A factory official, who did not wish to be named, said there was a gas leak, but declined to provide more details.
Police said the accident occurred when the tyres of a tanker lorry, which brought carbon disulfide to HIL caught fire and exploded as the gas was being transferred to the facility set up in the factory, injuring eight persons.
Three fire engines, which rushed to the area, doused the flames.
Ernakulam District Collector K Mohammed Y Safirulla said the situation is under control.
Hindustan Insecticides Limited is a public sector enterprise under the Ministry of Chemicals and Fertilizers.