Clarification On Chemical Dwell Times

I often receive feedback on articles I've written in the past and much of the correspondence turns into topics for new articles. Below is a letter I received regarding an article focusing on dwell times:

"In a past article, you answered a question to a reader regarding dwell times of a disinfectant on the pads and matting in a gym. You indicated that you read the label of their disinfectant and said that the product needed a 10 minute wet dwell time to be effective. You also intertwine the words disinfecting and sanitizing and to the layman that can be confusing.

"The 10 minute claim on EPA registered detergent disinfectants is very ambiguous. That claim refers to the amount of time the test micro-organisms were subjected to the submitted disinfectant. Anyone knows, including the EPA, that it is virtually impossible to keep a surface wet for 10 minutes especially on a vertical surface. Any hospital grade detergent disinfectant that is worth its salt will kill most harmful pathogens in as little as 1 to 5 minutes including some spores. Unfortunately, due to the EPA rules for label claims it becomes almost impossible for a manufacturer to include all test results on their label due to space and font size.

"A general detergent disinfectant will accomplish much the same with a few exceptions such as spores and a number of super bugs. One factor that was not mentioned is the testing in the presence of blood serum. To be classified as a one-step cleaner/disinfectant the disinfectant must kill the pathogens in the presence of 5 percent blood serum. If the blood serum is not included in the testing then the disinfectant cannot not make the claim of a one-step disinfectant. The surface most first be cleaned with a detergent in step one and then the disinfectant as the second step."

I appreciate this feedback and will respond in a future article.

Your comments and questions are important. I hope to hear from you soon. Until then, keep it clean...

Mickey Crowe has been involved in the industry for over 35 years. He is a trainer, speaker and consultant. You can reach Mickey at 678-314-2171 or CTCG50@comcast.net.