In a controlled laboratory study, disodium octaborate tetrahydrate (DOT) applied to carpets with a carpet-cleaning machine at a rate of 509 ml DOT/8.15 liter H2O/100 m2 (two cups DOT/2 gal H2O/100 feet2) reduced survival and population growth of live Dermatophagoides farinae and Dermatophagoides pteronyssinus by ≥98% compared with water-cleaned and uncleaned carpets at 8 wk postcleaning. Cleaning with DOT was more effective against D. pteronyssinus than D. farinae.