2. Learning Objectives
• Upon completion of this chapter, participants will
be able to:
• State the definition of confined space at workplace
• Explain the legislations related to the confined space
occupations
• Explain the procedure of entry
2
3. Scope
– Definition of Confined Space
– Legislations Requirement
• OSHA 1994
• FMA 1967
• ICOP for Safe Working in Confined Space 2010
– The Needs to Enter Confined Space
– Procedure of Entering a Confined Space
3
4. Definition of Confined Space
What is a confined space?
• An enclosed or partially enclosed space,
• Is at atmospheric pressure during occupancy,
• Is not intended or designed primarily as a place of
work, and
• Is liable at any time to :
i. Have an atmosphere which contains harmful levels of contaminants
ii. Have an oxygen deficiency or excess
iii.Cause engulfment and
• Could have restricted means for entry and exit.
(From Industry Code Of Practice For Safe Working In Confined Space 2010)
4
6. LEGISLATIONS
6
•
OSHA 1994 FMA 1967 : SHW
Reg 1970
ICOP CONFINED
SPACE 2010
• General duties of employers and
self-employed persons to their
employees
– Sect. 15(1)
– Sect. 15(2)
• Confined space
definition
– Regulation 13
(1)
• Part II : Confined
Space Entry
Programme
• Part VI: General duties of
employees at work
– Sect. 24 (1)
• Pre-requisite
– Regulation 13
(2)
• PART III : Detail
Requirements
• Penalty
– Sect.19 (Penalty for Sect 15 –
18)
– Sect. 51 (General Penalty)
• PART IV : Duties
of Responsible
Persons
7. HAZARDS IN CONFINED SPACE
Hazardous Atmosphere
• Asphyxiating
• O2 deficiency
• O2 displacement
• Toxic
• H2S
• CO
• CO2
• NH3
• Cl2
• Flammable/Explosive
• Excessive O2
• Irritant (Corrosive)
• Primary
• Secondary
General Safety Hazard
• Communication
• Difficulty to detect unconscious worker
• Unable to hear commands/danger signals
• Physical
• Thermal
• Noise
• Radiation
• Vibration
• Ergonomic
• Electrical Shock
• Slips, trips and falls
• Engulfment
• Psychosocial
• Claustrophobia
• Biological
• Bites
7
8. HAZARDS IN CONFINED SPACE
8
Hazardous Atmosphere
• Asphyxiating
• O2 deficiency
• O2 displacement
• Toxic
• H2S
• CO
• CO2
• NH3
• Cl2
• Flammable/Explosive
• Excessive O2
• Irritant (Corrosive)
• Primary
• Secondary
Asphyxiating
O2 deficiency
•O2 consumption
during activities
such as welding,
heating,
chemical
reactions,
human physical
activities
O2 displacement
•Displacement by
another gas such
as Helium,
Argon, Nitrogen,
CO2
Toxic
H2S
PEL = 10 ppm
CO
PEL = 25 ppm
CO2
PEL = 5000 ppm
NH3
PEL = 25 ppm
Cl2
PEL = 0.5 ppm
Flammable/
Explosive
O2: leakage from
O2 supply fitting
Heat: Welding/gas
cutting
Fuel: solvents
(spray painting),
chemical reaction
Explosive Range
Irritant
Primary
•Effect on the
entire body
causing
inflammation of
skin, dermatitis,
eyes irritation
•Cl2, HCl, H2SO4,
NH3
Secondary
•Produce
systemic toxic
effects addition
to surface
irritation causing
blurring of
vision, cancer
•Benzene, CCl4,
TCE
17 TOO RICH
15 -------------UEL-------------
5 ----------------LEL--------------
TOO WEAK
0
EXPLOSIVE
19.5 < O2 < 23.5
9. HAZARDS IN CONFINED SPACE
General Safety Hazard
• Communication
• Difficulty to detect
unconscious worker
• Unable to hear
commands/danger signals
• Physical
• Thermal
• Noise
• Radiation
• Vibration
• Ergonomic
• Electrical Shock
• Slips, trips and falls
• Engulfment
• Psychosocial
• Claustrophobia
• Biological
• Bites
• Bacteria/ Virus/ Fungus
9
Thermal
Effect
T too high
Heat Stress, heat stroke,
death
T too low
Hypothermia, numbness
Noise
Caused by activities/
equipments
Interior tends to cause
sound to reverberate
Radiation
X-rays, radiation
gauges, Isotopes,
lasers
Cancer, skin
inflammation,
leukemia
Vibrations
Whole body
Headache, nausea,
vomiting, abnormal bowel
Hand-arm
White finger, numbness,
gangrene
Ergonomics Awkward positions Illuminations
Electrical
Shock
Short-circuit during
activities
Slips, trips
and falls
Soft tissue injuries, fractures,
dislocations, head injury, coma,
death
Engulfment
Suffocation in a loose material
stored in hopper or silo
10. PROCEDURE FOR ENTRY
Duties of
parties
involved
AE SP AGT ES PI FW ERT
Health
requirements
Health Status
Declaration by
AE
Health Status
Declaration by
OHD
Entry
procedure
(before)
Request for
Work by WL/PA
Isolation of
Work Area &
Confined Space
Initial Cleaning
& Draining
/Purging
Initial
Ventilation
Evaluation of
the confined
space
conditions
Entry
procedure
(during)
Continuous
Ventilation
PPE &
Equipment to
be prepared
Issuance of
Permit to Work
Entry and Work
Work
Completed
Rescue and
Emergency
Procedure
Emergency
Action
Emergency
Equipment
Emergency
Response Drill
10
11. PROCEDURE FOR ENTRY
BEFORE DURING AFTER EMERGENCY
AE • Knowledge on hazard
• Declare fitness
• LOTO
• Use equipment required
correctly
• Communicate with
stand-by person
regularly
• Attach yourself to the
lifeline or safety harness
in case of emergency
• Can work as far as 15m
from the exit as long as
he wears the lifeline
equipment
• LOTO, housekeeping • Immediately
evacuate from
confined space if
required
• Attach to the lifeline
or safety harness in
case of emergency
SP • Knowledge on hazard
• Monitor the condition of equipment required
for the entry
• Aware of possible
behavior effects to AE
• Ensure accurate count
and identification of AE
• Remain OUTSIDE
• Communicate with AE
and/or FW regularly
• Take action when
unauthorised person
attempt to enter
• Housekeeping • Summon rescue &
emergency services
• Perform non-entry
rescue only
AGT • Update knowledge on hazard
• Identify hazards & recommend control
measures
• Familiar with all equipment used
• Test and interpret the reading level of
gaseous
• Test and interpret the
reading level of gaseous
11
12. PROCEDURE FOR ENTRY
BEFORE DURING AFTER EMERGENCY
ES • Update knowledge on hazard
• Supervise all the activities
• Ensure PTW has been filled, ensure specified
test has been conducted, specified
procedures & equipments are in place b4
endorsed PTW
• Verify that the rescue services are available &
functioned
• Brief entry team on hazards, PTW &
emergency procedures
• Supervise all the
activities
• Remove unauthorised
individuals who attempt
to enter
• Ensure entry operation
remain consistent as in
PTW
• Supervise all the
activities
• Closed PTW
• Conduct debriefing
session regarding CS
entry programme &
any hazards
confronted during
entry
• Terminate the entry
and cancel PTW if
required
• Be in-charge of
communication
during emergency
PI • Update knowledge on hazard
• Identify hazards & recommend control
measures
• Ensure there is no other incompatible activity
in the area of CS
• Authorise the permit to work
• Endorse the
cancellation &
closure of the permit
to work
FW • Knowledge on hazard • Ensure the work area are
safe
• Communicate with SP
from time to time
• Be prepared to put out
any undesired flame
• Standby outside CS
for reasonable period
after work complete
• Ensure no activity
which can result in
the release of
flammable gases
• Alert SP & warn AE
if fire/ dangerous
situations
• Give order to exit all
AE when the
situations warrants
it / directed by SP or
ES
ERT • Well-trained & equip with necessary rescue
equipments
• Standby incase of
emergency
• Rescue from CS
following well-
planned & well-
executed rescue
procedures
12
13. PROCEDURE FOR ENTRY
Isolation of Work Area
• Barricades and signage outside – DANGER, CONFINED SPACE, ENTER BY PERMIT
ONLY
• Put up barriers to divert traffic & pedestrians
Isolation of CS
• Electrical isolation: LOTO; ensure no unauthorized activation
• Piping and valve isolation: blanks / spades
• Moving parts: tied down with chains and locks; ensure zero energy
condition
Removal of means of isolation
• Only by the people who carried out the isolation, or otherwise authorized by the entry supervisor.
13
14. PROCEDURE FOR ENTRY
Initial Cleaning & Draining
• All identified liquids are drained and flushed out in an appropriate manner.
• Cleaning processes and methods used may need to be adapted to meet each separate set of
circumstances
• Potentially dangerous materials which may be trapped in sludge, scale or other deposits, may be released
when disturbed or heat is applied
• CS should be allowed to return to acceptable thermal environment prior to entry.
• Any contaminants removed from the CS are exhausted to a location where they present no hazard to
persons or equipment
Purging
• After the cleaning, CS shall be cleared of contaminants using suitable purging agents
• To purge flammable contaminants, precautions shall be taken to eliminate sources of ignition, including
static electricity discharges.
• Any contaminants removed from the CS are exhausted to a location where they present no hazard to
persons or equipment
• After purging, the CS is dried, or left to dry naturally
• CS is now ready for the AE
14
15. PROCEDURE FOR ENTRY
15
When purging a gas
which is lighter than
air such as NH3, CO2
can be used. After
purging is complete,
the chamber need to
be purged again, this
time with clean air
from the top.
Suitable to ventilate
flammable gases as
to control the point
of gas exit point.
Also recommend for
Hydrogen Sulphide
as the gas is widely
disperse by wind.
18. PROCEDURE FOR ENTRY
Ventilation
• Always use fresh air for ventilation – NEVER USE OXYGEN.
• Check with Gas Detector to determine contaminant gas.
• All electrical ventilation equipment must be earthed.
• Make sure air intake is far away from toxic material.
• Remove all ignition sources.
• Use proper ducting.
• Make sure all confined space entry points available are open.
• Make sure to use intrinsically safe equipment when ventilating flammable mixtures.
• Filter the exhaust if necessary to prevent air pollution.
• Ensure that the ventilation system does not pose as an obstruction during
emergency exit
Initial ventilation
• Ventilate all confined areas completely with normal air, using recommended
procedures even if no hazards were detected during testing.
• Choose the best method for ventilation e.g. mechanical ventilation, push-pull
ventilation
18
19. PROCEDURE FOR ENTRY
Risk Assessment
• Conduct risk assessment before carry out work involving entry into a confined space
• Risk assessment method may be in accordance to Guidelines for Hazard
Identification, Risk Assessment and Risk Control (HIRARC) or other relevant method
• Risk assessment conducted by an assessor if chemical hazardous to health is used in
the confined space
19
Risk Control
• Employer to establish and implement procedures and practices of hazard control
that provide safe entry into the confined space based on risk assessment conducted
• specify acceptable entry conditions
• isolate the confined space
• purging, inerting, flushing or ventilating the confined space
• verifying acceptable condition throughout the duration of entry
20. PROCEDURE FOR ENTRY
Evaluation of the Confined Space Condition
• Pre-entry Testing
• The AGT must test the confined space atmosphere before every entry, and confirm safety
conditions
• Sequence of test: first for oxygen, then for flammable gases and vapours, and finally for
toxic gases
• If space is too large and isolation is not feasible, pre-entry testing shall be performed to
the extent feasible e.g. sewer
• Remote area evaluation may need to be undertaken by persons wearing supplied air
respiratory protective equipment
• Note that: PEL may be way below 10% of LEL for the same chemical, such as acetone!
• Test air at the top, middle and bottom, and in remote areas
• Check spaces around pipes, ducts, valves and other areas where vapors can accumulate
• Use the most sensitive equipment available!
20
21. PROCEDURE FOR ENTRY
Gas Detector
• Used by an AGT, or sometimes by the AE,
• to detect levels of gases in the confined space
• display the concentrations
• to give warning alarm if the level is dangerous.
• operations – diffusion (personal monitoring ) or pump(pre entry testing
• Gas Detector Function :
• Continuously Monitor the gas concentration
• Displays the concentration
• Warns when the levels are unsafe
• Types of operation :
• Diffusion : for personal monitoring 21
22. PROCEDURE FOR ENTRY
Continuous Ventilation
• Ventilation shall be provided continuously throughout the period of occupancy
• Air from forced ventilation shall be from a clean source, free from contaminants
• The atmosphere shall be periodically tested to ensure ventilation is preventing
the accumulation of hazardous atmosphere
22
23. PROCEDURE FOR ENTRY
PPE
• All authorized entrants must use the standard protection PPE;
• as required by the company, and
• any other special PPE required for the job.
• The types of PPE required will be mentioned in the Permit to Work or PTW sheet
• The Entry Supervisor is responsible for ensuring that this is done, prior to every entry
23
RESPIRATORY PROTECTION
HAND PROTECTION
HEARING PROTECTION
HEAD PROTECTION
EYE PROTECTION
FACE PROTECTION
FOOT PROTECTION
BODY PROTECTION
24. Types of respiratory protection :
Supplied Air
Respirator
(SAR)
Air Purifying
Respirator
(APR)
PROCEDURE FOR ENTRY
BREATHING APPARATUS
• Supplies breathing air from a compressed air source, whenever the atmosphere is no longer
safe to breathe.
• It is designed to permit the wearer to work safely in an atmosphere that is dangerous to
human because of
• Presence of Toxic gases (Hydrogen Sulphide, Carbon Monoxide etc),
• Oxygen Deficiency,
• Other hazards : Smoke etc
25. PROCEDURE FOR ENTRY
Self Contained Breathing Apparatus (SCBA)
• is used whenever the atmosphere is not suitable for normal breathing and for emergency /
rescue operation.
• nominal duration is 30 minutes with working duration of 20 minutes (depending on person’s
breathing and work rate)
Warning whistle and pressure gauge
LDV
Pressure
reduce valve
Cylinder strap
Waist belt
Shoulder strap
Air cylinder
26. PROCEDURE FOR ENTRY
Self Contained Breathing Apparatus (SCBA)
• nominal duration is 30 minutes with working duration of 20 minutes (depending on person’s
breathing and work rate)
Cylinder Pressure
(At Gauge – Bar)
Cylinder Capacity
(Indicated on
cylinder)
Total Duration
(mins)
Working Duration
(- 10 min)
200 Bar 6 Liter 30 20
190 Bar 6 Liter 28.5 18.5
180 Bar 6 Liter 27 17
170 Bar 6 Liter 25.5 15.5
160 Bar 6 Liter 24 14
Calculation Method
Cylinder Capacity (At Cylinder) x Cylinder Pressure (At Gauge) = Liters of Air
Liter of Air (At Cylinder) / Breathing Rate (40 Liter/Min) = Total Duration
Total Duration – Safety Factor (-10 Min) = Working Duration
* 80% of a 200 Bar Cylinder Charging Capacity is 160 Bar
Degree of
work
O2
required
(L/min)
Air
required
(L/min)
Rest 0.3 1.5
Light 0.3 – 1.0 1.5 – 5.0
Moderate 1.0 – 1.5 5.0 – 7.5
Heavy 1.5 – 2.0 7.5 – 10.0
Very
heavy
2.0 – 6.0 10.0 –
30.0
27. PROCEDURE FOR ENTRY
Other Equipments
• Ensure ventilation equipment is installed according to the type of hazardous gas
expected
• Ensure lighting equipment gives adequate lighting for the work to be done
• Ensure ladders and manholes are in position for safe access and egress
• Ensure emergency escape and rescue equipment are on standby
• Test communication equipment to ensure they are in good working order
• Check any other equipment required
27
28. PROCEDURE FOR ENTRY
28
Chest Bag (Highly Visible; Anti-Static)
Cylinder (2L)
Chest Bag (Highly Visible; Anti-Static)
Constant Flow Valve / Pressure Reducer
Air hose
Pull pin assembly
Hood (Flame retardant)
Half mask and exhalation valve
Push fit connector and air diffuser
29. PROCEDURE FOR ENTRY
Emergency Retrieval Equipment : Tripod with Recovery Device
29
⊙ Ideal safety device
for rescue in
confined spaces
with vertical access.
⊙ Aluminium
Telescopic Tripods
with adjustable legs
with locking pins to
hold them into place
& safety chains on
feet to prevent
flaying.
⊙ Double locking
system to stop falls
immediately &
incorporates an
energy dissipation
element.
⊙ It has an integral
manual winching
mechanism for
retrieval adapted for
the tripod.
30. PROCEDURE FOR ENTRY
Distress Signal Unit (DSU)
30
will emit at 103 dBA
noise within 15
seconds of non-
activity,
reason
to wake up the
worker, if possible,
to warn others of his
condition.
31. PROCEDURE FOR ENTRY
Issuance of PTW
• The AGT carries out a gas test and fills the results in the PTW
• The ES checks the JHA produced by the Work Supervisor (Permit Applicant)
• The ES checks to ensure all the isolation and entry conditions are meet before
signing the PTW
• Preparation for entry : PPE, tools, gas testing
• Lighting, Ventilation, Emergency preparedness
• The contractor receives the PTW and prepares for the work in the Confined Space
• Employer must ensure preventive steps to control the hazards have been complied
with, before the PTW is issued
• ES must sign the permit
• AE must ensure the permit is complete before bringing it to the work area
• Validity period and work scope is mentioned in the permit
• ES may revoke or cancel the permit
31
33. PROCEDURE FOR ENTRY
PTW working/terminating condition
33
Revalidation of PTW
• Normally a permit is valid for a set
working day ( 8 or 12 hours) unless
specified on the permit
• If work is to continue after or the
work to be handed over to a
different shift, the permit must be
revalidated by both the PI and PA
• AA may also be required to sign as
permitting the work to continue
• Each company may have different
procedures for the duration and
frequency of revalidation
Permit Suspended
• If for any reason the job cannot be
completed within the permit
validation period or if materials are
not readily available ( e.g a
replacement valve may take 10 days
to arrive ) the permit must be
suspended
• The work site is made as safe as
possible, any isolation carried out
may be required to be kept “tagged”
in the isolated position until the new
part arrives, a new permit is issued
and the job is eventually completed
PTW Cancelled / Closed
• Once the job is cancelled or
completed, the site must be made
safe before the permit is returned to
the permit holder and signed off
• On completion, further tests may be
required to prove the work e.g. Leak
test, electrically or pneumatically
operated to check for serviceability,
and a further permit may have to be
issued for this. Some companies
incorporate this ability to test within
the original permit
• On completion, all permits are
brought together and signed off by
both the PI and PA
• A debriefing is required on identified
deviations from the specified
conditions, and the PTW reviewed if
necessary
Upon revalidation, cancellation, completion :
◦ All copies brought together, and signed by signatories
concerned.
◦ Copy kept for 1 year, or until next job, whichever is later.
34. PROCEDURE FOR ENTRY
PTW working/terminating condition
• Points to be Observed :
• If an emergency alarm sounds, all permits should be returned to the control
room, if safe to do so, and personnel should go to their mustering area.
• Permits will only be reissued once the emergency is over and if it safe to continue
to work in that area. This is suspension of permit.
• On completion of the work, the area must be left in a clean and safe as per
original condition, and the permit must not be signed off and the certificates
closed, until the area has been checked by the ES / PI.
34
35. PROCEDURE FOR ENTRY
Entry and Work
• Start work only after the permit is approved by ES
• All workers take their positions:
• Stand-by person: Monitors outside the confined space, always alert to
changing situations, communicates with entrants
• AGT: conducts gas monitoring, prior to every entry
• AE : Use PPE, bring the right work tools, confined space and do the
specified job only, check work scope
• Emergency response team is on standby
• Maintained throughout the entry operation (as required by PTW)
• Monitoring instrument suitable for measuring the presence of gases have
been calibrated and give direct readings
35
36. PROCEDURE FOR ENTRY
Entry and Work
• If a hazardous atmosphere is detected during entry or during work :
• Everyone shall leave the space immediately
• The PTW is suspended temporarily
• Determine the source of the hazardous atmosphere
• Measures shall be implemented to protect employees from the hazardous
atmosphere
• Before any subsequent entry, test or monitor as necessary to determine if
entry conditions are acceptable
36
37. PROCEDURE FOR ENTRY
Work Completed
• Housekeeping
• Debriefing
• De-isolate, de-energize
• PTW closed
• Hand-over
37
