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be aware!Standards for professionals,

H S E W

“A WAY OF LIVING”

December 2010

NLEDITION

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H2S - HYDROGEN SULPHIDESAFETY

NAM (50% Shell/50% Exxon/Mobil) participates in the joint venture of

European Shell exploration and production companies in a number of

European countries. Within this joint venture NAM acts as the centre for

natural gas operations, particularly for land-based activities. In all activities,

safety is priority number 1.

H2S (Hydrogen sulphide)H2S (hydrogen sulphide) may occur in drilling, production and processing facilities during the production of oil and natural gas. It is extremely poisonous and harmful to the environment.

What to do in case of an H2S alarm(from a personal gas detector or a site alarm)

• Stop all work / leave the vehicle immediately.• Put on the escape mask immediately.• Leave the site at right angles to the wind direction.• Report the incident immediately.• Go to an assembly point located upwind.• Report there to the Person Responsible for the Site• Follow further instructions.

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H2S - HYDROGEN SULPHIDESAFETY

Before you start work at an H2S site:• You must have permission from the Person Responsible for the Site (NAM) to enter the site• You must be familiar with the hazards of H2S.• You may not have a beard.• You have a tested H2S detector in the vicinity of your face.• You must be carrying an escape mask, which you must have tested yourself.• You have determined the wind direction by looking at the wind cone.• You have determined the easiest escape route yourself according to the direction of the wind.

In the event of exposure, call a doctor or ambulance immedi-ately and fill in the “Information sheet for doctors / ambulance medics” which is also in the H2S “bijdehandje”.

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H2S - HYDROGEN SULPHIDESAFETY

From 2007, NAM no longer uses the MAC value, but the Dutch national "exposure limit" value. The exposure limit for H2S is set at 1.6 ppm (parts per million over an average of 8 hours).

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H2S - HYDROGEN SULPHIDESAFETY

H2S conc. (ppm) (possible) consequences

> 0.02 • “rotten egg” smell

1.6 • exposure limit (average over 8 hours)

10 • evacuation limit

100 • numbing of the olfactory nerves in 3 to 15 minutes • stinging of eyes and throat • risk of pulmonary oedema

200 • acute numbing of olfactory nerves • stinging of eyes and throat • risk of pulmonary oedema

500 • impairment of mental abilities • loss of sense of balance • numbing of respiratory organs in 30 to 45 min. • lethal after 30 to 60 min.

700 • rapid loss of consciousness (max. 15 min.) • breathing stops • lethal after 12 to 15 min.

1000 • immediate loss of consciousness • acute numbing of breathing • “knock down effect” • lethal within 3 min.

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H2S - HYDROGEN SULPHIDESAFETY

Do not attempt any rescue actions if you do not haverespiratory equipment and if you are alone!

Do you have questions?Or do you want more information?You can always approach the Person Responsible for the Site (NAM).

see other side

for doctors/ambulance medics INFORMATION SHEET

HYDROGEN SULPHIDE

Name of victim

H S2

Employer

Date of birth

datewas involvedin an accident on

The concentration of H2S in the air, measured at

the location of, and shortly after, the accident

was parts per million (ppm).

He/she has inhaled H2S gas.

on

am/pm

Address

H2S is very toxic to the bodily systems. Additionally it irritates the mucous membranes of the eyes and the respiratory tract. Effects depend on the concentration and duration of the exposure (see H2S poisoning table).

The substance enters the body almost entirely through the respiratory tract. Absorption through the skin is of no significance. The absorbed results in the internal suffoca-tion of cells because it inhibits the absorption of oxygen. The main cause of this is the inhibition of the activity of metal-containing respiratory enzymes in the cell, i.e. cytochromoxides. Within the organism, H2S is quickly converted to non-toxic sulphur compounds, namely sulphates and thiosulphates. Free in the blood is respon-sible for acute systemic effects. H2S is exhaled through the lungs and excreted as sulphides and sulphates via the kidneys.

UN nummer 1053Cas nummer 7783-06-4

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