Too much washing away of germs with antibacterial soap may also make you sick, according to study results published in the online edition of the journal Environmental Health Perspectives and reported by HealthDay News.

For the study, researchers examined data from the 2003–2006 National Health and Nutrition Examination Survey (NHANES). Scientists compared triclosan and bisphenol A (BPA) levels with that of cytomegalovirus (CMV), a common virus that infects people of all ages, found in the urine of adults and children older than 6 who are diagnosed with allergies or hay fever.

Triclosan is an antimicrobial agent used in soaps, toothpastes and other health and hygiene products. BPA is a chemical used to construct plastics and other consumer products.

Findings showed that children and teens with increased levels of triclosan were more likely to suffer from hay fever and other allergies.

These findings may support the “hygiene hypothesis,” said Allison E. Aiello, PhD, MS, an associate professor at the University of Michigan School of Public Health.

The hygiene hypothesis states that very clean and hygienic environments may reduce our exposure to microorganisms that help our immune systems develop.

“It is possible that a person can be too clean for their own good,” Aiello said.

In addition, researchers found that people older than 18 who were exposed to high BPA levels also had escalated CMV levels, possibly indicating a weakened immune system.

Click here to learn how to avoid making “healthy” habits, such as hand washing, more bad than good for you.