SAN FRANCISCO (CN) - A state judge on Thursday refused to permit a cancer-risk expert to testify about the amount of exposure to the active ingredient in Monsanto's Roundup weed killer California has determined causes cancer in the first-ever trial over the herbicide's carcinogenicity.
San Francisco County Superior Court Judge Suzanne Ramos Bolanos sided with Monsanto, after its lawyers accused attorneys representing a retired groundskeeper dying of non-Hodgkin lymphoma of trying to sneak the topic into evidence, despite a pre-trial ruling barring testimony about California's Proposition 65.
Proposition 65 requires manufacturers to put warning labels on products that contain chemicals at certain levels the state believes are carcinogenic.
"Monsanto was never put on notice for that," Bolanos ruled. "To introduce this now is highly prejudicial, because they didn't have the opportunity to cross-examine him [the expert] and they didn't have the opportunity to call their own expert to discuss the significance or the lack of significance of the NSRL listing, which can be misleading to the jury unless it is completely explained to them."
NSRL stands for No Significant Risk Level, the daily intake level calculated by California regulators to result in one excess case of cancer in a population of 100,000 exposed people. NSRLs are established for many of the chemicals listed under Proposition 65.
The NSRL for glyphosate is 1,100 micrograms per day, according to the website for California's Office of Health Hazard Assessment.
Plaintiff's attorney Brent Wisner disputed Bolanos' bench ruling. He said Monsanto was in fact on notice that the expert, Christopher Portier, would testify about the NSRL because it had seen and responded to Portier's comments on the topic during a state public comment period.
Portier is a highly regarded expert in cancer-risk assessment, and his testimony on the NSRL could bolster the case, filed by DeWayne Johnson in 2016 after he developed cancerous lesions over most of his body. His lawyers say he has two years to live.
"I think you should take a hard look" at this, the Baum Hedlund Aristei Goldman attorney told Bolanos. "As of right now, this court is allowing foreign regulatory decisions about glyphosate to come into the record but not the state of California, and I don't know how that can be a valid ruling."
Wisner added that if Portier wasn't allowed to testify about the NSRL, another expert witness would.
The warning did not sway Bolanos.
Last year, California added glyphosate to its Proposition 65 list based on the 2015 finding by the World Health Organization's International Agency for Research on Cancer (IARC) that glyphosate is a "probable" carcinogen.
Monsanto sued over the California designation, and in February, a federal judge barred state regulators from requiring Monsanto to use cancer warning labels, though glyphosate remains on the Proposition 65 list.
Monsanto opposed listing glyphosate as a carcinogen under Proposition 65 because California had based its decision on the "fatally flawed" IARC finding, "which ignored crucial scientific data that undermines its conclusion," Monsanto said in a June 2017 statement.
"OEHHA's [Office of Health Hazard Assessment] decision to list glyphosate is contrary to its own scientific assessment, which determined that glyphosate is not carcinogenic, as well as the conclusions of the U.S. Environmental Protection Agency (EPA), the European Chemicals Agency (ECHA), and every regulatory body in the world that has studied glyphosate," the statement read.
The IARC classification prompted a slew of lawsuits in the United States, including Johnson’s.
