POE-tallowamine (Glyphosate coformulant): EFSA toxicological assessment

EFSA was asked by the European Commission to prepare a statement on the co-formulant polyethoxylated (POE) tallowamine (CAS no. 61791-26-2) based on the toxicological evaluation of POE-tallowamine presented by the Rapporteur Member State (RMS) Germany in the context of the peer review of glyphosate.

POE-tallowamine belongs to a group of substances used as surfactants, which are present in many glyphosate-based formulations. The RMS considered that a toxicological assessment of this surfactant could be necessary at Member State or zonal level for plant protection product authorisations, and therefore a toxicological evaluation including health-based reference values was provided in the RAR.

EFSA did not have the possibility to review the original data for most of the endpoints summarised in chapter B.6.13 of the RAR, and some endpoints are not fully addressed, therefore EFSA cannot support the RMS’s current assessment and considers that reliable reference values Acceptable Daily Intake (ADI), Acceptable Operator Exposure Level (AOEL), and Acute Reference Dose (ARfD) cannot be established and further data have to be submitted. Therefore the exposure assessment for operators, workers, bystanders, residents and consumers could not be performed. Compared to glyphosate, a higher toxicity of the POE-tallowamine was observed on all endpoints investigated.

The hypothesis of a possible synergistic toxicity between glyphosate and tallowamine co-formulant could not be verified. Dose additivity may be expected, at least regarding the irritation potential of the mixture to eyes and possibly mucosal tissues as both compounds share these irritation properties. Considering the low oral toxicity of glyphosate after single or repeated administrations, a likely explanation for the poisoning occurrences observed in humans is that it is mostly driven by the POE-tallowamine component of the formulation.

The genotoxicity, long-term toxicity and carcinogenicity, reproductive/developmental toxicity and endocrine disrupting potential of POE-tallowamine should be further clarified. There is no information regarding the residues in plants and livestock  and limited information is available on ecotoxicology. Therefore, the available data are insufficient to perform a risk assessment in the area of human and animal health  or on the effects on the environment for the co-formulant POE-tallowamine.

Data gaps were identified and listed (see EFSA Journal 2015;13(11):4303, pp 10-11).

 

Request for the evaluation of the toxicological assessment of the co-formulant POE-tallowamine