Welding Safety

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Welding Safety

• WY MSHA State Grant Program

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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

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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

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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

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Health HazardsGases Fumes

• Generally, gases and fumes come from
• Base material filler material
• Coatings paints
• Shielding gases chemical reactions
• Process consumables used
• Contaminants in the air

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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

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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

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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

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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

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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

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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

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Short-term exposures

• Arc welding should never be performed within 200
  feet of degreasing equipment or solvents

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Long-term exposures

• Studies of welders, flame cutters, and burners
  have shown that welders have an increased risk of
  lung cancer
• andpossibly cancer of the larnyx and urinary
  tract
• Remember welding smoke can include cancer
  causing agents such ascadmium, nickel,
  beryllium, chromium, and arsenic

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Long-term exposures

• Welders may experience a variety of chronic
  respiratory problems, including
• Bronchitis, asthma, pneumonia, emphysema,
  pneumoconiosis, decreased lung capacity,
  silicosis, and siderosis

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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

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Other Health Risks

• Heat exposure
• Heat stress, heat stroke
• burns, eye injuries from hot slag, metal chips,
  sparks, and hot electrodes

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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

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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

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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

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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

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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
• Dont change electrodes with bare hands, wet
  gloves or while standing on wet or ungrounded
  surfaces

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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

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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

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Dangerous Machinery

• All machines in the area with moving parts must
  be guarded to prevent workers 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

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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

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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

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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

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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.

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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

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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

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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.

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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

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Compressed Gas Hazards

• After a specific hazard(s) has been identified
• you can implement appropriate control method(s)
• You can use appropriate PPE

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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

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Engineering Controls and Work Practices

• Welding booths should be painted with dull
  finishes so they dont reflect UV light
• Acoustic shields between the worker and noise
  sources can reduce exposures
• Noisy machinery can be totally enclosed

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Engineering Controls and Work Practices

• Modify the process or follow safe work practices
  so that hazards are eliminated or reduced to the
  minimum
• Dont 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

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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

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Filter Lens Shade Numbers

• SMAW 1/16 - 5/32 10
• Gas SAW - 1/16 - 5/32 11 (nonferrous)
• Gas SAW 1/16 5/32 12 (ferrous)
• SMAW 3/16 ¼ - 12
• 5/16 3/8 electrodes 14
• Atomic Hydrogen Welding 10 - 14
• Carbon Arc Welding CAW 14

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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

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Protective Clothing

• Fire resistant gauntlet gloves
• Headcap
• High top hard toed shoes
• Leather apron
• Faceshield
• Flame retardant clothing
• Safety Glasses
• Safety helmet

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Hearing Protectors

• Ear plugs and/or muffs should be worn during
  noisy operations such as air arcing or grinding
• Most welding operations are noisy

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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