17%, mental and physical agility are noticeably impaired; death
comes quickly if it drops only a few percent more. At these levels
unconsciousness takes hold so rapidly that the victim will be
unaware of what is happening.
High oxygen levels are also dangerous. As with too little, too
much can also impair the victim’s ability to think clearly and act
sensibly. Oxygen-enriched atmospheres represent a severe fire
hazard. From clothing to grease, materials will burn much more
vigorously under these conditions. Common causes of oxygen
enrichment include leaks from welding cylinders and even from
breathing apparatus.
Detecting risk
There are three categories of risk which must be detected reliably
in order to protect human life, and the environment.
)
Ex – risk of explosion by flammable gases.
)
Ox – oxygen; risk of asphyxiation by oxygen displacement or
risk of increase of flammability by oxygen enrichment.
)
Tox – risk of poisoning by toxic gases.
Gas detectors should be calibrated every six months to ensure
optimum operation and Dräger’s X-dock, which was launched
last year, is a docking station management system which ensures
portable gas detection devices on board any platform are working
correctly.
This intelligent instrument management hub enables simple
day-to-day testing of portable gas detectors and easy management
of maintenance cycles.
Safety for the future
When it comes to gas-related accidents, most eventualities do
not ‘just happen’. Each of these accidents is more often than not, a
culmination of a series of individually minor events that combine
and add up to cause a more serious problem.
Lord Cullen’s 13 month Public Inquiry into the Pipe Alpha
disaster led to a radical overhaul of safety practices and those
changes are still in place.
We have now entered the ageing infrastructure phase of the
industry, therefore challenges remain with regards to fire and gas
detection and emergency shutdown systems.
Around half of offshore platforms are beyond their original
design life with many assets commissioned in the early 1970s now
forecast to continue operating to 2030 and beyond. Investment in
new assets and the extension of the life of existing plant present
both safety and commercial challenges.
At Oil & Gas UK’s Piper 25 Conference in 2013, Lord Cullen said:
“The Piper Alpha disaster led to changes in the framework within
which offshore safety requires to be managed.”
He noted that the achievement of safety is critically
dependent on leadership in its management and on motivation of
the workforce, and a positive and learning culture.
It is the responsibility of any company operating in a hazardous
area to carry out the appropriate risk assessment depending on the
probability of the occurrence of toxic or explosive incidents.
Certain areas present a higher risk probability, yet if such
locations are not easily identifiable it is important to distribute
gas detection sensors across the entire hazardous area to help to
manage the risk.
