Hazard Recognition

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Confined Space Entry

Hazard Recognition

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Objectives:

Upon completion of this module, the participant will be able to:

Confined Space Entry

Identify the important safety considerations for working in

confined spaces.

Recognize the hazards associated with confined spaces.

Identify the potential consequences if these hazards are not

properly addressed.

Describe precautions to be taken before entering a confined

space.

Describe required actions to prevent incidents.

Hazard Recognition

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What is a confined space?

A Confined Space is any enclosed or substantially enclosed space

which has one or more of the following characteristics:

Confined Space Entry

Has limited ventilation or could potentially contain

hazardous levels of gasses/vapors;

Is not designed to be normally occupied;

Has restricted access and/or egress.

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Examples:

Process vessels (e.g., towers, drums, reactors)

Storage tanks (including floating roof pontoons)

Spheres

Silos/hoppers

Exchanger shells

Vessel skirts and stack liners

Boilers, Heaters, and Furnaces

Tank car (rail) and Tank trucks

Sewers, Tunnels, and Pipelines

Air Blower Ducts (e.g., APH)

Excavated trenches or pits greater than 1.25m in

depth where there is a risk of exposure to harmful/toxic

vapors, or engulfment

Enclosed basement at sub-station

Equipment sheeted-in for weather protection, asbestos

stripping, or spark containment, and without sufficient free

area to maintain adequate natural ventilation

Confined Space Entry

Hazard Recognition

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Is this tank safe

to enter?

Are there any

precautionary

measures I should

take before entry?

Should I have a

standby attendant?I can just peek in the

manhole, right?

Confined Space Entry

Hazard Recognition

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What is a confined space entry?

Confined Space Entry includes putting one's head or

torso into an open man way.

Some tasks, such as atmosphere gas testing, may

require workers to reach into vessels or equipment

without actually entering the space.

Local site procedures and the site Permit to Work

system should ensure that the hazards are

assessed and that control measures are in place

to protect individuals from any oxygen deficient

atmosphere, harmful materials, powered

equipment, and energy sources which may be

present inside the equipment.

Confined Space Entry

Hazard Recognition

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This is a confined

space entry.

Confined Space Entry

Do you SEE what I see?

What is missing in this

picture ?

Has this person taken

responsibility for his

actions ?

Has he thought

through this activity to

determine what can

hurt me?

Hazard Recognition

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What are the Hazards?

Every year people die in nitrogen rich/oxygen deficient

atmospheres because of complacent work attitudes and

failure to adhere to safe work practices.

See also the Nitrogen Tool Box

Module

Confined Space Entry

Hazard Recognition

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Human Physiological Response to Less Oxygen

Confined Space Entry

Hazard Recognition

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When a person enters an oxygen deprived atmosphere the oxygen level in the arterial blood drops to a low level within 5 - 7 seconds.

Loss of consciousness follows in 10 - 12 seconds.

Heart failure and death ensue if person does not receive any oxygen within 2 - 4 minutes.

Nitrogen

How long does it take to have an effect?

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• Brain becomes starved of oxygen – you pass out

• Your brain shuts down the body

• It only takes one breath

What happens when you breathe in

nitrogen?

Confined Space Entry

Hazard Recognition

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Oxygen Displacement Agents

In addition to N2, other gasses can replace oxygen by

their presence in or around a confined space.

H2S, CO, CO2, Hydro Carbons which may be slowly

released from tower/reactor/drums’ internals Will Displace

Oxygen and/or lead to intoxication!

The result is the same!

Confined Space Entry

Hazard Recognition

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• Oxygen concentration dropped to below 10%.

• Workers were in the confined space, which

was not correctly ventilated causing

displacement of air by solvent and vapor.

• The workers were using fresh air respirators

for protection against toxic solvent vapor not

against low O2 atmosphere.

Result:

• Crucial in Risk Assessment is participation of all parties understanding

the work method in developing RAs.

• Good understanding of ventilation principles for confined spaces,

particularly those with more than one compartment.

Learning / Recommendations:

Confined Space Entry

Industry Incident

Hazard Recognition

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People were killed inside a tower

where H2S was slowly released from

ceramic rings in a tower packing.

People became drunk when they

were working inside a tower in which

some benzene/toluene was residing

in rusty particles of a tray drip pan.

Confined Space Entry

Industry Incident

Hazard Recognition

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Using tools and specific work methods inside confined spaces

can end up in disasters as well.

1. Contractor was killed inside a confined space

during a coating job. The solvent vapors

ignited and he was caught in the fire.

2. An explosive atmosphere was discovered

while coaters were using a new technique of

coating with a pistol inside a tent which was

mounted around a storage tank (Near Miss).

Confined Space Entry

Industry Incident

Hazard Recognition

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Electrical / Mechanical Hazards

We talked about gasses displacing

oxygen, but what about other types

of hazards while working in restricted

or confined spaces?

Confined Space Entry

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Using tools and specific work methods inside confined spaces.

Contractor was killed inside a confined space when a 220 Volt powered machine was used and the cable was damaged on a sharp edge inside the confined space.

Confined Space Entry

Industry Incident

Hazard Recognition

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Working above each other.

Climbing, hoisting,

opening/closing tray hatches.

Contractor was killed while his

safety harness was not

connected and he was climbing

out of the confined space on a

rope ladder.

Confined Space Entry

Industry Incident

Hazard Recognition

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Inadequate atmosphere.

Insufficient oxygen (should be the same as at grade on earth - 21%).

Minimum 19.5% and maximum 23%;

Explosive atmosphere (should be <10% LEL);

Poisoning gasses slowly releasing from materials like tower packing,

catalyst beds and filters like H2S and CO or entering the space

because it’s not completely blanked off;

Fumes due to hot work (e.g., welding, burning);

Application of solvent-based coatings/paints which can give rise to a

flammable atmosphere;

Disturbing sludge during manual cleaning which can give rise to

higher gas readings;

Ingress of contaminants from outside the confined space (e.g.,

exhaust from a mobile generator located close to the man way, from

contaminated compressed air, hose mistakes N2 instead of Air).

Most common causes of fatalities inside confined spaces:

Confined Space Entry

Hazard Recognition

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Slips, Trips, Falls, Hit by, Electrocution.

Slippery surfaces, strange tower / vessel shapes, open trays, baffle

plates, strips instead of full trays;

No means for securing safety harnesses, use of robe ladders instead

of proper climbing means such as tray hatches, secured ladders or

scaffolds;

Open hatches in trays, manholes on top of vessels, people entering

and working in the confined space at different levels (e.g. distillation

tower);

Hoisting, (de) bolting, removing trays, strips, packing or catalyst beds;

Ventilators in the way;

Higher voltage powered lighting and tools instead of lower voltage

powered equipment.

Most common causes of fatalities inside confined spaces:

Confined Space Entry

Hazard Recognition

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Trench = Confined Space

(person can potentially kneel

and have his head below

grade)

Confined Space Entry

Do you SEE what I see?

Imagine potential gasses

nearby: CO2, N2, CO

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Is it steam or gas

coming out of the skirt

of the vessel?

Can we stick our head

in to have a look?

Hazard Recognition

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SEE

Voltage ?

Glass bulb OK ?

Confined Space Entry

Hazard Recognition

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Responsibilities for Confined Spaces

Don’t become the Operator who was standing aside the hospital bed of a Maintenance Technician. Crying because he did not take the time to properly blank and clean a confined space. The Maintenance Technician almost died due to exposure to CO!

YOU !

Confined Space Entry

Hazard Recognition

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Key considerations :

For entry into an inert or oxygen deficient (<19.5% O2) environment, refer

to the Guidelines for Inert Entry.

These guidelines are to be used in conjunction with other existing site safe

work procedures, for example, Permit to Work Procedures, Tank

Cleaning Procedures, and the Guidelines for Inert Entry.

Local legal requirements must be met. Where the criteria in these

guidelines differ from applicable legal requirements, the more stringent

should be adopted, unless there is a conflict. If there is a conflict, the

local legal requirements control.

Confined Space Entry

Hazard Recognition

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Basic Principles:

Atmosphere Inside a

confined space is as good

as Outside at grade in

clean and normal air!

If not possible then

management must

approve special

procedures after a

thorough risk assessment

according to:

Never work in an

explosive atmosphere.

Not with or

without breathing

apparatus!!!

Confined Space Entry

Hazard Recognition

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Never try to ‘sweeten’ the air in a confined space with

oxygen as this can greatly increase the risk of fire or

explosion.

Equipment should be made sweet by:

• Emptying, e.g. displacing products/hydro carbons with nitrogen (not with air)

• Washing, potentially with a special soap if needed or……

• Steaming out such no hydro carbons and other toxics are left behind

• Opening equipment to air, first to ventilate with air through natural draft if possible

• Preventing ready access to open manholes

• Using Mechanical Ventilation if needed

Confined Space Entry

Basic Principle:

Hazard Recognition

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Basic Principles:

• Guard is able to get help when needed (e.g. has radio)

• Knows that he should never go inside when he observes

mishaps! He should get appropriate assistance with

breathing apparatus and means to rescue when needed.

There is always a man

way / man hole guard

outside the confined

space when people are

inside or the man way /

man hole is blocked with

a physical barrier/

STOP sign

“TO PREVENT

PEOPLE FROM

ENTERING”

Confined Space Entry

No one enters without

additional protection /

help from others

Hazard Recognition

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ExerciseHypothetical Situation Actions

A tank is open but not yet free of

hydro carbon sludge. There is

hot work planned close to the

confined space entry. You are

the Operator responsible for the

area. What do you do?

Report to supervisor and make sure

that everybody knows that hot work

is out of the question.

Confined Space Entry

A required blank list is not

maintained by the Process

department. You are planning to

work inside. What do you do?

You are not going inside the

confined space before the blank list

and all other documents are

completed, ensuring that nothing is

overlooked!!!

Hazard Recognition

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ExerciseHypothetical Situation Actions

You are not trained and qualified

to take test/sample of the air

inside a confined space. You are

assigned the task. What do you

do?

An Equipment Inspector asks you

if it’s OK to look inside without

going in. What do you do?

You get a competent resource to do

the testing. Meanwhile manholes

are kept barricaded !

You only give permission if the

entire process is completed:

Condition tested OK, report

completed

Work permit issued, manhole

guard/ you are present

Confined Space Entry

Hazard Recognition

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ExerciseHypothetical Situation Actions

You see people working with 220V tools, cables laying over sharp edges of the manhole and trays inside the vessel. What do you do?

Stop the work and let people get

extra low voltage equipment (42v

OR LOWER) and, where

necessary, residual current

devices).

People placed a combustion air

driven generator close to a

confined space. What do you

do?

You see a manhole guard

working a few meters away from

a manhole. What do you do?

You ensure that it’s going to be

relocated to a safer position.

Meanwhile no entry !

You check if there are people inside

(W/O ...) and if not, the man way is

barricaded , (rules clear?

Supervisor? Near Miss?)

Confined Space Entry

Hazard Recognition

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Objectives Review:

Upon completion of this module, the participant will be able to:

Let’s make sure that confined spaces are helping rather then killing us!

Confined Space Entry

Identify the important safety considerations for working in

confined spaces.

Recognize the hazards associated with confined spaces.

Identify the potential consequences if these hazards are not

properly addressed.

Describe precautions to be taken before entering a confined

space.

Describe required actions to prevent incidents.