2. Welding
Welding joins two pieces of metal by the use of
heat, pressure, or both
Brazing or soldering involves a filler metal which
has a lower melting point than the metal pieces
to be joined
Metal cutting is done by heating the metal with a
flame and directing a stream of pure oxygen
along the line to be cut
3. Welding
Arc Welding
Shielded Metal Arc Welding (SMAW)
Metal Inert Gas (MIG)
Tungsten Inert Gas (TIG)
Plaza Arc Welding (PAW)
Submerged Arc Welding (SAW)
And Many More…..more than 80 in all
4. Health Hazards
Gases and Fumes…
Welding “Smoke” is a mixture of very fine particles
called fumes and gases
Welding “Smoke” contains fumes and gases including…
Chromium, nickel, arsenic, asbestos, manganese, silica,
beryllium, cadmium, nitrogen oxides, phosgene,
acrolein, flourine compounds, carbon monoxide, cobalt,
copper, lead, ozone, selenium, and zinc
5. Health Hazards…Gases & Fumes
Generally, gases and fumes come from…
Base material & filler material
Coatings & paints
Shielding gases & chemical reactions
Process & consumables used
Contaminants in the air
6. Health Hazards
It is difficult to list all the health effects of welding
exposures because the fumes may contain so
many different substances that are known to be
harmful
The individual components of welding “smoke”
can affect just about any part of the body,
including the lungs, heart, kidneys, & central
nervous system
7. Health Hazards
Exposure to welding “smoke” may have…
Short-term effects…
Effects happen at or very soon after exposure
Long-term effects
Effects may happen after repeated overexposures or
an extended time after the exposure
8. Short-term exposures
Exposure to zinc, magnesium, copper and
copper oxide can cause metal fume fever
Symptoms of metal fume fevere may occur 4 to
12 hours after exposure
Symptoms include…
Chills, thirst, fever, muscle ache, chest
soreness, coughing, wheezing, fatigue, nausea,
and metallic taste in mouth
9. Short-term exposures
Welding “smoke” can irritate the eyes, nose,
chest and respiratory tract
Welding “smoke” can cause coughing,
wheezing, shortness of breath, bronchitis,
pulmonary edema, and pneumontis
Welding “smoke” can cause nausea, loss of
appetite, vomiting, cramps, and slow digestion
10. Short-term exposures
Exposure to cadmium can be fatal in a short time
Ultraviolet radiation can react with oxygen and
nitrogen to form ozone and nitrogen oxides
These gases are deadly at high concentrations
and can also cause irritation of nose and throat
and cause serious lung disease
11. Short-term exposures
Ultraviolet rays given off by welding can react with
hydrocarbon solvents such as…
Trichloroethylene; 1,1,1-trichloroethane; methylene
chloride; & perchloroethylene to form phosgene gas
Even a very small amount of phosgene gas may be
deadly
Early symptoms include dizziness, chills, and cough and
usually take 5 – 6 hours to appear
12. Short-term exposures
Arc welding should never be performed within
200 feet of degreasing equipment or solvents
13. Long-term exposures
Studies of welders, flame cutters, and burners
have shown that welders have an increased risk
of lung cancer…
and…possibly cancer of the larnyx and urinary
tract
Remember… welding “smoke” can include
cancer causing agents such as…cadmium,
nickel, beryllium, chromium, and arsenic
14. Long-term exposures
Welders may experience a variety of chronic
respiratory problems, including…
Bronchitis, asthma, pneumonia, emphysema,
pneumoconiosis, decreased lung capacity,
silicosis, and siderosis
15. Long-term exposures
Other health problems…
Heart disease, skin diseases, hearing loss,
chronic gastritis, gastroduodentis, and ulcers of
the stomach and small intestine
Reproductive risks
16. Other Health Risks…
Heat exposure…
Heat stress, heat stroke
burns, eye injuries from hot slag, metal chips,
sparks, and hot electrodes
17. Other Health Risks…
Visible light, and ultraviolet and infrared radiation
Intense light can cause damage to retina
Infrared radiation may damage the cornea and
result in cataracts
Invisible UV light can cause “arc eye” or
“welders’ flash”
May include sandy or gritty eye, blurred vision,
intense pain, tearing, burning and headache
18. Other Health Risks…
Permanent eye damage
Skin burns
Skin cancer
Noise
Can result in stress, increased blood pressure, may
contribute to heart disease, tiredness, nervousness,
and irratability
19. Musculoskeletal Injuries
Back injuries, shoulder pain, tendonitis, reduced
muscle strength, carpal tunnel syndrome, white
finger, and knee joint diseases
Injuries may be caused by overhead work,
vibration and heavy lifting
20. Electrical Hazards
Even though welding generally uses low voltage,
there is still a danger of electric shock
Wet work areas, Cramped work spaces
Falls, fractures and other accidents can result
from electrical exposure
Even small shock can cause brain damage
Death can occur from large shocks
21. Electrical Hazards
Always use dry gloves
Always wear rubber soled shoes
Always use insulating layers
Protect yourself from surfaces that conduct electricity
When working on electrically powered machinery, make
sure the frame is grounded
Keep insulation on all welding equipment and
components dry and in good condition
Don’t change electrodes with bare hands, wet gloves or
while standing on wet or ungrounded surfaces
22. Fire and Explosion Hazards
Intense heat and sparks can cause fires or
explosions if in the vicinity of combustible or
flammable materials
Welding and cutting should only be performed in
areas free of combustible materials such as
trash, wood, paper, textiles, plastics, chemicals,
and flammable dusts, liquids and gases
23. Fire and Explosion Hazards
Never weld or cut on containers that have held a
flammable or combustible material unless the container
is thoroughly cleaned or filled with an inert gas
A fire inspection should be performed prior to leaving a
work area and for at least 30 minutes after the operation
is completed
Fire extinguishers should be nearby, of proper size, type
and number for the hazards involved
24. Dangerous Machinery
All machines in the area with moving parts must
be guarded to prevent worker’s contact
Hair, clothing, fingers, etc.
When repairing machinery by brazing and
welding, power must be disconnected, locked
out, and tagged so the machinery cannot be
started up accidentently
25. Trips and Falls
To prevent trips and falls…
keep work areas clear of equipment, machines,
cables, and hoses
Always properly maintain and use handrails
Always use and maintain safety lines, harnesses
and lanyards
Always make sure that scaffolds are properly
assembled and used
26. Welding Hazards in Confined
Space
A work area with limited access, little or no
airflow, not intended for continuous occupation
May also have dangerous atmospheres, hazardous
configurations, or other hazards
All employees working in or around confined
space must be trained
27. Welding Hazards in Confined
Space
Never weld or cut in explosive, flammable,
combustible or other dangerous environments
Always use all necessary Personal Protective
Equipment (PPE), including, harness and
lanyard, respiratory protection, eye protection,
etc.
Never work in confined space without a trained
attendant
28. Welding Hazards in Confined
Space
Always leave gas cylinders and welding power
sources outside the confined space…
Only take hoses or welding leads into confined
space
Always removed hoses and/or leads when
leaving confined space for breaks, shift or crew
changes, etc.
29. Welding Hazards in Confined
Space
No worker should work in an area with less than
19.5% or more than 23.5% oxygen content
Never ventilate with oxygen
Use continuous mechanical ventilation and
proper respiratory protection
All pipes, ducts, power lines, etc. that are not
necessary for the work should be
disconnected/locked out/tagged out
30. Compressed Gas Hazards
Gas welding and cutting use a fuel gas and
oxygen which are stored in high pressure
cylinders
Most fuel gases are explosive
Pure oxygen will increase the flammability of any
combustible/flammable material
31. Compressed Gas Hazards
All cylinders should have caps or regulators
Pressure regulators must be designed for gas in use
Check all equipment and components prior to use
Cylinders must be stored upright and secured
Oxygen and fuel gas cylinders must be stored
separately
Be aware of flashbacks and backfires??
Close cylinder valves when work is completed or left
unattended during breaks, etc.
32. Reducing Noise Hazards
Identify hazards and potential hazards prior to
beginning hot work
Read the MSDS sheet to identify the hazardous
material used in welding and cutting products,
and the fumes that may be generated
Make sure that you know what you are welding
before beginning
Cadmium exposure can be fatal in a very short time
33. Compressed Gas Hazards
After a specific hazard(s) has been identified…
you can implement appropriate control
method(s)
You can use appropriate PPE
34. Engineering Controls and Work
Practices
Substitute less hazardous materials for
hazardous materials
Use cadmium-free silver solders
Use asbestos- free electrodes, gloves, and hot
pads
Use ventilation to move away or dilute hazards
Use work area barriers to protect others working
in the same general area
35. Engineering Controls and Work
Practices
Welding booths should be painted with dull
finishes so they don’t reflect UV light
Acoustic shields between the worker and noise
sources can reduce exposures
Noisy machinery can be totally enclosed
36. Engineering Controls and Work
Practices
Modify the process or follow safe work practices so that
hazards are eliminated or reduced to the minimum…
Don’t weld on painted surfaces; use water table under
plasma arc cutting to reduce noise; Grind instead of air-
arcing; use sub arc; position yourself away from fumes;
remove nearby flammables/combustibles; properly
maintain equipment; proper housekeeping; use lowest
possible amperage; hold electrode perpendicular and
close to work surface
Never weld or cut within 200 feet of degreasing
equipment or solvents
37. Personal Protective Equipment
(PPE)
PPE must be used in conjunction with
engineering controls and safe work practices
Use of one does not eliminate the need for the other
Eye protection should be used in all welding
operations
Wear face shields or helmets and goggles or safety
glasses
Use appropriate filters on eye protection
39. Filter Lens Shade Numbers
Soldering = #2
Torch Brazing = #3 or #4
Light cutting up to 1 inch = #3 or #4
Medium cutting 1 inch to 6 inches = #4 or #5
Heavy cutting over 6 inches = #4 or #6
Light gas welding up to 1/8” = #4 or #5
Medium gas welding 1/8” to ½ “ = #5 or #6
Heavy Gas Welding over ½ “ = #6 or #8
40. Protective Clothing
Fire resistant gauntlet gloves
Headcap
High top hard toed shoes
Leather apron
Faceshield
Flame retardant clothing
Safety Glasses
Safety helmet
41. Hearing Protectors
Ear plugs and/or muffs should be worn during
noisy operations such as air arcing or grinding
Most welding operations are noisy
42. Respirators
Must be specific to the hazard
Must be fitted, cleaned, stored and maintained in
accordance to regulation and manufacturers
specs
NIOSH recommends respirators whenever a
carcinogen is present