The manufacturers and the active and inactive ingredients are the main differences between Ortho Home Defense Max and Spectracide Bug Stop Home Barrier insecticides. The Scotts Company, LLC, manufactures Ortho products, while Chemisco, a division of United Industries Corporation, makes Spectracide products.
Ortho Home Defense Max has a formula that combines a 0.05 percent concentration of bifenthrin, the active ingredient, with 0.0125 percent concentration of the inactive ingredient, zeta-cypermethrin. Both chemicals are classified as pyrethroids. The Spectracide Bug Stop formula's active ingredient is a 0.025 percent concentration of gamma-cyhalothrin, also a pyrethroid, blended with unspecified inactive ingredients.
Pyrethroids, which can remain in soil for up to eight months, must never be used in or around water sources or drains. Pyrethroids are highly toxic to aquatic life forms.