The situation was brought under control several hours later and a report was lodged with the Department of Environment (DOE) for further investigation, according to the Kulai fire and rescue station.

Its spokesman, Bahtiar Selamat, said the Johor operations centre received an emergency call at 8.22pm about the incident at a store along Jalan Besar, Kampung Baru, Sengkang.

A total of 21 personnel, assisted by a hazmat unit, rushed to the scene to find a chemical spill involving methyltriocdylammonium chloride, hydrogen peroxide solution and n-methyl cyclohexylamine.

“There were 30 tanks containing alkaline material, and one of the tanks burst, with the contents flowing into the nearby river,” according to a Sinar Harian report.

“Two victims at a location nearby experienced vomiting. The fire brigade built three embankment layers to prevent the waste from flowing into the river.

“The flow of the chemicals has been stopped and the situation is safe. The operation ended at 2.30am,” he said.

Bahtiar said they had lodged a complaint with the DOE, which is expected to carry out checks on the extent of pollution in the river.