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
- Prometon
- Chemical class
- Methoxy-s-triazine; WSSA Group 5 photosystem II inhibitor.[2][1]
- Mode of action
- WSSA Group 5: Photosystem II inhibitors (triazines)[2][1]
- Signal word
- Pramitol 25E Herbicide: Caution[1]
The 2025 limits
Under the July 2025 label, Pramitol 25E may not be used in residential settings, on railroads, on slopes above desirable plants or water, or within 100 feet of a potable well.[1]
It is limited to spot treatments of no more than 100 square feet per acre, and to one application a year on industrial sites.[1]
Roots reach farther than you think
Feeder roots of trees and shrubs often spread well past the drip line. Don't apply, drain or rinse equipment anywhere the chemical can reach the roots of plants you want to keep, and never use it on land to be cropped.[1]
Where it is used
It works mainly through the roots. Water it in with at least ¼ inch right after spraying, or apply just before rain soaks the root zone, or it won't act.[1]
Mow, remove or hoe in any weeds taller than 4 inches before you apply.[1]
For faster burndown of green growth, part or all of the water can be replaced with oil, though the label notes the concentrate may swell natural rubber hoses and fittings.[1]
It can also go under new asphalt to stop weeds pushing through, but not under coatings less than 2 inches thick, and it will not control woody brush or vines.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Pramitol 25E Herbicide[1] | Control Solutions, Inc. | 53883-505 | 25.0% | emulsifiable concentrate (2 lb active per gallon; contains petroleum distillates) | Caution |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Pramitol 25E Herbicide | Industrial sites and noncrop areas: around buildings, storage areas, fences, pumps, fuel tanks, lumberyards and tank farms (not residential settings) | Annual and susceptible perennial weeds and grasses such as downy brome, goosegrass, quackgrass, puncturevine, goldenrod and plantain; johnsongrass, bindweed and wild carrot at the higher rate | 0.5–0.875 pt product per 500 sq ft[1] Calibrate a 1- to 3-gallon sprayer so 1 gallon covers 500 sq ft, then mix 1/2 to 7/8 pint with water to make 1 gallon. The use restrictions cap industrial sites at 0.20 lb prometon per 500 sq ft, which works out to 0.8 pint of this 2 lb-per-gallon product, once a year. |
Safety and environmental hazards
People
Signal word CAUTION: harmful if swallowed or absorbed through skin and causes moderate eye irritation. It contains petroleum distillates, so vomiting can cause aspiration pneumonia. Handlers wear long sleeves, long pants, socks, shoes and chemical-resistant gloves.[1]
Pets
Don't enter or allow entry into treated areas until sprays have dried. The label also prohibits use in residential settings.[1]
Bees and pollinators
No direct bee warning, but the label says it is toxic to plants and can harm the forage and habitat of pollinators next to the treated site if spray drifts.[1]
Fish and water
Don't apply to water or where surface water is present. Prometon can reach groundwater on permeable soils with a shallow water table, and must not be applied within 100 feet of a drinking-water well.[1]
Common questions
- Can I use Pramitol on my gravel driveway at home?
- No. The current Pramitol 25E label says not to apply the product in a residential setting.[1]
- How long does prometon keep ground bare?
- Applied to the soil, it usually inhibits plant growth for a year or more, provided rain or watering carries it to the roots.[1]
- Why didn't prometon kill my weeds?
- Most of its action is through roots, so very dry soil or too little rain after application can give poor control.[1]
Sources
- U.S. EPA Pesticide Product Label System, “Pramitol 25E Herbicide label, EPA Reg. No. 53883-505 (EPA-stamped, July 16, 2025).” www3.epa.gov/pesticides/chem_search/ppls/053883-00505-20250716.pdf (accessed 2026-10-06)
- Weed Science Society of America, “Summary of Herbicide Mechanism of Action According to the Weed Science Society of America.” wssa.net/wp-content/uploads/WSSA-Mechanism-of-Action.pdf (accessed 2026-10-06)