The end of ugly bath ducklings?

Actu GP La fin des vilains petits canards de bain ?

Rubber bath toys are a cornucopia for bacteria and fungi which are potential disease initiators. A study gives details of their risk factors and the measures to protect ourselves against them.


A delight for children enjoying a bath time splash, bath toys which spray water are nonetheless microbial breeding grounds in the making. A Swiss-American team has seized hold of the subject by analyzing the bacteria and fungi which colonize these modern objects that provide aquatic fun for young and old alike.

Reservoirs of microbes

The researchers collected 19 bath toys (ducks as well as crocodiles and other shapes) from four Swiss households. Simultaneously, 6 identical toys were used by an adult experimenter for 11 weeks under controlled conditions (clean water vs. dirty water). All the toys were then cut in half to see which accumulations of bacteria (or biofilms) had “grown” inside them. The outcome was indisputable: there were more biofilms in toys truly used than in the controls. Most importantly, 33% of the toys collected from households were positive for Legionella pneumophila, involved in Legionnaire’s disease, 47% were positive for staphylococci responsible for various infections, particularly of the skin, and 50% were positive for streptococci, indicating fecal contamination. Worse still: 61% contained a bacterium known for its resistance to antibiotics, Pseudomonas aeruginosa, which poses a significant problem for vulnerable patients in hospitals. Some fungi synonymous with potential fungal diseases completed this unappetizing picture.

Fluids and plastic are to blame

In addition to this list, the team identified the factors that promoted the growth of these biofilms: the PVC and silicone of which the toys were made (perfect anchorage and food supply for the bacteria via the leached carbon); tap water quality (naturally contaminated but low in nutrients); bodily fluids and personal care products (a feast for the bacteria); contamination by bacteria from the external environment introduced by the bather.

Blocking the water hole

To prevent any skin infection, otitis or gastroenteritis due to unfortunate “splashes”, the authors recommend, in addition to the use of different manufacturing materials, emptying toys of water - even boiling them after use. Or more drastically, blocking the water drainage hole, at the risk of disappointing their toddlers. As for the most radical, they can always throw the ducks out…with the bathwater.



Neu L et al. Ugly ducklings - the dark side of plastic materials in contact potable water. Biofilms and Microbiomes 2018; 4:7