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Cause of the Accident

There are several causes to the phosgene accident on 23th January 2010.The flow rate of

phosgene going out from the cylinder was experiencing problems. This was because of the

permeability of the hose carrying the phosgene was already low due to the fact that phosgene

can seep through the PTFE lining and corrode the stainless steel.

The worker was severely injured due to the fact that the phosgene was not purged with

Nitrogen.Usually,the hoses are purged with nitrogen to prevent pressure build-up inside the

hose.However,as already said the corrosion in the stainless steel due to the permeability of

phosgene ruptured the internal lining of the hose and along with the pressure buildup,the hose

could not take the pressure,hence spraying phosgene to the atmosphere killing the veteran

worker.

Another cause was DuPonts standard operating procedure require the hoses be replaced

every 30 days.This was because of the corrosion effect of the phosgene fluid which was able

to seep through the hose would take about a month or more to damage the PTFE

lining.However,the hose that cause the accident was only replaced 7 months ago. The

software used at the plant had been modified and it no longer notified the operators when to

replace the hoses. As a result, the hoses were used much longer than the prescribed life.

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Lesson Learnt

Basically the operators in the DuPont Plant were not in check to keep the maintenance

secure.If they had replaced the hoses based on their regular standard operating

procedures,then the phosgene would have been secured within the hoses and the workerwould have not been dead.The software that was used should also be revised and remodified

to alert the operators when to replace the hoses.

The shed that was used to place the phosgene should have been enclosed to avoid the

phosgene to spread in the atmosphere,injuring the other workers.Initially,the management

wanted to enclose the shed.The constructions were supposed to be completed by December

2005 but the deadline was not met and was extended four times, hence the shed was never

enclosed even on the day of the accident.

When the operators experienced flow problems on the day of the accident, they should havehalted procedures and inspect the hoses to avoid any accidents from occurring.Proper PPE

should also have been used which made workers wear gas masks when dealing with toxic

chemicals.

The hoses could have also been replaced with Monel which is a type of nickel alloy.Although

it would cost more than its stainless steel counterpart, the phosgene would not have been able

to corrode through the monel pipe,hence ensuring that the hose would not rupture due to

chemical corrosion.