California will add glyphosate, the active ingredient in Roundup herbicide, to the list of chemicals known to the state to cause cancer on July 7, the state’s Office of Environmental Health Hazard Assessment (OEHHA) announced.
That doesn’t mean Roundup can’t be used anymore. It only requires companies to warn people when exposing them to significant amounts of glyphosate. The significant amount is proposed to be 1,100 micrograms per day.
The agency originally announced the move in September 2015, but Monsanto—the producer of Roundup—filed a lawsuit to stop it. The state court denied stay on the case on June 15, meaning the state can put glyphosate on the list of carcinogens while the legal dispute continues. Monsanto intends to appeal.
Roundup is the most common herbicide in the world. It’s easy to use and relatively cheap. But multiple health and environmental issues have cropped up since Monsanto introduced it to market in 1974.
The World Health Organization’s International Agency for Research on Cancer (IARC) declared in 2015 that glyphosate probably causes cancer, with a particularly strong link to non-Hodgkin’s lymphoma.
Some regulators, including those in France, Sri Lanka, and counties in California, have banned the herbicide. Others, such as the U.S. Environmental Protection Agency (EPA), the European Chemical Agency, and Health Canada, consider glyphosate safe.
These decisions have been controversial. For example, the EPA’s positive stance on glyphosate was faced with the allegation, based on emails released in March, that leading EPA pesticide official Jess Rowland colluded with industry leaders to suppress investigations on the herbicide’s health effects.
An advisory panel of scientists held in March confirmed the EPA’s decision to list herbicide as noncarcinogenic, but some of the panelists “believed that there is limited but suggestive evidence of a positive association between glyphosate exposure and risk of [non-Hodgkin’s lymphoma],” according to the panel’s report.
The varying scientific opinions result from looking at the available data in different ways—placing more or less emphasis on certain findings, differing methodologies, and so on.
The level of risk is also a matter of debate. IARC’s rating of glyphosate for carcinogenicity puts it in the same class as red meat. Its rating is not about the magnitude of risk, but rather, the magnitude of evidence of carcinogenicity. Some have criticized IARC for causing inordinate panic because of this rating system.
A number of other concerns have been raised about glyphosate. Studies have suggested that for pregnant women, exposure to glyphosate may lead to miscarriages, shorter pregnancies, or lower birth weights. Some preliminary studies have even linked it to gluten intolerance.
There’s also growing evidence that other ingredients in pesticides make them more toxic than their active ingredients alone. One study determined Roundup to be 125 times more toxic than plain glyphosate.
Roundup is also tied closely with the use of genetically modified organisms (GMO), a point of concern for many customers. The use of glyphosate boomed after Monsanto began selling its crops designed to be resistant to glyphosate. These “Roundup Ready” crops could be sprayed with glyphosate without being harmed, as the herbicide would only kill weeds, thus eliminating the need for complex spraying schedules and other measures previously employed.
The German pharmaceutical company Bayer is in the process of purchasing Monsanto for $66 billion.
Tara MacIsaac contributed to this report.