What would bath time be without rubber duckies? Probably not as much fun—but also a whole lot cleaner, according to a study published in the journal Biofilms and Microbiomes.
That's because it turns out those squeaky toys are far from squeaky clean thanks to “potentially pathogenic bacteria" in four out of the five bath toys examined by researchers.
For the study, Swiss and American researchers looked at the biofilm communities inside 19 bath toys collected from random households as well as six toys used in controlled clean or dirty water conditions. They found that all of the examined bath toys “had dense and slimy biofilm" on their inner surfaces. What's more, 56% of the real-use toys and all of the dirty-water toys had fungi build up. ?
Although the researchers note exposure to bacteria and fungi may have some benefits, the strong existence of grime in bath toys is still concerning. They note, “Squeezing water with chunks of biofilm into their faces (which is not unexpected behavior for these users) may result in eye, ear, wound or even gastro-intestinal tract infections."
Besides tossing all your bath toys, what can parents do?
The researchers say more experimental work is needed. But, for starters, it doesn't hurt to remove water from the toys after usage or give them a good, regular dunk in boiling water. The researchers also said they would like to see more regulations on the polymeric materials used for many bath toys.
There is, however, one simple solution—it just comes at the cost of rubber duckie's squeak. “In fact, the easiest way to prevent children from being exposed to bath toy biofilms is to simply close the hole," the researchers say of toys like this water-tight duck. “But where is the fun in that?"
[A version of this post originally appeared April 13, 2018. It has been updated.]