Adjuvants in commercial pesticides : Not safe

Lack of information on the effects of all pesticide ingredients makes them appear safer than they are — potentially causing serious harm to people and the environment

image of Pesticides adjuvants

New regulations are needed to protect people and the environment from toxic pesticide ingredients that are not currently subject to safety assessments. This is the conclusion of “Ignoring Adjuvant Toxicity Falsifies the Safety Profile of Commercial Pesticides“, the first comprehensive review of gaps in risk assessments for “adjuvants” – ingredients added to pesticide formulations to enhance the function or application of the active ingredient. Ignoring the potential dangers of other ingredients in commonly used commercial pesticides leads to inaccuracies in the safety profile of the pesticide solution, as well as confusion in scientific literature on pesticide effects.

Key Points

  • Adjuvants Can be More Toxic Than Active Principles
  • Regulatory Guidance Values for Pesticides Can be Miscalculated by Ignoring Adjuvant Toxicity
  • Exposures to Adjuvants Have Health Effects on Human Populations


Commercial formulations of pesticides are invariably not single ingredients. Instead they are cocktails of chemicals, composed of a designated pesticidal “active principle” and “other ingredients,” with the latter collectively also known as “adjuvants.” These include surfactants, antifoaming agents, dyes, etc. Some adjuvants are added to influence the absorption and stability of the active principle and thus promote its pesticidal action. Currently, the health risk assessment of pesticides in the European Union and in the United States focuses almost exclusively on the stated active principle. Nonetheless, adjuvants can also be toxic in their own right with numerous negative health effects having been reported in humans and on the environment. Despite the known toxicity of adjuvants, they are regulated differently from active principles, with their toxic effects being generally ignored. Adjuvants are not subject to an acceptable daily intake, and they are not included in the health risk assessment of dietary exposures to pesticide residues. Here, we illustrate this gap in risk assessment by reference to glyphosate, the most used pesticide active ingredient. We also investigate the case of neonicotinoid insecticides, which are strongly suspected to be involved in bee and bumblebee colony collapse disorder. Authors of studies sometimes use the name of the active principle (for example glyphosate) when they are testing a commercial formulation containing multiple (active principle plus adjuvant) ingredients. This results in confusion in the scientific literature and within regulatory circles and leads to a misrepresentation of the safety profile of commercial pesticides. Urgent action is needed to lift the veil on the presence of adjuvants in food and human bodily fluids, as well as in the environment (such as in air, water, and soil) and to characterize their toxicological properties. This must be accompanied by regulatory precautionary measures to protect the environment and general human population from some toxic adjuvants that are currently missing from risk assessments.

Review and Press Release

  • Commercial pesticides: Not as safe as they seem, eurekalert, 8-Mar-2018.
  • Ignoring Adjuvant Toxicity Falsifies the Safety Profile of Commercial Pesticides, Frontiers in Public Health, 22 January 2018.
  • Featured image : pesticides are never used alone but in combination with adjuvants. Agricultural preparations of pesticides include adjuvants mixed with an active principle to increase toxic effects. For glyphosate-based herbicides, the active principle primarily targets the EPSPS enzyme but needs adjuvants such as polyethoxylated tallow amine to penetrate into plant tissues and cells. These adjuvants can also be toxic in their own right; numerous toxic effects have been reported in humans and the environment. However, adjuvants are regulated differently than active principles, and their long-term toxic effects are generally ignored and thus missing from pesticide risk assessment procedures. credit frontiersin.

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