Chemical Dwell Time, Does it Really Matter?

Performing janitorial services in commercial bathrooms is more than just quickly cleaning toilet bowls and wiping down surfaces. Team members have a balancing act of getting in-and-out as quickly as possible, while fulfilling the mission of properly cleaning and sanitizing surfaces. This can be challenging when cleaning formulations call for “dwell time” to deliver the desired results.

Contact time, or dwell time, refers to the amount of time that a disinfecting product needs to sit (or dwell) on a surface in order to kill organisms. It would be nice if you could simply “spray and wipe” to properly clean and sanitize surfaces, but most applications require up to 10 minutes (or more) of dwell time to kill bacteria and germs. Not allowing for the appropriate dwell time will affect the results, reducing the number of bacteria that are killed. This extra time can be a challenge for janitorial staff, especially when cleaning is being done during operating hours.


  • pressure sprayer is an excellent tool for applying chemical disinfectants. These allow cleaning solutions to be applied to small and large areas faster, and without the hand fatigue of a trigger sprayer. Pressure sprayers come with different types of pump seals, based on the type of solution you are using (alkaline or acidic.) There are also models made specifically for foaming solutions, which can be very effective for use with vertical surfaces that require dwell time. A foaming chemical sprayer also increases dwell time, enabling the product to completely emulsify and digest tough scum build-up, layers of grease, and proteins.
  • Proper sanitation begins with clean surfaces; this is typically a two-step process. First clean the surface, then apply the disinfectant to (dwell) sanitize. While all-in-one disinfectants can perform both functions, they but do require a specified amount of contact time to kill 99% of the germs.
  • To optimize the necessary dwell time, custodians can use their pressure sprayer to apply chemicals in an systematic pattern as they work their way around the restroom. By the time they are finished with the entire bathroom, they can return to their starting place to begin wiping up the solution.
  • Environmentally friendly, green cleaning, solutions may require more dwell time to be effective.
  • Dwell times are unique by product. Always be sure to read the back of the chemical bottles to ensure that you are using the product as directed.

For information on Solo CLEANLine sprayers see: