The reputation of Roundup, whose active ingredient is the world’s most widely used weed killer, took a hit on Tuesday when a federal court unsealed documents raising questions about its safety and the research practices of its manufacturer, the chemical giant Monsanto.
Roundup and similar products are used around the world on everything from row crops to home gardens. It is Monsanto’s flagship product, and industry-funded research has long found it to be relatively safe. A case in federal court in San Francisco has challenged that conclusion, building on the findings of an international panel that claimed Roundup’s main ingredient might cause cancer.
The court documents included Monsanto’s internal emails and email traffic between the company and federal regulators. The records suggested that Monsanto had ghostwritten research that was later attributed to academics and indicated that a senior official at the Environmental Protection Agency had worked to quash a review of Roundup’s main ingredient, glyphosate, that was to have been conducted by the United States Department of Health and Human Services.
The documents also revealed that there was some disagreement within the E.P.A. over its own safety assessment.