Find out what’s lurking in your new clothes

It’s so much fun to wear new clothes, making you feel fresh and fashionable. But if you’re sporting new duds without washing them first, you’re also putting on chemicals and allergens embedded in the fibers. Find out whether you should take new clothes from the shopping bag—and if you should toss them straight in the hamper.

One chemical found on new clothes is formaldehyde, which manufacturers use to prevent wrinkles. For some, the chemical can set off allergic contact dermatitis, a form of eczema, says dermatologist Dr. Ronald R. Brancaccio, director of the Skin Institute of New York. The amount of formaldehyde used on clothes has decreased in recent years, he says, but many people are also allergic to the dyes used. “In the old days, the formaldehyde resins were considered to be the most common,” Brancaccio says. “The textile dyes are by far and away the most common allergen.”

When it comes to germs, it’s hard to tell how clean a new clothing item is after it’s been tried on by an unknown number of people. But it’s rare to catch an illness from a piece of new clothing, Brancaccio says. However, it’s common sense to clean the garment before wearing it, he says. “For a non-allergic person, it’s probably not necessary to wash before wearing,” he says. “It’s something I do because I don’t know where it has been manufactured or handled. But I can’t think of any diseases that have been spread by unwashed new clothing. I don’t think it’s (medically) necessary to wash new clothing beforehand, but I personally think it’s a good idea.”

While the risk of infection is low, Dr. Philip M. Tierno Jr., professor of microbiology and pathology at the NYU School of Medicine, says people should still wash new garments before wearing them. There may be chemicals or finishing agents on the clothes, as well. “If the risk is one to 10, 10 being a highest, I’d put it at a three for new clothes,” he says.

The germ-factor depends on where it’s manufactured, and the number of people who handle it before you. “If you are talking about bathing suits and underwear that have been tried on, that increases the risk, and yet it’s still about a five,” Tierno says. “It’s best in my opinion to wash those garments that come directly in contact with your flesh.”

Certain garments worn close to the body are more likely to be exposed to fecal matter or vaginal flora if people try them on without undergarments, Tierno says. It is also possible to pick up MRSA, a common staph bacteria, from new clothes that have been tried on by others. “The good thing is most germs die off over time because clothing is very dry,” he says. “They don’t live long because clothing is not suitable for long life of these germs. Luckily, there’s a very low incidence of infection.”