
Its chief of operations, Alimaddia Bukri, said in a statement the gas leaked from a 1,000-litre-capacity tank about 10am and 21 firefighters from the Kapar fire and rescue station responded to a distress call at 10.14am.
They found one female and three male workers suffering from breathing difficulties.
They were attended to on site by a medical team, he said, adding that a Hazmat (hazardous materials) team had rushed there from the Shah Alam fire and rescue station.
He said three of the workers, two male and the female, were rushed to the Tengku Ampuan Rahimah Hospital in Klang for further treatment and that their condition was stable.
“The clean-up process is ongoing,” he said.