Four physicians at Kagoshima University, Japan, report that an analysis
of 56 cases of Roundup poisoning suggests that the surfactant (a so-called
"inert" ingredient) in Roundup causes the herbicide's acute toxicity rather
than the herbicidal ingredient, glyphosate. Most of the victims ingested
Roundup accidentally or as attempted suicide.
Fifteen percent of Roundup's volume is the surfactant polyoxethyleneamine
(POEA), while 41 percent is glyphosate. POEA is over three times as acutely
toxic as glyphosate and belongs to a class of surfactants which includes a
spermicidal agent. This class of compounds is known to cause
gastrointestinal and central nervous system symptoms and hemolysis; these
symptoms are similar to the symptoms exhibited by the Roundup poisoning
The physicians report that they also studied two other patients who had
ingested surfactants. These patients had symptoms very similar to Roundup
Glyphosate has been assumed to have low animal toxicity because the
enzyme system which it inhibits is specific to plants. This study is further
evidence that estimates of the toxicity of a pesticide need to be based on
the entire formulation, rather than just the active ingredients.
1. Sawada. Yusuke, Yoshikazu Nagai, Masashi Ueyama, and Isotoshi
Yamamoto. 1988. Probable toxicity of surface-active agent in commercial
herbicide containing glyphosate . The Lancet 1 (8580):299.
2. Monsanto Company. 1985. Monsanto material data sheet: Roundup
herbicide. St. Louis, MO.
Citation for this article: Cox,Caroline 1988,
"Roundup's inert surfactant is poisonous", Journal of Pesticide Reform, Vol
8, No. 1, Spring 1988, pp 30.
Copyright © 1988
Coalition for Alternatives to Pesticides.