IR3535 – Questions and Answers

What is IR3535?

IR3535 (Ethyl Butylacetylaminopropionate) is an insect repellent that was developed by MERCK as an alternative to DEET. It is an effective product and works very well against midges and other biting insects in European and North American environments. Be aware that this product shouldn’t be relied upon in tropical areas where there can be a serious risk from insect bourne disease.

How does it work?

Insects use odours for navigation in nature. There are various substances in nature which provide messages to insects. For example, there are substances which help mosquito males to find females or guide mosquito females to a host for blood feeding. B-alanin is a natural substance which provide the gentle message to keep insects away. This effect is named the “repellent effect”.

For the development of IR3535, B-alanin was modified to intensify this signal. Therefore, IR3535 is a repellent and causes insects to move away from from treated skin, textiles and hair. Some repellents also show an insecticidal effect. That means some other repellents may kill insects after contact. However, IR3535 only provides a message to repel and does not attack the insect.

Does it work for all insects?

Generally, it works well with all the insects that are trying to find you so that they can bite you and feed off you – mosquitoes, midges, sand flies, biting flies and fleas, etc. It also works reasonably well with ticks and chiggers, but it doesn’t work with spiders and stinging insects – bees, wasps and hornets, etc. Fortunately though these insects don’t usually come looking for you to deliberately sting you, so the best strategy with stinging insects is to try and keep out of their way.

Is it safe?

IR3535 only provides a message to insects and does not show any potential to kill them. In addition, IR3535 is skin friendly an shows an excellent safety profile. This was confirmed by World Health Organisation (WHO), Environmental Protection Agency (EPA in USA) and many other authorities world wide. IR3535 has been used in repellent products in europe for more than 30 years and there were never reports about serious side effects.

Can it be used by pregnant women and chidren under the age of 2?

Yes. Many authorities (as well as WHO) investigated the safety of IR3535 in detail. IR3535 received an excellent safety grading and is specifically highlighted when children’s use is mentioned. The French Ministry of Health recommended IR3535 for children and pregnant women during the Chikungunya epidemics. IR3535 is used today world wide in many specific children’s repellent products. In most cases, a product label will provide you good instructions for children’s use of that specific product. The application of repellents to children should be performed by adults at all times.