A new report by environmental health advocacy group Friends of the Earth (FOE) claims new types of German chemical giant Bayer’s Roundup weed killing products marketed to US consumers pose more health risks than earlier versions, The New Lede reports.

FOE’s analysis was disputed by Bayer, which it described as “deeply flawed”, the 22 October report said.

In its report, FOE said it found four chemicals recently added to Roundup products were scientifically proven to cause a range of health problems, including reproductive defects, kidney and liver damage and neurotoxicity.

The analysis followed Bayer’s pledge that it would remove glyphosate from its Roundup herbicide products sold for residential lawn and garden use starting in 2023, The New Lede wrote.

Bayer, which acquired US agrochemical company Monsanto in 2018, made the pledge to try to curtail the filing of future litigation as it battles thousands of lawsuits filed against Monsanto by cancer patients who claim they developed non-Hodgkin lymphoma from using Monsanto’s Roundup and other glyphosate-based herbicides, the report said.

Bayer, which acquired Roundup as part of its US$63bn acquisition of US agrochemical company Monsanto in 2018, was facing thousands of lawsuits filed against Monsanto by cancer patients who claim they developed non-Hodgkin lymphoma from using Roundup and other glyphosate-based herbicides, the report said.

But FOE said it found the chemicals used in the new Roundup formulations were, on average, 45 times more toxic to humans experiencing chronic exposure than glyphosate-based Roundup. The chemicals were around four times more acutely toxic, the group said.

In addition, all four of the added chemicals posed greater risk of long-term and/or reproductive health problems compared to glyphosate, based on the Environmental Protection Agency’s (EPA) evaluation of safety studies, FOE said.

Of the four chemicals found in the products – diquat dibromide, fluazifop-P-butyl, triclopyr, and imazapic – diquat dibromide is of the most concern, according to FOE.

diquat dibromide：ビピリジニウム系に分類される非選択形除草剤の1つ。イギリスの企業、Plant Protectionが開発した。
　　　　　　　　　　　商品名レグロックスで除草剤としての利用のほか、ジャガイモの収穫前の蔓枯らしにも使われることがある。ダイコートと発音することもある。
fluazifop-P-butyl：アリールオキシフェノキシプロピオン酸系の除草剤
triclopyr：葉面除草剤および殺菌剤として使用されるピリジングループの有機化合物
imazapic ：多くの広葉雑草を防除し、牧草地、放牧地、および特定の種類の芝生の一部の草を防除または抑制

With long term exposure, the chemical, which is banned in the European Union, was 200 times more toxic than glyphosate, the group said.

It was also 27 times more toxic in acute exposures, the group said.

Kendra Klein, FOE deputy director for science and an author of the report, said the EPA should be providing stronger oversight.

Bayer was quoted as saying the report was factually incorrect and out of line with regulatory assessments for measuring risk.

“A recent … report contains false claims about the active ingredients in Roundup Lawn & Garden products. The active ingredients in all Roundup Lawn & Garden products have been thoroughly studied, reviewed and approved by independent experts at the Environmental Protection Agency (EPA) and used safely and effectively in many different weed-control products from a variety of companies for decades,” the company said in a statement.

“The report reaches its … conclusion through a methodology that is entirely inconsistent with how leading regulatory and health experts measure risk in how people use these products in the real world and in accordance with the label.”

The EPA had not responded to a request for comment, The New Lede wrote.