Ortho Ant & Roach Killer 18oz

Worth it for contractors dealing with pest problems in cabins, shops, and job site trailers. The triple-action formula combines instant knockdown with 6-week residual protection, plus it sanitizes surfaces by killing 99.9% of bacteria left behind by insects. The professional-grade formula outperforms basic grocery store sprays.

This aerosol shines for quick pest control in recreational properties, construction trailers, and anywhere Montana’s Box Elder bugs and stink bugs become problems.

Active Ingredients and Performance

The combination of cypermethrin (0.030%), pyrethrins (0.011%), and prallethrin (0.011%) creates a one-two punch that basic ant sprays can’t match. Pyrethrins and prallethrin deliver the instant knockdown — bugs stop moving on contact. Cypermethrin provides the residual control that keeps working for weeks after application.

The quaternary ammonium compounds (octyl decyl dimethyl ammonium chloride at 0.006% and dioctyl dimethyl ammonium chloride at 0.003%) add the sanitizing action. These kill 99.9% of Staphylococcus aureus and Klebsiella pneumoniae on hard surfaces — the bacteria that insects track across countertops and baseboards.

Active Ingredient	Concentration	Function
Cypermethrin	0.030%	6-week residual control
Pyrethrins	0.011%	Instant knockdown
Prallethrin (ETOC)	0.011%	Fast-acting nerve agent
Octyl decyl dimethyl ammonium chloride	0.006%	Sanitizing action
Dioctyl dimethyl ammonium chloride	0.003%	Sanitizing action

The 18-ounce aerosol weighs approximately 1.51-1.53 pounds and measures 2.63 x 2.63 x 9.75 inches — standard size that fits under sinks and in utility closets where it’s needed most.

Application Versatility

The target pest list covers Montana’s most common invaders: ants, roaches, spiders (including Black Widow), centipedes, scorpions, silverfish, Asian Lady Beetles, Box Elder bugs, and Brown Marmorated stink bugs. That Box Elder bug control matters in Montana — they swarm south-facing walls every fall looking for winter shelter.

Safe application areas include kitchens, bathrooms, closets, basements, attics, garages, crawl spaces, campers, boats, and cabins. The non-staining formula means contractors can spray baseboards without worrying about marking up finished surfaces. Specific treatment zones include baseboards, dark corners, under and behind sinks, behind stoves and refrigerators, around plumbing, door and window frames, and inside cabinets.

Unlike Ortho’s Home Defense Max line that promises up to 12 months of indoor protection, this aerosol focuses on immediate knockdown with 6-week follow-up control. It competes directly with Raid and Hot Shot aerosols but differentiates with the odorless, sanitizing formula.

Real-World Performance

User reviews average 4.7 out of 5 stars. Contractors appreciate the truly odorless formula compared to competitors, easy application in hard-to-reach areas, and weeks of residual protection after initial spray.

The main limitations: restricted shipping to Alaska, California, and Hawaii, plus potential for aerosol cans to leak or lose pressure if stored improperly. Store these cans indoors — Montana’s temperature swings will kill the propellant pressure faster than a punctured tire.

Application is straightforward: shake well, hold upright, spray directly on insects or into hiding spots, wet surfaces slightly without runoff, and ensure wet contact time for sanitization. Keep it away from food surfaces, remove pets and cover aquariums, then wait for spray to dry before re-entry.

The Contractor’s Take

This aerosol delivers more than typical grocery store ant spray. The sanitizing action alone justifies choosing it for food service areas, break rooms, and anywhere hygiene matters alongside pest control.

The 6-week residual won’t match dedicated perimeter treatments, but for spot applications and emergency knockdown, it performs. Keep a can in the work truck for those surprise wasp nests and spider situations that pop up on every job site. The odorless formula means you won’t gas out the crew or homeowner.

Works on most hard surfaces including wood, tile, drywall, metal, and plastic, but test porous surfaces first to avoid staining. Not for direct food-contact surfaces. The formula is toxic to fish and aquatic life — keep it away from water sources.

Covered by Scotts No-Quibble Guarantee for refund with proof of purchase, plus standard 90-day retailer return policies. That’s confidence backing from a company that knows their chemistry works.

Frequently Asked Questions

Q: How long does the residual protection really last? A: Manufacturer claims up to 6 weeks of residual control for certain pests. Real-world performance depends on surface type and traffic. High-contact areas like door frames need reapplication sooner than protected spaces like behind appliances.

Q: Can this replace a professional exterminator service? A: For spot treatments and minor infestations, yes. For whole-structure problems or recurring issues, it’s a supplement, not a solution. Think of it as the first line of defense, not the entire battle plan.

Q: What’s the difference between this and the Ortho Home Defense Max line? A: Home Defense Max typically offers longer residual control (up to 12 months indoors) while this 18oz aerosol focuses on immediate knockdown with 6-week follow-up protection. This aerosol also includes the sanitizing feature that Home Defense Max doesn’t offer.

Q: Is the “odorless” claim legitimate? A: User reviews consistently praise it as truly odorless compared to competitors. The non-staining formula contains no chemical scent — a real advantage when treating living spaces.

Q: Which Western Building Center locations stock this product? A: Available in the Lawn & Garden / Farm department under Chemicals/Traps/Fert classification. Contact your local store for current inventory.