Is it safe to shower in chlorinated tap water daily?
Yes for most families, but hot showers can add disinfection byproducts to bathroom air.
What to know
Chlorine and chloramine help keep public tap water safer from germs. The trade-off is that treated water can form disinfection byproducts, including trihalomethanes.
Showering is different from drinking a glass of water. Hot water, spray, and steam can move some trihalomethanes from water into bathroom air. That does not mean daily showers are an emergency. It means the easy fixes are worth doing.
Run the bathroom fan, crack the door, keep showers a little shorter, and avoid very hot water when you can. If someone has asthma or sensitive airways, a certified shower filter may help with chlorine smell and irritation. Check the filter certification before buying.
What the research says
A 2000 Risk Anal study measured trihalomethanes in chlorinated tap water and bathroom air during residential showers and baths. It found that showering raised airborne trihalomethane levels.
A 2013 J Expo Sci Environ Epidemiol study measured trihalomethanes in shower water, shower air, bathroom air, and blood after controlled 10-minute showers. Blood trihalomethane levels rose after showering.
The practical move is not panic. Ventilate the bathroom and reduce hot, steamy exposure when it is easy.
The research at a glance
| Study | Journal | Year |
|---|---|---|
| Assessment of airborne exposure to trihalomethanes from tap water in residential showers and baths. | Risk Anal | 2000 |
| The influence of physicochemical properties on the internal dose of trihalomethanes in humans following a controlled showering exposure. | J Expo Sci Environ Epidemiol | 2013 |