Hazardous fluid storages are like a genie in a bottle

Sagar Dhara

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, will 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’s 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.

Plant start-up accidents after prolonged shutdowns common
The probability of an accident happening is higher when plants are re-started after prolonged shutdowns due to lack of regulatory authority guidance and oversight on the steps required to re-start 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 wee hours of 7 May morning, leaving 12 dead and hundreds hospitalized. The plant was permitted to re-start production three days prior to that after being shut for six weeks in 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 polymerization 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 bystander population of the impending danger.

On the same day, seven workers from Shakti Paper Mills, located near Raigarh, were hospitalized for exposure to chlorine gas, three of them in serious condition. In their haste to re-start 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.

Repeated start-up accidents, but no learning
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 re-started after a prolonged lockout. The wind direction was blowing away from populated areas kept casualties down to one dead and 140 hospitalized.

Nor are start-up accidents unique to India. A South Korean plant, Hanwha Total, located near Seosan was re-opened on 4 May 2019 after a six-week shutdown. A fortnight later, the its styrene tank released emissions on two consecutive days. The accident investigation states, negligence of Hanwha that they had not followed process safety management without considering the risk of polymerization of styrene monomer in the storage tank.”

Material valued more than human life
India has hesitantly fixed systems to minimize 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 persons, journalist Rajkumar Keshwani 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.

Immediate, root and underlying causes for accidents
Major accidents have immediate, root and underlying causes. Temperature rise of stored liquids are the immediate cause for polymerization reactions that happened in the LG Polymers and the Carbide accidents. The root cause for these accidents lie in management failures that allowed the tank refrigeration systems in both plants to be switched off, and other similar failures.

The underlying causes of both accidentslie in fault lines of society that prioritize market play over human lives. To fill the empty coffers of the Andhra Pradesh government and to allow the influential distillery industry to make profits, 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 re-start polystyrene production, though not an essential commodity, is a raw material for making liquor bottles.

Union Carbide made Sevin, a carbamate group pesticide in 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 for making 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 facility 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 managements. 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.

Published with the permission of the author.

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The author is an environmental engineer with specialization in risk analysis

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May 23, 2020

Sagar Dhara

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