By Diana Novak Jones

A federal judge on Monday allowed the majority of claims to move forward in sprawling litigation that claims chemical hair relaxer products made by L'Oreal USA, Revlon and others cause cancer and other injuries.

Illinois-based U.S. District Judge Mary Rowland denied most of the companies’ arguments in their motion to dismiss the complaint in the multidistrict litigation over the products. The litigation includes more than 8,000 lawsuits.

The judge said the plaintiffs had put forward sufficient facts to support their allegations accusing the companies of negligence, defective design of the products and failure to warn customers of the risks.

Of the 15 counts in the complaint, Rowland dismissed three entirely and a portion of a fourth, finding the plaintiffs had not done enough to bolster their claims that the companies committed fraud.

The products, which include chemicals to permanently straighten textured hair, are typically marketed to women of color. The first lawsuits hit court dockets after the October 2022 publication of a National Institutes of Health study that found women who used the products multiple times a year were more than twice as likely to develop uterine cancer.

Representatives for L’Oreal and Revlon did not immediately respond to requests for comment.

In a statement posted online after the first lawsuits were filed, L'Oreal said it was "confident in the safety of our products and believe the recent lawsuits filed against us have no legal merit."

A Revlon representative previously told Reuters the company did not “believe the science supports a link between chemical hair straighteners or relaxers and cancer.”

Several smaller cosmetics companies are named in the lawsuits, including some based in India.

Jennifer Hoekstra, one of the lead attorneys for the consumers, said on Monday the ruling backs their argument that the products and the companies' instructions for using them caused cancer.

(Reporting by Diana Jones; editing by Leigh Jones and Lincoln Feast.)