Insight into the confusion over surfactant co-formulants in glyphosate-based herbicides

TY - JOUR

T1 - Insight into the confusion over surfactant co-formulants in glyphosate-based herbicides

AU - Mesnage, Robin

AU - Benbrook, Charles

AU - Antoniou, Michael N.

PY - 2019/6/1

Y1 - 2019/6/1

N2 - Glyphosate is the active ingredient in glyphosate-based herbicides (GBHs). Other chemicals in GBHs are presumed as inert by regulatory authorities and are largely ignored in pesticide safety evaluations. We identified the surfactants in a cross-section of GBH formulations and compared their acute toxic effects. The first generation of polyethoxylated amine (POEA) surfactants (POE-tallowamine) in Roundup are markedly more toxic than glyphosate and heightened concerns of risks to human health, especially among heavily-exposed applicators. Beginning in the mid-1990s, first-generation POEAs were progressively replaced by other POEA surfactants, ethoxylated etheramines, which exhibited lower non-target toxic effects. Lingering concern over surfactant toxicity was mitigated at least in part within the European Union by the introduction of propoxylated quaternary ammonium surfactants. This class of POEA surfactants are ∼100 times less toxic to aquatic ecosystems and human cells than previous GBH-POEA surfactants. As GBH composition is legally classified as confidential commercial information, confusion concerning the identity and concentrations of co-formulants is common and descriptions of test substances in published studies are often erroneous or incomplete. In order to resolve this confusion, laws requiring disclosure of the chemical composition of pesticide products could be enacted. Research to understand health implications from ingesting these substances is required.

AB - Glyphosate is the active ingredient in glyphosate-based herbicides (GBHs). Other chemicals in GBHs are presumed as inert by regulatory authorities and are largely ignored in pesticide safety evaluations. We identified the surfactants in a cross-section of GBH formulations and compared their acute toxic effects. The first generation of polyethoxylated amine (POEA) surfactants (POE-tallowamine) in Roundup are markedly more toxic than glyphosate and heightened concerns of risks to human health, especially among heavily-exposed applicators. Beginning in the mid-1990s, first-generation POEAs were progressively replaced by other POEA surfactants, ethoxylated etheramines, which exhibited lower non-target toxic effects. Lingering concern over surfactant toxicity was mitigated at least in part within the European Union by the introduction of propoxylated quaternary ammonium surfactants. This class of POEA surfactants are ∼100 times less toxic to aquatic ecosystems and human cells than previous GBH-POEA surfactants. As GBH composition is legally classified as confidential commercial information, confusion concerning the identity and concentrations of co-formulants is common and descriptions of test substances in published studies are often erroneous or incomplete. In order to resolve this confusion, laws requiring disclosure of the chemical composition of pesticide products could be enacted. Research to understand health implications from ingesting these substances is required.

KW - Glyphosate

KW - Pesticides

KW - POEA

KW - Regulatory tests

KW - Risk assessment

KW - Surfactants

UR - http://www.scopus.com/inward/record.url?scp=85063913449&partnerID=8YFLogxK

U2 - 10.1016/j.fct.2019.03.053

DO - 10.1016/j.fct.2019.03.053

M3 - Review article

C2 - 30951798

AN - SCOPUS:85063913449

SN - 0278-6915

VL - 128

SP - 137

EP - 145

JO - Food and Chemical Toxicology

JF - Food and Chemical Toxicology

ER -