Bob’s Red Mill is facing a federal class action, filed in San Francisco Friday, after the world’s most used weedkiller, glyphosate, was discovered in both its organic and non-organic oats.

Citing a recent report by the Environmental Working Group finding traces of the ‘known carcinogen’ glyphosate in Cheerios, Quaker Oats and other oat-based breakfast foods, plaintiffs Tamara Frankel and Natasha Paracha said Friday that Bob’s Red Mill knew its oat products contain or likely contain the chemical, but didn’t disclose it on the label.

Instead, they say, the Oregon-based company labeled the products with phrases such as “gluten free,” “wheat free” and “purity tested,” leading consumers to believe them to be healthy.

“Consumers have a reasonable expectation that material product information, such as the presence of a probable carcinogen like glyphosate, will be provided by a product manufacturer, especially when the manufacturer affirmatively identifies the health-related attributes of its products such as “Gluten Free”, “Whole Grain”, and “Friend of the Heart,” the complaint states, adding that the labeling amounts to “misleading half-truths.”