ETHYL BUTYLACETYLAMINOPROPIONATE

Ethyl butylacetylaminopropionate, commonly known by its trade name IR3535, is a synthetic compound widely used as an insect repellent due to its efficacy in protecting against a variety of biting insects such as mosquitoes, ticks, and flies. 
Ethyl butylacetylaminopropionate was developed as a safer and more environmentally friendly alternative to traditional repellents like DEET, offering effective protection with a lower risk of skin irritation and toxicity.
Ethyl butylacetylaminopropionate is an ester derived from the combination of ethyl alcohol and butylacetylaminopropionic acid, and it functions primarily by interfering with the insects’ sensory receptors, thereby preventing them from detecting human hosts. 

CAS Number: 52304-36-6
Molecular Formula:C11H21NO3
Molecular Weight:215.29
EINECS Number: 257-835

Ethyl butylacetylaminopropionate is effective against several insects and is considered an alternative repellent to DEET and Icaridin, thanks to its very low toxicity and equal efficacy. 
Officially considered safe and effective for use in children over 2 months of age and pregnant and breastfeeding women by the World Health Organization, this repellent has been used in Europe for over 30 years, and its use has been increasing worldwide.

Ethyl butylacetylaminopropionate is a synthetic molecule derived from a natural amino acid, b-alanine, and its alternative chemical formula name is beta-alanine, n-acetyl-N-butyl-ethyl ester. 
Ethyl butylacetylaminopropionate is known as IR3535 or EBAAP in the literature. 
This molecule was developed in the early 1970s using targeted molecular design following functional structure guidelines similar to those reported by Boeckh.

In his study, repellency of a chemical was correlated with a structural pattern consisting of an amide group linked by a lipophilic chain to an sp3 (i.e., an oxygen atom without a double bond) hybridized oxygen within a group such as hydroxyl or ester. 
Ethyl butylacetylaminopropionate repellent (hereafter referred to as IR3535) is currently used in over 150 consumer products world-wide. 
Despite its commercial history of more than 10 years world-wide and 25 years in European countries, IR3535 has been introduced as a product in the U.S. only recently (1999).

Its mode of action is non-toxic to humans when used as directed, and it has been approved for use in numerous countries around the world in a variety of formulations including sprays, lotions, and wipes.
Due to its favorable safety profile and pleasant sensory characteristics — it is generally odorless and non-greasy — ethyl butylacetylaminopropionate is popular in personal care products designed for use by children and adults alike, including those with sensitive skin. 

In addition to personal use, it is also employed in outdoor settings such as camping, hiking, and military applications where reliable insect protection is essential to prevent insect-borne diseases and discomfort.
Ethyl butylacetylaminopropionate is a natural product found in Averrhoa bilimbi with data available.

Ethyl butylacetylaminopropionate is an insect repellent whose trade name is IR3535 and was developed and commercialized by Merck KGaA (Germany). 
Ethyl butylacetylaminopropionate is a colorless and odorless oil with a good skin feel in final products, and it is biodegradable.

The mechanism of action is still under investigation, but it probably related to the intolerance of mosquitos and other invertebrate animals to its odor.
Ethyl butylacetylaminopropionate 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.

Insect repellent M 3535 Ethyl butylacetylaminopropionate is a potent anthelmintic that is toxic to zebrafish with a lethal concentration 50 (LC50) of 140 mg/L at 72 hours post fertilization (hpf). Insect repellent M 3535 causes morphological abnormalities and cardiac defects in early embryonic development of zebrafish by potentially inducing the production and accumulation of reactive oxygen species (Reactive Oxygen Species) and activating oxidative stress responses, thereby activating the endogenous apoptosis pathway.

Ethyl Butylacetylaminopropionate cream can be used as an insect repellent against mosquitoes, deer ticks, body lice, and biting flies. 
Products containing this active ingredient are applied to exposed human skin.

Melting point: < -20 °C
Boiling point: bp0.2 108–110 °C; bp0.5 126–127 °C
Density: 0.987 ± 0.06 g/cm³ (Predicted)
Refractive index: nD20 1.452–1.455
Flash point: 318 °F (159 °C)
Storage temperature: Sealed in dry, room temperature
Solubility: Slightly soluble in Acetonitrile, Chloroform, Ethyl Acetate, Methanol
pKa: -0.57 ± 0.70 (Predicted)
Form: Oil
Color: Colourless
InChI: InChI=1S/C11H21NO3/c1-4-6-8-12(10(3)13)9-7-11(14)15-5-2/h4-9H2,1-3H3
InChIKey: VZRKEAFHFMSHCD-UHFFFAOYSA-N
SMILES: N(C(=O)C)(CCCC)CCC(=O)OCC
LogP: 1.650 (estimated)

Ethyl butylacetylaminopropionate is prized not only for its effectiveness in repelling a wide spectrum of insects but also for its excellent safety and environmental profile, which distinguishes it from many older synthetic repellents. 
Unlike DEET, which can sometimes cause skin irritation or damage certain plastics and synthetic materials, Ethyl butylacetylaminopropionate is gentle on the skin and does not typically degrade clothing or gear, making it especially suitable for frequent or long-term use.

From a chemical perspective, the molecule belongs to the class of amino acid esters and works by masking the chemical cues insects rely on to locate humans, such as carbon dioxide and body odors, rather than by killing or immobilizing insects.
This subtle mode of action contributes to its low toxicity and reduces the likelihood of insects developing resistance.

Moreover, ethyl butylacetylaminopropionate is biodegradable and exhibits minimal environmental persistence, which means it breaks down relatively quickly in natural settings and poses less risk to non-target organisms such as aquatic life, pollinators, and beneficial insects. 
Because of these qualities, it has been widely accepted and recommended by health authorities, including the World Health Organization, for use in regions where vector-borne diseases like malaria, dengue, and Zika virus are prevalent.

In commercial formulations, Ethyl butylacetylaminopropionate is often combined with sunscreens and moisturizers, enhancing its appeal as a multifunctional personal care ingredient. 
It is also found in some insect-repellent clothing treatments and camping equipment, where it provides an added layer of protection without harmful residues. 
The combination of safety, efficacy, and pleasant sensory properties has made ethyl butylacetylaminopropionate a preferred ingredient in insect repellents globally, particularly for families, outdoor enthusiasts, and travelers seeking effective protection with minimal adverse effects.

Ethyl butylacetylaminopropionate is a tertiary carboxamide, a member of acetamides and an ethyl ester.
Ethyl butylacetylaminopropionate is effective in repelling several different insects such as mosquitoes species and also midges, ticks and head lice. 
Ethyl butylacetylaminopropionate is as effective as DEET against Aedes and Culex mosquitoes, but may be less effective than DEET against Anopheles mosquitoes, vectors of malaria.

A 2013 review concluded that Ethyl butylacetylaminopropionate is as effective as 20% DEET against Anopheles, citing that some studies reported possibly shorter protection of just 3.8 hours.
In areas with malaria, the NHS recommends 50% DEET or at least 30% DEET or 20% icaridin instead of IR3535.
Ethyl butylacetylaminopropionate, 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.
Ethyl butylacetylaminopropionate also helps prevent bites from ticks that may transmit Lyme disease.
Ethyl butylacetylaminopropionate, also known as insect repellent m 3535 or EBAAP, belongs to the class of organic compounds known as tertiary carboxylic acid amides. 

Tertiary carboxylic acid amides are compounds containing an amide derivative of carboxylic acid, with the general structure RN(R1)C(R2)=O (R1-R2 any atom but H). 
Based on a literature review a significant number of articles have been published on Ethyl butylacetylaminopropionate. 
Ethyl butylacetylaminopropionate has been identified in human blood as reported by (PMID: 31557052 ). 

Ethyl butylacetylaminopropionate is not a naturally occurring metabolite and is only found in those individuals exposed to this compound or its derivatives. 
Technically Ethyl butylacetylaminopropionate is part of the human exposome. 

The exposome can be defined as the collection of all the exposures of an individual in a lifetime and how those exposures relate to health. 
An individual's exposure begins before birth and includes insults from environmental and occupational sources.

Uses Of Ethyl butylacetylaminopropionate:
Ethyl Butylacetylaminopropionate is an insect repellent for application to human skin and clothing in public health applications, to repel biting arthropods such as mosquitoes, flies and ticks.
Ethyl butylacetylaminopropionate is primarily used as an effective insect repellent in a wide range of personal care products designed to protect individuals from bites by mosquitoes, ticks, flies, and other biting insects, which are known carriers of diseases such as malaria, Lyme disease, dengue fever, and Zika virus. 

Ethyl butylacetylaminopropionate is formulated into sprays, lotions, creams, wipes, and aerosols, allowing for versatile application depending on user preference and environmental conditions, making it suitable for everyday use as well as for outdoor recreational activities like hiking, camping, fishing, and gardening.
Beyond personal protection, Ethyl butylacetylaminopropionate is also utilized in products aimed at vulnerable populations, including children and people with sensitive skin, because of its mild irritation profile and non-greasy texture, which enhances user comfort and compliance in applying insect repellents. 

Additionally, it is incorporated into insect-repellent clothing and gear, such as treated tents and nets, providing a passive and long-lasting barrier against insect bites in both civilian and military settings where vector control is crucial.
Moreover, due to its biodegradability and low environmental impact, ethyl butylacetylaminopropionate is favored in environmentally conscious formulations that aim to reduce ecological harm while maintaining effective protection against insect-borne illnesses. 

Ethyl butylacetylaminopropionate is often recommended by public health organizations for use in endemic regions where controlling insect vectors is a vital part of disease prevention strategies, and it is also included in travel kits for people visiting tropical or subtropical areas.
The uses of ethyl butylacetylaminopropionate extend from personal insect repellents for everyday consumers to specialized products designed for high-risk populations and environments, combining safety, efficacy, and environmental responsibility in its role as a key active ingredient in insect vector control.

Ethyl butylacetylaminopropionate is widely incorporated in a variety of commercial insect-repellent formulations because it offers effective and long-lasting protection against a broad spectrum of arthropods, making it invaluable for individuals living in or traveling to areas where insect-borne diseases are endemic. 
Its inclusion in topical products like lotions, gels, and sprays allows users to apply the repellent directly to the skin or clothing, providing a personal protective barrier that reduces the risk of bites and subsequent disease transmission.

In addition to direct application on skin, Ethyl butylacetylaminopropionate is frequently used in combination with other active ingredients such as sunscreens, moisturizers, and anti-inflammatory agents, creating multifunctional products that meet diverse consumer needs by simultaneously protecting against insects and environmental elements like ultraviolet radiation and dry skin. 
This makes such products highly convenient for outdoor enthusiasts, athletes, and workers exposed to harsh outdoor conditions, who require both skin care and insect protection in a single formulation.

Ethyl butylacetylaminopropionate also finds application in military and occupational health contexts, where soldiers and outdoor workers face prolonged exposure to insect-rich environments that pose a threat to their health and operational effectiveness. 
In these settings, Ethyl butylacetylaminopropionate-treated uniforms, head nets, and camping gear offer passive but essential protection, reducing reliance on frequent topical application and enhancing compliance.

Furthermore, ethyl butylacetylaminopropionate is increasingly utilized in consumer products aimed at families with children, since its favorable safety profile means it can be used safely on young skin and is less likely to cause irritation or adverse reactions compared to some older repellents. 
This has led to its widespread acceptance in pediatric formulations and products marketed specifically for infant and child use.

On an environmental level, because Ethyl butylacetylaminopropionate degrades quickly and does not accumulate in ecosystems, it is preferred for use in ecologically sensitive areas and in integrated pest management programs that aim to balance human protection with wildlife conservation. 
Its role in such programs supports sustainable vector control strategies that reduce chemical load in the environment while maintaining public health standards.

Safety Profile Of Ethyl butylacetylaminopropionate:
Ethyl butylacetylaminopropionate is a transparent, colourless, odourless liquid mixture proven safe, as demonstrated by acute toxicity, local tolerability, phototoxicity and repeated-dose toxicity assays. 
Further, Ethyl butylacetylaminopropionate is non-genotoxic and has thus been considered a safe insect-repellent ingredient by the US Environmental Protection Agency since 1999. 

Moreover, Ethyl butylacetylaminopropionate is classified as a hypoallergenic substance based on skin irritation tests. 
Ethyl butylacetylaminopropionate is mainly used as a mosquito/mite repellent sprayed on the body or clothing during outdoor activities. 
Ethyl butylacetylaminopropionate does not have a sticky texture or an offensive odour, which makes it uniquely well-suited for topical use. 

Further, the effects of Ethyl butylacetylaminopropionate-based insect repellents can last up to 4 h with a single spray. 
Ethyl butylacetylaminopropionate is yet to be linked to any toxic effects and is thus considered safe even in cases of exposure via ingestion, inhalation or skin penetration.

Ethyl butylacetylaminopropionate is generally considered to have a favorable safety profile with low toxicity; however, like many chemical repellents, it can pose certain hazards if improperly handled or overused. 
Prolonged or repeated skin exposure may cause mild irritation, redness, or allergic skin reactions in sensitive individuals, especially those with pre-existing skin conditions or allergies.

Inhalation of spray aerosols containing Ethyl butylacetylaminopropionate in poorly ventilated areas can potentially lead to respiratory tract irritation, coughing, or discomfort, so it is important to use such products in well-ventilated environments and avoid direct inhalation. 
Accidental contact with the eyes can result in irritation, redness, or a burning sensation, necessitating immediate rinsing with plenty of water.

Though rare, ingestion of Ethyl butylacetylaminopropionate-containing products can cause gastrointestinal symptoms such as nausea, vomiting, or abdominal discomfort, and in such cases, medical attention should be sought promptly. 
Environmental hazards are minimal due to the compound’s rapid biodegradability, but excessive release into aquatic systems should still be avoided to protect sensitive aquatic organisms.