Canada’s health ministry Health Canada is planning a phase-out of two neonicotinoid herbicides that have been linked to death of aquatic insects and honey bees.

Health Canada’s Pest Management Regulatory Agency (PMRA) planned to phase out the outdoor use of thiamethoxam manufactured by Syngenta and clothianidin manufactured by Bayer over three to five years, wrote Reuters on 15 August.

The chemicals – widely used to protect soyabean, canola and corn from insects – were found in a review to accumulate in water bodies in high enough concentrations to harm aquatic insects on which fish and birds feed.

The outdoor use ban was subject to a 90-day consultation period, with a final decision expected in late 2019, according to Reuters.

Health Canada also intended to make a final decision by the end of the year on whether to also ban Bayer’s imidacloprid, another neonicotinoid pesticide.

Canada’s move came after the EU in April approved a measure to ban all outdoor use of neonicotinoids, and while the USA had not yet taken such actions, it was reviewing neonicotinoids and seeking public comment on proposed action.

Syngenta said it was disappointed with Canada’s decision and suggested that the PMRA had not considered all relevant information.

Bayer believed its clothianidin had a “favourable” environmental profile, reported Reuters.

Neonicotinoids are a class of pesticides applied at seed treatment or sprayed on leaves that have been linked by research to declining honey bee populations.