05 Aug Is DEET Toxic or Safe? Should you use it?

As you may have read in my post on July 19, 2019 about natural mosquito repellents, I truly hate mosquitos and only because they love to bite me. My first known exposure to DEET was on my trip to SE Asia. I had bought a small bottle out of fear of both mosquito bites and the disease SE Asian mosquitoes carry. At the time, I was ignorant of what exactly DEET is and that I could be exposing myself to a toxic chemical. All I cared about was not getting bit and not getting sick. Since then, I’ve done my research to find out if DEET is toxic or safe to use as a bug repellent.

Why should I use mosquito and bug repellent?

1. Mosquito bites sting and itch, if you’re reactive to their little injection of fluid they swap out for your blood. The itch can be obnoxious and last days.
2. Some people experience significant swelling at the site of a mosquito bite.
3. Ain’t nobody wanna get bit. My blood is my blood, let’s keep as much of it in me as possible.
4. Mosquitoes are known to carry many serious diseases, including but not limited to Zika Virus, West Nile virus, Yellow Fever, Malaria and Japanese Encephalitis.
5. Bug repellents, to varying degrees, protect from more than just mosquitoes. They also repel ticks, biting flies, gnats, fleas and chiggers. Which also means they prevent any diseases these bugs carry.

What is DEET?

DEET (N, N-diethyl-meta-toluamide) is a synthetic bug repellent first developed to protect military personnel in infested areas in the 1940s. It became available for public use and manufacturing in the 1950s. DEET is a very effective bug repellent present in most commercial bug repellent products including topical sprays, wrist bands, and clothing.

If it’s effective, why should I be concerned?

Although considered safe by the EPA (Environmental Protection Agency) in 2017, DEET has remained a controversial subject.

Duke University pharmacologist Mohamed Abou-Donia researched the effects of frequent and prolonged DEET exposure on rats and found diffuse brain cell death and behavioral changes. Following these results, he recommended humans should stay away from products containing the chemical. However, other studies have concluded few people have a sensitivity to DEET, especially when applied sporadically and according to the instructions on the label.

Aside from Abou-Donia’s research, other studies have noted the harmful effects on nerve health resulting in:

• Impaired learning, concentration, and memory
• Reduced control of muscle movement
• Seizures
• Impaired breathing
• Agitation, aggressive behavior
• Low blood pressure
• Skin irritation
• Nausea, vomiting, oral irritation

The severity of the effect DEET has on a person is individualized. It depends on a person’s susceptibility, health and immune status, detox capabilities and amount of exposure. If you know your body needs help detoxing and you’re sensitive to all your exposures, you’re more likely to notice the toxic effects of chemicals like DEET. Similarly, if you’re exposed to DEET daily, you are also much more likely to notice toxic effects.

Is DEET toxic?

From the 2017 CDC report on the Toxicology of DEET:

• Approximately 9.6% of DEET evaporates off of skin and into the air within 1 hour. DEET can remain in the air, in detectable amounts, as a vapor for 5 hours.
• DEET is also introduced to the environment by washing it off in showers or swimming in pools, lakes, rivers, or oceans. Once washed off, DEET enters the watershed and can consequently affect our ecosystem in large ways. Plants and animals feed and hydrate through these watersheds à We eat the plants and animals. The CDC states that DEET “may” degrade in sunlit waters, but I’m not 100% confident in that statement. The CDC also states “Data suggests” DEET is biodegradable in aerobic soil, and assumes it would “slowly” biodegrade in anaerobic soil. The stats were not given on how long it would take for DEET to break down in the soil.
• When examining urine samples, “Most of the DEET that is absorbed into your body is excreted quickly through your urine either unchanged or as a metabolite. A small portion of the DEET that is taken in is excreted in the feces.” Translation: DEET is poorly absorbed by the body. What they’re trying to say is if DEET is poorly absorbed, it’s less likely to affect body tissues.
• Both the EPA and CDC recommend the use of DEET, pregnant women and children included. This is because DEET effectively repels ticks and mosquitoes and therefore protects people from associated (and awful) diseases such as Lyme, Malaria, Zika Virus, Dengue Fever, etc. Note: special dosing / application recommendations are indicated for pregnant women and children.

The safety statement by the CDC, the EPA, and many research studies is very few people experience notable health complaints directly related to proper use of DEET. In my research, this seems to always be carefully stated. So, should you choose to use DEET, always use as directed by your product. I will personally stick to the natural stuff! 😉

Food for thought

As of yet, there is no endocrine-disruptor studies for DEET. The CDC claims there are no known endocrine effects related to DEET exposure. It’s important to note that they were looking at physical morphologies of endocrine glands (cellular and tissue structure) and not changes in circulating hormone levels. This information is not yet available.

So, is DEET safe to use?

My goal is not to shame you for using DEET in the past or in the future. I want to EMPOWER you to make decisions that are best for your health. What you put on your body is ultimately your decision and I’m not here to tell you what to do with it but rather to deliver information.

There are a few things I like to keep in mind related to DEET:

1. Your skin is one big protective organ. It also has the ability (for better or worse) to absorb what you put on it.
2. There are scientific reports (and some smaller clinical reports) that indicate toxicity of DEET to the nerve health and lung health.
3. Governing agencies have to consider the general public health and will put the greater population’s health above your individual health. When it comes to bugs that carry really nasty long-term diseases, they’re going to side with an effective repellent that will severely limit the spread of diseases.
4. Governing agencies sometimes have commercial goals in mind also…
5. I’ll always error on the side of natural combinations that have been used for generations compared to relatively new synthetic compounds.

Special note: The diseases carried by mosquitoes, ticks and other bugs can be detrimental to your health. If you will be in an area where these diseases are common, diligent use of effective bug repellent is highly recommended.

Click here for more information on natural bug repellents.

Dr. Lexie Ching
Naturopathic Doctor Bend
(541) 797-0167
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Resources
Mark S et. al. Comparative efficacy of insect repellents against mosquito bites. The N Engl J Med. 2002; 347:13-18. DOI: 10.1056/NEJMoa011699
Abou-Donia, et. al. Increased neurotoxicity following concurrent exposure to pyridostigmine bromide, DEET, and chlorpyrifos. Fundamental and Applied Toxicology. 1996; 34:201-222.
Keith, Sam, et al. “Toxicological profile for DEET (N, N-diethyl-meta-toluamide).” (2017).