EDMONTON -- Alberta's energy regulator has laid charges against three oil and gas companies after a release of poisonous hydrogen sulphide that affected human health.

Five charges have been laid against Tourmaline Oil Corp. and Topaz Oil Corp., and three charges have been laid against CWC Energy Services Corp.

The charges fall under the Environmental Protection and Enhancement Act and the Gas Conservation Act.

They are related to a hydrogen sulphide leak near Spirit River, Alta., on Feb. 25, 2018.

Hydrogen sulphide is a colourless and poisonous flammable gas that smells like rotten eggs and can cause chest pain, difficulty breathing, vomiting and headaches.

All three companies are to appear in a Grande Prairie court on Feb. 19.