EBA Rationalisation on a
Sour Gas Plant
or
How to loose 12lbs in a day.
Neil Grace MSc CMFOH CMIOSH
Senior Occupational Hygienist
Centrica Energy
Emergency Breathing Apparatus (EBA)
Rationalisation on a Sour Gas Plant or
How to loose 12lbs in a day!
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Centrica had never operated an
onshore plant with high concentrations
of Hydrogen Sulphide (H2S - sour
gas).
Original well samples showed
4500ppm, however later tests would
confirm 2500ppm coming ashore.
Although, during the Acid plant process
this can reach concentrations of up to
65% (650,000ppm) H2S.
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Original EBA (2002)
A self contained
escape set to allow
safe egress from
site.
Several versions
were considered
resulting in…
A PVC wrap around
vest that contained a
steel cylinder with a
velcro fastener.
EBA - Design evolvement (2005)
A forum was set up following concerns
around the EBA sets.
A lighter carbon-fibre cylinder
replaced the heavy steel ones
(reduction of 10lbs).
The vest was re-designed with an
improved harness and adjustment for
comfort & fit.
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Why Change again?
• Although improved, they are still an excessive
weight and not designed to be worn for long
periods.
• This resulted in personnel starting to feel the
physical effects of long term use.
.
• Additional hazard when climbing ladders or any
activity that may require lifting or working at
height
Time For Review – 2013 onwards
A working party was put convened
Safety Reps/HSE
Production
Maintenance
Senior
management
An agreement was reached to purchase
and trial a filtered escape hood.
EH20 Escape hood
EH20 Escape hood
Lightweight/compact
No external air supply
Pre-sealed tamper proof
Easy to deploy
No Maintenance
required
5 year shelf life
Improved moral of the
workforce
Reduced
musculoskeletal issues
Size comparison
EH20
in
carry
case
Current
EBA Set
EH20 Escape hood – Disadvantages
The unit is a
one shot
use.
• The advantages of
the hood far
outweigh the cost of
replacing.
The hood can’t
protect in the
Acid plant
area, potential
high levels of
65% H2S.
• A new dispersion
model to identify the
limitations for site
use.
EH20 Escape hood
Hoods filter is
tested to 5000ppm
H2S.
The TEAM
requested a full
“real world” test.
Tested at the HSL
facilities in Buxton.
HSL Testing - February 2013
Measurements of
protection were made
in HSL’s leakage
chamber using a salt
aerosol challenge.
Six volunteers
from site
undertook a
simulated escape
exercise.
HSL Testing
• Results - when donned and fitted correctly the EH20
should provide adequate short-term emergency
protection.
• Results - for escape purposes against
concentrations up to 10,000 ppm.
• A “safety factor” was introduced setting 2000ppm as
the in house “max use concentration”.
Dispersion Model - High concentration to 2000ppm (centre to green circle)
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EH20 Trial on Site
The trial of the new hoods was introduced
via a Management of Change process.
A hood and a H2S monitor was issued to
shift personal.
These masks are only for use on the
NMT site.
Anybody entering the Sour Gas plant
MUST use a bottle EBA set.
Full EBA will remain an option for anybody not
comfortable with the new escape hoods.
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EH20 – Results of Trial
Initial trial went well and was extended to other site teams.
Feedback has been very positive.
Improvement in moral of staff.
Reduction in Musculoskeletal complaints.
We have taken another
hood to HSL and carried
out similar testing as a
fall back option.
It performed well and
passed the required
criteria.
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How to loose 12lbs in a day?
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