The manufacturer of a popular weedkiller won support Wednesday from the Missouri House for a proposal that could shield it from costly lawsuits alleging it failed to warn customers its product could cause cancer.

The House vote marked an important but incremental victory for chemical giant Bayer, which acquired an avalanche of legal claims involving the weedkiller Roundup when it bought the product’s original St. Louis-area-based producer, Monsanto.

The legislation now heads to the Missouri Senate with several weeks remaining in the annual legislative session. Bayer pursued similar legislation this year in Idaho and Iowa, where it has mining and manufacturing facilities, but it fell short in both states.

Bayer disputes claims that Roundup’s key ingredient, glyphosate, causes a cancer called non-Hodgkin’s lymphoma. But it has set aside $16 billion and already paid about $10 billion of that amount to resolve some of the tens of thousands of legal claims against it.

Though some studies associate glyphosate with cancer, the U.S. Environmental Protection Agency has said it is not likely to be carcinogenic to humans when used as directed.

The Missouri legislation says that federally approved pesticide labeling “shall be sufficient to satisfy any requirement for a warning label regarding cancer” — effectively thwarting failure-to-warn allegations in future lawsuits.

“We are grateful that members of the Missouri House have supported farmers and science over the litigation industry,” Bayer said in a statement Wednesday.

A coalition that includes Bayer has run ads on radio stations, newspapers and billboards supporting the legislation.

Farmers overwhelmingly rely on Roundup, which was introduced 50 years ago as a more efficient way to control weeds and reduce tilling and soil erosion. For crops including corn, soybeans and cotton, it’s designed to work with genetically modified seeds that resist Roundup’s deadly effect.

More than a dozen majority party Republicans joined Democrats in voting against the legislation as it passed the House on a 91-57 vote. Some Democrats made personal pleas to vote no.

“If you vote for this bill, you are voting for cancer — and it will hurt my feelings, and I will not smile at you on the elevator,” said state Rep. LaDonna Appelbaum, who is undergoing treatment for cancer.

Supporters said it was important to protect Bayer, whose North American crop science division is based in the St. Louis area, from lawsuits that could jeopardized the availability of Roundup. They cited concerns that Bayer eventually could pull Roundup from the U.S. market, leaving farmers dependent on alternative chemicals from China.

“This bill isn’t about cancer, it’s really about the process of what’s taken place within the courts,” said Republican state Rep. Mike Haffner, chair of the House Agriculture Policy Committee.