What happens if you use expired mosquito repellent?

Author: Milton Wunsch  |  Last update: Thursday, August 14, 2025

‍There is no one-size-fits-all answer here, but the general consensus is that bug sprays have a shelf life of around three years. At that point, you should probably throw them out – not because they will harm you, but because they might be less effective in repelling bugs.

Is it okay to use expired mosquito repellent?

Using expired Odomos or any mosquito repellent cream can pose several risks, including: Reduced Efficacy: The active ingredients in the cream may degrade over time, making it less effective at repelling mosquitoes. This increases the risk of mosquito bites and potential transmission of diseases like dengue or malaria.

Does expired DEET still work?

DEET-based bug sprays, such as Off, won't technically expire but may become less effective over time. The same goes for bug sprays that use picaridin, oil of lemon eucalyptus, or para-menthane-3,8-diol.

What is the shelf life of mosquito repellent?

Although these additives in bug spray are quite stable and can last a long time, it is generally recommended to dispose of insect repellent after three years. This isn't necessarily because the product expires—but rather, it loses its efficacy.

Why is DEET banned in Europe?

DEET is a widely used repellent that deters pests by making it harder for them to smell humans. Despite being effective, it has faced controversy over potential health and environmental impacts, including skin irritation and toxicity concerns. Some countries have even banned DEET due to these risks.

Does Sunscreen Expire? How About Insect Repellent?

How toxic is DEET to humans?

DEET is commonly found in insect repellants. If used properly, the health risk of using these products is very low. DEET products are extensively used with very little risk to human health. Occasionally, there have been reports of people having negative reactions after excessive use of repellents containing DEET.

Why should we avoid DEET?

People that have left DEET products on their skin for extended periods of time have experienced irritation, redness, a rash, and swelling. People that have swallowed products containing DEET have experienced stomach upset, vomiting, and nausea. Very rarely, exposure to DEET has been associated with seizures in people.

Is off with DEET safe?

The human health risk assessment concluded that there are no risks of concern because no toxic effects have been identified when used as a dermally applied insect repellent, and there is no dietary or occupational exposure for DEET.

What is the oldest mosquito repellent?

One of the most effective mosquito repellents is one of the oldest around. DEET was first developed for use by the U.S. Army in 1946, and it became available to the public in 1957. Many other products have hit the market since then, but few compare to DEET.

Should you sleep with DEET on?

To avoid overexposure, be sure to remove DEET product before going to bed (shower or use a wash cloth to remove from skin).

What happens if you don't wash off DEET?

Very often, people don't wash the product off their skin after returning indoors. This can result in overexposure, especially in cases where a product is applied too often (at short intervals) or daily for several days. A small amount of DEET is absorbed into the body when applied to the skin.

Why does DEET have a bad reputation?

Why does DEET have a reputation for being harmful? DEET is neither intended nor safe for ingestion. Dr. Amin notes that oral intake can result in side effects such as nausea, vomiting, and (in rare cases) seizures.

Can you use out of date DEET?

There may be a small reduction in effectiveness over time, but not much. It should be perfectly safe to use.

What are the long term side effects of mosquito repellent?

The burning of mosquito repellents can release harmful pollutants such as particulate matter, CO, VOCs, SO2, and NO2 [26-29]. Acute respiratory infections such as colds, asthma attacks, and pneumonia are brought on by the constant or extended use of various repellents (at least 8–10 hours per day) [30].

What to do with expired bug spray?

Check with your local solid waste management authority, environmental agency or health department to find out whether your community has a household hazardous waste collection program or a similar program for getting rid of unwanted, leftover pesticides.

Why was DEET banned?

Kim said a 1991 review found many cases where high DEET concentrations were linked to severe skin reactions and neurological problems including seizures. Doctors also onsidered DEET to be the probable cause of the deaths of three children, although the link was not proven, she said.

Does mosquito repellent expire?

How long bug sprays last. ‍There is no one-size-fits-all answer here, but the general consensus is that bug sprays have a shelf life of around three years. At that point, you should probably throw them out – not because they will harm you, but because they might be less effective in repelling bugs.

How long does DEET stay active?

For reference, a repellent containing 15% DEET typically provides up to six hours of mosquito protection, while a repellent with 25% DEET typically provides up to 8 hours of mosquito protection.

What smell do mosquitoes hate?

Mosquitoes are turned off by several natural scents, including citronella, peppermint, cedar, catnip, patchouli, lemongrass, lavender and more. You can add some of these plants to your landscaping to fend them off.

What do professionals use to keep mosquitoes away?

N,N-diethyl-3-methylbenzamide (DEET) remains the standard by which all other repellents are judged.

Why do people want DEET free?

In recent years, concerns have surfaced about the use of the insect repellent DEET. There have been a small number of serious neurotoxic effects reported in small children, as well as documented mosquito resistance and accumulation of DEET in some public waterways.

Is DEET banned in Canada?

Health Canada decided to limit DEET concentration to 30% in the country since 2002 due to an increased long-term risk observed with repeated applications. DEET is often sold and used in spray or lotion in concentrations up to 100%.

What is the safest bug spray to use?

DEET, picaridin, and natural oils like lemon and eucalyptus oil are all very common and safe ingredients found in bug repellent. Some people prefer to stay away from DEET, as it can burn when it gets in your eyes and often comes with a potent smell.

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