(Beyond Pesticides, February 13, 2014) French scientists from the University of Caen have revealed one more layer of the myth behind so-called “inert” ingredients in pesticides, concluding that pesticide risk assessments that focus exclusively on active ingredients substantially underestimate the potential hazards of the product as a whole. The findings in Major pesticides are more toxic to human cells than their declared active principles indicate that inert ingredients in pesticides can magnify the effects of active ingredients, sometimes as much as 1,000-fold.
In conducting their study, Robin Mesnage, Ph.D. and his team of scientists, including Gilles-Eric Seralini, exposed three human cell lines to the active ingredients of three herbicides, three insecticides, and three fungicides. The team then exposed the cell lines to the well-known commercial formulations that include these active ingredients which also contained “inerts,” and compared the results.
Overall the study concluded that the commercial combinations had a magnifying effect on the toxicity of the active ingredients. While many might assume that three insecticides tested ranked highest in toxicity, the study actually ranked fungicides as having the highest on-average toxicity, followed by herbicides, then insecticides. Leading the pack for on-average toxicity in the herbicides was the well-known Monsanto product, Roundup, which contains the active ingredient glyphosate and several inert ingredients. Used to kill weeds on lawns, in gardens and crop production, including soybeans and corn, glyphosate is one of the most widely used herbicides in the U.S.
The researchers cautioned that the study should not be used to set safety standards. As Environmental Health News explains, “The study relied upon a simple, short-term and relatively insensitive measurement of toxicity — cell viability, or what percentage of cells survived. Many adverse effects do not cause cell death, so tests of pesticides need to use more sensitive endpoints, such as endocrine disruption.” In other words, this study is pointing out the worst case scenarios that go unmonitored and untested. It still does not consider the multitude of chronic health effects that may be amplified by commercial mixes of inerts and active ingredients.
The Known Unknown
Unfortunately despite these kinds of findings and other scientific research pointing to similar issues, inert ingredients remain steeped in “trade secret” mystery and access to meaningful information concerning these ingredients is not required under existing regulations.
Under EPA’s interpretation of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), pesticide manufacturers are only required to list the active ingredients in a pesticide product, leaving consumers and applicators unaware of the possible toxic substances present in the inert ingredients of pesticide products they are using. Even more concerning is EPA’s failure to require testing of these “inert” ingredients or the complete pesticide formulation before it is registered by the agency.
Pesticide manufacturers argue against the disclosure of inert ingredients on pesticide product labels, maintaining that their products could be duplicated. Quite often, inert ingredients constitute over 95% of the pesticide product. Limited review of inert ingredients in pesticide products, like this study and others find, has highlighted a primary flaw with the regulatory process. Rather than adopt a precautionary approach when it comes to chemicals with unknown toxicity, EPA allows uncertainties and relies on flawed risk assessments that do not adequately address exposure and hazard. Then, when data becomes available and hazards, these pesticides, both active ingredients and inerts, have already left a toxic trail on the environment and people’s well-being.
In 2009, U.S. Environmental Protection Agency’s (EPA) seemed on track to clear up some of the mystery of undisclosed ingredients when it `proposed mandating public disclosure of all inert ingredients. However, the agency has taken follow-up actions to promulgate a final rule or publish suggestive guidance.
This study raises yet another interesting issue for EPA concerning not only disclosing inert ingredients and testing them individually, but reassessing how pesticide products on the whole are approved and assessed for safety.
Beyond Pesticides continues to advocate for improved pesticides safety standards that take into account the full-spectrum of health and environmental impacts. For more information about inert ingredients and pesticides as a whole, please visit Beyond Pesticide’s webpage, What’s in a Pesticide?
Source: Environmental Health News
All unattributed positions and opinions in this piece are those of Beyond Pesticides.