "Apply and re-apply a repellent according to the label instructions," and "Be sure to use a product with a protection time that fits your activity." Some labels carry the EPA's voluntary repellency awareness graphic, which shows protection time for mosquitoes and ticks at a glance. Bloc Off Spray is lab-tested for 6+ hours against mosquitoes, ticks and other biting insects.
Shelf life by active ingredient
The formula around the active (the water, oils and other ingredients that carry it) ages too. This summarizes published sources; it is not Superbloc testing.
| Active ingredient | What sources say | Keep or replace? |
|---|---|---|
| DEET | In theory, an almost unlimited shelf life (HowStuffWorks) | Keep if it passes the 60-second check and is within the brand's window |
| Picaridin (icaridin) | Nearly endless (HowStuffWorks); about 3 years for Sawyer's picaridin products (Sawyer to CBS Minnesota, 2018) | Follow the brand's window |
| IR3535 | About 2 years before it starts to break down (HowStuffWorks) | Replace after about 2 years |
| OLE and PMD | Do not technically expire but can lose potency over time, like DEET and picaridin (Business Insider) | Run the 60-second check; replace if scent or texture has changed |
Does picaridin expire? Slowly, but the sources above differ, so follow the brand's own guidance. Our picaridin vs DEET guide compares the two actives. PMD and oil of lemon eucalyptus are among the active ingredients the CDC lists for preventing mosquito bites, alongside DEET, picaridin, IR3535 and 2-undecanone. Permethrin is a clothing treatment rather than a skin repellent; check its own label.
Do bug sprays lose effectiveness over time?
Yes, gradually. In Michigan State University Extension's words, "Stored pesticides will lose their effectiveness over time." MSU lists the signs: oil-based products can separate or turn to sludge, and with aerosols the nozzle can clog or the propellant stop working. Scent can shift too. Heat speeds it up.
Does DEET expire?
DEET itself is one of the most stable actives there is, but the lotion or spray around it can separate, change scent or clog over time, so an old bottle still deserves a quick check. A lower percentage means more frequent reapplication, not a spray that has gone bad.
Does OFF! bug spray expire?
OFF! and Deep Woods OFF! are the most searched brands for this question.
- Shelf life. HowStuffWorks reports that OFF! recommends discarding bug spray more than 3 years old. A product Q&A on the retailer DoMyOwn lists 2 to 3 years for OFF! Deep Woods Insect Repellent V stored in a cool, dry place.
- Damaged cans. SC Johnson, the maker of OFF!, told CBS Minnesota in 2018 that a damaged can should be replaced.
- The code on the can. Per the DoMyOwn listing, the numbers on the bottom are batch or lot numbers, not a plain expiration date. DoMyOwn points buyers to SC Johnson at 800-558-5252 to decode them.
Shelf life by brand: what each company or source says
Where we found no public figure, we say so rather than guess.
| Brand | What the brand or a public source says | What to do |
|---|---|---|
| OFF! and Deep Woods OFF! (SC Johnson) | About 3 years (HowStuffWorks). Deep Woods V: 2 to 3 years stored cool and dry (DoMyOwn Q&A). Replace a damaged can (SC Johnson, 2018) | Lot code on the can bottom; SC Johnson decodes it at 800-558-5252 |
| Sawyer | 10 years when stored correctly (HowStuffWorks). In 2018 a Sawyer engineer told CBS Minnesota about 10 years for its DEET products and about 3 years for its picaridin products | Follow the guidance on your bottle |
| Ranger Ready | About 3 years (HowStuffWorks) | Replace after about 3 years |
| Natrapel (Tender Corporation) | Replace every three years (CBS Minnesota, 2018) | Replace after about 3 years |
| Ortho Home Defense (home insecticide, not a skin repellent) | About 3 years stored properly, and may lose effectiveness after (a brand answer on a Lowe's product Q&A) | Follow the label |
| Repel | No public figure found | Check the printed date or call the number on the pack |
| Raid (home insecticide, not a skin repellent) | No public figure found | Check the printed date or call the number on the pack |
| Aerogard (Australia) | No public figure found | Check the batch or expiry printed on the can or pump |
| Bloc Off (The Superbloc) | Spray and wipes carry a printed expiry and batch date | Check the date printed on the pack |
Raid and Home Defense: bug killers, not repellents
Raid and Ortho Home Defense are insecticides for the home and its surfaces, not skin repellents. Home Defense lasts about 3 years stored properly, per the Lowe's Q&A above; we found no figure for Raid. Either way, follow the label. The EPA makes the same point about repellents: "If you don't follow the label directions, the product may not be as effective as you expect."
How to tell how old your bug spray is
- A printed expiration or best-by date. Use it as written; it assumes reasonable storage.
- A manufacture date. Add the brand's suggested shelf life: with a 3-year window, a spray made in spring 2024 is due around spring 2027.
- A lot or batch code. A stamped string of letters and numbers, often on the can bottom. You may not be able to read it, but the brand can.
For our own bottles, check the date printed on the pack: Bloc Off spray and wipes both carry a printed expiry and batch date.
The 60-second check: date, shake, smell
- Date or code (15 seconds). If it is clearly past the brand's suggested window, replace it and skip the rest.
- Shake test (20 seconds). A healthy formula returns to an even liquid. Separation that will not shake out, cloudiness, yellowing or a tacky texture means it has changed. Spray once: a sputtering nozzle or a weak aerosol is another sign.
- Smell test (20 seconds). A sour, rancid or sharply different smell means the formula is breaking down. With a plant-based spray, where scent is part of the experience, a change stands out quickly.
Pass all three? Enjoy your weekend. Fail any one? Retire it and restock.
Is expired bug spray dangerous, or just weaker?
What happens if you use expired mosquito repellent? For most people, the realistic downside is weaker protection, not harm: HowStuffWorks says a spray past its date may not work quite as well, so protection time can get shorter and less predictable. Replace anything that has changed in smell, color or texture, and follow the label directions. This is general product care guidance, not medical advice. If you have a question about your skin or health, talk with a healthcare professional.
Store it so it lasts all season
- Keep it cool. Heat is the biggest enemy of shelf life, so skip the glovebox and the summer trunk. Michigan State University Extension suggests a dry room at 55 to 65 degrees Fahrenheit. Avoid freezing too.
- Keep it out of the sun. A dark cabinet beats a sunny windowsill.
- Original bottle, tightly closed. This limits air, evaporation and leaks.
- Date it. MSU suggests writing the date you got it on the container and using older product first.
Packing repellent away while mosquitoes are out of sight for the winter (here is where mosquitoes go in winter)? The same cool, dark cupboard keeps it ready for spring.
A note from our formulator on water-based sprays
Our co-founder and formulator Cassidy Huang spent two years with a Taiwan-based chemist developing Bloc Off Spray, which is water-based and alcohol-free. Water-based formulas reward good habits: keep the bottle cool, out of direct sun and tightly closed, shake it before each use, and never leave it in a hot car.
Bloc Off Wipes solve a different problem: each of the 10 wipes is individually wrapped, so it stays sealed until you open it. They are TSA-friendly too (see our guide to bringing bug spray on a plane).
How to get rid of old bug spray
- Read the label first. It often carries disposal directions.
- Check your local program. The EPA suggests asking your local solid waste authority, environmental agency or health department about household hazardous waste collection; local rules can be stricter than the label.
- Never pour it down a drain. The EPA notes that many municipal drinking water and wastewater systems cannot remove all pesticides.
- Aerosol cans. University extension guidance says to empty the can completely before the trash, and never to puncture, burn or crush it.
- Still unsure? The National Pesticide Information Center can help at 1-800-858-7378.
Restocking? What to look for
- Bloc Off Spray uses 8% PMD (para-menthane-3,8-diol) derived from lemon eucalyptus, lab-tested for 6+ hours against mosquitoes, ticks and other biting insects. It is DEET-free, alcohol-free and water-based, with aloe vera and chamomile, in a 4 oz (118 ml) bottle for $15.
- Bloc Off Wipes are $13 for 10 individually wrapped wipes, with top notes of lemon and eucalyptus finishing with pine and cedarwood.
For both formats at once, the Family Mosquito Protection Pack bundles 2 sprays and 2 wipe packs (10 wipes each) for $51. Then all that is left is getting outside.
Frequently asked questions
Does bug spray expire if unopened?
Yes, but slowly. An unopened bottle kept cool and dark outlasts one that rode around in a hot car. OFF! and Ranger Ready suggest about 3 years; Sawyer says 10.
How long does bug spray last on your skin?
It depends on the active and concentration; HowStuffWorks cites about five hours for roughly 20% DEET. Check the protection time on the label, and apply and re-apply according to the label instructions, as the EPA advises.
Does Deep Woods OFF! expire, and how do I read the code on the can?
A DoMyOwn product Q&A lists 2 to 3 years for OFF! Deep Woods Insect Repellent V stored cool and dry. The numbers on the can bottom are lot numbers; SC Johnson can decode them at 800-558-5252.
Does picaridin expire?
The active is very stable (HowStuffWorks calls its shelf life nearly endless), but a Sawyer engineer told CBS Minnesota in 2018 that its picaridin products last about three years. Follow the guidance on your bottle.
How should I throw away old bug spray?
Follow the label, then ask your local solid waste authority about household hazardous waste collection, as the EPA suggests. Never pour it down a drain.
Written by Tanya Lee, Co-Founder of The Superbloc, with formulator Cassidy Huang. Updated 2026-11-09. Sources: CDC, EPA, Michigan State University Extension, HowStuffWorks, CBS Minnesota, university extension guidance.