How safe are hair extensions? A Haz Waste Program researcher looks for clues.

The Hazardous Waste Management Program’s work is focused on the places and products that people encounter every day. Program staff are deeply devoted to rooting out the incidental toxic exposures that could be hiding in our homes, our gardens, our workplaces, our auto repair shops, or our hair salons.

The wide reach of these efforts often means that the Program’s work can’t help but touch on staff members’ personal lives. That is certainly the case for Haz Waste Program research intern Dawn Johnston.

Dawn was practically raised in a hair salon: “My mom has been an award-winning master barber and stylist for, like, almost 50 years,” she says. “She's owned a salon, she's developed products. So, I've helped her throughout my life.”

Because Dawn has been a helping hand in her mother’s business for as long as she can remember, she’s extremely familiar with the myriad of products floating around in a typical hair salon, particularly products marketed to Black women and people of color.

Now, Dawn has a master’s degree from the Department of Environmental & Occupational Health Sciences in the University of Washington’s School of Public Health. While science has become her professional pursuit, her interest in hairstyling hasn’t waned.

In 2025, she came across a Consumer Reports study that found dangerous chemicals like lead, arsenic, and mercury in every popular synthetic hair braid product tested. The study raised questions for Dawn: Are there specific characteristics of these products that could make them more dangerous? Do factors such as price, color, or type of fiber indicate that a product is more likely to be toxic?

“I also wear hair extensions myself sometimes,” she explains. “So, I was curious as a user. And I was a toxicology student, so I had these multiple components that led to a perfect project.”

In coordination with advisors at UW and the Haz Waste Program’s research team, Dawn developed a study using the Program’s handheld X-ray fluorescence (XRF) analyzers and laboratory analysis to examine the lead content of various hair braiding products. Previously, Dawn had learned how to use XRF analyzers – a technology that uses X-rays to measure the chemical composition of materials – during an earlier project that tested consumer products for signs of “forever chemicals,” like PFAS, with her UW mentor Dr. Diana Ceballos and Dr. Trevor Peckham from the Haz Waste research team.

Using both XRF and laboratory analysis, Dawn detected lead in 10 of the hair braid products she tested. An abstract for Dawn’s research project can be viewed here.

In the future, Dawn hopes more synthetic hair braiding products are tested for toxic chemicals. She would also like to see more studies looking into how various practices by stylists and users of hair extensions might influence the level of exposure to chemicals in those products.

In general, she says consumers deserve to know more about the hair products they buy in stores or use in salons.

“I think the products that are testing as safer are just going to win, and that’s going to create new drivers towards transparency,” Dawn says. “A lot of beauty product sellers might think we don't care about safety, but it's not that we don't care. It's just that we don't know.”

At the Haz Waste Program, experts work hard to learn how everyday products affect your health. That’s why the Program helps support research projects like Dawn’s. The more we know, the easier it will be for King County residents to make safer and smarter decisions at home and in our communities.

What you can do

Want to find safer beauty products? These sites can help: EWG Skin Deep, Black Beauty Project, or COSMOS Standard (for natural/organic products).