NTP Glyphosate and Glyphosate Formulations Research
Glyphosate is the most widely used herbicide in the United States and worldwide. It is applied as a formulation (or mixture) with other substances that help the plant absorb the glyphosate. Glyphosate acts as an herbicide by preventing susceptible plants from making proteins that are needed for growth. Over the past 25 years, use of glyphosate has risen dramatically due to development of glyphosate-resistant genetically modified crops. Most people are exposed to glyphosate by ingestion of food or water containing glyphosate residues. Individuals who regularly handle glyphosate products as part of their occupation may experience higher exposures.
There is considerable public interest in the potential health risks to humans from exposure to glyphosate. In 1992, NTP reported that rodents exposed to glyphosate in feed showed little evidence of toxicity, and there was no evidence of glyphosate causing genotoxicity, or damage to DNA.
Recently, several public health agencies have evaluated the scientific literature to identify whether exposure to glyphosate is a cancer hazard for humans.
- In March 2015, the International Agency for Research on Cancer (IARC) concluded that glyphosate is a probable human carcinogen based on evidence from studies in humans and experimental animals. The IARC evaluation also reported that glyphosate-based formulations are generally more toxic than glyphosate alone.
- In November 2015, the European Food Safety Authority concluded that glyphosate is unlikely to pose a carcinogenic hazard to humans.
- In May 2016, the Joint Food and Agricultural Organization of the United Nations/World Health Organization Meeting on Pesticide Residues concluded that glyphosate is unlikely to pose a carcinogenic risk to humans from exposure in the diet.
- Currently, the United States Environmental Protection Agency (EPA) is completing a new human health risk assessment on glyphosate including an evaluation of its carcinogenic potential.
Due to the different interpretations of the scientific evidence regarding potential health risk for humans, public concern for glyphosate use and exposure, and reported differences in toxicity of glyphosate products, NTP is undertaking additional research to investigate the potential genetic and mechanistic toxicity of glyphosate and glyphosate formulations. NTP will also examine the published scientific literature for information about effects of glyphosate on non-cancer outcomes.