Mixture toxicity

Our position.

Over the years, crop protection products have become increasingly specialized in order to target specific pests and weeds. Farmers also have to guard against resistance, which can occur if the same product is over-used. Therefore, a variety of crop protection products is available to control the same pests, weeds and diseases. As a result, a combination of crop protection products can be present in either the environment or as “multiple residues” in the food. Consumers are concerned about these combinations and want to know what this means for the environment and human health.

We include below some frequently asked questions that you may find interesting as well:

General Questions

What does "cocktail effects" or "mixture toxicity" mean?

"Mixture toxicity" describes the effect that occurs when the toxicity of a combination of different chemicals is higher than the toxicity of each of the individual substances. However, this is not commonly the case.

"Mixture toxicity" occurs when chemicals have a common toxicity. In these cases, toxicity levels can add up or even - in very rare occasions - combine to have a so-called synergistic effect.



BASF Position

The effects of combinations of chemicals are referred to as mixture toxicity. This term describes the effect that the toxicity of the combination of chemicals is higher than the toxicity of individual components of the mixture. In fact, we are exposed to mixtures of man-made and natural chemicals every day. Also because of this, current risk assessment procedures for single substances are highly conservative, giving confidence that additive effects are covered in the majority of cases. Even so, BASF is convinced that this topic needs to be taken up to further reduce potential risks.


Therefore, BASF has increased research activities in the area of mixture toxicity and scientifically evaluates the safety of its products regarding combination effects.


BASF currently evaluates mixture toxicity in its products containing more than one active ingredient (e.g. crop protection products) to ensure that they can be used safely for the farmer, the consumer and the environment.


In cases where its products are part of a mixture in the human diet or in the environment (e.g. surface water), BASF works on science-based solutions to evaluate whether these combinations are of (eco)toxicological concern.


Currently, there is no harmonized and internationally-accepted method to assess the risk posed by chemical mixtures to human health and the environment. BASF contributes to scientific solution development together with regulatory bodies, academia and other relevant stakeholder groups.


BASF favors a mixture assessment approach based on available scientific knowledge instead of a general increase of existing safety factors. By this scientific approach, only substances displaying common toxicity shall be evaluated together. To ensure a solid evaluation, BASF believes that all existing data, e.g., from food consumption or residue monitoring programs should be made available.


BASF is committed to identifying and implementing appropriate measures to manage potential risks effectively and maintain high standards of consumer and environmental protection.