Introduction:
Major industrial chemical accidents are low frequency, but highly significant events in terms of loss of lives, injuries, environmental impact and material damage. These accidents may occur in industrial process, energy-related and transport activities. They are generally associated with either large inventories of flammable, explosive, or very reactive substances or of common toxic chemicals in process industries or smaller quantities of very toxic and persistent chemicals.
The frequency and severity of these accidents seems to have increased during the last few years (Seveso, Mexico, Bhopal, Basle, etc.,). This increased frequency may be related to the rapid development of the chemical and petrochemical industries, the diversification of derived products, the increase in the size of plants, storage and carriers,the progressive industrialization in developing countries, and the proximity of plants to densely populated areas.
Chemical accidents involve a series of events starting with a technical breakdown or human error initiating uncontrollable physio-chemical phenomena, such as runaway chemical reactions, fires and explosions.These events are followed by propagation beyond the plant boundaries of toxic compounds in gaseous or liquid phase or as particulates. Damage may also be cause by the blast of explosions or the heat of fires.
Human beings and non-human targets may suffer injury from acute and/or residual exposure in the form of immediate, acute effects or long-term consequences. Action should be undertaken to prevent the occurrence of such accidents through the introduction of safer process technologies, the improved performance of safety devices, and by the reduction of human error. Once an accident
occurs, engineering systems (scrubbers, flares, venting systems, etc.) should intervene to mitigate its consequences.
Major chemical disasters worldwide:
Disaster is a rarity in the chemical industry, but negligence or misfortune can so easily result in devastating consequences.
CONSIDERING THE potentially dangerous materials and processes employed in the chemical sector, most producers can be justifiably proud of their health and safety records. Occasionally, however, things do go wrong.
Aside from the immediate implications surrounding a major incident, such as loss of life, a threat to the environment or the destruction of plants and surrounding buildings, the damage to the industry's reputation is almost irrevocable.
"The Seveso disaster [in Italy] in 1976 was a major environmental incident and the trigger that made people realize that a Europe-wide environment policy was needed it marked the birth of the [Seveso] directive," says Verbist.
"But without doubt, Bhopal [in India] in 1984 was the most important catastrophe ever seen in the chemical industry,"he says. "At that time,chemical industry was already preparing the Responsible Care initiative, but Bhopal triggered its launch the following year.
OPPAU, GERMANY - September 21, 1921
Workers at BASF's Oppau site, in Germany, decided that the best course of action to loosen a 4,500 tonne mound of ammonium nitrate (AN) and ammonium sulfate that had solidified was to detonate several dynamite charges.
The accident destroyed around 80% of the homes in Oppau and ripped the roofs off houses as far as 25km (10 miles) away.
TEXAS CITY, TEXAS, US - April 16, 1947
On the morning of April 16, 1947, a French ship -The Grand camp -was being loaded with ammonium nitrate (AN) fertilizer. With over 2,000 tonnes of AN on board, a fire started in the hold. Not wanting to damage the cargo, the captain refused to use water on the flames and opted instead to control the fire using the steam system.
A 15ft (4.6m) wave swept a barge ashore, buildings were destroyed - including a Monsanto chemical plant nearby - and the ship's anchor was found more than a mile away. There were around 3,500 injuries and 576 people were killed.
TEXAS CITY, TEXAS, US - March 23, 2005
The 2005 disaster at UK oil major BP's Texas City refinery, in Texas, US, was considered the nation's worst industrial disaster in 15 years.
A series of explosions occurred when a hydrocarbon isomerization unit was restarted and a distillation tower flooded with hydrocarbons. As a result, 15 were killed and another 180 were injured. BP admitted to charges and accepted fines last year, with BP America chairman Bob Malone conceding that the company was guilty of a felony "for failing to have adequate written procedures for maintaining the ongoing mechanical integrity of process equipment at the Texas City refinery.
JILIN CITY, CHINA - November 13, 2005
A series of explosions rocked China-based Jilin Petrochemical's 70,000 tonne/year aniline complex in Northeast China, killing five and injuring 70. Benzene also leaked into the Songhua river and caused millions of people to go without drinking water, with many fleeing their homes.
BHOPAL, INDIA - December 3, 1984
A gas leak at US-based Union Carbide's pesticide plant in Bhopal, India, is cited as one of the chemical industry's greatest tragedies.
On December 3, 1984, methyl isocyanate gas leaked from the facility during the early hours of the morning while local residents slept. Around 2,000 people died immediately, with another 8,000 dying later.
FLIXBOROUGH, UK - June 1, 1974
In 1974, cyclohexane vapor leaked from ruptured pipework at the Nypro (UK) site at Flixborough. This resulted in an explosion that killed 28 people and injured 36.
Offsite, 53 injuries were reported. Property in the surrounding area was also severely damaged.
TOULOUSE, FRANCE - September 21, 2001
Around 300 tonnes of ammonium nitrate (AN) exploded, destroying the site and wrecking buildings 3km (1 mile) away in the city center.The blast left a crater 50m (164 feet) wide and 10m deep. It was responsible for the death of 30 people, and 10,000 injuries.
The blast left a crater 50m (164 feet) wide and 10m deep. It was responsible for the death of 30 people, and 10,000 injuries.
SCHWEIZERHALLE, SWITZERLAND - November 1, 1986
Water used to extinguish a major fire at the Sandoz chemical factory in 1986 washed chemicals into the river Rhine, one of Europe's busiest waterways. The spill caused severe pollution, which took years to eradicate, and killed an estimated 500,000 fish.
