What Is DEET And Is It Safe?

by | Oct 14, 2017 | Tips and Info | 8 comments

Anybody who has travelled to tropical regions or visited a country where mosquitoes and their diseases are a problem, you will most likely have used repellents with DEET.

You are most likely reading this post because you have been asking ‘What is DEET?’. In short, DEET stands for ‘diethyltoluamide‘ and it is the most common active ingredient used in synthetic insect repellents. This is one of its various scientific names which is why those of us who aren’t chemists (the majority of the population) simply refer to it as ‘DEET’.

DEET rich insect repellents are generally considered as the most effective at keeping away the bugs and mosquitoes, hence its boom in the past few decades.

You may well have been triggered to ask this question after seeing the detrimental effect that DEET has on certain types of clothing or plastic when it comes in contact. You may also be reluctant to use it due to the almost toxic odour it can give off.


A History Of DEET

DEET is best in these environments

After World War 2 and the jungle warfare that troops experienced, the US military decided to invest a lot of time into finding the ‘perfect’ insect repellent. DEET was successfully synthesised in 1946 and used by the military straight away. In 1955, DEET was used as a pesticide and it then entered the civilian world in 1957 where it has been the main ingredient of insect repellents ever since.

Since then, DEET has been applied to a range of repellents such as lotions, aerosols and creams.


How Does DEET Work?

Believe it or not, DEET works in such a way that it stops insects from being able to smell you. Many people think that it poisons the insects when they bite but this isn’t the case.

mosquito piercing skin

The chemicals present in DEET actually corrupt the insects’ antennae so that they cannot detect your scent or presence. This beats many other chemicals present in repellents which don’t always prevent the insects from landing on you.

As well as mosquitoes, DEET is also proven to be effective against a range of other creatures such as ticks, leeches, gnats and fleas.


How Long Does DEET Last?

This all depends on the percentage. The higher percentage of DEET in a repellent actually indicates how long the repellent lasts, not how many mosquitoes it’ll stop from biting you.

Take a repellent with 10% DEET, this will last you about 2 hours. Now take a repellent with over 90% DEET, this can last as long as 12 hours.

It is generally recommended that you use a product with at least 20% DEET to ensure a high level of protection.


Is DEET Safe To Use?

This is one of those questions that has turned into a never-ending debate and is something that several studies have a whole heap of for and against arguments.

Ultimately, it comes down to personal choice and what studies you prefer to rely on. It’s fair to say, though, that the majority of studies come back with results that, if DEET is applied correctly and with care, that there is no harm in using such repellents.

You may read things about DEET such as:

  • DEET is poisonous.
  • Too much DEET can affect the nervous system causing seizures.
  • DEET is harmful to the environment.
  • DEET used in pregnant mothers can cause birth defects.
  • DEET causes cancer.
  • DEET melts plastic and discolours clothing.


Wait A Second!

Before alerting panic stations and heading over to an ‘all natural’ insect repellent product, it should be taken into account that the vast majority of studies are VERY specific and apply to a tiny number of tested subjects.

DEET on hiking kit

Let’s look at what happens when we dig a little deeper into certain theories. Some of the following information is based on a study carried out in 1998 (and since reviewed in 2014) by the Environmental Protection Agency:

  • Most cases where DEET has been toxic are down to misuse.
  • 46 seizures and 4 deaths have been reported because of DEET. Considering the number of users over the past 80 years, this makes the chances of it happening approximately 1 in 100 million.
  • All studies claiming that DEET is linked with cancer have proven to be flawed, DEET is not classified as a carcinogen.


Now, the only thing I would agree with is that DEET can melt plastic and discolour clothing. When I say ‘melt plastic’ I don’t mean that it turns to liquid in your hands, not quite. Just that if held in continuous contact with plastic, a very high percentage of DEET can very slightly change the composition or disfigure the plastic.

As for it discolouring clothing, I have never personally experienced this, I’ve only read certain reports that it can disintegrate tights and nylon fabrics. In fact, if I’m going on a long trek where I’ll be sweating a lot then I often apply the DEET rich repellent to my clothing and have never experienced any problems. You should just be careful if you are planning on applying it to more delicate fabrics.

A quick note on pregnant women and breastfeeding- there’s no solid evidence that it’s harmful to use DEET products but to remain on the cautious side it’s often recommended to stick to products with 50% DEET or less. If you’re completely paranoid then you can use Picardin products.


DEET And The Environment

The truth is that there has been little research on DEET’s effects on the environment.

DEET is okay for the environment

There have been reports that DEET can prove to be toxic to certain species such as fish and other aquatic creatures. These have, for the most part, been debunked by the same in-depth report written out by the Environmental Protection Agency. The 2014 review of the report stated: “the Agency has not identified any risks or concern to human health, non-target species or the environment”.


Is DEET Safe For Children

Is alcohol safe for adults?

The answer to both the above questions is yes, if used correctly. Most of the information labels on DEET products will state that it is safe for children older than a few months and that it shouldn’t be used under clothes, near the eyes or mouth, and not applied to open wounds.

It’s simply a case of applying common sense and following the instructions on the label. A lot of DEET products offer specific child-friendly repellents which are apparently less-irritating and have a lower percentage of DEET.

You can see these products, and the best insect repellents that I have every used, in my review of the best mosquito repellents.


To Conclude

What is DEET? It is the most common active ingredient used in synthetic insect repellents.

Thumbs up for DEET

Is it safe? Yes, the evidence is by far in DEET’s favour. The potential health risks mentioned above are on a minimal level. It’s not something that you should be worrying about at all. DEET has, for years, been the most relied upon ingredient in insect repellents for decades and it is used to great effect.

Since I started using DEET strong products, I have tried out a variety of other repellents that don’t contain DEET and they are nowhere near as effective.

If this post has provided better clarification to what DEET is and convinced you that it is, in fact, the way to go in terms of repellents then check out my post on the best mosquito repellents:

What is the best mosquito repellent?

Or if it’s specifically midges you want to combat:

What is the best midge repellent?

As always, thanks a lot for reading and please leave any questions or comments in the box below! 🙂




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