I carry around a toiletries bag. I put my toothbrush there right after brushing in a restaurant or some public area.

These strangely similar articles(1, 2) suggest toothbrushes have to be aired. Why exactly? What harm does the wetness on the bristles cause?

  • 6
    $\begingroup$ There might be some issue with the bristles, but the much bigger problem is that the wet environment furthers the grows of bacteria and mold... $\endgroup$
    – Gerhard
    Commented Jul 24, 2015 at 17:40
  • 5
    $\begingroup$ I'm voting to close this question as off-topic because it isn't very chemistry related. You might try biology.SE for it, though I doubt they'll accept it with open arms without research. $\endgroup$
    – M.A.R.
    Commented Jul 24, 2015 at 18:22

1 Answer 1


The good people at the American Academy of Pediatric Dentistry have a number of useful resources available to shed light on questions such as yours.

I direct you to a manuscript entitled Microbial contamination of toothbrushes and their decontamination in which it is written:

Storage conditions of toothbrushes are an important factor for bacterial survival. Dayoub et al. and Meier et al. reported that the number of microorganisms in the toothbrushes kept in aerated conditions was lower than in toothbrushes stored in plastic bags. Several authors have reported that bacterial contamination can be reduced by washing toothbrushes after use, and drying in aerated conditions. Caudry et al. reported that a wet environment increases bacterial growth and cross contamination. Therefore, as time increases between one toothbrushing and another, more microorganism development can occur in the toothbrushes a wet/moisture environment.

The references cited in the above passage are detailed in the linked PDF. Happy brushing!


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