The recurring accidents during the transportation of hazardous chemicals point to the need for greater precautions and more stringent standard operating procedures.
In fact, it is high time to make it mandatory for experts to accompany such consignments.
In the Hindustan Insecticides Limited’s case at Eloor, the negligence in transportation might have led to the leakage and the subsequent accident.
S. Mani, Joint Director of Factories and Boilers, said the negligence during the transportation of the chemical from the Vallarpadam Container Terminal to the factory caused the accident. The authorities had found a crack in the manifold valve of the truck providing an escape route for the Nitrogen blanketing of the imported chemical, he said.
The dangerously low auto ignition temperature of carbon disulphide (CS2) might have been another contributing factor. The chemical turns into vapour as soon as it gets into contact with air. It may ignite or even explode on slight contact with heat. Also, when heated to decomposition, it emits highly toxic fumes of sulfur oxides and can react vigorously with oxidizing materials.
The vapour or liquid can ignite on contact with steam pipes, particularly if rusted. This exactly seems to have happened in the case of the accident.
“CS2 vapour drops down as it has higher density than air. This brought it in contact with the tyres and exhaust pipe of the tanker which had just came to a halt after transporting the consignment from Container Terminal,” said M.T. Regi, chemical inspector, Factories and Boilers Department.
The valve in the tanker used to unload the chemical is usually has a blind as an additional safety mechanism in case the valve fails to hold on and prevent the leakage of the content inside. This dummy is removed before unloading the chemical. In this case, the chemical had breached this seal and as soon as it was removed vapour got released, said Mr. Regi.
Inspection a must
R. Prasad, Ernakulam Divisional Fire Officer, said such consignments should be loaded and unloaded only after inspection by experts taking into account the possibility for leakage during transportation.
The scant regard for safety was on display on the spot when an HIL official opened the bent pipe of the tanker even as measures were being taken to plug the leakage.
The chemical was safely unloaded from the tanker by the evening in the presence of experts.
Major tragedy averted
A major tragedy was averted since the material affects the central nervous system, cardiovascular system, eyes, kidneys, liver, and skin if left uncontrolled. It may be absorbed through the skin as a vapour or liquid, inhaled or ingested.
District Collector K. Mohammed Y. Safirulla has ordered an inquiry into the leakage of carbon disulphide at HIL when the chemical was being unloaded from the transportation tanker. The Joint Director of Factories and Boilers who has been entrusted with the inquiry has been asked to submit a report on the incident within two days.
