Transcript Welding Safety - Innovation for Construction and Engineering

Doris Kemp
BCT 480
Welding joins two pieces of metal by the use of heat
and/or pressure
 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
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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
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Generally, gases and fumes come from…
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Base material & filler material
Coatings & paints
Shielding gases & chemical reactions
Process & consumables used
Contaminants in the air
Welding “Smoke” is a mixture of very fine particles
called fumes and gases
 Welding “Smoke” contains fumes and gases
including…
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 Chromium, nickel, arsenic, asbestos, manganese, silica,
beryllium, cadmium, nitrogen oxides, phosgene, acrolein,
fluorine compounds, carbon monoxide, cobalt, copper,
lead, ozone, selenium, and zinc
 cancer causing agents include: cadmium, nickel,
beryllium, chromium, and arsenic
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Exposure to welding “smoke” may have…
Short-term effects
 Effects happen at or very soon after exposure
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Long-term effects
 Effects may happen after repeated overexposures or an
extended time after the exposure
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Welding “smoke” can :
 irritate the eyes, nose, chest and respiratory tract
 cause coughing, wheezing, shortness of breath, bronchitis,
pulmonary edema, and pneumonitis
 cause nausea, loss of appetite, vomiting, cramps, and slow
digestion
Studies of have shown that welders have an
increased risk of lung cancer and, possibly, cancer of
the larynx and urinary tract
 Welders may experience a variety of chronic
respiratory problems, including:
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 Bronchitis, asthma, pneumonia, emphysema, pneumoconiosis,
decreased lung capacity, silicosis, and siderosis
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Other health problems include:
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Heart disease
skin diseases
hearing loss
chronic gastritis
ulcers of the stomach and small intestine
other reproductive risks
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Heat exposure
 Heat stress,
 heat stroke
 Skin burns and skin cancer
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Noise
 Can result in stress, increased blood pressure, may contribute to
heart disease, tiredness, nervousness, and irritability
Eye damage- More than 5% of all eye injuries in the
construction industry are associated with welding,
cutting, and brazing
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 damage to retina
 damage to cornea, resulting in cataracts
 permanent eye damage
Invisible UV light can cause “arc eye” or “welders’
flash”
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 May include sandy or gritty eye, blurred vision, intense pain,
tearing, burning and headache
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
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Use cadmium-free silver solders
Use asbestos- free electrodes, gloves, and hot pads
Use work area barriers to protect others working in
the same general area
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Construction personnel that is welding should be
properly trained and qualified
 Inspect work area for fire hazards before welding
 Make provisions for ventilation before welding
 Compressed gas cylinders should always be secured
in an upright position when not in use and handled
with extreme care
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Gas cylinders should be stored at least 20 feet away
from flammable materials and heat sources
 Oxygen cylinders should be stored at least 20 feet
away from gas cylinders and combustible materials.
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 When not possible, use a 5 ft tall noncombustible barrier with a
30 min. fire-resistance rating or better
All combustible materials should be removed from
welding area or covered with noncombustible
material, prior to welding
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 If covered, a worker that has experience using a fire
extinguisher should be posted near as fire watch
Workers should stand to the rear or side of
regulators when opening valves on tanks
 Proper PPE should be worn, even by workers not
welding
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Don’t weld on painted surfaces
Use water table to reduce noise
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
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PPE must be used in conjunction with engineering
controls and safe work practices
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 Use of one does not eliminate the need for the other
Eye protection should be used in all welding
operations
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 Wear face shields or helmets and goggles or safety glasses
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Use appropriate filters on eye protection
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Fire resistant gauntlet gloves
Head cap
High top hard toed shoes
Leather apron
Face shield
Flame retardant clothing
Safety Glasses
Safety helmet
Hearing plugs and/or muffs
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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
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
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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
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All machines in the area with moving parts must be
guarded to prevent worker’s contact
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e.g. hair, clothing, fingers
When repairing machinery by brazing and welding,
power must be disconnected, locked out, and tagged
so the machinery cannot be started up accidentally
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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
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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
 Adequate ventilation must hold fumes and smoke to
levels within the safe breathing range set forth
in 29 CFR 1926 subpart D
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No worker should work in an area with less than
19.5% or more than 23.5% oxygen content
 Use continuous mechanical ventilation and proper
respiratory protection
 When adequate ventilation cannot be achieved,
workers must be provided with air supplying
respirators as described in 29 CFR 1926 Subpart E
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Always leave gas cylinders and welding power
sources outside the confined space…
 Only take hoses or welding leads into confined space
and remove when leaving for breaks, shift or crew
changes
 All pipes, ducts, and power lines that are not
necessary for the work should be disconnected/locked
out/tagged out
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When transporting and handling, valve cap should be
securely in place
 Cylinders should never be lifted by valve cap
 Cylinder valve should be closed when cylinder is
empty, being moved or not in use
 Cylinders should be secured to a pallet, cradle, or
sling board for hoisting
 Cylinders should not be dropped, bumped, struck or
receive any other huge impact
 Cylinders should be thawed with warm water when
frozen in place
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Fuel, gas and oxygen hoses must be easily and clearly
distinguishable.
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 Oxygen and gas hoses must not be interchangeable
When oxygen and fuel hoses are taped, no more than 4
inches per foot of hose may be taped
 Gas and oxygen hoses must be inspected before every
shift and removed if defects are found.
 Torches should be inspected before each shift to detect
leaks
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 Tip openings should be kept clean and unclogged
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Torches should be lighted by friction lighters
Only use manual electrode holders designed specifically
for arc welding
 All current-carrying parts should be properly insulated
for maximum voltage encountered
 Cables must be properly insulated, flexible and able to
handle maximum current required
 All equipment and cables should be inspected before
each shift and should be removed if any defects are found
 Operations should be shielded appropriately as to
protect other workers in the area
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Subject to damage
from other activities in
the vicinity
Cylinder laying
in a horizontal
position.
Electrical cord in
Contact with the
cylinder
Compressed Gas Cylinder Safety
Chain
Cylinders are not protected from falling. Note
that the Chain is not secured across.
Compressed Gas Cylinder Safety
Electrical
Cord
1. Cylinder not secured
3. Subject to damage.
2. Cylinder should be stored
4. Electrical cord draped over.
Compressed Gas Cylinder Safety
1. Small cylinder not tied off
2. Combustibles stored with cylinders
3. Bad housekeeping
4. Acetylene and Oxygen stored
too close together and no chain.
Compressed Gas Cylinder Safety
1. Cylinder with no valve or cap installed
2. Laying horizontal on the ground
3. Subject to damage
Compressed Gas Cylinder Safety
Electrical arc
damage
Cylinder is damaged. Should be taken out of service immediately!
Compressed Gas Cylinder Safety
Cylinder should be in storage protected from damage and not
laying on the ground regardless if it is full or empty
Compressed Gas Cylinder Safety
Old, corroded cylinder that should have been disposed
of a long time ago.
Compressed Gas Cylinder Safety
Forklift
1. Cylinders laying on the ground and improperly stored
2. Subject to damage from forklift operation in vicinity
Compressed Gas Cylinder Safety
1. Feed line exposed to damage/leak that could cause a fire/explosion
2. Tripping Hazard
Compressed Gas Cylinder Safety
1. Inadequate housekeeping
2. Valve caps should be installed.
Compressed Gas Cylinder Safety
1.
Unsecured acetylene cylinder 2. Exposed to damage
Compressed Gas Cylinder Safety
Unsecured cylinders
Compressed Gas Cylinder Safety
Regulator left pressurized after use
Compressed Gas Cylinder Safety
Improper Storage
Compressed Gas Cylinder Safety
Tie Off?
Compressed Gas Cylinder Safety
Improper storage of
cylinders- acetylene and
oxygen stored next to each
other
Compressed Gas Cylinder Safety
Evidence of smoking next to acetylene
cylinders
Compressed Gas Cylinder Safety
This cylinder should be
taken to storage and
housekeeping should be
improved.
Compressed Gas Cylinder Safety
Unsecured
cylinder
Compressed Gas Cylinder Safety
Unsecured Cylinder
Compressed Gas Cylinder Safety
Cooking equipment
within 20 ft
of containers
Compressed Gas Cylinder Safety
Not Tied
Compressed Gas Cylinder Safety
Tied
oxy-acetylene torch connected
To bottles without the torch
connected.
Compressed Gas Cylinder Safety
Not in use.
Should be
Stored.
No cap installed
Housekeeping
Compressed Gas Cylinder Safety
Cylinder not in use
with regulators still
On the cylinder
Free standing
cylinder
Compressed Gas Cylinder Safety
Free standing
cylinder
Compressed Gas Cylinder Safety
Free standing cylinders
Chain
Compressed Gas Cylinder Safety
Cylinder
tied only
With a bungee
cord
Compressed Gas Cylinder Safety
Cylinders not
Secured properly
Compressed Gas Cylinder Safety
Free standing
cylinders
Exposed to damage
From construction
Activities in area
Compressed Gas Cylinder Safety
Free standing
cylinders
Compressed Gas Cylinder Safety
Cylinder laying on its side
Compressed Gas Cylinder Safety
Coll, R. (2002, October 17). Compressed Gas Cylinder Training Slides.
Retrieved September 10, 2009 from , Web site:
http://siri.uvm.edu/ppt/cgcsafety/sld001.htm
Goetsch, D. (2010). Construction safety and the OSHA standards.
Boston: Pearson.
Saverio (2003). Welding Safety. Retrieved September 10, 2009
from , Web site:
http://www.authorstream.com/Presentation/Saverio-42953Welding-Safety-2003-Health-Hazards-HazardsGases-Fumes-Shortterm-Entertainment-ppt-powerpoint/