All EPA disinfectants require a 10-minute contact time on precleaned, hard, nonporous surfaces.

• A. True
• B. False
• C. Only for liquids
• D. Only for metal surfaces

Answer: (A)

Disinfectant contact time is set by the product label and can vary between products. EPA-registered disinfectants require the surface to stay visibly wet for the specific dwell time stated on that product’s label in order to achieve disinfection. Because labels differ, some products call for only a minute or two, others for five minutes, ten minutes, or more, depending on the formulation and the organisms targeted. Therefore there isn’t a universal ten-minute rule for all EPA disinfectants. Precleaning matters because organic matter can shield microbes and reduce effectiveness, and hard, nonporous surfaces are the typical targets described on many labels. But the exact dwell time and steps are determined by each product’s label. Always follow the label for the correct contact time.