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Welding%20Safety

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Welding Safety WY MSHA State Grant Program Welding Welding joins two pieces of metal by the use of heat, pressure, or both Brazing or soldering involves a filler ... – PowerPoint PPT presentation

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Title: Welding%20Safety


1
Welding Safety
  • WY MSHA State Grant Program

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 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

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
  • andpossibly cancer of the larnyx and urinary
    tract
  • Remember welding smoke can include cancer
    causing agents such ascadmium, 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
  • Dont 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 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

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 dont 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
  • 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

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

38
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

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
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