AUTHORIZED GAS TEST

(AGT) TRAINING

INTRODUCTION TO GAS TESTING

Gas testing involves testing for toxic and flammable gases using portable gas detection

equipment, and is an integral part of establishing a safe system of work in the offshore oil

and gas industry. Gas tests are performed to ensure that the environment in which we work

is safe from the hazards of combustible or toxic gases, and that the worksite contains

sufficient oxygen such that it is safe to breathe.

AGTs are responsible for performing these duties for a facility in accordance with specified

precaution.

AGTs are formally authorized (as demanded by today's training) as competent to carry out

gas testing in a facilities.

REQUIREMENT FOR BEING AN AGT

An AGT must;

• Must have successfully completed the authorized gas tester training course

with 70% pass of class work

• be able to demonstrate the ability to survey potentially hazardous areas

using the detection equipment available and have been assessed as competent.

•Be able to demonstrate the use of a BA set in a confined space and have been

assessed as competent

• Be aware of the capabilities and limitations of gas test equipment

WHEN IS GAS TESTING REQUIRED

• As specified on the applicable risk assessment and/or permit

e.g. hot work of any type where heat is used or generated

including welding, flame cutting, grinding, etc.

• Where work may cause an uncontrolled release of

hydrocarbons, other flammable or toxic materials.

• Where electrical instrumentation work which may cause sparks

will be used in a hazardous area.

• Where there will be entry into a confined space

• For gas alarm investigations.

REGULARATORY BACKUP

FOR GAS TESTING

LIFE SAVING RULES

2/25/2011 6

• How many Life Saving Rules does the Shell Group have?

• Could you mention the Life Saving Rules related to Gas

testing and Confined space entry?

The 12 Life Saving Rules

Rule #1 Work with a valid Work Permit when

required

A Work Permit describes what you must do to stay safe.

You should Understand the Work Permit and follow it

Confirm that the Work Permit is valid

Confirm with the Supervisor or the person in charge of the work that it is safe to start work.

If you are the Supervisor or the person in charge of the work you should Confirm if a Work Permit is required for this work.

Confirm that the workplace has been inspected before work starts

Explain how the Work Permit keeps you safe

Confirm the Work Permit is signed

Confirm that it is safe to start work.

Get a new Work Permit when the work or the situation changes

Confirm that the work is completed

Rule #2

Air is tested to stop explosions and/or make sure you can breathe the air

safely.

You should Confirm with the Supervisor or the person in charge of the work that the air is tested

Confirm with the Supervisor or the person in charge of the work it is safe to start work

Stop work if you smell gas

If you are a Gas Tester you should Understand which tests the Work Permit requires and how often

Use certified equipment for the tests

If you are the Supervisor or the person in charge of the work you should Confirm that gas testing is carried out as per Work Permit

Request more gas tests if necessary

Confirm that it is safe to start work.

Conduct gas tests when required

Rule #3

Verify isolation before work begins and use the

specified life protecting equipment

Isolation separates you from danger, such as electricity, pressure, toxic materials,

poisonous gas, chemicals, hot liquids or radiation to keep you safe.

Specified life-protecting equipment by the Work Permit, such as breathing

apparatus, electrical arc flash protection or chemical resistant suits protect you

from danger.

You should Understand the isolations that protect you from danger

Confirm with the Supervisor or the person in charge of the work that isolations are in place

Confirm with the Supervisor or the person in charge of the work it is safe to start work.

If you are the Supervisor or the person in charge of the work you should Confirm isolation is in place, for example, lock switches, separate pipes with spades, or lock

access doors

Confirm no stored energy or other dangers remain

Confirm that it is safe to start work.

A confined space, such as a vessel, tank or pipe can contain explosive gas,

poisonous air or other dangers such as, a lack of oxygen, things that can fall on you

or you can fall from. Authorised access keeps you safe.

You should

Confirm with the Supervisor or the person in charge of the work that it is safe to start work.

Confirm with the Attendant that you can enter a confined space

Follow the requirements of the Work Permit

If you are an Attendant you should

Approve and control access to a confined space

Have means of communication with people in the confined space

If you are the Supervisor or the person in charge of the work you should

Confirm that the requirements of the Work Permit are in place

Confirm that a qualified Attendant is always present when people are in a confined space

Confirm that gas testing is carried out as per Work Permit

Confirm that it is safe to start work.

Rule #4

Obtain authorisation before entering a confined space

Rule #5

Obtain authorisation before overriding or disabling

safety critical equipment

Safety-critical equipment must work correctly to keep you safe.

Examples of safety-critical equipment include isolation devices/emergency shut down valves, trip

systems, relief valves, fire and gas alarm systems, certain level controls, alarms, crane computers, and

In-Vehicle Monitoring Systems.

You should Obtain authorisation from the Supervisor before overriding or disabling safety-critical

equipment

If you are the Supervisor you should Point out the safety-critical equipment in your work place.

Confirm the authorisation comes from the right level

Rule #6 Protect yourself against a fall when

working at height

Rule #7 Do not walk under a suspended load

Rule #8 Do not smoke outside designated smoking

areas

Rule #9 No alcohol or drugs while working or driving

Rule #10 While driving, do not use your phone and

do not exceed speed limits

Rule #11 Wear your seat belt

Rule #12 Follow prescribed Journey Management Plan

SUMMARIES

2/25/2011 14

Why are we here?

• Life Saving Rules # 1- 5 have to do with today’s training • The work environments you work in are capable of ending

your life and that of others within minutes: Remember Iriama.

• The work environments you work in are capable of causing damage to assets worth millions of Dollars.

• This training can save your job. How many people have been consequence managed since 1st July 2009 on account of the 12 LSRs?

• What is your take?

GAS TESTING & MONITORING

Introduction to Gas Hazards

What is Gas?

• The name gas comes from the word chaos which indicates disorder

• Gas is a swarm of molecules moving randomly and chaotically; constantly colliding with each other and anything else around it.

• Gases fill any available volume and due to the very high speed at which they move will mix rapidly into any atmosphere in which they are released

What is Gas?

Different gases are all around us in everyday

life.

• The air we breath is made up of several

different gases including Oxygen and

Nitrogen

• Natural Gas (Methane) is used in many

homes for heating and cooking

• Car exhausts produce gases which contain

Carbon Monoxide and Carbon Dioxide

What is Gas?

Gases can be lighter, heavier or about

the same density as air

Gases can have an odour or be odourless

Gases can have colour or be colourless

PROPERTIES OF GASES Behaviors of Gases;

Behavior of gases is governed by

• gas properties and

• environment

It is difficult to predict the behavior of gas releases.

Explosive air/gas mixtures can occur at varying heights and locations within a plant.

How ever particular attention should be paid to areas around pipe work joints, valves, tank inlet/outlet, vents

and drains and all areas adjacent to this.

The behavior of gas releases will depend upon :

• the environment and

• on whether the gas was released slowly (e.g as an evaporating liquid) or

• as a high pressure escape from a leak such as a flange failure.

A clear understanding of the nature of a gas release and its probable behavior is essential to ensure that effective

representative measurements are obtained.

NOTE;

Gas releases are therefore generally affected by the following factors/

* Their relative density at the points of release

* Gas velocity of release

* Gas temperature at point of release

* Air current

* Evaporation

Gas Hazards

1. Flammable

– Risk of fire and or explosion,e.g. Methane, Butane, Propane

2. Toxic– Risk of poisoning,

e.g. Carbon Monoxide, Hydrogen Sulfide, Chlorine

3. Asphyxiant– Risk of suffocation,

e.g. Oxygen deficiency, Nitrogen, Carbon Dioxide

There are three main types of gas hazards

Flammable Risk

• Fire Triangle

Three factors are always

needed to cause

combustion:

1. A source of ignition

2. Oxygen/Air

3. Fuel in the form of a gas

or vapourFuel

FIRE

Flammable Risk

• Each gas / air mixture

is ignitable over it‟s

flammable range

L.E.L. (lower

explosive limit)

U.E.L. (upper

explosive limit)

0% v/v gas

100% v/v air

too lean

flammable

range

too rich

100% v/v gas

0% v/v air

Only Gas, No Air

UEL

Ideal mixture

LEL

Only Air, No Gas

Power of explosion

Flammable Risk

Stoichiometric Point

SOME DEFINITIONS

LEL = LOWER EXPLOSIVE LIMIT

Definition:

LEL: is the lowest amount/concentration of a gas/vapor in the atmosphere that is capable of igniting when there is an ignition source e.g., LEL for methane is 5% (v/v)

UEL = UPPER EXPLOSIVE LIMITUEL: is the highest concentration of a gas in the atmosphere that is capable of igniting when there is an ignition source e.g., UEL for methane is 15% (v/v)

Is the point in the ideal mixture range where we have the best mixture of fuel/gas and oxygen for a complete combustion

Stoichiometric point

% LEL AND % UEL OF SOME AGT SUBSTANCES

Substance Formula LEL (VOL %) UEL (VOL %)

Acetone CH3CHO 2.15 13.0

Acetylene C2H2 2.4 88.0

Butane C4H8 1.5 8.5

Ethane C2H6 3.O 15.5

Ethylene C2H4 2.7 34.0

Hexane C6H12 1.2 7.4

Hydrogen H2 4.0 75.6

Methane CH4 5.0 15.0

Propane C3H8 2.0 9.5

Flash Point• Flash Point (F.P. oC)

– The flash point of a flammable liquid is the lowest

temperature at which the surface of the liquid emits

sufficient vapour to be ignited by a small flame.

– Don‟t confuse with Auto-Ignition Temperature as the

two can be very different:

Gas / Vapour Flash Point OC Ignition Temp. OC

Methane <-20 595

Kerosene 38 210

Bitumen 270 310

Auto-Ignition Temperature• The auto-ignition temperature

or kindling point of a

substance is the lowest

temperature at which it will

spontaneously ignite in a

normal atmosphere without an

external source of ignition,

such as a flame or spark.

• Apparatus for use in a hazardous

area must not have a surface

temperature that exceeds the

ignition temperature

• EX1b apparatus are

EXplosion proof

Toxic Risk

• Some gases are poisonous

and can be dangerous to life

at very low concentrations.

• Some toxic gases have strong

smells like the distinctive

„rotten eggs‟ smell of

(.

• Others are completely

odourless like Carbon

Monoxide (CO).

Hydrogen sulphide H2S

Toxic Risks

• A toxic gas that is a risk in

the home is CO.

• CO is a product of

incomplete combustion in

power generating set at

home.

• Fireplaces

Toxic Risk• The unit of measurement

most often used for the concentration of toxic gases is parts per million (ppm).

• For example 1ppm would be equivalent to a room filled with a total of 1 million balls and 1 of those balls being red. The red ball would represent 1ppm.

1 million balls

1 red ball

Toxic gas limits & terminology

• Time Weighted Average (TWA)

– Toxic gas limits related to concentration & time

• Short Term Exposure Limit (STEL)

– The maximum allowable concentration over 15 minutes.

• Long Term Exposure Limit (LTEL)

– The maximum allowable concentration over an 8 hour period.

• Permissible Exposure Limit (PEL)– is the maximum amount/concentration of a

chemical that a worker may be exposed to under OSHA regulation.

Toxic gas limits & terminology contd.

• PEL-TWA

– The average amount of a chemical that a worker can be exposed to 8 hours a day, 5 days a week.

• Units of measure

– Parts per million (ppm)

– Milligrams per cubic metre (mg/m3)

• Levels

– COSHH (Control of Substances Hazardous to Health Regulations)

– OSHA (Occupational Safety and Health Administration)

– NIOSH (National Institute for Occupational Safety and Health)

Effects of exposure to Carbon MonoxidePPM CO

Time Symptoms

35 8 hours The maximum exposure allowed by OSHA in the workplace over an eight hour period.

200 2-3 hours Slight headache, tiredness, fatigue, nausea and dizziness.

400 1-2 hours Serious headache-other symptoms intensify. Life threatening after 3 hours.

800 45 minutes Dizziness, nausea and convulsions. Unconscious within 2 hours. Death within 2-3 hours.

1600 20 minutes Headache, dizziness and nausea. Death within 1 hour.

3200 5-10

minutes

Headache, dizziness and nausea. Death within 1 hour.

6400 1-2

minutes

Headache, dizziness and nausea. Death within 25-30 minutes

12,800 1-3 min Death

2

Effects of exposure to Hydrogen Sulphide

PPM H2S Time Symptoms

10 - 20 2 hrs + Eye Irritation, headache, and nausea

50 - 100 1 hr + Slight eye and respiratory tract irritation

200 - 300 1 hr + Marked eye and respiratory tract

irritation and chemical pneumonia

400 - 700 ½ hr + Unconsciousness and possibly, death

1000 + Immediate Unconsciousness and possibly, death

The maximum exposure allowed by OSHA in the workplace over an eight hour period = 10 PPM.

GENERATION OF HYDROGEN SULPHIDE (H2S)

Hydrogen Sulphide can occur in high concentration in the produced

fluids from a reservoir.

It is possible that a reservoir can start producing H2S at any time

particularly where water injection is concerned.

H2S may be expected to be generated on installations in the following

circumstances:

In Storage tanks

The production of H2S is most likely if the amount of sea water in

storage tanks is high and constant i.e. the same sea water remains in the

storage tanks over a prolong period.

In untreated water injection systems

Deoxygenated sea water is likely to encourage the growth of sulphate

reducing bacteria (SRB), and if retention time prior to injection is

considerable eg during system shutdown H2S might be produce.

EFFECTS OF HYDROGEN SULPHIDE ON PERSONNEL

When hydrogen sulphide is inhaled by any individual it

passes directly through the lungs into the blood stream. If

the individual breaths in so much H2S that the body can

not oxidize all of it, it builds up in the blood and the

individual becomes poisoned. The area of the brain which

controls breathing becomes paralyzed, the lungs stop

working and the person is asphyxiated. (OSHA regulated

H2S permissible levels for unprotected worker as shown in

previous slide)

The way in which H2S affects an unprotected worker

depends on the following;

* duration of exposure,

* Frequency of exposure

* Intensity of exposure

* Susceptibility of the worker

THE EFFECTS OF H2S ON EQUIPMENTS

H2S is highly corrosive to steel and at high stress levels extreme metal

embrittlement may occur in a very short time

Due to the extremely damaging effects of H2S, the interior of any vessel

which has constant sea water must be properly treated through some

chemical biocides.

Biocides can damage the cells of the SRB and thus control H2S

production

The use of GREEN BIOCIDES is highly recommended as a sustainable

approach

GREEN BIOCIDES are environment friendly chemicals

2

• We all need to breathe the oxygen (O2) in air to live.

• Air is made up of several different gases including oxygen.

• Normal ambient air contains an oxygen concentration of 20.9% v/v.

• When the oxygen level dips below 19.5% v/v, the air is considered oxygen-deficient.

• Oxygen concentrations below 16% v/v are considered unsafe for humans.

Asphyxiant (oxygen deficiency)

Risk

Asphyxiant (oxygen deficiency)

Risk

• Oxygen depletion can be caused by:

– Displacement

– Combustion

– Oxidation

– Chemical reaction

• Levels of oxygen below 6% are fatal!

Asphyxiant (oxygen deficiency)

Risk100% v/v O2

0% v/v O2

20.9% v/v

normal

16% v/v

depletion

6% v/v fatal

Asphyxiant (oxygen deficiency) Risk

• Air is made up of several different gases including oxygen.

• Normal ambient air contains an oxygen concentration of 20.9% v/v.

• When the oxygen level dips below 19.5% v/v, the air is considered oxygen-deficient.

• Oxygen concentrations below 16% v/v are considered unsafe for humans.

Name Symbol

Percent by

volume (%

v/v)

Nitrogen N2 78.084

Oxygen O2 20.9

Argon Ar 0.9

Carbon

DioxideCO2 0.03

Neon,

Methane,

Helium,

Krypton,

Hydrogen,

Xenon

Various Trace

Air Composition

Asphyxiant gas limits

• Oxygen, Nitrogen

• Not flammable or toxic

• < 6% v/v O2 FATAL

• > ambient changes flammable limits

• O2 depletion caused by:

– Displacement

– Combustion

– Oxidation

– Chemical reaction0% v/v O2

19.0% v/v O2 Low alarm

20.9% v/v O2 Ambient

100% v/v O2

23.0% v/v O2 High alarm

Oxygen Enrichment

• It is often forgotten that Oxygen enrichment can also cause a risk.

• At increased O2 levels the flammability of materials and gases increases.

• At levels of 24% items such as clothing can spontaneously combust.

• Oxyacetylene welding equipment combines oxygen and acetylene gas to produce an extremely high temperature.

• Leaks from the O2 cylinders is the main hazard.

• Sensors have to be specially certified for use in O2 enriched atmospheres.

Relative Density

• Helps determine sensor placement

• The density of a gas / vapour is compared with airwhen air = 1.0

• Vapour density < 1.0 will rise

• Vapour density > 1.0 will fall

Relative density: is a measure of the

density of a gas relative to the density of air. It is an indication of the buoyancy of a gas i.e., whether it is heavier or lighter than air.

Relative Density of Gases

GAS CHEMICAL FORMULA DENSITY(AIR=1)

Hydrogen 0.07

Methane 0.54

Ammonia 0.6

Hydrogen cyanide 0.93

Carbon Monoxide 0.97

Ethylene 0.97

Air 1.0

Nitric Oxide 1.04

Ethane 1.05

Formaldehyde 1.07

Methylamine 1.08

Hydrazine 1.1

Methanol 1.1

Oxygen 1.1

Hydrogen Sulphide 1.18

Ethylene Oxide 1.5

Carbon Dioxide 1.5

Propane 1.55

Butane 2.1

Ether (diethyl) 2.5

Hazardous Area

Classification

Area Classification

• There are certain parts within

the restricted Areas where the

presence of flammable mixtures

are more likely than others

• These areas have been divided

into 3 Zones or Divisions

• The classification is based on

the likelihood of occurrence and

duration of a flammable

atmosphere

Area Classification

Continuous

hazard

(>1000hrs/annum)

Intermittent

hazard (>10<1000hrs/annu

m)

Possible

hazard (<10hrs/annum)

Europe/IEC Zone 0 Zone 1 Zone 2

North America

(NEC 505)Zone 0 Zone 1 Zone 2

•Two main systems are used:

–Europe / IEC

–North America (NEC 505 / 500)

Area Classification Examples

• Zone 0– Vapour Space in Fixed Roof Tank

– Rim Seal of Floating Roof Tank

– Open Oil Saver Pit

• Zone 1– Vents

– Drain Trays

• Zone 2– Leakage due to plant failure or operational error

The Need For Gas

Detection

The Need For Gas Detection

• Gas detection is mainly used to monitor areas where hazardous levels of gas are not normally present.

• They are designed to give early warning of the build up of gas before it becomes a hazard.

• Various national and international laws exist that demand the use of gas detection to protect people and plant.

• Many local codes of practice also exist that ensure health and safety policies are employed.

• Insurance companies will not provide cover to businesses that cannot prove that they have taken appropriate safety measures to detect hazardous gases.

The Need For Gas Detection

The Need For Gas DetectionNoxious gas

Two victims of a toxic gas

leak are helped by

paramedics at a hospital

in Managua, Nicaragua,

on Monday. More than 100

factory workers in

Nicaragua were

hospitalized after they

were poisoned by a gas

leak at a textile factory in

the capital.

The worst disasterin the history of the

chemical industry remains

1984's methyl isocyanate

leak in the city of Bhopal,

which killed 10,000

people, and maimed or

blinded more than 100,000

others.

The Need For Gas Detection

Toxic gas leak sickens

55 plant workers

FIFTY-FIVE workers at a

polystyrene factory in Samut

Prakan province collapsed and

were hospitalised yesterday

after inhaling toxic gas

reportedly leaked from a

nearby factory.

Ten Hurt By Toxic

Fumes

City's Water Treatment Plant

Closed After Accident.

Seven people, including two

passers-by, were treated and

released from Holland Community

Hospital. Dr. Ken Kuper, an

emergency room physician at

Holland Community Hospital, said

mild exposure to chlorine gas is

"really quite benign." However,

prolonged exposure in a confined

space can lead to asphyxiation and

death, and direct contact with the

mixture can burn the skin.

The Need For Gas Detection

A fire was sparked by a

pipeline explosion at a

Philadelphia Gas Works

facility Friday night.

(CNN) -- Residents were being

asked on Saturday to curb use

of natural gas after a dramatic

gas pipeline explosion that lit

up the Philadelphia night sky

late Friday and left some

residents without heat.

Typical Areas

Requiring Gas

Detection

Typical areas that require Gas Detection

Chemical Plants Power Stations Water Treatment Plants

Boiler Rooms Hospitals Tunnels

TYPICAL PLANT AREAS AND POSIBLE AGT

GASES

PLANT TYPICAL AGT GASES

Chemical plant General hydrocarbons, Hydrogen Sulphide

and Ammonia

Water treatment Methane, Hydrogen Sulphide and Chlorine

Power Station Natural Gas, Hydrogen, Carbon monoxide,

oxygen

Boiler Rooms Methane, Carbon monoxide

Tunnels Methane, Hydrogen Sulphide, Carbon

Monoxide and oxygen

Laboratories General hydrocarbons Hydrogen Sulphide

and Ammonia

Plants Sumps Methane Hydrogen Sulphide Carbon

dioxide

Process Areas, Pump rows, Compressor

station, raw materials storages

General hydrocarbons Hydrogen Sulphide

and Ammonia

Principles of Gas Detection

And

Gas Detectors

Gas Detector

• Is a device which can sample the air and detect a variety of contaminant gases, flammable and check for oxygen concentration in a given environment.

• Gas detector measures the concentration of a gas(s) and gives an alarm when the gas concentration reaches a preset threshold value.

• Gas detectors enable the detection of gases prior to the commencement of an operation, during and after an operation.

Gas Detector• Gas detectors are basically preventive tools- to prevent combustion and

inhalation of toxic gases

• To prevent combustion, detectors measure the O2 level in relation to the

presence of the explosive or combustion gas. (Approximately 16% O2

required for combustion

• Measurement looks at the lower explosive limit (LEL); above the LEL the

detector bleeps indicating the presence of the set combustible gas(s)

• For toxic gas(s), a detector detects the gas it is set to – H2S, CO, Cl2, PH3,

etc.

Gas Detectors• There are single gas detectors and multi gas detectors

• Similar to gas detectors are gas monitors.

• A detector could be fixed or portable

• Detectors are very important while working in confined space.

It is important to gas test a confined space wearing a B.A. set,

prior to commencement of operations.

Fixed Detectors (gas monitors)

• A fixed detector is permanently installed in a location to provide continues monitoring of plant and equipment. Often they cover a given range or area.

• Fixed gas detectors are used to give early warning signs of leaks from plants containing flammable gases or vapours within the plant.

• They are particularly useful where there is possibility of leak into an enclosed space or partially enclosed space where flammable gases could accumulate.

Sample Fixed Gas Monitor

Portable Gas Detector

• Portable gas detectors are small handheld devices that

could be used for testing atmospheres in confined spaces

prior to entry.

• Useful for tracing leaks or to give early warning of the

presence of flammable gases or vapour when hot work is

being carried out in a hazardous area.

Sample Portable Gas Detector

Use of Portable Gas Detectors

• Portable Gas detectors could be used actively

or passively

• Active Use• The operator carries the instrument around while

monitoring:

The general area

The atmosphere within a confined space

Checking for leaks from likely sources, e.g. drains or flanges.

Use of Portable Gas Detectors

• Passive Use• The instrument is positioned in one place to monitor

the atmosphere.

Temporarily for a period of hours or days

Note:The operator should switch on the gas detector and note the readings

in a gas-free area, before entering a hazardous area.

Other User Guide• For leak seeking or monitoring known leaks or ingress points, the probe

should be placed as close to the source as possible with the operator being

upwind of the source and as far away as the probe will allow while still

being able to monitor the readout.

• For testing atmospheres of confined spaces, the sample probe should be

positioned inside the space with the operator remaining outside where

practicable. The operator should monitor a number of points inside the

space, using extended probes where necessary, to take into account vapour

pockets and stratification.

Note that portable gas detectors are always point detectors. But fixed gas

detectors are point or open path detectors.

Point or Open Path Detector

Point Detector – These measure the

concentration of the gas at the sampling point

of the instrument.

Point or Open Path DetectorOpen Path Detector – Also known as beam detectors, topically

consist of radiation source and a physically separate, remote detector. The detector measures the average conc. of gas along the path of a beam. The unit of measurement is conc. multiplied by path length, %LEL m or PPM m

Open path detectors systems could be designed with path length of 100m or more

Draw back – Impossible to differentiate a reading due to a high conc. along a

small path of the beam from a low conc. distributed over a longer length.

Gas

IR

Source

IR

Detectors

Infrared Gas Detection

S R

S R

S R

Fog, Rain,Snow,Dirt

Sample & Reference

signal strengthsIR

Source

IR

Detectors

Gas

SENSORS

• Gas detectors detect gases through sensors.

• There are different types, the choice of sensor should be guided by

the following:

Gas to be detected;

Expected range of concentration;

Whether detector is fixed or portable;

Whether detector is point or open path;

Presence of other gases that could affect readings or

damage sensor

Types of Sensors• Flammable gas detectors

Photo ionization useful for both type of instruments

Ultrasonic used in fixed instruments.

Semiconductor

Fame temperature used for fixed instruments

Flame ionization mainly fixed but also useful for portable equipment

Thermal conductivity mostly fixed but could be used for portable equipment

Infrared used in portable and fixed instruments and

Catalytic (Pellistor)- fixed and portable instruments

Types of Sensors

• Oxygen Detectors

Electrochemical- Used for portable and

fixed instrument

Paramagnetic – Used in portable

instruments

Zirconia-type – Used in fixed instruments

Gas Testing Procedure

Gas Testing Procedure• Gas tests shall be carried out to obtain results which are

representative of the entire space and the test equipment shallbe:

– Specific to the gases that have to be tested andsensitive at the TLV

– Of an approved type, e.g. intrinsically safe;

– properly calibrated and maintained

– within its validation period

– Checked that is functioning correctly, at the start ofeach day.

• As a general rule, tests shall be carried out in the following sequence:

– oxygen content

– flammable gas

– toxic gas

Gas Testing Procedure

• The permit for the work should specify the tests needed and

the test frequency.

• For both active and passive use, the Gas tester should switch

on the gas detector and note readings in a gas-free area,

before entering a hazardous area.

• Test results should be recorded on the permit for the

work or a gas test certificate

• If actively testing an area by walking through it, the

operator should hold the sample probe in front to

determine if it is safe to continue in that direction.

• It is advisable to sample at high and low levels,

depending on the gas properties and location of the

release.

Gas Testing Procedure

• When reading the monitor, make sure you avoid trips and

falls; hence it is proper to stand still while checking

instrument reading

• This will also give a more accurate reading for that location

as it will take into account the finite response time of the

equipment.

• For leak seeking or monitoring known leaks or ingress points,

the probe should be placed as close to the source as possible

with the operator being upwind of the source and as far away

as the probe will allow while still being able to monitor the

readout.

Gas Testing Procedure

• For testing atmosphere of

confined space, the sample

probe should be

positioned inside the space

with the operator

remaining outside where

practicable. The operator

should monitor a number

of points inside the space

accounted vapour pockets

and stratification

A competent person tests confined space before entry.

Testing for Asphyxiant Qualities

• Atmospheres containing less

than 19.5% vol. oxygen are

considered to be oxygen-

deficient.

• Atmospheres containing

more than 21.5 % vol. oxygen

should be treated as oxygen

enriched.

• The Oxygen content may be checked with a portable

Oxygen analyser to ensure it is not less than 19.5%

prior to entry without breathing apparatus

Flammability Testing• If the concentration of flammable vapors or gases in the space to be

entered is equal to or greater than 10 percent of the lower explosive

limit, the space shall be labeled "Not Safe for Workers" and "Not Safe

for Hot Work

• For entry into a confined space without breathing apparatus, the

maximum concentration of flammable gases must never exceed 1%

LEL.

• Where flammable vapours are present at concentrations greater than 1%

LEL but less than 10% LEL, entry is only permitted with breathing

apparatus.

• Hot Work is not permitted where flammable vapours greater than 1%

LEL are detectable anywhere inside the confined space.

• Where flammable vapours present exceed 10% LEL, no entry is

allowed whether or not breathing apparatus is worn.

%LEL (LFL) is a combined measure of the fire/explosion hazard, and of the toxic hazard of

general hydrocarbons, when the HRA and JHA establish that there are no specific toxics

present.

Toxicity Testing

• If a space contains an air concentration of a material, which

exceeds permissible exposure limit (PEL) or is IDLH, the space is

unsafe for workers entry.

• In order to protect workers from possible adverse health effects,

OSHA, NIOSH, ACGIH have established PEL for most

flammable vapours and gases

• However, note that exposure limits are not some magic threshold

that define the border between safe and dangerous. A PEL that

was acceptable in 1950 may be recognized as dangerously high

today. Therefore, always do everything reasonable to limit

exposure to chemicals or dusts in the first place.

Permissible Entry Level

Parameter Permissible Entry Level

% O2 19.5% to 23.5%

Lower Explosive Limit <10%

Carbon Monoxide +35 PPM

Hydrogen Sulphide +10 PPM *15 PPM

Aromatic Hydrocarbon +1 PPM * 5 PPM

* STEL – Employee can work in the area up to 15minutes

+ LTEL – Employee can work in area 8 hrs (longer with appropriate respirator)

SOME AGT GASES

RELATIVE DENSITY

CH4 METHANE 0.55

CO CARBON MONOXIDE 0.97

CO2 CARBON DIOXIDE

H2S HYDROGEN SULFIDE 1.18

C3H8 PROPANE

C4H10 BUTANE

C2H6 ETHANE 1.05

Cl2 CHLORINE

H2 HYDROGEN

O2 OXYGEN

N2 NITROGEN

He HELIUM

Alarms• Gas detectors/monitors measure the concentration of gases and

give an alarm when the gas concentration reaches a present threshold value.

• Sensors send signals to monitor and the monitor automatically sounds alarm at preset concentration.

• The alarm should not stop or reset unless deliberate action is taken

• The alarm should be audible or visible or preferably both.

• Note that it is important for an alarm to warn of fault condition. If a detector fails, it could falsely indicate a safe condition such as allowing a zero reading. Hence it is important that there should be no non – detectable fault conditions in the detector, where possible.

A low battery Alarm

• This is usually present on portable instruments

• Often the manufacturer‟s instructions should give details

of the expected battery life time after charging properly

and the operating time left after the low battery alarm is

activated.

• However, if the low battery indicator does activate, the

instrument should be recharged in a safe area, away from

the area being monitored, before the detector shuts down.

At What Gas Conc Should the

Detector Alarm?

• A detector should be set to alarm at a level low enough to ensure the

health and safety of people but high enough to prevent false alarm.

• False alarm are mostly caused by fluctuations in sensor output, due to:

– Environmental changes such as:

• Ambient temperature

• Pressure and

• Humidity and

– Sensitivity to other gases or vapours, sensor drift

• Likely solution would be the use of two detectors- the alarm level must

be registered by both detectors before the alarm activates.

Gas detectors must be maintained and operated

properly to do the job they are designed to do.

Always follow the guidelines provided by the

manufacturer for any gas detection equipment you use!

The Control of Substances Hazardous to Health

Regulations 2002 is a United Kingdom Statutory

Instrument that stipulates general requirements on

employers to protect employees and other persons from

the hazards of substances used at work by risk

assessment, control of exposure, health surveillance and

incident planning

COSHH

The United States Occupational Safety and Health

Administration (OSHA) is an agency of the United States

Department of Labor. It was created by Congress under the

Occupational Safety and Health Act, signed by President

Richard M. Nixon, on December 29, 1970. Its mission is to

prevent work-related injuries, illnesses, and deaths by issuing

and enforcing rules (called standards) for workplace safety

and health. The agency is headed by Deputy Assistant

Secretary of Labor.

The OSH Act, which created OSHA also created the National

Institute for Occupational Safety and Health (NIOSH) as a

research agency focusing on occupational health and safety.

NIOSH, however, is not a part of the U.S. Department of

Labor.

OSHA & NIOSH

USE OF DRAGA X-AM 2000 PRACTICAL

TRAINING

COMPONENTS

+-buttonl Navigation

OK-button

lSwitch on

lquit

Segment Display

Catalytic Ex

Sensor

Horn

> 90 db

Front Cover

Power pack operating time >12 h

XXS-

Sensor CO

XXS-Sensor

H2S

XXS-Sensor

O2

Visual

Alarm

Visual

Alarm

Crocodile

-Clip

What is what?

Saved

Screw

SWITCHING-ON DRÄGER X-AM 1100/1700/2000

•Press and hold the “OK”-key for 3 seconds•Display counts down 3-2-1•Blinking LEDs, the acoustic alarm sounds andthe vibrating alarm pulsates

•The self-test begins automatically and showsthe following:

-The installed software version-The expected lifetime (X-am 1100/1700)

-The alarm levels

-The TWA and STEL alarm settings

-The next calibration date

SWITCHING ON

Look at video

SWITCHING OFF DRÄGER X-AM 1100/1700/2000

• Press and hold the “+” and “OK" keysat the same time for more than 3 sec.

• The LEDs will flash and a long beep will sound.

• The instrument is switched off

SWITCHING OFF

Look at video

• Press any key and the display illumination

is switched on for about 30 sec.

• In an alarm situation, the display illumination

is automatically switched on

DISPLAY ILLUMINATION

DISPLAY ILLUMINATION

Look at video

MENU FRESH AIR CALIBRATION

FRESH AIR CALIBRATION

• This procedure is a fresh air calibration, which is placed in the quick menu with help of the CC-Vision Software.

• Press “+”-key three times

• The following icon is shown

• Press the “OK ”-key and choose the fresh air calibration menu

• Real values are shown• Press the “OK ”- key• OK appears in the display• Fresh air calibration is finished

If the oxygen sensor value does not show 20.9% or is not stable, or the combustible or toxic sensors do not show “0” under

fresh air conditions, then the instrument must be fresh air calibrated. Perform “Fresh Air Cal” only in a clean air environment.

Look at video

MENU MAXIMUM VALUE

MENU MAXIMUM VALUE

• The Max Value function displays the lowest oxygen reading and the highest Ex, CO, and H2S readings from the time the readings

were last reset. Max Values will be stored in memory until they instrument is switched on again.

• Press the “OK ”-key once

• The Maximum Value and the minimum value for the O2 sensor are show. These values have been occured since the last time the instrument was switched on.

• Press the “OK”- key again.TWA and STEL values appears in the display

• or press the “+”-key once

• Instrument returns to measurement mode

Look at video

TWA (Time Weighted Average) is the time-weighted average gas concentration (normally over an 8 hour period) that an unprotected worker can be exposed to over an 8 hour workday and 40 hour work week without adverse effects.

The STEL (Short Term Exposure Limit) is the maximum allowed gas concentration that an unprotected worker can be exposed within a 15 minutes period.

NOTE

TWA

• When the TWA analysis is activated:

• Press the “OK ”-key two times

• icon appears in the display

• The maximum workplace concentration is shown

• Press the “OK”-key again and the STEL values are shown.

• or press the “+”-key once

• Instrument returns to measurement

MENU FUNCTIONS

Look at video

MENU FUNCTIONS

• When STEL analysis is activated:

• Press the “OK ”-key three times

• icon appears in the display

• The STEL values are shown

• Press the “OK ”-key or the “+”-key once

• Instrument returns to measurement

STEL

Look at video

• Alarm level can be changed with the help

of the CC-Vision software

A1 GAS CONCENTRATION ALARM

A1 GAS CONCENTRATION ALARM

• Audible-, visual- and vibrating alarms

repeat periodically

• The display character “A1” will alternate

with the concentration in the display

• An Ex, CO or H2S alarm, the audible and

vibrating alarms can be acknowledged

by pushing the “OK ”-key.Look at video

• Alarm level can be changed with the help

of the CC-Vision software

• Double audible-, visual- and vibrating

alarms repeat periodically

• The display character “A2” will alternate

with the concentration in the display

• The audible, visual and vibrating alarms can

NOT be acknowledged (silenced) in “A2”

or in an O2 “A1” alarm

A2 GAS CONCENTRATION ALARM

Follow the prescribed safety procedures.

A2 GAS CONCENTRATION ALARM

Look at video

TWA and STEL values will be cancelled when the instrument is switched off. Follow the prescribed safety procedures.

STEL ALARM

Click the picture to watch video

Click the picture to watch video

STEL ALARM

• Alarm level can be changed with the help

of the CC-Vision software

• Audible-, visual- and vibrating alarms

repeat periodically

• The display character “A2” will alternate

with the concentration in the display

• Icon flashes

• The alarm can NOT be acknowledged

Look at video

TWA and STEL values will be cancelled when the instrument is switched off. Follow the prescribed safety procedures.

TWA

ALAR

M• Alarm level can be changed with the help

of the CC-Vision software

•Audible-, visual- and vibrating alarms

repeat periodically

•The display character “A2” will alternate

with the concentration in the display

• Icon flashes

•The alarm can NOT be acknowledged

TWA ALARM

Look at video

A1 LOW BATTERY ALARM

Click the picture to watch video

This is activated when the battery has less than 10 minutes of operation – please change the batteries or charge the instrument.

A1 LOW BATTERY ALARM

• Audible-, visual- and vibrating alarms

repeat periodically

• Icon flashes

• The alarm can be acknowledged

with “OK”-key

Look at video

A2 LOW BATTERY ALARM

A2 LOW BATTERY ALARM

• Audible-, visual- and vibrating alarms

repeating periodically

• Icon flashes

• The instrument will automatically shut down

in about 10 seconds

• Instrument switches off

• The alarm can NOT be acknowledged

Look at video

ERROR ALARM

ERROR ALARM

An error is an indication that something needs to be looked at in the instrument immediately. The instrument should be removed from

service and the error corrected before further use

• Audible-, visual- and vibrating alarms

repeat periodically

• The icon appears in the display

• These alarms may be silenced with the

“OK” - key, but the gas display will still

indicate a fault

Look at video

OVER RANGE

OVER RANGE

• Audible-, visual- and vibrating alarms

repeat periodically

• is shown

• The alarm can NOT be acknowledged

Look at video

If the measuring range is exceeded, the following display is shown instead of measured value display.

Follow the prescribed safety procedures.

UNDER RANGE

• Audible-, visual- and vibrating alarms

repeat periodically

• is shown

• The alarm can NOT be acknowledged

The measured concentration has drifted into the negative range. This can e.g. happen, when the fresh air calibration was done in an

area where a concentration of gas was present. Please fresh air calibrate the instrument in a clean environmental.

UNDER RANGE

Video ansehenLook at video

• Press the “OK ”-key to acknowledge

• Press the “OK ”-key again

• An Error code is shown

(Use the instructions to determine what the

error code means.)

• Press the “OK ”-key again.

More error code could be shown.

• Or press “+M”-key to return to

measurement

ERROR DISPLAY

ERROR DISPLAY

Look at video

• Press the “OK ”-key

• A Notice Code is shown

(Use the instructions to determine what the

notice code means.)

• Press the “OK ”-key again.

More notice codes could be shown

• Or press “+M”-key to return to

measurement

NOTICE

NOTICE

Look at video

DATA READ OUT

DATA READ OUT

Look at video

• In the display, “PC” appears when the

instrument is connected via IR interface

to a personal computer

• A „Bump Test“ is a function test. Before using the instrument, it is important to check

following:

• Gas channels are not blocked (e.g. with dirty membranes )

• The sensors are calibrated correctly

• The correct alarms are shown

• The alarm levels have been adjusted correctly

FUNCTION TEST

AUTOMATIC BUMP TEST

AUTOMATIC BUMP TEST

• Slide the instrument into the bump test cradle

• The Bump Test Station automatically recog-

nizes the instrument

• Gas is supplied to the sensors

• The values increase

• Audible and visible A1/A2 alarms are shown

• Is the Bump test is correct, “OK” appears

in the display

• The bump test is completed

• If the bump test is not correct,

• A channel error “_ _” is shown for the

specific sensor

• The instrument should be calibrated or contact

your local service.

MANUAL BUMP TEST

• Slide the instrument into the calibration

cradle

• Press “+M”-key three times

• Manually supply the gas

• The values increase

• Audible and visual A1/A2 alarm are shown

• Press the “OK ”-key

• The bump test is completed

• Or a channel error “_ _” is shown for the

specific sensor

• The instrument needs to be calibrated or

contact your local service

MANUAL BUMP TEST

Do not charge underground or in areas, where explosions can occur! There is a danger of explosion! The chargers are not designed in

accordance with the regulations for fire and explosion protection..

CHARGING THE BATTERY PACK

• Slide the instrument into the charging module

• Connect the charging module with a

single- or multi-charger

• The instrument is charging

• Red LED blinks -> instrument is charging

• Red LED lights stay on -> instrument is

fully charged

• 4 hours are needed for a complete charge

CHARGING THE BATTERY PACK

Do not charge the battery in explosion hazard areas. Alkaline-Batteries are part of the Ex-approval. Only the following

types should be used:

Energizer No. E91

Energizer No. EN91

Varta Type 4106

The use of alkaline batteries other than those described above invalidates the intrinsic safety approval for the instrument

and could

result in unsafe operation.

• Loosen the screw with the help of a Allen key

• Remove the battery case

• Insert the 2 alkaline- or NiMh batteries

• Pay attention to the polarity of the batteries

• Install the battery case and tighten the screw

POWER SUPPLY

BATTERY CASE

OVERVIEW OF THE ICONS

Error Icon

Notice Icon

Fresh Air Calibration Icon

PEAK / Maximum Value Icon

TWA Value Icon

Bump Test Icon

1-Button-Calibration Icon

Span Calibration Icon

Password-Protected Menu

Battery Icon

STEL Value Icon

Special symbols provide a quick message about the instrument status

THANK YOU FOR YOUR ATTENTION!

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Regulations; both local and international

• Occupational Safety & Health Administration(OSHA) –standard 29 CFR 1910.134

• Confined Space regulations 1997.

• The Management of Health and Safety at Work Regulations 1999.

• The Control of substances Hazardous to Health Regulations 2002.

• The Provision & Use of Equipment Regulations 1998

• Mineral Oil Safety Regulations (MOSR) 1997

• Factories Act No. 16 of 1987

– Requires that personnel be adequately protected from respiratory hazards

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Three (3) groups of respiratory hazards:

Hazardous substances: Particulates, Vapours, Sprays Mists, Fogs,

Smoke, Gases, Dusts

Confined Spaces

Toxic or Oxygen deficient environment

It is necessary to use respiratory protection (respirators) when working in environments with such respiratory hazards.

A breathing or respiratory hazard exist when a toxic contaminant is present in the air at a high enough level to cause harm when it is inhaled.

The damage may occur immediately or it may take years for effects to show up

An immediate breathing hazard also exists when the air does not contain enough oxygen to support life.

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[II] Atmosphere Supplying Respirators

Full Mask (B) SCBA(A) SAR

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The Occupational Safety & Health Administration has set standards for

worker respiratory protection

All respirator filter cartridges must have the certification from recognized institutions

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Medical Evaluation: OSHA Regulations require that a medical evaluation be conducted to determine the respirator user’s capability to perform their anticipated work tasks while wearing respiratory protection.

Fit testing: OSHA Regulations require that Fit Testing be conducted to ensure that the respirator properly fits the individual using the respirator.

Medical evaluation and fit testing are required annually for respirator users

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• If a label states a respirator must be worn

when using the chemical or material

• If the work environment contains dusts,

vapour, mists, fumes etc that pose a

health hazard

• If the work environment lacks breathable

air

When must a respirator be used?

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• Do not use for protection against air contaminants other than those listed on the cartridge.

• Do not use a respirator when conditions prevent a good face-piece seal.

• Respirators do not provide protection to exposed areas of the body

• APR (Respirators) do not provide protection when working in a toxic environment.

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Breathing Apparatus Set

(Set Description & Ancillary Equipment)

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2/25/2011 133

Open Circuit or Closed Circuit• Open Circuit

• Breathing apparatus type in which the exhaled air is released into the ambient. There are two basic types:

The ‘Demand Type’( Negative

Pressure) and

The ‘Pressure Demand Type’

• The demand type only supply air on demand

• The pressure demand or positive pressure type supplies a steady stream of air to stop toxic fumes or smoke from leaking into the mask

• Closed Circuit• Breathing apparatus

type to which the exhaled air is re-circulated. There are two types:

• The ‘compressed or Liquid Oxygen type’,

and

• The ‘Oxygen –generating type’.

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Parts of a B.A. Set

• Parts of the Face Mask

Visor

Outer –Mask

Inner – Mask

Face Mask Straps

Neck Strap

Speech Diaphragm

Demand Valve

Second Stage Reducer

Auto-First Breath Mechanism

Pre-Doffing Anti- Pressure Leak

Button

The Face Mask

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BASIC CHECKS (Pre – Operation Checks)

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Introduction• Prior to use of set it is very important to carry

out required checks

• Failure to carry out such checks could lead to undesired exposure in the irrespirable atmosphere

• The check consist of the following:

- Physical checks

- High Pressure checks

- Low pressure checks

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Conclusion• All the above necessary checks should be done

and confirmed okay.

• The set can then be coupled preparatory for donning and

• After donning same checks should be carried out to prepare the set for next donning operation

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Basic B.A. Arithmetic

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Introduction• The duration of use for any B.A. set depends on two

key functions:

The air content of the cylinder and

The breathing rate of the wearer

• For safe use of equipment it is important to ascertain the following:

1. Full content

2. Work duration

3. Safety margin

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Recall Physiology of Respiration

• When air is taken in the primary gas needed by man in the process is oxygen and carbon dioxide is expelled.

• The demand for oxygen is dependent on the activity which the person is engaged in at the time of demand

• Anxiety, fear can lead to increase in air demand.

• On the average a man walking briskly takes in about 37.3 litres of air per minute.

• For practical purpose this Value is rounded up to

40 litres per minute.

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B.A. Capacity•Every B.A. Set is charged to a given cylinder

capacity usually at 14.7psi.

•The cylinder capacity in bars could be 200bar, 250bar, and 300bar.

•Every cylinder has a water capacity in litres (9L, 7L etc.)

•The cylinder capacity in relation to the consumption capacity of the person determines the work duration of the cylinder.

2/25/2011 142

Basic Calculations

•Full Duration:

Cylinder capacity x average water capacity

Average human air consumption.

So for 200bar cylinder = 200 x 9 = 45 minutes

40

2/25/2011 143

Basic Calculations

•Work Duration:

The available time for the wearer to perform a given task = full duration – safety margin.

For 200bar cylinder, the work duration

‘w’ = (45 – 10)minutes = 35minutes.

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Basic Calculations

•170bar = 28mins.

•180bar = 30mins.

•190bar = 33mins.

•200bar = 35mins.

•250bar = ?

•300bar = ?

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CONFINED SPACE ENTRY

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Group Standards and Requirements

• The Hazard and Effects Management Process (HEMP) shall be applied for confined space entry (CSE) activities. The HEMP shall include the following steps:

-Identification of the hazards; -Assessment of the risks using the Risk Assessment Matrix (RAM);

-- Detailed analysis of the hazards, e.g. by job hazard analysis (JHA), in case of activities assessed as high or medium risk on the RAM;

-- Description of the necessary controls and recovery measures.

-If a generic HEMP exercise and the guidance in this document have been incorporated into CSE procedures, the job specific HEMP shall focus on identifying the controls and recovery measures for the particular CSE and location;

-• The HEMP shall demonstrate that alternatives to entering the space have been considered and that all reasonably practicable steps have been taken to eliminate asphyxiant, flammable, toxic and other hazards;

-• The CSE criteria for oxygen, toxic and flammable levels and for breathing apparatus in Section 7.0 of this document are mandatory;

-• A rescue plan shall be prepared and implemented for every CSE;

-• Every CSE shall be authorised and controlled by a permit to work.

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CONFINED SPACE ENTRY

The Factories Act No. 16 of 1987 , the MOSR of 1997 require the employer to comply with any specific regulations that apply to work in dangerous or potentially dangerous areas.

The Shell companies, and OSHA have elaborate guidelines and recommended practices for controlling Health, Safety and environment hazards during Confined space Entry (CSE).

Other Relevant Regulations UK. Based.Confined Space regulations 1997.The Management of Health and Safety at Work Reg. 1999.The Control of substances Hazardous to Health Reg. 2002.The Provision & Use of Equipment Reg. 1998

TESTING CONFINED SPACES

Testing of a confined space must be carried out before it is certified as been save to enter.

The test should check for the presence of gas or toxic fumes and the adequacy of the supply and

content of oxygen.

NOTE; an acceptable result must be obtained before work in any confined space proceeds.

One common way of practically making a confined space safe for entry is by PURGING OR

INERTING.

Purging could mean introducing external air or use of an inert gas so as to deplete confined space of

toxic or hazardous gases.

One common problem with INERTING is that it could yield to further oxygen deficiency.

Where possible all tests in confined spaces should be conducted from outside. Where this is

impractical the following basic rule should be adhered to when entering a confined space for any

activity;

* wear approved Breathing Apparatus

* Know what type of gas or vapors to be expected

* Ensure all isolations to the confined space have been implemented

* Use gas tester with a probe

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Confined Space: Fully or partially enclosed space with a risk of serious injury from hazardous substances or conditions within the confined space. (CSE) may be complete body entry, or inserting a head into man way openings, hatches, pipe ends etc.Permit To Work (PTW) principal authorisation/clearance document signed by a Competent Person(s) for all non-routine or potentially hazardous activities to be carried out in restricted Areas under stated and accepted precautions with designated Action Parties for the enforcement of compliance.Attendant(Standby) :outside the confined space, and is responsible for assistingthe entrant in exiting the confined space, and calling foremergency assistance when required.

CONFINED SPACE ENTRY

Definitions/ Key persons involved in CSE activities

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CONFINED SPACE ENTRY

Definitions/ Key persons involved in CSE activities

Entrant: The person who enters a confined space.The safety representative: is the qualified person who evaluates the hazards, prescribes required equipment and precautions and issues the Confined Space Entry Permit.Operations supervisor: (Permit Issuer), who is responsible for making sure that the confined space is safe for entry, and that the supervisor in charge of the work and the attendant are fully familiar with the hazards, controls and recovery measures;Supervisor: (Permit Holder), in charge of the work who is responsible for making sure that the workers comply with the controls specified on the permit, and for providing means of rescuing persons from the space in case of an emergency;

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Examples of Confined Spaces:

• Tanks

• Manholes

• Boilers

• Furnaces

• Sewers

• Silos

• Hoppers

• Vaults

• Pipes

• Trenches

• Tunnels

• Ducts

• Bins

• Pits

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CONFINED SPACE ENTRY

CSE Hazards. What are the dangers expected from CSE?

1. Oxygen Deficiency. Normal 2. Oxygen Enrichment.( O2 > 21.5%)3. Fire explosion4. Presence of Toxic gases or fumes5. Residues left in the space (process materials)6. Physical Hazards7. Unsafe conditions(Nature of work, moving machinery parts, close contact, egress during emergency, Hot conditions, etc) 8. Ingress of material(faulty isolation, collapse, fluids/solids, etc)9. Accumulation of dust in the space.10.Psychological issues11. Biological hazards

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The Law (MOSR, Factories Act, the Management of Health and Safety at Work Regulations 1999 stipulates to carry out sufficient Risk Assessment for all work activities for determining what measures are necessary for safety.

This in most cases will include assessment of:

• The task to be carried out• The environment• Working materials and tools• Suitability(competences)of those carrying out the task• Arrangement for emergency rescue.

CONFINED SPACE ENTRY

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CONFINED SPACE ENTRY

CSE CONTROLS A. Appointment of competent persons and adequate

training and instruction of employees as required.B. Avoid entry into confined spaces through work

planningC. If entry is unavoidable, follow a system of work e.g.

PTWD. Put in place adequate emergency arrangements

before work starts.

Elaborately this may mean:1. Isolation: Mechanical/electrical.(LOTO, physical

isolation, etc)2. Clearance of process materials before entry3. Checking size of entry 4. Ventilation5. Testing of air (Gas testing/ Monitoring)

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CONFINED SPACE ENTRY

CSE CONTROLS

6. Provision of special tools and lighting.7. Provision of BA8. Emergency planning (Prepared rescue plan, Rescue harness, Communication, checking how alarm is raised, first Aid, rescuers etc)9. A valid PTW for the work10. Shut down11. Control of Ignition Sources12. Control of radiation Sources13. Control of Internal Combustion Engines and

Cylinders14. Personal Protective Equipments

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CONFINED SPACE ENTRY

CSE Recovery & Emergency Management.

• Access and Escape

• Attendant

• Rescue Team

• Rescue plan

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A means must be providedfor both safe normal entryor exit , and emergencyextrication.

Tripods with hoist, lifeline, and full body harness are often used for emergency extrication.

Ladders may be used for ordinary entry and exit.

CONFINED SPACE ENTRY

2/25/2011 158

RESCUE PLAN