DEET vs 2-Undecanone

DEET (chemical name, N,N-diethyl-meta-toluamide) is the active ingredient in many repellent products. It is widely used to repel biting pests such as mosquitoes and ticks. Every year, an estimated one-third of the U.S. population use DEET to protect them from mosquito-borne illnesses like West Nile Virus, the Zika virus or malaria and tick-borne illnesses like Lyme disease and Rocky Mountain spotted fever.

EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

DEET is designed for direct application to people's skin to repel insects. Rather than killing them, DEET works by making it hard for these biting bugs to smell us. After it was developed by the U.S. Army in 1946, DEET was registered for use by the general public in 1957. Approximately 120 products containing DEET are currently registered with EPA by about 30 different companies.

EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

2-undecanone (chemical name: methyl nonyl ketone)

CDC Yellow Book 2024, Mosquitoes, Ticks, and Other Arthropods (Wayback Machine capture)

EPA characterizes the active ingredients DEET and picaridin as "conventional" repellents. The biopesticide repellents (OLE, PMD, IR3535, and 2-undecanone) are derived from, or are synthetic versions of, natural materials.

CDC Yellow Book 2024, Mosquitoes, Ticks, and Other Arthropods (Wayback Machine capture)

In 2007, a new repellent, BioUD, with the active ingredient 7.75% 2-undecanone, originally derived from wild tomato (Lycopersicon hirsutum Dunal f. glabratum C. H. Müll) plants, was registered by the U.S. Environmental Protection Agency.

Witting-Bissinger BE, Stumpf CF, Donohue KV, Apperson CS, Roe RM. Novel arthropod repellent, BioUD, is an efficacious alternative to deet. J Med Entomol. 2008 Sep;45(5):891-8. PMID 18826032

Methyl nonyl ketone is a dog and cat repellent/training aid and iris borer deterrent. The pesticide is used in households, paths, patios, solid waste containers and on ornamental plants.

U.S. EPA, R.E.D. FACTS Methyl Nonyl Ketone, EPA-738-F-95-033, July 1995

DEET is designed for direct application to people's skin to repel insects. Rather than killing them, DEET works by making it hard for these biting bugs to smell us. After it was developed by the U.S. Army in 1946, DEET was registered for use by the general public in 1957. Approximately 120 products containing DEET are currently registered with EPA by about 30 different companies.

EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

After completing a comprehensive re-assessment of DEET, we concluded that insect repellents containing DEET do not present a health concern. Consumers are advised to read and follow label directions when using any pesticide product, including insect repellents. Based on extensive toxicity testing, we believe that the normal use of DEET does not present a health concern to the general population, including children. We completed this review and issued a reregistration decision (called a RED) in 1998.

EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

The human health risk assessment concluded that there are no risks of concern because no toxic effects have been identified when used as a dermally applied insect repellent, and there is no dietary or occupational exposure for DEET. However, a Final Decision on the DEET registration review case will occur only after the EPA has completed an Endocrine Disruptor Screening under FFDCA section 408(p).

EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

2-undecanone -- EPA pesticide regulatory information (or methyl nonyl ketone) (1 product)

U.S. EPA, Skin-Applied Repellent Ingredients, last updated January 23, 2026

Methyl nonyl ketone is a dog and cat repellent/training aid and iris borer deterrent. The pesticide is used in households, paths, patios, solid waste containers and on ornamental plants.

U.S. EPA, R.E.D. FACTS Methyl Nonyl Ketone, EPA-738-F-95-033, July 1995

Products containing DEET currently are available to the public in a variety of liquids, lotions, sprays, and impregnated materials (e.g., towelettes, roll on). Formulations registered for direct application to human skin contain from 5 to 99% DEET.

EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

In general, higher concentrations of active ingredients provide longer duration of protection, regardless of the active ingredient. Products with <10% active ingredient might offer only limited protection, often 1-2 hours. Products that offer sustained-release or controlled-release (microencapsulated) formulations, even with lower active ingredient concentrations, might provide longer protection times. Studies suggest that DEET efficacy tends to peak at a concentration of approximately 50% and that concentrations above that do not offer a marked increase in protection time against mosquitoes.

CDC Yellow Book, Mosquitoes, Ticks, and Other Arthropods (Wayback Machine capture 2026-09-19)

ACTIVE INGREDIENT 2-Undecanone [CAS# 112-12-9] ..... . 7.75% OTHER INGREDIENTS ............................. .. 92.25%

U.S. EPA accepted label, Bio-UD-8 Spray, EPA Reg. No. 82669-2, January 8, 2009

2-undecanone -- EPA pesticide regulatory information (or methyl nonyl ketone) (1 product)

U.S. EPA, Skin-Applied Repellent Ingredients, last updated January 23, 2026

In general, higher concentrations of active ingredients provide longer duration of protection, regardless of the active ingredient.

CDC Yellow Book 2024, Mosquitoes, Ticks, and Other Arthropods (Wayback Machine capture)

Higher concentration repellents may protect people for longer. However, they are not better at keeping insects away. 5,6,7 Repellents with less than 10% of an active ingredient may only offer protection for short periods of time (1-2 hours). 5

NPIC, Insect Repellents General Fact Sheet

Studies in EPA's database indicate that DEET repels ticks for about two to ten hours, and mosquitoes from two to twelve hours depending on the percentage of DEET in the product.

EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

Ben's 100 Insect Repellent | 10 | 10 | DEET | 98.11 | Tender Corp. | 56575-7

EPA, Find the Repellent that is Right for You, search results for DEET, cfpub.epa.gov/oppref/insect_s

While this technical information is based on scientific testing guidelines and approved study methods, there are variations in the resulting protection times because of differences in the testing conditions.

EPA, Find the Repellent that is Right for You

Any products listed are for informational purposes only. Inclusion of a product listed/referenced is not an endorsement. * EPA and the U.S. Government do not endorse any product or service. * The information in this database was last updated in June 2019.

U.S. EPA, Find the Repellent that is Right for You

| BIO-UD-8 Spray | 5 | 2 | 2-undecanone | 7.75 | HOMS LLC | 82669-2

U.S. EPA, Insect Repellents: Use and Effectiveness search results for 2-undecanone

Product Name Hourly Protection Time for Mosquitoes Hourly Protection Time for Ticks Active Ingredient(AI) AI% in Product Formula Company Name EPA Registration Number

U.S. EPA, Insect Repellents: Use and Effectiveness search results for 2-undecanone

Any products listed are for informational purposes only. Inclusion of a product listed/referenced is not an endorsement. * EPA and the U.S. Government do not endorse any product or service. * The information in this database was last updated in June 2019.

U.S. EPA, Find the Repellent that is Right for You

Repels mosquitoes for up to 4.5 hours Repels mosquitoes that may carry West Nile Virus for

U.S. EPA accepted label, Bio-UD-8 Spray, EPA Reg. No. 82669-2, January 8, 2009

Repels ticks that may transmit Lyme Disease for up to 2 hours

U.S. EPA accepted label, Bio-UD-8 Spray, EPA Reg. No. 82669-2, January 8, 2009

Shake well before using. This bottle is. designed to spray upside down. For best results spray skin every 4.5 hours.

U.S. EPA accepted label, Bio-UD-8 Spray, EPA Reg. No. 82669-2, January 8, 2009

EFFECTIVE PROTECTION from Mosquitoes, Gnats, No-See-Ums, Biting Flies, Ticks (including ticks that may cause Lyme disease), Chiggers and Fleas

EPA notification label, OFF! Insect Repellent II, EPA Reg. No. 4822-380, 15% DEET aerosol, November 13, 2009

Repels ticks and other arthropods

U.S. EPA accepted label, Bio-UD-8 Spray, EPA Reg. No. 82669-2, January 8, 2009

Protection for up to 4.5 hours from Repels ticks and other arthropods mosquitoes that may transmit West Nile Virus

U.S. EPA accepted label, Bio-UD-8 Spray, EPA Reg. No. 82669-2, January 8, 2009

Repels ticks that may transmit Lyme Disease for up to 2 hours

U.S. EPA accepted label, Bio-UD-8 Spray, EPA Reg. No. 82669-2, January 8, 2009

Almost everyone has been bitten by a mosquito. Mosquitoes can spread pathogens (germs) through bites. A person who gets bitten by a mosquito and gets sick has a mosquito-borne disease like West Nile virus, dengue, or malaria.

CDC, About Mosquitoes (Wayback Machine capture of cdc.gov/mosquitoes/about/index.html)

In the United States, some ticks carry pathogens that can cause human disease, including: * Alpha-gal syndrome * Anaplasmosis * Babesiosis * Bourbon virus * Colorado tick fever * Ehrlichiosis * Hard tick relapsing fever * Heartland virus * Lyme disease * Powassan virus * Rickettsia parkeri rickettsiosis * Rocky Mountain spotted fever * Soft tick relapsing fever * STARI * Tularemia

CDC, About Ticks and Tickborne Disease (Wayback Machine capture of cdc.gov/ticks/about/index.html)

DEET is approved for use on children with no age restriction. There is no restriction on the percentage of DEET in the product for use on children, since data do not show any difference in effects between young animals and adult animals in tests done for product registration.

EPA, DEET (epa.gov/insect-repellents/deet), fetched 2026-09-22

Insect repellents containing DEET, picaridin, IR3535, and 2-undecanone can be used on children without age restriction

CDC Yellow Book, Mosquitoes, Ticks, and Other Arthropods (Wayback Machine capture 2026-09-19)

Insect repellents containing DEET, picaridin, IR3535, and 2-undecanone can be used on children without age restriction (see EPA webpage on Using Insect Repellents Safely and Effectively with Children ).

CDC Yellow Book 2024, Mosquitoes, Ticks, and Other Arthropods (Wayback Machine capture)

Check the product label to see if there is a minimum age for use. If no age limit is on the label, the EPA has not put age restrictions on the product.

NPIC, Insect Repellents General Fact Sheet

An adult should apply this product to children under 10 years of age. Do not allow children to apply this product

U.S. EPA accepted label, Bio-UD-8 Spray, EPA Reg. No. 82669-2, January 8, 2009

Use EPA-registered insect repellents with one of the following active ingredients. When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women.

CDC, Preventing Mosquito Bites (Wayback Machine capture 2026-09-16)

When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breastfeeding women. DEET Picaridin (known as KBR 3023 and icaridin outside the United States)

CDC, Preventing Mosquito Bites (Wayback Machine capture 2026-09-16)

The safety of daily application of N, N-diethyl-m-toluamide (DEET) (1.7 g of DEET/day) in the second and third trimesters of pregnancy was assessed as part of a double-blind, randomized, therapeutic trial of insect repellents for the prevention of malaria in pregnancy (n = 897). No adverse neurologic, gastrointestinal, or dermatologic effects were observed for women who applied a median total dose of 214.2 g of DEET per pregnancy (range = 0-345.1 g).

McGready R, et al. Safety of the insect repellent N,N-diethyl-M-toluamide (DEET) in pregnancy. Am J Trop Med Hyg. 2001 Oct;65(4):285-9. PMID 11693870

DEET crossed the placenta and was detected in 8% (95% confidence interval = 2.6-18.2) of cord blood samples from a randomly selected subgroup of DEET users (n = 50). No adverse effects on survival, growth, or development at birth, or at one year, were found. This is the first study to document the safety of DEET applied regularly in the second and third trimesters of pregnancy.

McGready R, et al. Am J Trop Med Hyg. 2001 Oct;65(4):285-9. PMID 11693870

Use Environmental Protection Agency (EPA)-registered insect repellents containing DEET, picaridin, IR3535, Oil of Lemon Eucalyptus (OLE), para-menthane-diol (PMD), or 2-undecanone. Look for an EPA registration number (EPA Reg. No.) on the insect repellent product label. This registration number means the company provided EPA with technical information on the effectiveness of the product.

CDC, Preventing Tick Bites (Wayback Machine capture of cdc.gov/ticks/prevention/index.html)

Other than the safety tips listed above, EPA does not recommend any additional precautions for using registered repellents on children or on women who are pregnant or lactating.

CDC Yellow Book 2024, Mosquitoes, Ticks, and Other Arthropods (Wayback Machine capture)

Use mosquito repellents (containing DEET, IR3535 or Icaridin) after dusk.

World Health Organization, Malaria fact sheet

To lower your risk of getting dengue, protect yourself from mosquito bites by using: * clothes that cover as much of your body as possible; * mosquito nets, ideally sprayed with insect repellent, if sleeping during the day; * window screens; * mosquito repellents (containing DEET, Picaridin or IR3535); and * coils and vaporizers.

World Health Organization, Dengue and severe dengue fact sheet

No evidence of maternal toxicity, developmental toxicity, or mutagenicity is associated with methyl nonyl ketone. Based on available information, no toxicological endpoints of concern (including short term or intermediate term) were identified.

U.S. EPA, R.E.D. FACTS Methyl Nonyl Ketone, EPA-738-F-95-033, July 1995

When DEET was applied to the skin of volunteers by researchers, they found that a small amount of the DEET was taken into the body through the skin. When DEET and alcohol are applied to the skin, more DEET is taken into the skin compared with DEET alone. Drinking alcohol may also cause more DEET to be absorbed through the skin. Sunscreen products that contain DEET may cause more DEET to be taken into the body through the skin.

NPIC, DEET General Fact Sheet

DEET generally is of low acute toxicity, and, based on the available toxicological data, the Agency believes that the normal use of DEET does not present a health concern to the general U.S. population (the Agency's human risk assessment has identified no toxicologically significant effects in animal studies.) DEET has been classified as a Group D carcinogen (not classifiable as a human carcinogen.)

EPA, R.E.D. FACTS: DEET, EPA-738-F-95-010, April 1998

In summary, since 1960, there have been 14 cases of seizure, including four deaths, potentially related to DEET exposure, for which other more likely causes have not been identified. An additional 32 cases of seizure reported to the national DEET registry are currently under review.

EPA, Reregistration Eligibility Decision (RED) DEET, EPA738-R-98-010, approved April 13, 1998

people using DEET each year, the observed incidence of recognized seizures is about one per 100 million users.

EPA, Reregistration Eligibility Decision (RED) DEET, EPA738-R-98-010, approved April 13, 1998

In studies using laboratory animals, methyl nonyl ketone exhibited no toxicity via the oral and inhalation routes and was placed in Toxicity Category IV (the lowest of four categories) for these effects.

U.S. EPA, R.E.D. FACTS Methyl Nonyl Ketone, EPA-738-F-95-033, July 1995

Methyl nonyl ketone was slightly toxic (Toxicity Category III) for dermal toxicity, eye irritation and dermal irritation and was a weak dermal sensitizer.

U.S. EPA, R.E.D. FACTS Methyl Nonyl Ketone, EPA-738-F-95-033, July 1995

Methyl nonyl ketone is a dog and cat repellent/training aid and iris borer deterrent. The pesticide is used in households, paths, patios, solid waste containers and on ornamental plants.

U.S. EPA, R.E.D. FACTS Methyl Nonyl Ketone, EPA-738-F-95-033, July 1995

DEET is a plasticizer and can damage certain rubber, plastic, vinyl, or elastic materials such as contact lenses, eyeglass frames and lenses, watch crystals, combs, painted and varnished surfaces, and certain synthetic or treated fabrics.

NPIC, DEET Technical Fact Sheet (archived)

Will not damage nylon, cotton, or wool.

EPA amended reregistration label, Cutter Insect Repellent #10GE, EPA Reg. No. 121-53, 10% DEET, March 18, 2009

Optional Label Claims: - Can be applied on skin & clothing

U.S. EPA accepted label, Bio-UD-8 Spray, EPA Reg. No. 82669-2, January 8, 2009

N,N-diethyl-meta-toluamide (DEET) is an insect repellent used in households/domestic dwellings, on the human body and clothing being worn, on cats, dogs, horses and pet living/sleeping quarters. There are no food uses.

EPA, R.E.D. FACTS: DEET, EPA-738-F-95-010, April 1998

Do not use any product on pets or other animals unless the label clearly states it is for animals.

EPA, Using Insect Repellents Safely and Effectively

Reports of pets being exposed to DEET in amounts that would make them sick are rare. Pets that have been overexposed to DEET have shown varying effects, including vomiting, shaking, excitement, lack of coordination, and seizures.

NPIC, DEET General Fact Sheet

Do not use any product on pets or other animals unless the label clearly states it is for animals.

U.S. EPA, Using Insect Repellents Safely and Effectively

"Do not allow persons or pets to enter the treated area until sprays have dried."

U.S. EPA, R.E.D. FACTS Methyl Nonyl Ketone, EPA-738-F-95-033, July 1995

Methyl nonyl ketone is a dog and cat repellent/training aid and iris borer deterrent. The pesticide is used in households, paths, patios, solid waste containers and on ornamental plants.

U.S. EPA, R.E.D. FACTS Methyl Nonyl Ketone, EPA-738-F-95-033, July 1995

Based on a total of 4996 mosquitoes collected on negative control persons, the overall five hour protection rate was 97.4% [95%CI: 97.1-97.8%], not decreasing over time. Picaridin 20% performed equally well as DEET 20% and better than picaridin 10%.

Van Roey K, et al. Field evaluation of picaridin repellents reveals differences in repellent sensitivity between Southeast Asian vectors of malaria and arboviruses. PLoS Negl Trop Dis. 2014 Dec 18;8(12):e3326. PMID 25522134

Formulations containing > or = 20% active ingredient were highly effective, with <10% of the ticks crossing through the treatment bands for any challenge during the 12 h. At least 40% of ticks exposed to any formulation for any challenge fell or crawled off the volunteers.

Carroll JF, Benante JP, Kramer M, Lohmeyer KH, Lawrence K. Formulations of deet, picaridin, and IR3535 applied to skin repel nymphs of the lone star tick (Acari: Ixodidae) for 12 hours. J Med Entomol. 2010 Jul;47(4):699-704. PMID 20695288

There was no difference in effectiveness between the 20% spray and 20% lotion formulations of picaridin. The 10% IR3535 lotion was significantly less effective than the formulations with higher concentrations of repellent. In the formulations tested, deet, picaridin, and IR3535 provided lasting protection against A. americanum.

Carroll JF, et al. J Med Entomol. 2010 Jul;47(4):699-704. PMID 20695288

No differences were found in mean repellency over 6 h after application between BioUD versus 7 and 15% deet for Ae albopictus. For Ae. aegypti, no differences were found over the same time period for 7% deet. Compared with 15% deet, BioUD mean repellency was lower over the 6-h test period.

Witting-Bissinger BE, Stumpf CF, Donohue KV, Apperson CS, Roe RM. Novel arthropod repellent, BioUD, is an efficacious alternative to deet. J Med Entomol. 2008 Sep;45(5):891-8. PMID 18826032

Laboratory trials were conducted to determine the repellent activity of BioUD against the American dog tick, Dermacentor variabilis (Say), on human skin and cloth. BioUD repelled ticks at least 2.5 h after application to human skin.

Witting-Bissinger BE, Stumpf CF, Donohue KV, Apperson CS, Roe RM. Novel arthropod repellent, BioUD, is an efficacious alternative to deet. J Med Entomol. 2008 Sep;45(5):891-8. PMID 18826032

In 2007, a new repellent, BioUD, with the active ingredient 7.75% 2-undecanone, originally derived from wild tomato (Lycopersicon hirsutum Dunal f. glabratum C. H. Müll) plants, was registered by the U.S. Environmental Protection Agency.

Witting-Bissinger BE, Stumpf CF, Donohue KV, Apperson CS, Roe RM. Novel arthropod repellent, BioUD, is an efficacious alternative to deet. J Med Entomol. 2008 Sep;45(5):891-8. PMID 18826032