Yes, bleach can be quite dangerous if ingested by a child — but a new study published in Occupational & Environmental Medicine suggests that even just “passive exposure” to the chemical in the home is associated with a higher chance of childhood respiratory illness and other infections.

The researchers examined over 9,000 children between the ages of 6 and 12 throughout 19 schools in the Netherlands, 17 schools in Finland, and 18 schools in Barcelona, Spain. They measured their levels of exposure to bleach, then attempted to test the negative impact it had on their health. Parents were asked to complete questions about the frequency of their children’s flu, tonsilitis, sinusitis, bronchitis, otitis, and pneumonia during the past 12 months. They were also asked whether they had used bleach in some way to clean their homes once a week.

Interestingly, the authors found that nearly 72 percent of respondents from Spain used bleach frequently in their homes, while only 7 percent of Finnish households did. Spanish schools, meanwhile, were cleaned with bleach regularly while Finnish schools were not. Researchers found that the frequency of infections among children was linked to higher amounts of bleach use by parents at home — and the differences were quite evident when it came to the flu, tonsilitis, and other infections (the risk of flu was 20 percent higher in bleach households, and the risk of recurrent tonsillitis 35 percent higher in bleach households). The risk of any other infection happening again was 18 percent higher among the children exposed to bleach.

Bleach and other cleaning products might damage the lining of lung cells, causing inflammation and making it easier for infections to occur, the authors argue. Of course, it's been known for some time that common household cleaning products aren't meant to be inhaled or ingested; just breathing in your typical Lysol spray can make you feel dizzy or nauseous. But the study reinforces the importance of being aware of the adverse side effects of bleach and other household items.

The American Lung Association suggests sticking to soap and warm water as opposed to bleach or ammonia, as it may often do the trick just as well. For scrubbing floors or sinks, use baking soda to really get the gritty dirt out of the cracks. And vinegar mixed with water is a good glass cleaner.

“The high frequency of use of disinfecting cleaning products may be of public health concern, also when exposure occurs during childhood,” the authors write in their conclusion. They also noted that the frequent use of these products was often “caused by the erroneous belief, reinforced by advertising, that our homes should be free of microbes.”

Source: Casas L, Espinosa A, Borras-Santos A, Jacobs J, Krop E, Heederik D. “Domestic use of bleach and infections in children: a multicentre cross-sectional study.” Occupational & Environmental Medicine, 2015.