Recently, Costa Rican President Rodrigo Chavez signed a decree banning the fungicide chlorothalonil in Costa Rica. The decree points out that chlorothalonil is a non-systemic fungicide widely used on vegetables, fruits and other crops. However, its persistence in the environment and its negative effects have attracted people's attention.
Degradation of chlorothalonil in soil may produce metabolites that could affect health and the environment, and the chemical is highly toxic to fish and aquatic invertebrates, especially during rainfall. The European Food Safety Authority (EFSA) says contamination of groundwater by chlorothalonil metabolites is a serious concern.
In addition, chlorothalonil is classified as a possible human carcinogen by the International Agency for Research on Cancer (IARC) and is considered a potential endocrine disruptor affecting embryonic development.
In April 2023, the Ministry of Health, the Ministry of Environment and Energy, and the Costa Rican Sewerage Institute issued a technical report proposing different recommendations for the management of chlorothalonil, including a ban on the use of the pesticide chlorothalonil. The Constitutional Court subsequently required the reporting provisions to be enforced. Therefore, the Ministry of Health, the Ministry of Environment and Energy, and the Ministry of Agriculture and Livestock signed a decree prohibiting the use of chlorothalonil.
