United States Prevention, Pesticides EPA-738-F-95-010 

Environmental Protection And Toxic Substances APRIL 1998 

Agency (7508W) 

R.E.D. FACTS 

***DEET*** 

Pesticide All pesticides sold or distributed in the United States must be registered 

Reregistration by EPA, based on scientific studies showing that they can be used without 

posing unreasonable risks to people or the environment. Because of advances 

in scientific knowledge, the law requires that pesticides which were first 

registered before November 1, 1984, be reregistered to ensure that they meet 

today's more stringent standards. 

In evaluating pesticides for reregistration, EPA obtains and reviews a 

complete set of studies from pesticide producers, describing the human health 

and environmental effects of each pesticide. The Agency develops any mitigation measures or regulatory controls needed to effectively reduce each pesticide's risks. EPA then reregisters pesticides that can be used without posing 

unreasonable risks to human health or the environment. 

When a pesticide is eligible for reregistration, EPA explains the basis for 

its decision in a Reregistration Eligibility Decision (RED) document. This fact 

sheet summarizes the information in the RED document for reregistration case 

0002, N,N-diethyl-meta-toluamide and other isomers (DEET). 

Use Profile 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. 

It is used to control biting flies, biting midges, black flies, chiggers, deer flies, 

fleas, gnats, horse flies, mosquitoes, no-see-ums, sand flies, small flying insects, 

stable flies, and ticks. Formulations include liquids, pressurized liquids, readyto-use formulations and impregnated material. DEET is applied by aerosol 

can, by hand, non-aerosol pump sprayer, package applicator, and pump spray 

bottle. 

Regulatory DEET was first registered in the U.S. in 1957 after first being developed 

History by the U.S. Army in 1946 for use by military personnel in 

insect-infested areas. A Registration Standard for DEET was issued in December, 1980 (PB81-207722), and a subsequent Data Call-In (DCI) 

for DEET (issued September, 1988) required additional animal and avian 

toxicity data. 

Currently, 225 DEET products are registered. DEET products that are 

applied directly to the skin and/or clothing are available in numerous formula­
tion types (e.g. aerosol and non-aerosol sprays, creams, lotions, sticks, foams, 

and towelettes). Product concentrations range from .4% a.i. to 100% a.i. 

Human Health Toxicity 

Assessment In studies using laboratory animals, DEET generally has been shown to 

be of low acute toxicity. It is slightly toxic by the eye, dermal and oral routes 

and has been placed in Toxicity Category III (the second lowest of four 

categories) for these effects. 

[NOTE: For acute oral, dermal, ocular and inhalation toxicity: 

Category I = very highly or highly toxic 

Category II = moderately toxic 

Category III = slightly toxic 

Category IV = practically non-toxic] 

Dietary Exposure 

Because of its use pattern, people are not exposed to residues of DEET 

through the diet. 

Occupational and Residential Exposure 

Based on DEET’s indoor/residential use pattern, handlers (mixers, 

loaders, and applicators) are not exposed to DEET. 

Human Risk Assessment 

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.) 

Although DEET’s use has been implicated in seizures among children, 

the Agency believes that the incident data are insufficient to establish DEET as 

the cause of the reported effects. However, because of DEET’s unusual use 

pattern (direct application to human skin and clothing) and its association with 

seizure incidents, the Agency believes it is prudent to require clear, common 

sense use directions and improved label warnings and restrictions on all DEET 

product labels. 

Environmental 

Assessment Environmental Fate 

Because of its limited use pattern, the only environmental fate study 

required for DEET was hydrolysis. From that data, it was concluded that 

DEET is stable to hydrolysis at pH levels found in the environment. 

Ecological Effects 

Because DEET is only applied directly to the human body/clothing, cats, 

dogs, pet quarters and household/domestic dwellings, it is considered to be an 

“indoor residential” use. A limited set of toxicity data for indoor-use pesticides 

2 
Risk Mitigation 

Additional Data 

Required 

is required to determine precautionary label statements and for assessing 

environmental hazards in case of spills. The available data characterize DEET 

as slightly toxic to birds, fish, and aquatic invertebrates and as practically 

nontoxic to mammals. 

Ecological Effects Risk Assessment 

Ecological risk assessments are not conducted for pesticides with 

exclusively indoor use patterns. Application of DEET to the human 

body/clothing, cats, dogs, pet quarters, and household/domestic dwellings, is 

not likely to adversely affect terrestrial wildlife or aquatic organisms. 

DEET is a personal insect repellent that is widely used among the U.S. 

population, including children, and is one of the few residential-use pesticides 

that is applied directly to the skin. Although the available toxicological data to 

not indicate a health concern under normal use conditions, DEET’s use has 

been associated with possible adverse effects. For all of these reasons, the 

Agency believes it is prudent to require improved label warnings and product 

restrictions. A listing of the required labeling statements for DEET 

formulations is included in the RED, Section V. The Agency had deferred its 

decision on the combination DEET/sunscreen products until it has solicited the 

views of various governmental agencies and other groups. Sunscreen products 

are intended for frequent, generous use, and DEET products are intended for 

spare, infrequent use. The Agency is concerned that use of the combination 

products may promote greater use of DEET than is needed for pesticidal 

efficacy and thus pose unnecessary exposure to DEET. In addition, childsafety claims must be removed from all end-use product labels in order to be 

reregistered. Child-safety claims are misleading and irreconcilable with the 

intended use and pesticidal ingredients of DEET products. From the 

toxicological data reviewed by the Agency for DEET, and from DEET incident 

data, there appears to be no correlation between the percent active ingredient 

in the product and its safety. Therefore, the Agency does not believe that 

certain DEET formulations are inherently safer for children. DEET 

uses/formulations with labels that make cosmetic claims must be labeled such 

that label statements and use directions regarding insect repellency appear first 

and more prominently on the label. 

EPA is not requiring additional generic studies for DEET to confirm its 

regulatory assessments and conclusions. 

The Agency is requiring product-specific data including product 

chemistry and acute toxicity studies, product efficacy data, revised Confidential 

Statements of Formula (CSFs), and revised labeling for reregistration. 

Product Labeling All DEET end-use products must comply with EPA's current pesticide

Changes Required product labeling requirements and with those labeling requirements imposed in

3 
Regulatory 

Conclusion 

For More 

Information 

this RED. For a comprehensive list of labeling requirements, please see section 

V. of the DEET RED document. 

1. All products must incorporate a series of 14 statements informing the 

consumer on the method of application, special precautions for children, and 

directions for medical attention. 

2. For aerosol and pump spray formulations: labels must direct the consumer 

not to spray in enclosed areas, avoid direct spraying on the face and must be 

packaged in containers which will ensure the product will not be inadvertently 

sprayed in the eyes. 

3. Other labeling requirements include: specifying percent active ingredient in 

terms of DEET; use of the term “first aid”; addition of a toll-free number for 

consumer support; requirement to use permanent labels; all cosmetic claims 

must be less prominent that the term “Insect repellent”; and all direct or 

indirect claims of child safety must be removed. 

With the exception of products/formulations that combine DEET and 

sunscreen, all uses/formulations of DEET are eligible for reregistration 

provided all labels are amended as specified in the RED. The use of currently 

registered products containing DEET in accordance with approved labeling 

will not pose unreasonable risks or adverse effects to humans or the 

environment. Therefore, all uses of these products are eligible for 

reregistration. The Agency will defer its decision regarding the reregistration 

eligibility of products/formulations that combine DEET and sunscreen until the 

Agency has solicited the views of various governmental agencies and other 

groups. Additionally, the Agency will not act on any pending registration 

applications under section 3 until that time. 

DEET products will be reregistered once the required product-specific 

data, including efficacy data, revised Confidential Statements of Formula, and 

revised labeling are received and accepted by EPA. Products which contain 

active ingredients in addition to DEET will be reregistered when all of their 

other active ingredients also are eligible for reregistration. 

EPA is requesting public comments on the Reregistration Eligibility 

Decision (RED) document for DEET during a 60-day time period, as 

announced in a Notice of Availability published in the Federal Register. To 

obtain a copy of the RED document or to submit written comments, please 

contact the Pesticide Docket, Public Response and Program Resources 

Branch, Field Operations Division (7506C), Office of Pesticide Programs 

(OPP), US EPA, Washington, DC 20460, telephone 703-305-5805. 

Electronic copies of the RED and this fact sheet can be downloaded 

from the Pesticide Special Review and Reregistration Information System at 

703-308-7224. They also are available on the Internet on EPA's gopher 

4 
server, GOPHER.EPA.GOV, or using ftp on FTP.EPA.GOV, or using WWW 

(World Wide Web) on WWW.EPA.GOV. 

Printed copies of the RED and fact sheet can be obtained from EPA's 

National Center for Environmental Publications and Information 

(EPA/NCEPI), PO Box 42419, Cincinnati, OH 45242-0419, telephone 513­

489-8190, fax 513-489-8695. 

Following the comment period, the DEET RED document also will be 

available from the National Technical Information Service (NTIS), 5285 Port 

Royal Road, Springfield, VA 22161, telephone 703-487-4650. 

For more information about EPA's pesticide reregistration program, the 

DEET RED, or reregistration of individual products containing DEET, please 

contact the Special Review and Reregistration Division (7508W), OPP, US 

EPA, Washington, DC 20460, telephone 703-308-8000. 

For information about the health effects of pesticides, or for assistance in 

recognizing and managing pesticide poisoning symptoms, please contact the 

National Pesticides Telecommunications Network (NPTN). Call 

toll-free 1-800-858-7378, between 9:30 am and 7:30 pm Eastern Standard 

Time, Monday through Friday. 

5