The label is the law. Rates and restrictions below are taken from the product labels listed under Sources. Your product's own label governs; read it before you mix or apply. Mixing calculator · Disclaimer
- Active ingredient
- (S)-Hydroprene (CAS 65733-18-8)
- Chemical class
- Juvenile hormone analogue; IRAC Group 7A juvenile hormone mimics.[2]
- Mode of action
- IRAC Group 7A: Juvenile hormone mimics: juvenile hormone analogues[2]
- Signal word
- Zoecon RF-259 Emulsifiable Concentrate with Gentrol IGR: Caution[1]
Two ways it ends an infestation
The label describes hydroprene as a synthetic juvenile hormone look-alike. Exposed cockroaches and bed bugs become sterile adults, while stored product pests, drain flies, fruit flies and fleas die in the pupal stage.[1]
The front panel claims 120 days of protection per treatment, and gives a minimum retreatment interval, based on efficacy, of 45 to 120 days.[1]
Where it is used
For bed bugs, treat under beds, the underside of box springs, behind nightstands and where carpet meets the wall. Never treat linens or mattresses. Retreat at 14 days for heavy infestations.[1]
For drain and fruit flies, coat the inside of drains, downspouts and catch basins, since larvae develop in the scum on pipe walls. Repeat every 2 to 4 weeks depending on severity.[1]
It can be tank mixed with an adulticide, such as Zoecon Catalyst, to kill adults quickly while hydroprene stops the next generation. Follow the stricter of the two labels.[1]
Before spraying a pantry, remove all food and don't put it back until the spray dries. Throw out infested food packages, and don't spray into electrical equipment.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Zoecon RF-259 Emulsifiable Concentrate with Gentrol IGR[1] | Wellmark International | 2724-351 | 9.0% | emulsifiable concentrate | Caution |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Zoecon RF-259 Emulsifiable Concentrate with Gentrol IGR | Walls, floors, baseboards, cracks and crevices, closets, attics, basements and crawlspaces | Cockroaches, bed bugs, stored product pests, drain flies, fruit flies | 1 fl oz product per gallon of water[1] One gallon of the mix covers 1,500 sq ft of surface. Mix only what you'll use within 48 hours, and shake or stir before each use. |
| Zoecon RF-259 Emulsifiable Concentrate with Gentrol IGR | Enclosed spaces such as warehouses (fogging) | Cockroaches and stored product pests | 1 fl oz product per 12,000 cubic feet[1] Shut off ventilation, keep the room closed for 30 minutes after fogging, and air it out before anyone goes back in. |
Safety and environmental hazards
People
Signal word CAUTION. The label warns it is harmful if swallowed or absorbed through skin and causes moderate eye irritation. It contains petroleum distillates, so vomiting may cause aspiration pneumonia.[1]
Pets
The hazard statement covers domestic animals too: avoid skin and eye contact. Leave a fogged room closed for 30 minutes and ventilate it before anyone, people or pets, reenters.[1]
Bees and pollinators
This indoor label has no bee warning. Its uses are structures, food handling establishments and vehicles, not outdoor flowering plants.[1]
Fish and water
The only environmental instruction is not to contaminate water, food or feed when storing or disposing of the product.[1]
Common questions
- Does hydroprene kill adult cockroaches?
- No. The label says exposed cockroaches become adults that can't reproduce. Pair it with an adulticide if you need adults gone quickly.[1]
- How much Gentrol concentrate goes in a gallon?
- One ounce, which is one of the 1 oz bottles, per gallon of water. That gallon treats about 1,500 square feet of surface.[1]
- Can hydroprene be used in kitchens?
- Yes, in food and non-food areas, but remove or cover food and food-contact surfaces first, or clean them afterward to remove residue. Never spray food directly.[1]
Sources
- U.S. EPA Pesticide Product Label System, “Zoecon RF-259 Emulsifiable Concentrate with Gentrol IGR label, EPA Reg. No. 2724-351 (EPA-stamped, Dec. 1, 2009).” www3.epa.gov/pesticides/chem_search/ppls/002724-00351-20091201.pdf (accessed 2026-10-06)
- Insecticide Resistance Action Committee, “IRAC Mode of Action Classification Scheme, Version 11.5 (Feb. 2026).” irac-online.org/documents/moa-classification/ (accessed 2026-10-06)