European health authorities warned on Tuesday that two insecticides, including a widely-used one made by Bayer, may affect the developing human brain and should be more tightly controlled to limit human exposure.
The products - acetamiprid and imidacloprid - belong to popular class of insecticides called neonicotinoids, which have recently been in the spotlight due to links with plunging populations of bees. Imidacloprid is one of the most widely used insecticides in the world.
The European Union voted in April to ban three neonicotinoids - including imidacloprid which is primarily manufactured by Bayer - for two years amid safety and environmental concerns.
In Tuesday's move, the European Food Safety Authority (EFSA) recommended guidance levels for exposure to the products be lowered while further research is carried out to provide more reliable data on so-called developmental neurotoxicity.
"Acetamiprid and imidacloprid may adversely affect the development of neurons and brain structures associated with functions such as learning and memory," EFSA said in a statement from its Rome headquarters.
"Some current guidance levels for acceptable exposure to acetamiprid and imidacloprid may not be protective enough to safeguard against developmental neurotoxicity and should be reduced."