Hazardous fluids in storage like a genie in a bottle

A well looked-after genie will behave itself and do its master’s bidding, but one that is not will try to jump out of its bottle and, if it succeeds, cause havoc outside. Toxic or flammable fluids stored in tanks are like genies in a bottle. If the tank is well-maintained, the stored liquids and gases will help make profits for plant owners. If the tank lacks maintenance or its plant is shut down, the stored fluids will try to spill out of the tank. If they succeed, they will leave a trail of injury and destruction.

The probability of an accident is higher when plants are restarted after prolonged shutdowns due to lack of regulatory authority guidance and oversight on the steps required to restart such plants. Two recent accidents bear testimony to this.

Styrene vapour was released from a tank in the LG Polymers plant located in Visakhapatnam in the early hours of May 7, leaving 12 dead and hundreds hospitalised. The plant was permitted to restart production three days prior to that after being shut for six weeks due to the COVID-19 lockdown. During this period, the concentration of a chemical inhibitor in the styrene tank may have reduced and the cooling system for the styrene may have been switched off. Consequently, a polymerisation reaction seems to have increased the temperature and pressure in the tank, popping the relief valve. Styrene vapours gushed out of the tank and drifted downwind as an aerosol cloud. Low night-time windspeeds kept vapour concentrations high up to 7-9 km from the plant. No siren was sounded to warn the nearby population of the impending danger.

On the same day, seven workers from Shakti Paper Mills, located near Raigarh, were hospitalised for exposure to chlorine gas, three of them in serious condition. In their haste to restart the plant, the management sent the workers to clean a chlorine tank without testing the tank for gas pockets or providing the workers with personal protective equipment.

Plant start-up accidents are not recent occurrences, yet we have not learnt lessons from them. In 1985, two tonnes of chlorine were released from Calico Mills in Trombay. The accident happened as the plant was being restarted after a prolonged lockout. Fortunately, the wind was blowing away from populated areas and that kept casualties down to one dead and 140 hospitalised.

India has hesitantly fixed systems to minimise accidents if high-value material is likely to be lost but not where lives may be lost. The 1988 naphtha vapour explosion in Indian Oil Corporation Ltd’s (IOCL) Mathura refinery that killed seven workers was caused by a spark from the tail pipe of an IOCL jeep that started its engine when in a naphtha vapour cloud. After this accident, spark arresters became mandatory for vehicles entering refineries. After the 1997 LPG explosion in Hindustan Petroleum Corporation Ltd’s Visakhapatnam refinery that killed 60 persons, smoking areas and naked flames close to LPG tank farms were banned.

Prior to the 1984 Bhopal gas tragedy that killed 25,000 people, journalist Rajkumar Keshwani had warned in three articles that Bhopal was on the brink of a disaster. A state government minister responded saying, “The carbide plant is not a small pebble that can be picked up and put elsewhere.” Poor siting of facilities with hazardous materials is due to flawed land use development. Injury to people in the LG Polymers accident is partly due to residential areas being too close to the plant.

Major accidents have immediate, root and underlying causes. Polymerisation reactions are the immediate cause for the LG Polymers and the Carbide accidents. The root cause for both accidents are due to deeper management failures that allowed the tank refrigeration systems in both plants to be switched off, and other similar management failures. The underlying causes of both accidents lie in the fault-lines of our socio-economic system. To fill the empty coffers of the Andhra Pradesh government and make profits for the influential distillery industry, liquor sale was permitted immediately after the COVID-19 lockdown was lifted partially. But liquor bottles were in short supply, so LG Polymers was permitted to restart polystyrene production. Polystyrene, though not an essential commodity, is a raw material for making liquor bottles.

Union Carbide made Sevin, a carbamate group pesticide, at its Bhopal plant. Soon after the plant went into production, Sevin lost market space to the next generation pesticides —phorates and synthetic pyrethroids, and the company slipped into losses. Consequently, safety and environmental management standards in the plant plummeted.

If the existing laws and regulators have failed to increase plant safety, it is time to make fundamental changes.

A legal definition for unacceptable environmental impact of an activity does not exist. In granting environmental clearances, the tacit premise is that almost all impact is acceptable if consent conditions are followed by plant operators. The reality is that inconvenient conditions are flouted, and regulatory agencies have neither the machinery nor the will to catch violations. Unacceptable impact must now have a legal definition for environmental clearance to have meaning.

To isolate hazardous facilities from populated areas, land use plans must be strictly adhered to. People’s participation in environmental decision-making should increase by mandating potentially impacted people to do environmental impact assessments and annual environmental and safety audits rather than project management. After all, the risk that a hazardous facility poses was thrust on them. Plant workers must have the right to warn regulatory authorities of the probability of a major accident if they feel it is imminent. This is the most effective way of keeping the genie in the bottle.

(The writer is an environmental engineer)