This document provides information on construction safety, with a focus on hot work safety, high risk work safety, and safety tools. It discusses hazards and safety procedures for hot work including welding, gas cutting, and grinding. It also covers high risk work such as work at heights, lifting and rigging, confined space entry, excavation work, and electrical work. It emphasizes the importance of pre-task planning, including job safety analyses, and using permit to work systems to identify hazards and controls before dangerous jobs.

1. Construction Safety
Engr. Ali Kamal Mostofa Rubel
MPH in Occupational Health & Safety
alikamalmostofa@gmail.com

2. Contents Title
01. Introduce
04. Safety Tools
04-1. Pre-task planning
04-2. Permit to work
02. Hot work safety
02-1. Gas cutting
02-2. Arc welding
02-3. Grinding
03. High risk work safety
03-1. Work at height
03-2. Lifting & rigging
03-3. Confined space entry
03-4. Excavation work
03-5. Electrical work

3. Switch Off Mobile Phones
No Smoking
In Case Of Emergency
1

4. 4
Work Stop Authority
1.The lowest standard you set is the highest standard the workforce will meet. You must be a Role Model!
2.Everyone has an obligation to stop work that is unsafe, and has a potential to cause injury to workers.
Introduce
ALARP (As Low As Reasonably Practicable)
What standard could be regarded as safe enough?

5. Hot work
02-1. Gas cutting
02-2. Arc welding
02-3. Grinding
2

6. Hot work safety
Welding hazards
6
Occupational hazards Electrical shock
Exposed live parts and cable insulation
are damaged
Note: The arc welding voltage of the
secondary welding of the arc welding
(handle welding) is 60- 90V, which is
not a safe voltage. Therefore, the first
and second wires of the welding
machine should ensure good insulation.
Fume, gas, arc flash, radiation
Flammable materials, spark
Welding
Fire

7. Hazard of welding
7
01
02
03
• Toxic gases
Ozone
Nitrogen Oxides
CO2
• Toxic fumes
Cadmium Oxide
Chromic acid
Copper fumes
Nickel fumes
Vanadium fumes
Zinc Oxide
• Radiation
Infra-red
Ultra-violet
Hot work safety
Welding

8. 8
Check all equipment for defects prior to use: cables & connection, earth clamps, & electrode holder
， make sure insulation is good.
The machine, cables and connections are in good condition/ clear of water
Do not touch the cable or welding tongs by wet hands..
Remove all inflammable materials from workplace.
Fire blanket and screen to be used to protect others and equipment. And fire watchman a
nd fire extinguisher to be available within the area.
Hot work safety
Welding
Use welding fume-extracting device, and keep good ventilation condition
Appropriate PPE to be worn ：Shawl , fume respirator(P1) , Welding Helmet, coveralls, welding
gloves, eye protection, safety boots, hearing protection, apron, leg protection.
Safety measure for welding

9. 9
 When transporting, a suitable hand truck, forklift, or similar handling
device will be used with the cylinder properly secured to the
device and the valve cap on
 Cylinders will not be dragged, dropped, rolled, or struck in
horizontal position, or allowed to strike each other or another
surface violently
 Roll only for short distances, using the curved bottom edge of the
cylinder
 Do not lift using the protective cap or with a magnet
Handling of gas cylinder
Hot work safety
Gas cutting

10. 10
 Cylinders will be placed upright with the valve end up, and a steadying device used to
secure them from being knocked over.
 Cylinders should be kept at least 10 meters away from open flames, hot metal, or other
sources of heat. And should be protected from direct sun and weather conditions.
 Compressed gas and oxygen cylinders must not be placed in confined/enclosed or no
ventilated areas
 Empty cylinders will be segregated from other cylinders and labeled or tagged “Empty” or
“MT”
 Oxygen cylinders not in use must not be stored within 20 feet (6.1 meters) of cylinders
containing flammable gases unless separated by a fire wall at least 5 feet (1.5 meters) tall
and having a fire-resistance rating of at least 1/2 hour
 Oxygen cylinders, fittings, caps, valves, couplings, and regulator hoses must be kept away
from oil, grease, and other combustible/flammable materials.
Hot work safety
Gas cutting
Storage of gas cylinder

11. 11
 Flashback devices must be installed at both the regulator and
torch end, on both lines, of oxygen/fuel gas systems
 Regulators and hoses will be leak tested immediately after they
are connected
 Cylinders must be kept far away from the welding/cutting
operation to prevent sparks, hot slag, and flames from reaching
them
 Acetylene cylinder valves will be opened 3/4 of a turn or less;
do not open valves more than 1-1/2 turns
 Do not strike an arc on a cylinder
 Valve protective caps will be kept on except when it is secured
and connected to dispensing equipment
Hot work safety
Gas cutting
Use of gas cylinder
An explosion of oxygen cylinder followed
by a fire occurred in a factory arising fro
m the use of oxyacetylene gas equipme
nt. Four persons were killed and another
two workers were injured in the accident.

12. 12
 Leaking or damaged hose or hose couplings
 Leaking or damaged fuel-gas pressure regulators and gauges and related
connections
 Leaking or damaged torch heads or shutoff valves and related connections
 Clogged tip openings
 Use a friction flint lighter to ignite gas torch, Never use matches, cigarette
lighters, burning paper, or lit cigarettes to light handpieces
Hot work safety
Gas cutting
Gas welding and cutting equipment must be inspected by the user at the beginning of
each shift to identify any of the following defects:

13. 13
• CHECK VALVES
• Are the basic safety device
• Prevents flash back accidents caused by “reverse
flow”
-Flashbacks can cause the most serious accidents
• Check valves can fail because of “dirt”or other
contamination
• FLASHBACK ARRESTORS
• Flashback arrestors are the ultimate safety device
• Usually have a check valve built into it, but, can also
stop a flame. The Heat sink element will absorb heat
from a fire, The element should also be kept free of
contamination and checked periodically
Check Valves and Flashback Arrestors
Hot work safety
Gas cutting

14. 14
1
Wear appropriate PPE as per required, including Helmet, coveralls, safety boots,
gloves, face shield, goggles, respirator, hearing protection etc.
2 Do not use damaged, uninspected or non-color coded grinding machine, check
and make sure the all parts are in good condition i.e.. safety guard, handle, switch
and fastener etc.
3 Check and make sure the cables are not damaged, and connected correctly.
4
Check and make sure grinding disc is dry, flawless and intact without notch. And m
ake sure grinding disc RPM speed must not lower than the grinding machine RMP.
5 Do not use grinder to cut flexibility or soft materials, i.e.. rope, web-slings, fabricate.
Grinding Operator shall follow the ten principals:
Hot work safety

15. 15
6 Ensure that only cutting discs are used for cutting and grinding discussed for gri
nding.
7
No grinding at the area existing inflammable materials or gas, Fire blanket an
d screen to be used to protect others and equipment.
8 Ensure suitable work space and work posture, and the work piece must be sec
ured properly. Make sure hold grinding machine with both hands.
9 Do not expose power tools to rain or wet condition.
10
Grinder is to be unplugged prior to the change out of disks or any maintenance or
work suspended.
Grinding Operator shall follow the ten principals:
Hot work safety

16. High risk work
03-1. Work at height
03-2. Lifting& rigging
03-3. Confined space entry
03-4. Excavation work
03-5. Electrical work
3

17. 17
To prevent incidents from fall, various types of controls shall be identified and risks associated with working
at heights to be considered during the design and execution planning stages shall be evaluated consideri
ng the hierarchy or controls and risk mitigation for the working at heights as follows:
Eliminate
Avoid work at height where you can
Fall protection
Ladder, Fixed/Mobile work
platforms
Fall protection
Scaffolding, guardrail system
Protective equipment
Lifeline use, anti-fall net, Roped acc
ess, net Personal anti-drop device
(safety belt, anti-drop device)
Elimination
Primary protection system
Secondary protection system
Protective Equipment
Falling Protection
Work at height

18. 18
 A certified full body harness must be worn whilst working above a height of 1.8m
 100% tie off is required when accessing outside the confines of a safe working platform> 1.8m
Tie off must to be a suitable and sufficient anchorage point
Falling Protection
Work at height

19. 19
Inspect ladder before use, ensure it is in a good condition
Secure ladder and ensure it cannot slip, footed or tied off
Where you can maintain 3 points of contact with the ladder
Ensure ladder angle of 75 degrees (1 unit out for every
4 units up)
Heavy tools & materials is not to be carried up or down a
ladder
Do not work from the top 3 rungs
1
2
3
4
5
6
Safety rules for ladders
Work at height

20. 20
 Tool ties/ tethers must be used for all WAH activities, Secure Equipment & Materials
 Do not throw equipment, materials (from above or from the ground)
 Good housekeeping and storage of materials must be maintained in elevated areas
 Designated and protected material storage areas, lanyards or belts , buckets for small
materials
 Erect barricades and exclusion zones where lifting or works are being conducted
overhead
 Protection must be installed – fans, nets and tunnels etc… in areas above pedestrian
routes
Dropped Objects Prevention
Work at height

21. 21
1
Only approved signal man to direct crane and comply with approved JSA
for lifting and hoisting.
2
Do not use uncertified, damaged, uninspected or non-color coded lifting
device or gear and homemade tools.
3
If weight of load or Working Load Limit(WLL) rating of the lifting gear is
unknown or lifting arrangement is overloaded, then do not lift, ensure the
SWL of lifting gear are visible.
4
No Lifting overhead of personnel and no lifting in the yard without cordoning
the lifting area.
5 No hoisting of unsecured or unfastened loads.
Lifting Safety
Crane Operator and Signal Man shall follow the ten principals:

22. 22
Lifting Safety
Crane Operator and Signal Man shall follow the ten principals:
6 Ensure webbing slings are protected from sharp edges and lifting gear
is inspected before use.
7 No hoisting or lifting with inadequate lighting or restricted visibility.
8 No hoisting or lifting when the wind speed is 6Beaufort(30mph) or
higher; or during electrical storm, heavy rain, snow or fog.
9
Avoid handling the load using your hands，operator must use tag
line or push stick.
10
Crane must be on level and safe ground and outriggers positioned fully
extended onto outrigger loading mats.

23. 23
Risk control
设备、吊索具Crane & Lifting gear 人员操作和指挥 Operation
Crane & Lifting gear Human error
Lifting Safety
Safety controls for lifting work
According to statistics, 86% of the lifting accidents are due to human error,
and the remaining 14% are environmental and equipment reasons.

24. 24
Confined Space Entry
Example 1
• Seven workers were killed in a tank that was undergoing maintenance and
cleaning at a plant in Mexico City. Four victims were maintenance
contractors and three victims were company employees.
• The deaths were due to unspecified toxins. The three company employees
had entered the tank in an effort to rescue the four contract employees.
Example 2
• A roll of duct tape was only 5 feet away, resting inside a reactor
chamber at a refinery. The chamber was being purged with
nitrogen, and cleanliness criteria dictated that all debris be
removed. In an attempt to retrieve the roll of tape, one worker
intentionally went inside and – due to the near-zero oxygen
concentration within the reactor – fell unconscious only to be dead
within minutes.
• The situation, already horrific, then got worse. An onsite foreman
quickly descended the ladder in an apparent attempt to rescue his
co-worker. He never returned.
FACT: Personnel attempting
rescue account for 40% of
all confined space fatalities
Accident case

25. Confined Space entry
Definition and example of Confined space
25
Confined Space
Definition Typical Confined Spaces
Large enough and so configured
that an employee can bodily
enter and perform assigned work
Limited or restricted means of entry
Boilers & furnaces
Chimney
Manhole
Pits
Silo & storage tanks
Bins/Caissons
Not designed for continuous human
occupancy
Trenches & Excavations
sewer
Ducts &Pipelines
Lack of natural ventilation and other
potential hazard
Underground utilities
Process vessels
Mobile waste containers

26. 26
• Oxygen Concentration
– <19.5% (oxygen deficient) >
23.5% (oxygen enriched) Inert
Gas
• Combustibles
– Methane
– Hydrogen
– Acetylene
– Propane
– Gasoline fumes
• Toxic Materials
– Carbon Monoxide
– Hydrogen Sulfide
– Welding fumes
– Corrosives
• Electricity
– Fixed hazards
– Temporary power
• Mechanical Hazards
– Mixers
– Rotating part
• Poor Environment
– Poor lighting
– Insufficient ventilation
– Improper access
• Others
– Engulfing
– Falling
– High Temperature And
Humidity
Confined Space entry
Potential Hazards

27. Safety controls for CSE
27
Preparation
Through training, system publicity, safety technology disclosure, operation
safety analysis, posting warning signs, and communicating work permit
requirements, operators can understand the relevant hazards and
corresponding safety control measures. Conduct gas detection, prepare for
ventilation and lighting
01
Process Control
Provide appropriate channels, tools, equipment, and take safety measures to
keep the confined space ventilated, isolated, insulated, emptied, etc., to
ensure that it is always under monitoring
02
Emergency Rescue
Emergency rescue plan, emergency response and rescue implementation,
emergency rescue equipment. After the operation, clean up the site and close
the restricted space.
03
07. Housekeeping& task
closure
06. Emergency rescue
05. Safety
watch/monitoring
04. Ventilation & Gas
detection
1. Awareness& Training
02. Job safety analysis
03. Permit to work
Confined Space Entry

28. 28
Excavation Safety
The bucket of this back hoe struck a
gas line
These workers are exposed to a fall
of more than 1.8 m without the ben
efit of required fall protection
Equipment is too close to excavation
edges, spoil pile too close, no access,
employee outside support system,
improper support system
Common issue of excavation work
Potential Hazards

29. PPE
Personal protective equipment is the ultimate protection for safety.
29

30. EHS Tools
04-1. Pre-task planning
04-2. Permit to work
4

31. 31
Step
Controls HAZID
Job Safety Analysis(JSA)
A comprehensive process that identifies
hazards associated with each step of a job
and develops solutions for each hazard
that will either eliminate or control the
hazard. The process involves subject
matter experts and personnel beyond the
front line supervisor. The process occurs
before the task goes to the field.
Pre-task planning
Job safety analysis

32. 32
No Work Step Identified Hazards Control Measure
01 Preparation
Not competent
Without plan and
awareness
Supervisor conduct and complete JSA, and discuss
relevant hazards and controls with all worker.
02 Access to roof Fall from roof
Portable industrial-grade ladders, secured against
movement, pitched at about 75 degrees (1 in 4) and
extending at least 35 inches (90 centimeters) above
the stepping-off point, may be suitable for minor
works.
03
Work near open
sides roof and near
edge
Fall from roof
Hole and defect roof
Confirm the bearing capacity of roof ，check weak area
04 Materials handling Dropping object 。。。。。。
Example of Job safety analysis
Pre-task planning
Job safety analysis

33. Pre-task meetings will be conducted prior to each task
33
Completed pre-task planning documents with
all employees directly involved in the activity
Hazards and control measures
Work scope, Area where
work is performed
JSA
Hazards and control measures
PPE
Evacuation and emergency procedures
Equipment used
Pre-Task Meetings/Tool box talks
Pre-task planning

34. Permit to work
Permit to work approval process
34
PTW
For the application and approval process of dangerous operations,
all safety precautions must be clarified and implemented before
the start of dangerous work, and the approval process can be
completed before starting the operation.
Applicant/ Performing Authority
Supervisor
Issuer/ Issuing Authority
Area Authority
Workforce
Site safety officer
Application Verification Review Approval Communication

35. 35
Permit
to
Work
Permit to Work
Implement precaution and
controls
Monitoring and inspection
JSA, develop safety control
measure
Issue permit and brief
requirement
Permit to work

36. THANK YOU