A second review of herbicide-like carcinogens was published in the United States on Wednesday.

It is the latest development in a raging controversy over glyphosate, the most widely used pesticide in the world, which most government regulators and food industry leaders say poses no health risk in the amounts that people get in their food.

"No question, our foods are safe," said Michael Siemienas, spokesman for General Mills, the maker of Cheerios.

The Environmental Working Group (EWG), which uses science to advocate environmental policy changes, tested 28 food products containing oats. It found that all but two contained traces of the herbicide that is widely used on everything from food crops to backyard weeds.

The levels, though, were far below the concentrations deemed unsafe by state and federal regulators.

The products included items made by Quaker Oats, a subsidiary of PepsiCo., And seven different kinds of Cheerios.

Scientists at EWG say they are more likely to be safe – 160 parts per billion per serving. But that level is much lower than other recommendations in the United States, including the one set by the Environmental Protection Agency.

"Tasha Stoiber, a Senior Scientist with EWG, said:" The EPA is a protector of children's health.

In a statement, Quake Oats said EWG's standard is an artificial safety level that will falsely alarm consumers.

"The Quaker products tested by EWG are safe," it said.

But the question of how much of a herbicide in kids' food is too much – and whether it is a carcinogen at all – has become hotly debated among scientists and regulators around the world, with no clear answer. The EPA, for example, sets a legal limit of 30 milligrams per kilogram in food; the Minnesota Department of Health, but it does not matter.

The controversy began in 2015 when the World Health Organization's International Agency for Cancer Research, or IARC, declared glyphosate a probable carcinogen. Monsanto, the maker of Roundup, launched a public-relations campaign in response, arguing that its product is safe, and that the organization had ignored other studies that proved it.

"Glyphosate has a more than 40-year history of safe and effective use," the company, which is now owned by Bayer Crop Science, said in a statement Wednesday.

The IARC finding has been disputed by other regulators in Europe. The Environmental Protection Agency is in the process of becoming more open, and is expected to be completed next year. But its initial finding is that glyphosate is probably not a cancer risk. It is based on the findings of the National Cancer Institute of 55,000 farmers and others who apply the herbicide regularly, which found no association between glyphosate and increased cancer risk.

Nonetheless, the finding by the IARC prompted California to also list the herbicide as a carcinogen, and it has been launched in California. In August, a jury found that a school groundkeeper had failed to properly ground a child, who developed a non-Hodgkin's lymphoma, of the cancer risk. They awarded him $ 289 million, but the judge reduced it to $ 78.5 million.

The trial also explored the issues of the safety of its flagship product and the company's research practices. The records suggest that Monsanto had ghostwritten research by outside academics, and reported conflicts within the EPA over its risk assessment. The company said the documents were taken out of context.

EWG, however, says that no amount of herbicide in food should be acceptable.

"We do not think it belongs in cereal," said Stoiber.

Glyphosate is used on oats just before harvest as a drying agent, she said. But, she said, companies like General Mills and Quaker Oats have alternatives, including using organic oils, which do not use chemicals. "We are asking for this pesticide out of oat-based products," Stoiber said.

Siemienas said that General Mills works with all its suppliers to minimize the use of pesticides.

As for glyphosate in its products, [Food and Drug Administration] and the EPA, "he said.