Arc Welding
What is Arc Welding?
 Generalized term used to describe welding
that uses an electric arc between an
electrode and the base material to melt and
join the metals.
 Common Names and Variations:
• Shielded Metal Arc Welding (SMAW) “Stick
Welding”
• Gas metal arc welding (GMAW) = Metal inert
gas (MIG), Flux-cored arc welding (FCAW),
Submerged arc welding (SAW)
• Gas tungsten arc welding (GTAW) or
Tungsten inert gas (TIG) welding
Stick Welding Cut-Away
Photo Courtesy of Lincoln Electric (http://www.lincolnelectric.com/knowledge/articles/content/arcweldfund.asp)
Hazards
• Welding is an inherently dangerous occupation.
• Even without malfunction the process exposes
those around it to heat, radiation, foreign
objects (slag), gases, and high electrical
current.
• Malfunctions in equipment often leads to very
dangerous situations.
Hazard: Heat
• The arc produced during welding can exceed
3000 degrees Celsius.
• Molten metal particles “splash” off the weld
and can cause burns and fires.
Protection: Heat
 Personal Protective Equipment (PPE)
is used to protect the worker from
heat, light and slag.
 Welding blankets are used to protect
surrounding areas from slag.
 Wearing PPE in hot climates poses the
risk of overheating. Hydration and
ventilation are a must.
Hazard: Radiation

1.
2.
Welding exposes the welder and anyone around the work area
to Ultraviolet (UV) Radiation. This exposure poses two risks:
Flash Burn - A burning of the surface of the eyeballs and/or
skin caused by the UV rays. Same effects as sun burn.
Retinal Burn - Burning of the retinal nerve caused by the
projecting of the extremely bright arc on the back of the
eyeball.
Protection: Radiation
 Flash burn and retinal burn can be prevented through the
proper use of PPE. A high quality shade can prevent eye
damage and is required (OSHA 1926.353(e)). The shade
number used should correspond to the work being performed.
Clothes that completely cover the body prevent flash burn to
the skin.
 Those working near the welder should be protected from flash
burn by a welding barrier that is set-up around the area.
Hazard: Gases

1.
A welder is faced with different hazards related to the
gases they are exposed to.
The welding process produces toxic fumes. The zinc
oxide and magnesium oxide fumes can cause Metal
Fume Fever. The symptoms of which can include:
headache, fever, chills, muscle aches, thirst, nausea,
vomiting, chest soreness, fatigue, gastrointestinal
pain, weakness, and tiredness. (American Welding Society)
Hazard: Gases
2.
3.
The shielding gases used in welding, while inert,
can cause asphyxiation in enclosed spaces. The
gases are used in the welding process to displace
oxygen from the area of the weld. If the gases are
contained in a small area the worker’s oxygen
levels will be depleted.
The gas cylinders used in the welding carry the
same risks of rupture and explosion as any
compressed gas cylinder.
Protection: Gases
 In order to protect the worker from toxic gases and
from the displacement of available oxygen proper
ventilation is required (OSHA 1926.353(a)).
 OSHA regulation (1926.353(b)) requires lifelines and
full-time spotters to be used for welding in confined
spaces.
 Care should be taken in the transport and use of all gas
cylinders.
Hazard: Electrical Current
 Arc welding draws a large amount of
current and passes it through the piece
of material in front of the worker.
Anytime electricity is involved there is a
risk of injury/death.
Protection: Electrical Current
 In order to avoid electrical shock welding should
be done in a dry environment. Avoid moist
conditions and standing water.
 In hot climates there is the possibility of sweat
soaked clothing becoming an electrocution hazard.
 Electrical equipment should be inspected
frequently. Splices must be rated at least as high
as the conductors they are joining and no splices
can be present in the 10 feet of conductor closest
to the welding torch (OSHA 1926.351(b)).
The Numbers
 The risk from fatal injuries from welding is
more than four deaths per 1,000 workers
over a working lifetime.
 For the construction industry, welders flash
(burn to the eyes) accounts for 5.6% of all
construction eye injuries.
 1/4 of all welding injuries are eye injuries.
 Explosions and electrocutions are rare but
tend to be very serious.
Specific Cases
 A construction worker was killed on June 30, 2004
in when a welding torch apparently ignited his
clothes while he was working inside a steel
drainage pipe at a construction site at Highway 29
in Napa. The man was trapped inside the pipe and
burned to death.
 On August 21, 1989 in British Columbia a welder
was discovered unconscious inside a titanium tank
he had been finish welding valves. The argon gas
used to shield the weld displaced the oxygen in the
bottom of the tank and worker died of
asphyxiation.