For the past several months, Monsanto has been in court challenging California’s decision to add the chemical glyphosate—the active ingredient in its herbicide Roundup—to the Proposition 65 list. It recently faced a setback when the California Supreme Court rejected Monsanto’s request to stay a lower court’s decision to include glyphosate among the 960 chemicals on the list.  California’s Office of Environmental Health Hazard Assessment (OEHHA) wasted no time after the decision and added glyphosate to the list on July 7, 2017.

What next? While Monsanto’s appeal of the listing still is pending in California’s Fifth District, the ruling in Monsanto Co. v. OEHHA has short-term consequences for companies that make products containing glyphosate and the people who sell them. These companies have one year—until July 7, 2018—to comply with the Proposition 65 requirements.

The law requires businesses to provide a “clear and reasonable” warning on their products that exposure to a listed “chemical known to the state to cause cancer or reproductive toxicity” is contained in the products. Monsanto and other companies that make products containing glyphosate will have to develop the requisite label or other warning material. Absent the warning, companies that make glyphosate products may face public or private civil suits under Proposition 65.

With the Proposition 65 list now nearing 1,000 chemicals, the effectiveness of all the warnings may be diluted. Some farmers and other consumers may stay away from products containing glyphosate, but Proposition 65 listings for popular and useful products may not significantly impact product sales.