Ethyl butylacetylaminopropionate is an insect repellent whose trade name is IR3535 and was developed and commercialized by Merck KGaA (Germany). It is a colorless and odorless oil with a good skin feel in final products, and it is biodegradable.[1][2][3]
Unlike icaridin, IR3535 can dissolve some plastics and synthetic fabrics, except polyethylene and polypropylene.[4][5][6]
IR3535 is effective in repelling several different insects such as mosquitoes species and also midges, ticks and head lice. It is as effective as DEET against Aedes and Culex mosquitoes, but may be less effective than DEET against Anopheles mosquitoes, vectors of malaria.[7][8]
A 2013 review concluded that IR3535 is as effective as 20% DEET against Anopheles, citing that some studies reported possibly shorter protection of just 3.8 hours.[9][6] In areas with malaria, the NHS recommends 50% DEET or at least 30% DEET or 20% icaridin instead of IR3535.[10][11][12] IR3535, among other repellents, is included in the World Health Organization (WHO) recommendation for areas with malaria. The WHO also notes that it may be necessary to reapply repellents every 3-4 hours in hot and humid climates.[13][14]
The mechanism of action is still under investigation, but it probably related to the intolerance of mosquitos and other invertebrate animals to its odor.
IR3535 is applied topically in human skin and prevent bites from mosquitos and ticks that might cause serious diseases, such as dengue, malaria, zika, West Nile virus, Lyme disease, among others.[16]