The label is the law. Read your product's label before you mix or apply; the rates here come from the labels listed under Sources.
- Active ingredient
- Naled
- Chemical class
- An organophosphate cholinesterase inhibitor, chemically 1,2-dibromo-2,2-dichloroethyl dimethyl phosphate. Naled breaks down to DDVP (dichlorvos), a related organophosphate insecticide.[1][2]
- Mode of action
- IRAC Group 1B: Acetylcholinesterase inhibitors: organophosphates[3]
- Signal word
- Dibrom Concentrate: Danger[1]
When spraying is scheduled near you
Local mosquito control or public health officials decide where and when to spray. They usually announce it a day or two ahead in community announcements, on social media or on their websites, and EPA encourages districts to tell residents at least 24 hours before spraying.[2]
EPA suggests staying indoors with the windows closed during spraying, keeping children from playing outdoors for four hours afterward, and covering outdoor furniture and grills beforehand. If you are outside when the spray comes through and it gets on you, rinse your skin and eyes with water.[2]
If you think you've had a reaction to naled spraying, talk to your doctor or call Poison Control at 1-800-222-1222.[2]
Cutting mosquitoes without spraying
EPA's list starts with getting rid of standing water, even small amounts. Where water can't be removed, such as an ornamental pond, use a mosquito larvicide, add fish that eat larvae, or keep the water moving with a fountain or aerator. Screens on windows and doors, EPA-registered repellents and long, light-colored clothing help prevent bites.[2]
Where EPA's review stands
EPA is re-evaluating naled under registration review. In September 2020 it released draft human health and ecological risk assessments for naled together with DDVP and trichlorfon, because naled and trichlorfon both degrade to DDVP.[2]
Where it is used
Naled has been registered in the United States since 1959. Besides mosquito control, it is used on food and feed crops and in greenhouses.[2]
EPA calls it one of the most widely used pesticides for aerial mosquito control, sprayed on about 16 million acres a year in the mainland United States, in large metropolitan areas as well as farm and rural areas.[2]
ULV sprayers on planes or helicopters release very fine droplets that drift through the air and kill mosquitoes on contact. The Dibrom Concentrate rate for aerial ULV mosquito control is 1/2 to 1 fl oz of undiluted product per acre, or 0.05 to 0.1 lb of naled.[2][1]
The label requires treatments to be based on mosquito surveillance, no more than once a day, no more than 2 fl oz per acre in 7 days and no more than 104 fl oz per acre a year, unless health or vector control officials document a disease threat. It also states that the product is not for use in and around the home by homeowners or professional applicators.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Dibrom Concentrate[1] | AMVAC Chemical Corporation | 5481-480 | 87.4% | concentrate for ULV mosquito and fly control by public health programs (Restricted Use Pesticide) | Danger |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Dibrom Concentrate | Adult mosquito control by ULV aerial application in wide-area public programs (residential areas, municipalities, marshes, swamps, woodlands, agricultural areas) | Adult mosquitoes | 0.5–1 fl oz undiluted product per acre[1] 0.05 to 0.1 lb naled per acre; the 1 fl oz rate where vegetation is heavy. No more than 2 fl oz per acre in 7 days or 104 fl oz per acre per year, except for documented public or animal health threats. |
Safety and environmental hazards
People
Dibrom Concentrate carries the signal word DANGER: it is corrosive, causes irreversible eye and skin damage and may be fatal if swallowed, and it is a restricted use pesticide because of that eye and skin hazard. For aerial mosquito spraying, EPA's 2020 draft risk assessment found potential risk to young children who touch outdoor surfaces shortly after application, but naled and DDVP break down so quickly that residues fall below levels of concern within 5 minutes to 3.4 hours.[1][2]
Pets
EPA advises bringing pets, pet food dishes and children's toys indoors before spraying and rinsing any uncovered items left outside.[2]
Bees and pollinators
The label says naled is highly toxic to bees exposed to direct treatment on blooming crops or weeds. EPA notes that spraying usually happens between dusk and dawn, when bees are typically in their hives, and that beekeepers can cover colonies during spraying or move them to a site that won't be sprayed.[1][2]
Fish and water
The label says naled is toxic to fish, aquatic invertebrates and wildlife and must not be applied over lakes, rivers, ponds, marshes or estuaries unless that is needed to reach adult mosquitoes and the weather will carry the spray away from the water. EPA calls the risk to wildlife from aerial mosquito spraying minimal because naled is applied at low rates from several hundred feet up and does not persist, though insects, crustaceans and spiders could be affected.[1][2]
Common questions
- Is it safe to go outside after mosquito spraying with naled?
- EPA recommends keeping young children from playing outdoors until four hours after spraying. Its draft assessment found that surface residues drop below levels of concern within 5 minutes to 3.4 hours, depending on the application rate, release height, droplet size and wind speed.[2]
- Can I buy naled to spray my yard for mosquitoes?
- No. Dibrom Concentrate is a restricted use pesticide for government public health and vector control programs and certified applicators, and its label says it is not for use in and around the home by homeowners or professional applicators.[1]
- Will mosquito spraying kill my bees?
- It can kill bees that are outside the hive when the spray comes through. EPA says spraying typically happens between dusk and dawn, when bees are usually inside, and suggests covering colonies during spraying or moving them out of the spray area.[2]
- How much naled actually reaches the ground?
- Very little, according to EPA: only 1 to 2 tablespoons of naled is applied per acre, and the amount that ultimately floats to the ground is small and dissipates quickly.[2]
Sources
- U.S. EPA Pesticide Product Label System, “Dibrom Concentrate label, EPA Reg. No. 5481-480 (EPA-stamped, July 20, 2021).” www3.epa.gov/pesticides/chem_search/ppls/005481-00480-20210720.pdf (accessed 2026-11-08)
- U.S. EPA, “Naled for Mosquito Control (last updated October 8, 2026).” www.epa.gov/mosquitocontrol/naled-mosquito-control (accessed 2026-11-08)
- Insecticide Resistance Action Committee, “IRAC Mode of Action Classification Scheme, Version 11.5 (Feb. 2026).” irac-online.org/documents/moa-classification/ (accessed 2026-11-08)