Toxicology and human health risk assessment of polyethoxylated tallow amine surfactant used in glyphosate formulations

• Published in: Regulatory toxicology and pharmacology 2019-10, Vol.107, p.104347, Article 104347
• Main Authors: Martens, Mark A., Bleeke, Marian S., Leopold, Vincent A., Farmer, Donna R.
• Format: Article
• Language: English
• Subjects: Administration, Inhalation; Administration, Oral; Amines - toxicity; Animals; Dietary Exposure; Dogs; Fats - toxicity; Food Contamination; Food risk assessment; Glycine - analogs & derivatives; Glyphosate; Guinea Pigs; Herbicides; Human health risk assessment; Humans; Inhalation Exposure; Irritants - toxicity; Mice; Occupational risk assessment; POE-T; POEA; Polyethoxylated tallow amine; Polyethylene Glycols - toxicity; Rabbits; Rats; Roundup; Surface-Active Agents - toxicity; Surfactants; Toxicity
• ISSN: 0273-2300; 1096-0295
• DOI: 10.1016/j.yrtph.2019.03.014

Roundup® branded herbicides contain glyphosate, a surfactant system and water. One of the surfactants used is polyethoxylated tallow amine (POE-T). A toxicology dataset has been developed to derive the most representative points of departure for human health risk assessments. Concentrated POE-T was very irritating to skin, corrosive to eyes, and sensitizing to skin. The irritation and sensitization potential of POE-T diminishes significantly upon dilution with water. Repeated dosing of rats with POE-T produced gastrointestinal effects but no systemic effect on organ systems. POE-T was not genotoxic and had no effect on embryo-fetal development or reproduction. The occupational risk assessment of POE- T for the agricultural use of glyphosate products has demonstrated that margins of exposure (MOEs) are 2517 and 100,000 for maximum and geometric mean dermal exposures, respectively. In the food risk assessment for relevant agricultural uses, the range of MOEs for consumption of foods from plant and animal origin were 330 to 2909. MOEs ≥100 are generally considered to be of no toxicological concern. Based on the results of the occupational and food risk assessments, it is concluded that there are no significant human health issues associated with the use of POE-T as a surfactant in glyphosate products. •Occupational and food risk assessments demonstrate large margins of exposure and safety of POE-T.•Product component exposure and toxicological datasets were considered in assessments.•POE-T based surfactant systems were not found to target any specific organ system after repeated oral or inhalation exposures.•The irritation potential of the concentrated surfactant is greatly reduced when diluted to an end-use spray solution.