Glyphosate plus a wealth of contaminants

October 2015

Photo Creative Commons
Glyphosate herbicide is sprayed on, and accumulated by, most GM crops.  Despite the fact that it's always used in formulations such as 'Roundup', "There is an unexpressed, widely believed assumption that the active principle against plant metabolism (glyphosate) is the most toxic compound of glyphosate-based herbicide formulations on non-target species." (Mesnage et al.)

These 'non-target species' include wildlife, livestock, pets and humans.

How valid is this 'widely believed' assumption?

Chemical glyphosate constitutes a minority ingredient in formulations (at most, less than 50% even in pre-diluted form, and sometimes no more than a few percent of the total).  Although the non-glyphosate constituents are referred to as 'inerts', they are put there to make the herbicide kill better.

While glyphosate itself specifically targets plant metabolism, the 'inerts' are not so fussy. 

Most ubiquitous of the 'inerts' are 'poly-ethoxylated alkyamines' (POEA) which are needed to help glyphosate penetrate the barrier of the outer cell membrane.  In tests, POEA on its own proved to be 10,000 times more toxic to isolated cells than glyphosate. 

Most other 'inert' ingredients are a trade secret and, therefore untested and untestable.  As weeds have become increasingly resistant to older Roundup formulae, more aggressive forms have come on the market: these contain the same old glyphosate combined with ever more aggressive 'inerts'.

Chemical glyphosate, as used in scientific experiments, has been found to contain a number of contaminants, including significant quantities of glyphosate's major derivative (AMPA), 1.5% formic acid (a.k.a. ant poison), and 2.85% formaldehyde (a.k.a. embalming fluid).  All are toxic and were found at toxic levels.  Some are carcinogens.

Chemical POEA has been found to be contaminated by dioxane, a carcinogen.

While POEA is added to Roundup to aid glyphosate penetration, it can give other environmental toxins a helping-hand into your crops, and therefore into your food, and into you too.

Also, POEA survives longer in the environment than glyphosate, which means it has more time to cause mischief.

Standard safety-testing of glyphosate involves feeding-studies using laboratory rats on a diet of standard rodent chow.  Laboratory rat feed has recently been found to be contaminated with variable quantities of GMOs, pesticides, heavy metals, PCBs, dioxins ... and glyphosate [1].

Regulatory tests to establish 'safe' levels of glyphosate intake have been bugged by inconsistency.  This is hardly surprising when you consider the scope for spurious toxins in 'standard' test and control feeds. Yet, the variability of toxic effects seems to have been used as a reason to ignore inconvenient findings.

At the end of the day, we need to know that what we are eating is safe no matter what contaminants or what combination of contaminants are present.  As the authors of a new review of the potential toxic effects of glyphosate and its commercial formulation stressed, a complete and more realistic reassessment of glyphosate is clearly called for.


We need to get rid of industry secrecy, get rid of all notions of 'inert' ingredients which are anything but, and pay a lot more scientific attention to the scientific quality of the materials used in supposed scientific safety tests.




R. Mesnage, et al., 2015, Potential toxic effects of glyphosate and its commercial formulations below regulatory limits, Food and Chemical Toxicology

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