Welding SafetyWelding Safety

WY MSHA State Grant Program

WeldingWelding 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

WeldingWelding

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

Health HazardsHealth 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

Health Hazards…Gases & FumesHealth 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

Health HazardsHealth 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

Health HazardsHealth 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

Short-term exposuresShort-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

Short-term exposuresShort-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

Short-term exposuresShort-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

Short-term exposuresShort-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

deadlyEarly symptoms include dizziness, chills, and cough and usually take 5 – 6 hours to appear

Short-term exposuresShort-term exposures

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

Long-term exposuresLong-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

Long-term exposuresLong-term exposures

Welders may experience a variety of chronic respiratory problems, including…

Bronchitis, asthma, pneumonia, emphysema, pneumoconiosis, decreased lung capacity, silicosis, and siderosis

Long-term exposuresLong-term exposures

Other health problems… Heart disease, skin diseases, hearing loss,

chronic gastritis, gastroduodentis, and ulcers of the stomach and small intestine

Reproductive risks

Other Health Risks…Other Health Risks…

Heat exposure…Heat stress, heat stroke

burns, eye injuries from hot slag, metal chips, sparks, and hot electrodes

Other Health Risks…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

Other Health Risks…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

Musculoskeletal InjuriesMusculoskeletal 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

Electrical HazardsElectrical 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

Electrical HazardsElectrical 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

Fire and Explosion HazardsFire 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

Fire and Explosion HazardsFire 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

Dangerous MachineryDangerous 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

Trips and FallsTrips 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

Welding Hazards in Confined SpaceWelding 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

Welding Hazards in Confined SpaceWelding 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

Welding Hazards in Confined SpaceWelding 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.

Welding Hazards in Confined SpaceWelding 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

Compressed Gas HazardsCompressed 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

Compressed Gas HazardsCompressed 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.

Reducing Noise HazardsReducing 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

Compressed Gas HazardsCompressed Gas Hazards

After a specific hazard(s) has been identified… you can implement appropriate control

method(s) You can use appropriate PPE

Engineering Controls and Work PracticesEngineering 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

Engineering Controls and Work PracticesEngineering 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

Engineering Controls and Work PracticesEngineering 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

Personal Protective Equipment (PPE)Personal Protective Equipment (PPE) PPE must be used in conjunction with

engineering controls and safe work practicesUse 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

Filter Lens Shade NumbersFilter 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

Filter Lens Shade NumbersFilter 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

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

Hearing ProtectorsHearing Protectors

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

Most welding operations are noisy

RespiratorsRespirators

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