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2-Undecanone vs Permethrin

The same eleven questions, side by side, each answer in the agency's words. No verdict from us: we sell a product built on one of these actives, so the agencies do the talking.

2-Undecanonemethyl nonyl ketone
Permethrina synthetic pyrethroid insecticide

Per EPA's tool

2-Undecanone

Registered; 1 product in EPA's tool; 5 h mosquitoes, 2 h ticks.

Permethrin

Registered since 1979; CDC says fabric only, never skin; Not in EPA’s tool.

What is it, and where does it come from?

2-Undecanone

2-Undecanone is methyl nonyl ketone; one 2008 paper says it was originally derived from wild tomato plants.

Source and detail: CDC Yellow Book 2024, U.S. EPA, Witting-Bissinger BE

2-Undecanone is methyl nonyl ketone; CDC's Yellow Book files it with the biopesticide repellents, derived from or synthetic versions of natural materials. A 2008 Journal of Medical Entomology paper says the 7.75 percent 2-undecanone in the repellent EPA registered in 2007 was originally derived from wild tomato plants. EPA's 1995 reregistration fact sheet describes methyl nonyl ketone as a dog and cat repellent, training aid and iris borer deterrent.

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
Permethrin

A synthetic pyrethroid that NPIC says acts like natural chrysanthemum extracts, registered by EPA as an insecticide.

Source and detail: EPA, NPIC

Permethrin is an insecticide in the pyrethroid family; NPIC's permethrin fact sheet says pyrethroids are synthetic chemicals that act like natural extracts from the chrysanthemum flower. EPA's Repellent-Treated Clothing page describes it as a broad spectrum, non-systemic, synthetic pyrethroid insecticide, registered as an insecticide for a variety of settings, and says that when used to pre-treat clothing it is an insect repellent.

Permethrin is an insecticide in the pyrethroid family. Pyrethroids are synthetic chemicals that act like natural extracts from the chrysanthemum flower.

NPIC, Permethrin General Fact Sheet

Permethrin is a broad spectrum, non-systemic, synthetic pyrethroid insecticide that targets adults and larvae of many species of biting, chewing, scaling, soil, and flying invertebrates. Permethrin is registered by the EPA as an insecticide for use in a variety of settings. When used to pre-treat clothing, it is an insect repellent.

EPA, Repellent-Treated Clothing

How does EPA treat it?

2-Undecanone

EPA lists 2-undecanone in one registered skin-applied product; no EPA skin-repellent fact sheet found.

Source and detail: U.S. EPA

EPA's skin-applied ingredients page, updated January 2026, lists 2-undecanone, or methyl nonyl ketone, as the active ingredient in one registered product. We found no EPA fact sheet for it as a skin repellent; the EPA chemical document we did find, the July 1995 R.E.D. Facts for methyl nonyl ketone, was written for its use as a dog and cat repellent, training aid and iris borer deterrent.

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
Permethrin

Registered since 1979, EPA says; on clothing by the military since 1990, factory-treated consumer clothing since 2003.

Source and detail: EPA

Registered since 1979, per EPA's Repellent-Treated Clothing page, which says permethrin was first registered in 1990 as a repellent on clothing by the military and that factory-treated consumer clothing was first registered in 2003. EPA's sentence is "The only insect repellent currently used for factory treatment of clothing is permethrin."

Permethrin has been registered since 1979. It was first registered in 1990 for use as a repellent on clothing by the military. At about the same time, we also approved permethrin as a spray for use on clothing and gear by consumers, as well as for commercial factory treatment of clothing and various types of gear. In 2003, we first registered consumer-oriented, permethrin factory-treated clothing products.

EPA, Repellent-Treated Clothing

The only insect repellent currently used for factory treatment of clothing is permethrin.

EPA, Repellent-Treated Clothing

What strengths are registered, and does strength change protection?

2-Undecanone

One label declares 7.75 percent; CDC says higher concentrations generally protect longer, regardless of the active.

Source and detail: CDC Yellow Book 2024, NPIC, U.S. EPA, U.S. EPA accepted label

One strength is on the record: the accepted label for Bio-UD-8 Spray (EPA Reg. No. 82669-2) declares 2-undecanone at 7.75 percent, and EPA's ingredients page lists the active in one registered product. On strength in general, CDC's Yellow Book says that in general higher concentrations of active ingredient provide longer protection regardless of the active, and NPIC says higher concentration repellents may protect longer but are not better at keeping insects away.

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
Permethrin

Permethrin at 0.5% on clothing repels and kills ticks, chiggers and mosquitoes, CDC says; labels list 0.50%.

Source and detail: CDC Yellow Book, EPA stamped label

CDC's Yellow Book says that at a concentration of 0.5 percent, permethrin-treated clothing repels and kills ticks, chiggers, mosquitoes and other biting and nuisance arthropods. The accepted label for a permethrin clothing treatment, EPA Reg. No. 50404-3, gives its active ingredient as permethrin 0.50 percent, and the accepted hang-tag label for factory-treated apparel, EPA Reg. No. 74843-2, gives permethrin at 0.52 percent.

At a concentration of 0.5%, permethrin-treated clothing repels and kills ticks, chiggers, mosquitoes, and other biting and nuisance arthropods.

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

ACTIVE INGREDIENT: Permethrin*……..……. 0.50%

EPA stamped label, CIC Residual Insecticide No. 1, EPA Reg. No. 50404-3, accepted October 6, 2015

Permethrin 0.52%

EPA stamped label, Insect Shield Repellent Apparel, EPA Reg. No. 74843-2, dated May 15, 2017

How long does EPA say it protects?

2-Undecanone

EPA's tool lists 5 hours for mosquitoes, 2 for ticks; the label says up to 4.5 and 2.

Source and detail: U.S. EPA, U.S. EPA accepted label

EPA's repellent search tool, whose database EPA says was last updated in June 2019, lists Bio-UD-8 Spray (EPA Reg. No. 82669-2, 7.75 percent) at 5 hours for mosquitoes and 2 hours for ticks. The product's 2009 accepted label says it repels mosquitoes for up to 4.5 hours and ticks that may transmit Lyme disease for up to 2 hours, and says for best results to spray skin every 4.5 hours.

| 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
Permethrin

Labels say six weeks or six washes when you treat clothing, 70, 50 or 25 washings when factory-treated.

Source and detail: CDC Yellow Book, EPA stamped label

The accepted label for a 0.5 percent permethrin clothing treatment, EPA Reg. No. 50404-3, says protection lasts a minimum of six weeks, with retreatment after six weeks or the sixth laundering; the hang-tag for factory-treated apparel, EPA Reg. No. 74843-2, says repellency remains effective for a bracketed 70, 50 or 25 washings. CDC's Yellow Book says treated materials retain repellency after repeated launderings but should be retreated per the label.

This product contains an active ingredient, which actually binds to the fabric being treated, providing residual protection, which lasts a minimum of six weeks [42 days], and holds up through several machine washings. Follow standard laundering procedures. Clothing should be retreated after six weeks [42 days] or after the sixth laundering to maintain adequate protection.

EPA stamped label, CIC Residual Insecticide No. 1, EPA Reg. No. 50404-3, accepted October 6, 2015

REPELLENCY REMAINS EFFECTIVE FOR [70][50][25] WASHINGS

EPA stamped label, Insect Shield Repellent Apparel, EPA Reg. No. 74843-2, dated May 15, 2017

Permethrin-treated materials retain repellency or insecticidal activity after repeated launderings but should be retreated as described on the product label to provide continued protection. Clothing treated before purchase is labeled for efficacy through many launderings.

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

ACTIVE INGREDIENT: Permethrin*……..……. 0.50%

EPA stamped label, CIC Residual Insecticide No. 1, EPA Reg. No. 50404-3, accepted October 6, 2015

Which pests do accepted labels name, and what does CDC say those pests carry?

2-Undecanone

The label names mosquitoes, ticks and other arthropods.

Source and detail: CDC, U.S. EPA accepted label

The accepted label for Bio-UD-8 Spray (EPA Reg. No. 82669-2) says it repels ticks and other arthropods, mosquitoes that may transmit West Nile virus, and ticks that may transmit Lyme disease. CDC says mosquitoes can spread pathogens through bites, naming West Nile virus, dengue and malaria, and counts Lyme disease among the diseases caused by pathogens some U.S. ticks carry.

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)
Permethrin

Labels name mosquitoes, ticks, chiggers, mites, ants, flies and midges.

Source and detail: EPA stamped label

The accepted label for a 0.5 percent permethrin clothing treatment, EPA Reg. No. 50404-3, says it repels and kills mosquitoes, chiggers, mites and ticks, in the label's words "including Ticks which carry Lyme Disease and Rocky Mountain Spotted Fever." The accepted hang-tag label for factory-treated apparel, EPA Reg. No. 74843-2, claims that it repels mosquitoes, ticks, ants, flies, chiggers and midges.

To repel & kill mosquitoes, chiggers, mites and ticks, including Ticks which carry Lyme Disease and Rocky Mountain Spotted Fever.

EPA stamped label, CIC Residual Insecticide No. 1, EPA Reg. No. 50404-3, accepted October 6, 2015

REPELS MOSQUITOES, TICKS, ANTS, FLIES, CHIGGERS, AND MIDGES

EPA stamped label, Insect Shield Repellent Apparel, EPA Reg. No. 74843-2, dated May 15, 2017

ACTIVE INGREDIENT: Permethrin*……..……. 0.50%

EPA stamped label, CIC Residual Insecticide No. 1, EPA Reg. No. 50404-3, accepted October 6, 2015

What do the agencies say about children?

2-Undecanone

CDC says no age restriction; the label says an adult should apply it to children under 10.

Source and detail: CDC Yellow Book 2024, NPIC, U.S. EPA accepted label

CDC's Yellow Book says repellents containing 2-undecanone can be used on children without age restriction, and NPIC's fact sheet says that if no age limit appears on a label, EPA has not put age restrictions on the product. The accepted label for EPA Reg. No. 82669-2 says an adult should apply it to children under 10 years of age and that children should not apply it.

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
Permethrin

No minimum age stated; EPA's 2009 review called treated clothing unlikely to pose significant hazard, toddlers included.

Source and detail: EPA

No CDC, EPA or label source we read states a minimum age for wearing permethrin-treated clothing. The closest agency statement is EPA's: its 2009 revised exposure and risk assessment evaluated multiple exposure scenarios for permethrin factory-treated clothing, including toddlers wearing or mouthing the clothing, and all scenarios showed the clothing is unlikely to pose any significant immediate or long-term hazard to people wearing it.

Our 2009 revised exposure and risk assessment evaluated multiple exposure scenarios for permethrin factory-treated clothing, including toddlers wearing or mouthing the clothing, and military personnel who wear permethrin-treated uniforms on a daily basis. All exposure scenarios showed that permethrin factory-treated clothing is unlikely to pose any significant immediate or long-term hazard to people wearing the clothing.

EPA, Repellent-Treated Clothing

What do CDC and WHO say about pregnancy?

2-Undecanone

CDC says EPA recommends no precautions for pregnant or lactating women beyond its usual repellent tips.

Source and detail: CDC, CDC Yellow Book 2024, U.S. EPA, World Health Organization

CDC's tick prevention page lists 2-undecanone among EPA-registered repellent actives, and CDC's Yellow Book says EPA recommends no precautions beyond its usual tips for registered repellents on women who are pregnant or lactating. The WHO malaria and dengue fact sheets we read do not name 2-undecanone. EPA's 1995 methyl nonyl ketone findings report no evidence of maternal toxicity, developmental toxicity or mutagenicity.

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
Permethrin

EPA says no evidence of reproductive or developmental effects to mother or child; no CDC statement found.

Source and detail: EPA

EPA's Repellent-Treated Clothing page says that, based on its review of scientific studies, there is no evidence of reproductive or developmental effects to mother or child following exposure to permethrin. No CDC or WHO page we read makes a permethrin-specific pregnancy statement.

Based on our review of scientific studies, there is no evidence of reproductive or developmental effects to mother or child following exposure to permethrin.

EPA, Repellent-Treated Clothing

What do NPIC and EPA report about absorption and toxicity?

2-Undecanone

EPA's 1995 review of the dog and cat repellent found no oral or inhalation toxicity in animals.

Source and detail: U.S. EPA

EPA's 1995 reregistration of methyl nonyl ketone, the dog and cat repellent, found no toxicity by the oral and inhalation routes in laboratory animals, Toxicity Category IV, the lowest of four, and slight toxicity, Category III, for dermal toxicity, eye irritation and dermal irritation, plus weak dermal sensitization. We found no EPA or NPIC toxicity review of the 7.75 percent skin product.

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
Permethrin

EPA says treated clothing gives low exposure and skin absorbs it poorly; NPIC says it may irritate skin.

Source and detail: EPA, NPIC

EPA's Repellent-Treated Clothing page says the amount of permethrin allowed in clothing is very low, that human exposure from wearing permethrin factory-treated clothing is low, and that available data show permethrin is poorly absorbed through the skin. NPIC says people who get permethrin on their skin may have irritation or tingling, burning and itching at that spot, and in the eyes it can cause redness, pain or burning.

The amount of permethrin allowed in clothing is very low, and scientific studies indicate that human exposure resulting from wearing permethrin factory-treated clothing also is low. Available data show that permethrin is poorly absorbed through the skin.

EPA, Repellent-Treated Clothing

When people get permethrin on their skin, they may have irritation or tingling, burning and itching at that spot. If permethrin gets in the eyes it can cause redness, pain or burning.

NPIC, Permethrin General Fact Sheet

Does it damage plastics, fabrics or gear?

2-Undecanone

The label carries no plastics or materials warning; no agency statement found.

Source and detail: U.S. EPA accepted label

The accepted label for Bio-UD-8 Spray (EPA Reg. No. 82669-2) that we read carries no plastics or materials warning. Its one line on gear is an optional claim that the product can be applied on skin and clothing, and no agency page we read says whether 2-undecanone damages plastics.

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
Permethrin

CDC says never on skin, only clothing, nets and fabrics; a label adds tents, sleeping bags and backpacks.

Source and detail: CDC Yellow Book, EPA stamped label

CDC's Yellow Book says permethrin should never be applied to skin, only to clothing, nets or other fabrics as the label directs. The label for a 0.5 percent permethrin treatment, EPA Reg. No. 50404-3, lists netting, tents, sleeping bags, backpacks, hammocks and camping chairs, with no treating inside a sleeping bag and only the exterior surfaces of a tent sprayed; the hang-tag for factory-treated apparel, EPA Reg. No. 74843-2, says dry cleaning removes the active ingredient.

Permethrin should never be applied to the skin but only to clothing, mosquito nets, or other fabrics as directed on the product label.

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

GEAR: MOSQUITO NETTING, NETS, TENTS, CANOPIES, SCREEN ENCLOSURES, SLEEPING BAGS, BACKPACKS, GROUNDCLOTHS, HAMMOCKS AND CAMPING CHAIRS: Do not treat inside of sleeping bag. Spray exterior surfaces of tent only.

EPA stamped label, CIC Residual Insecticide No. 1, EPA Reg. No. 50404-3, accepted October 6, 2015

DRYCLEANING REMOVES ACTIVE INGREDIENT- DO NOT DRY CLEAN

EPA stamped label, Insect Shield Repellent Apparel, EPA Reg. No. 74843-2, dated May 15, 2017

ACTIVE INGREDIENT: Permethrin*……..……. 0.50%

EPA stamped label, CIC Residual Insecticide No. 1, EPA Reg. No. 50404-3, accepted October 6, 2015

What do the agencies say about pets?

2-Undecanone

Only EPA's general rule applies: nothing on pets unless the label says so.

Source and detail: U.S. EPA

EPA's rule for every skin repellent applies: no product on pets or other animals unless the label clearly states it is for animals. We found nothing about animals on the skin label for EPA Reg. No. 82669-2; EPA's separate 1995 reregistration of methyl nonyl ketone as a dog and cat repellent requires the label line that persons and pets must not enter a treated area until sprays have dried.

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
Permethrin

NPIC says cats are more sensitive than dogs or people because they break it down slowly.

Source and detail: NPIC

NPIC says permethrin is more toxic to insects than to people and dogs, and that cats are more sensitive than dogs or people because their bodies take a long time to break it down. NPIC's technical fact sheet describes a report of 11 cats intentionally treated with products containing 45 to 65 percent permethrin: all 11 were hospitalized, with muscle tremors, seizures, incoordination and agitation, and four died.

Permethrin is more toxic to insects than it is to people and dogs. This is because insects can't break it down as quickly as people and dogs. Cats are more sensitive to permethrin than dogs or people because it takes their bodies a long time to break it down.

NPIC, Permethrin General Fact Sheet

A report of 11 cats intentionally treated with products containing 45-65% permethrin described adverse effects including muscle tremors, seizures, incoordination and agitation after exposure. Of the 11 cats that were treated, all were hospitalized, and four died after the exposure.

NPIC, Permethrin Technical Fact Sheet (archived)

Which studies are on the record?

2-Undecanone

One 2008 trial reported repellency against American dog ticks for at least 2.5 hours on skin.

Source and detail: Witting-Bissinger BE

Witting-Bissinger et al., Journal of Medical Entomology 2008, reported no difference in mean repellency over 6 hours between 7.75 percent 2-undecanone and 7 or 15 percent DEET against Aedes albopictus; against Aedes aegypti no difference was found against 7 percent DEET and mean repellency was lower than 15 percent DEET over the same period. The same paper reported repellency against American dog ticks for at least 2.5 hours on skin.

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
Permethrin

One trial found 3.36 times fewer tick bites on subjects wearing permethrin-treated outfits than untreated ones.

Source and detail: Miller NJ

Miller 2011 (Journal of Medical Entomology) found that subjects wearing outfits treated with permethrin received 3.36 times fewer tick bites than subjects wearing untreated outfits, with no statistically significant difference between commercial permethrin treatment and the do-at-home application method. In the same study, 97.6 percent of nymphs attached to subjects in untreated outfits were alive, against 22.6 percent on subjects in repellent-treated outfits.

Subjects wearing outfits treated with permethrin received 3.36 times fewer tick bites than subjects wearing untreated outfits. No statistically significant differences in number of tick bites were detected between commercial permethrin treatment (19.33%) and the do-at-home permethrin application method (24.67%).

Miller NJ, Rainone EE, Dyer MC, Gonzalez ML, Mather TN. Tick bite protection with permethrin-treated summer-weight clothing. J Med Entomol. 2011 Mar;48(2):327-33. PMID 21485369

On subjects wearing untreated outfits, 97.6% of attached nymphs were alive, whereas significantly fewer (22.6%) attached nymphs were alive on subjects wearing repellent-treated outfits.

Miller NJ, et al. J Med Entomol. 2011 Mar;48(2):327-33. PMID 21485369

Sources on this page.

21 sources. Every quote was fetched on or before 2026-09-22 and is stored with the page. Last reviewed 2026-09-22. All ten actives.

  1. CDC Yellow Book 2024, Mosquitoes, Ticks, and Other Arthropods (Wayback Machine capture). https://wwwnc.cdc.gov/travel/yellowbook/2024/environmental-hazards-risks/mosquitoes-ticks-and-other-arthropods
  2. 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. https://pubmed.ncbi.nlm.nih.gov/18826032/
  3. U.S. EPA, Skin-Applied Repellent Ingredients, last updated January 23, 2026. https://www.epa.gov/insect-repellents/skin-applied-repellent-ingredients
  4. U.S. EPA, R.E.D. FACTS Methyl Nonyl Ketone, EPA-738-F-95-033, July 1995. https://www3.epa.gov/pesticides/chem_search/reg_actions/reregistration/fs_PC-044102_1-Jul-95.pdf
  5. U.S. EPA accepted label, Bio-UD-8 Spray, EPA Reg. No. 82669-2, January 8, 2009. https://www3.epa.gov/pesticides/chem_search/ppls/082669-00002-20090108.pdf
  6. NPIC, Insect Repellents General Fact Sheet. https://npic.orst.edu/factsheets/repellents.html
  7. U.S. EPA, Insect Repellents: Use and Effectiveness search results for 2-undecanone. https://cfpub.epa.gov/oppref/insect_s/search_results.cfm?Rangetime=&hidSelected=1&ProductName=&Ingredient=2-undecanone&Company=null&Registration=
  8. U.S. EPA, Find the Repellent that is Right for You. https://www.epa.gov/insect-repellents/find-repellent-right-you
  9. CDC, About Mosquitoes (Wayback Machine capture of cdc.gov/mosquitoes/about/index.html). https://www.cdc.gov/mosquitoes/about/index.html
  10. CDC, About Ticks and Tickborne Disease (Wayback Machine capture of cdc.gov/ticks/about/index.html). https://www.cdc.gov/ticks/about/index.html
  11. CDC, Preventing Tick Bites (Wayback Machine capture of cdc.gov/ticks/prevention/index.html). https://www.cdc.gov/ticks/prevention/index.html
  12. World Health Organization, Malaria fact sheet. https://www.who.int/news-room/fact-sheets/detail/malaria
  13. World Health Organization, Dengue and severe dengue fact sheet. https://www.who.int/news-room/fact-sheets/detail/dengue-and-severe-dengue
  14. U.S. EPA, Using Insect Repellents Safely and Effectively. https://www.epa.gov/insect-repellents/using-insect-repellents-safely-and-effectively
  15. NPIC, Permethrin General Fact Sheet. https://npic.orst.edu/factsheets/PermGen.html
  16. EPA, Repellent-Treated Clothing. https://www.epa.gov/insect-repellents/repellent-treated-clothing
  17. CDC Yellow Book, Mosquitoes, Ticks, and Other Arthropods (Wayback Machine capture 2026-09-19). https://www.cdc.gov/yellow-book/hcp/environmental-hazards-risks/mosquitoes-ticks-and-other-arthropods.html
  18. EPA stamped label, CIC Residual Insecticide No. 1, EPA Reg. No. 50404-3, accepted October 6, 2015. https://www3.epa.gov/pesticides/chem_search/ppls/050404-00003-20151006.pdf
  19. EPA stamped label, Insect Shield Repellent Apparel, EPA Reg. No. 74843-2, dated May 15, 2017. https://www3.epa.gov/pesticides/chem_search/ppls/074843-00002-20170515.pdf
  20. NPIC, Permethrin Technical Fact Sheet (archived). https://npic.orst.edu/factsheets/archive/Permtech.html
  21. Miller NJ, Rainone EE, Dyer MC, Gonzalez ML, Mather TN. Tick bite protection with permethrin-treated summer-weight clothing. J Med Entomol. 2011 Mar;48(2):327-33. PMID 21485369. https://pubmed.ncbi.nlm.nih.gov/21485369/