Secret, undeclared pesticide ingredients may pose a risk to people, pollinators and the environment

Posted on: 21 February 2024

Scientists are calling for greater transparency in the full ingredient list of pesticides, arguing that farmers and consumers deserve to know exactly what is in them.

Secret, undeclared pesticide ingredients may pose a risk to people, pollinators and the environment

In a just-published article, authored by a researcher from Trinity, the case is made that secret ingredients could be posing risks to people, pollinators and the environment.

Pesticides are widely used in Ireland and can potentially have serious impacts on both wildlife and human health. Yet despite this, the full list of ingredients in a pesticide is kept secret. Dr Edward Straw, from the Botany Department at Trinity, argues that without full transparency, research into the negative effects of these ingredients cannot happen.  

Pesticides contain main ingredients; these are what makes the pesticide work. Pesticides also contain other ingredients, called co-formulants, and these help the main ingredient function.   


Pesticide producers are required to report what the main ingredients in a pesticide are, as well as some of the co-formulants that meet specific criteria set out by the EU. However, many co-formulants are kept secret, and are actually explicitly protected by EU law as trade secrets. Because of this, neither pesticide users, nor scientists really know what is in them.  

Lead author of the article, Dr Edward Straw, Research Fellow in Botany, in Trinity’s School of Natural Sciences, said: “It often takes research from independent scientists to alert the EU to the threat certain pesticides can present. But if we do not know what the ingredients in a pesticide are, we cannot test those ingredients. 

“There is no good reason for keeping these ingredients secret. The lack of transparency is putting the farmers who use the pesticides, and the people who eat the food made using the pesticides, at risk. 

“Recent research has found that some co-formulants in pesticides can be harmful to wildlife, like bees, as well as quite harmful to human health. With full transparency scientists could test pesticides better, identify any harmful co-formulants, and help make pesticides safer for nature and their users.”   


Dr Straw argues that the farmers applying the pesticides have a right to know what it is they are spraying, and that consumers have a right to know what is being sprayed on their food. 

In industries similar to pesticide production, like medicine production, there is not the same secrecy applied to these types of ingredients. Medicine packets openly list all the ingredients in the medicine, for example. 

This project has received funding from the Irish Research Council. The article, published by the journal of Environmental Science and Policy, is Open Access and can be read on the publisher's website.

Media Contact:

Thomas Deane | Media Relations | | +353 1 896 4685