Dow Jones reported the move by the Chinese State Environmental Protection Administration was an effort to cut down on sulfur dioxide emissions. Much of the country’s coal is high in sulfur, which has lead to high emissions by power plants.

Dow Jones said if enforced, the new rules could raise costs for Chinese energy producers.

A China Daily report did not specify what reductions would need to be made or what equipment had been proposed. However, it said the modifications would have to be made to both existing and future plants.