20 Welding Safety & Health Practice Questions & Answers

1. 1. A welder pauses between passes with the SMAW power source still switched on and finds a split in the insulation of the electrode holder lead. Why is this dangerous even though no arc is burning, and what should be done?

   • A.The hazard is the heat carried in the cable, so the split is harmless once the lead has cooled down between passes.
   • B.No voltage reaches the lead until the arc is struck, so the split may be wrapped with tape and the holder used for the shift.
   • C.Voltage appears only while current is actually flowing, so the holder is safe as long as dry gloves are worn.
   • D.Open-circuit voltage is present at the electrode any time the machine is on, so the lead is removed from service and repaired.✓ Answer

   An arc welding machine's open-circuit voltage is present at the electrode and holder from the moment the machine is energized, and it is higher than the voltage seen while welding, so the deceptively quiet moment between passes is when shock risk is greatest. Welding cables, holders and connections must be inspected before use and any lead with damaged insulation taken out of service until it is properly repaired.

   Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes — electric shock protection and inspection of cables and electrode holdersReport a problem with this question

2. 2. A welder in a damp basement is kneeling on a wet floor with sweat-soaked gloves and is leaning against the workpiece. What should the welder do first?

   • A.Stop and lay dry plywood over the wet floor, then carry on in the same damp gloves now that the floor is insulated.
   • B.Stop welding, change into dry flame-resistant gloves, and insulate the body from the wet floor and from the workpiece.✓ Answer
   • C.Turn the machine's output down to its lowest setting and keep welding until the heat of the work itself dries the gloves out.
   • D.Move the work clamp to the far end of the plate so the current path runs away from the spot where the body touches it.

   Moisture from sweat, damp clothing or a wet floor sharply lowers the resistance of the skin and of everything the welder is touching, so a voltage that would normally only be felt can drive a dangerous current through the body. The control is to break the circuit path: dry flame-resistant gloves in good repair, dry insulating material between the welder and the floor, and no bare contact with the workpiece.

   Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes — welding in damp conditions and use of dry flame-resistant glovesReport a problem with this question

3. 3. ANSI Z49.1 states that calling the cable and clamp that return welding current from the workpiece a "ground lead" or "ground clamp" is incorrect. What is the correct terminology and the related practice?

   • A.They are the return lead and earth clamp, and the clamp is stored on the power source frame so the frame stays grounded.
   • B.They are the ground lead and ground clamp, and the workpiece is grounded through them so no separate grounding is needed.
   • C.They are the ground lead and work clamp, and either name is acceptable as long as the machine frame itself is grounded.
   • D.They are the work lead and work clamp, and the workpiece is grounded separately from the welding current path.✓ Answer

   The work lead and work clamp carry welding current and are not a grounding conductor, which is why the standard rejects the shop habit of calling them ground lead and ground clamp; the workpiece is grounded independently unless the equipment is designed for an ungrounded workpiece. Treating the work lead as the ground also leads to the dangerous habit of leaving the clamp attached to the power source frame instead of to the work.

   Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes — work lead terminology and grounding of the workpieceReport a problem with this question

4. 4. A helper who watched several arc strikes without eye protection feels fine at quitting time but wakes at 2 a.m. with gritty, watering, light-sensitive eyes. What does this describe?

   • A.Photokeratitis, a UV burn of the eye surface whose symptoms typically appear several hours after the exposure.✓ Answer
   • B.Infrared cataract from radiant heat, which develops within hours of exposure and is relieved by rinsing the eyes.
   • C.Dryness caused by the shielding gas plume, which passes on its own and is prevented by safety glasses alone.
   • D.Spatter particles trapped under the eyelid, which are felt immediately at the arc rather than many hours afterward.

   Ultraviolet radiation from the arc burns the surface layer of the cornea, and because that tissue's nerve endings react only as the damaged cells break down, the pain and grittiness of arc eye typically begin hours after the exposure rather than at the arc. That delay is exactly why bystanders underestimate the hazard and why screens and eye protection are required for anyone in the welding area, not just the welder.

   Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes — arc radiation hazards and protection of persons in the welding areaReport a problem with this question

5. 5. A welder is choosing a filter lens for an arc process and current level not listed on the shop's chart. What approach does the shade-selection guidance in the welding safety standard call for?

   • A.Use one middle shade for every arc process and rely on the helmet's cover plate to make up the difference in brightness.
   • B.Start with a shade too dark to see the weld zone, then go lighter only until the zone is visible, never below the minimum.✓ Answer
   • C.Pick the lightest shade that still hides the arc glare, since a darker lens hides the weld pool and slows the work down.
   • D.Choose the shade by the electrode diameter alone, because current follows diameter and the process itself makes little difference.

   Shade requirements rise with the process and with the welding current because both determine how much ultraviolet and infrared energy the arc emits, so the published guide gives a minimum shade for each process and amperage band and a recommended shade for comfort. The working rule is to begin darker than needed and lighten only until the weld zone is visible, because a filter that is comfortable but below the minimum still lets damaging radiation reach the eye.

   Source: AWS F2.2, Lens Shade Selector, as referenced by ANSI Z49.1, Safety in Welding, Cutting, and Allied ProcessesReport a problem with this question

6. 6. A trainee argues that the welding helmet alone protects the eyes, so safety glasses are unnecessary. How does welding safety practice answer this?

   • A.Safety glasses with side shields are worn under the welding helmet and are required in the shop area at all times.✓ Answer
   • B.Glasses are needed only when chipping slag, so they may be left off while the helmet is down and put on for cleanup.
   • C.The helmet's filter meets the same standard as glasses, so glasses add nothing once a proper shade number is fitted.
   • D.Glasses are for grinders and helpers, while welders are covered by the helmet plus the flame-resistant cap beneath it.

   The helmet is raised, lowered and removed many times an hour, and slag, spatter, grinding sparks and flying chips come from other people's work as well as one's own, so primary eye protection has to be on the face continuously rather than only while an arc is burning. Impact-rated safety glasses with side shields are therefore worn beneath the helmet as the basic requirement for being in the shop at all.

   Source: ANSI/ISEA Z87.1, Occupational and Educational Personal Eye and Face Protection Devices, with ANSI Z49.1, Safety in Welding, Cutting, and Allied ProcessesReport a problem with this question

7. 7. Why does welding safety practice prohibit synthetic clothing such as polyester in the weld shop and call for wool or heavy cotton treated to be flame resistant?

   • A.Synthetics carry static that can set off the arc early, while natural fibers bleed the charge away to the work clamp.
   • B.Synthetics hold more moisture against the skin, which is the main reason burns from spatter go deeper in that clothing.
   • C.Synthetics melt and stick to the skin when sparks land, driving the burn deeper than a fabric that chars in place.✓ Answer
   • D.Synthetics block ultraviolet light poorly, so the skin under them burns even when the fabric itself never catches fire.

   Spatter and slag arrive far above the melting point of thermoplastic fibers, so a synthetic garment liquefies and adheres to the skin, holding the heat against it and turning a spark that would bounce off cotton into a deep contact burn that is hard to remove. Flame-resistant wool or heavy cotton chars instead of melting, which is also why sleeves and collars are buttoned, trouser cuffs are eliminated and trousers overlap the boot tops.

   Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes — protective clothing for welding and cuttingReport a problem with this question

8. 8. Overhead welding is done in a shop where the noise from air carbon arc gouging is high. What does welding safety practice require for the welder's ears?

   • A.Ear protection is optional overhead as long as a flame-resistant cap and cape sleeves with a bib are worn under the hood.
   • B.Noise is controlled by issuing earplugs first, because engineering controls on the equipment are treated as a last step.
   • C.Hearing protection is enough by itself, since earmuffs also keep spatter out of the ear canal during overhead work.
   • D.Noise is controlled at the source wherever possible, and flame-resistant earplugs are used where spatter can enter the ear.✓ Answer

   Noise is reduced first by acting on the equipment and the process, since personal protectors only work when they are correctly fitted and worn every minute of exposure, and they are the fallback when engineering controls cannot bring the level down. Ear canal protection against spatter is a separate hazard from noise, and any plug used for it must be flame resistant so a spark cannot ignite the plug in the ear.

   Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes — noise control and ear protectionReport a problem with this question

9. 9. A welding booth is being set up next to a walkway used by other trades. What arrangement protects the people nearby from the arc?

   • A.Screens or curtains rated for arc radiation, with the booth walls finished in low-reflectivity material to cut reflected UV.✓ Answer
   • B.An open booth with a warning sign, since people walking past are exposed too briefly for the arc to affect their eyes.
   • C.A clear plastic curtain hung to the floor, since the arc's harmful light is stopped by any barrier that blocks the view.
   • D.A polished sheet-metal partition, because a bright surface bounces the arc light back into the booth and away from others.

   Ultraviolet energy does not have to be seen directly to injure the eye: it reflects efficiently off bright, glossy or metallic surfaces, so a shiny partition can bounce the arc onto people the booth was meant to protect. Screens and curtains selected for arc radiation, with booth interiors finished in a dull low-reflectivity material, absorb rather than redirect the energy, and the screens are arranged to still allow air circulation at floor level.

   Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes — protection of persons adjacent to welding operationsReport a problem with this question

10. 10. A welder asks why the local exhaust hood must be kept close to the arc and why the head must stay out of the rising plume. Which statement is correct?

    • A.Fume and gas are the same thing, so a hood anywhere in the bay dilutes both once the plume has spread through the room.
    • B.The plume is only metal fume, so the hood works best downstream where the particles have cooled and settled out of the air.
    • C.Fume is condensed solid particles and the gases are invisible, and both are easiest to capture near the arc before spreading.✓ Answer
    • D.The plume is only a gas, so it rises out of the breathing zone by itself and general room air movement is enough.

    Welding fume is metal and flux vapor that has condensed into extremely fine solid particles, which is what makes the plume visible, while the gases present at the arc, such as ozone, oxides of nitrogen, carbon monoxide and the shielding gas itself, are invisible and are not removed by simply not seeing them. Contaminants are most concentrated and easiest to capture right where they are generated, so the exhaust is placed as near the source as practicable and the welder keeps the head out of the rising plume.

    Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes, and AWS F3.2, Ventilation Guide for Weld FumeReport a problem with this question

11. 11. A welder cuts galvanized steel angle for an hour and that evening has chills, fever, aching and nausea that clear by morning. What happened and what is the control?

    • A.Zinc oxide fume caused metal fume fever; remove the coating first, or use local exhaust and respiratory protection next time.✓ Answer
    • B.The heat caused a heat illness rather than a fume effect; drinking more fluids is the accepted control for this work.
    • C.Argon in the breathing zone caused the fever; the fix is to raise the shielding gas flow so the plume is pushed away.
    • D.Zinc fume is harmless, so the illness came from the flux, and it is prevented by switching to a low-hydrogen electrode.

    Heating zinc-coated steel vaporizes the coating, and the zinc oxide fume produces the delayed flu-like reaction known as metal fume fever, which typically appears some hours after exposure and resolves in a day. Recognition matters because the same delayed pattern can mask far more serious exposures such as cadmium plating, so the response is to identify the coating and base metal from the label or safety data sheet and control the fume at the source before the next cut.

    Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes — fumes and gases from coated base metalsReport a problem with this question

12. 12. Parts are degreased with a chlorinated solvent in a bay next to the welding station. Why is this a serious hazard, and what is the control?

    • A.The vapor is heavier than air and drifts into pits, so the only requirement is to keep the parts off the shop floor.
    • B.The vapor coats the metal and causes porosity, so the parts are simply wiped dry before they are brought to the arc.
    • C.The arc's ultraviolet light breaks the vapor down into phosgene, so degreasing is kept away from arc radiation.✓ Answer
    • D.The solvent vapor thins the shielding gas, and for that reason welding is allowed there only at a raised flow rate.

    Ultraviolet radiation from an arc decomposes chlorinated hydrocarbon vapors such as trichloroethylene and perchloroethylene into highly toxic gases including phosgene, and the reaction happens in the air itself, so the vapor does not have to touch the molten metal to become dangerous. Degreasing operations are therefore located and ventilated so that their vapors cannot reach any arc or atmosphere penetrated by ultraviolet light.

    Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes — chlorinated hydrocarbon degreasing near arc operationsReport a problem with this question

13. 13. A full oxygen cylinder must be moved from the storeroom to a workstation on another floor. Which handling practice is correct?

    • A.Lift it by the valve protection cap with a hoist hook, since the cap is threaded into the neck ring for that purpose.
    • B.Lay it on its side and roll it to the elevator, then stand it up, leaving the cap off to save time at the station.
    • C.Close the valve, fit the cap, and move it in a cradle or cylinder cart, then secure it upright at the workstation.✓ Answer
    • D.Lift it with a sling around the body of the cylinder, keeping the valve protection cap in place during the lift.

    A cylinder holds its contents at very high pressure, so the whole handling rule set exists to protect the valve: knock the valve off and the cylinder becomes an uncontrolled rocket. The valve is closed and the protection cap fitted before any move, the cap is never used as a lifting point, slings and magnets are not used to hoist cylinders because they can slip, and the cylinder is carried in a cradle, platform or cart and then secured upright at the point of use.

    Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes, and CGA P-1, Safe Handling of Compressed Gases in ContainersReport a problem with this question

14. 14. A worker is about to use the oxygen hose to blow spatter dust off his coveralls. What is wrong with this, and what else applies to oxygen apparatus?

    • A.Oxygen is flammable and would ignite on the clothing; it is safe for this use once the regulator is set to low pressure.
    • B.Nothing is wrong if the flow is low, though oxygen apparatus should still be kept clean and free of grease and oil.
    • C.Oxygen enriches clothing so that it burns violently; oxygen is never a substitute for air, and oil and grease are kept away.✓ Answer
    • D.Oxygen is inert and harmless on clothing; the real concern is only wasting gas, so a short blast is normally accepted.

    Oxygen does not burn, but it violently accelerates combustion, and gas blown into fabric saturates the fibers so that a spark which would normally die instead flares into a fire that is very hard to put out. For the same reason oxygen is never used as a substitute for compressed air to run tools, blow out lines, dust off clothing or ventilate a space, and oxygen cylinders, valves, regulators and hoses are kept free of oil and grease, which can ignite on contact with oxygen under pressure.

    Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes — prohibited uses of oxygen and oil-free oxygen apparatusReport a problem with this question

15. 15. An oxyfuel outfit is fitted with both reverse-flow check valves and flashback arrestors. What does each device do?

    • A.The check valve vents excess pressure out of the hose; the arrestor keeps oxygen from mixing with fuel gas inside the torch.
    • B.The check valve stops gas flowing backward into the wrong hose; the arrestor stops a flame travelling back up the hose.✓ Answer
    • C.The check valve stops a flame from reaching the cylinder; the arrestor limits the fuel gas pressure to a safe working level.
    • D.The check valve regulates the flow reaching the torch tip; the arrestor shuts the fuel gas off if the tip overheats in a cut.

    A reverse-flow check valve is a one-way valve: it prevents oxygen from entering the fuel hose or fuel gas from entering the oxygen hose, which is how an explosive mixture gets into the system in the first place. A flashback arrestor addresses what happens after ignition, quenching a flame front that has already started to travel back through the hose so it cannot reach the regulator and cylinder.

    Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes — oxyfuel gas apparatus, reverse-flow check valves and flashback arrestorsReport a problem with this question

16. 16. Cutting is to be done on a mezzanine floor with a pipe penetration and a floor drain nearby, and cardboard stock is stored on the level below. What does the hot-work principle require?

    • A.All cutting must be moved off the mezzanine, since covering openings is never accepted for hot work above stored goods.
    • B.Openings are covered and combustibles below are moved or shielded, because sparks and slag travel through and beyond.✓ Answer
    • C.A fire extinguisher set beside the cutting station is enough, because the openings in the floor are small in diameter.
    • D.Cutting may start with the cardboard directly below, since sparks lose their heat well before falling one floor down.

    The hot-work rule is written around how far sparks and hot slag actually travel, commonly taken as a radius of about 35 ft on the level and farther for plasma and air carbon arc cutting, and that radius extends downward and sideways through any opening. Wall and floor penetrations, drains and cracks are treated as part of the exposure, so they are covered, combustibles on the far side or the level below are moved or shielded, and heat conducted through metal walls and pipes is considered as well.

    Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes, and NFPA 51B, Standard for Fire Prevention During Welding, Cutting, and Other Hot WorkReport a problem with this question

17. 17. Cutting in a maintenance area finishes at 3:00 p.m. Why does the fire watch stay on after the torch is shut off?

    • A.To recharge the extinguishers used during the job, since the equipment must be restocked before the crew leaves.
    • B.To keep the area roped off until the metal cools down, because burns from hot metal are the hazard that remains.
    • C.To catch smoldering fires, because sparks can lodge in hidden combustibles and take time to break into open flame.✓ Answer
    • D.To sign the hot work permit as closed, since the watch has no duty at all once the cutting torch has been shut down.

    A spark that lands in dust, insulation, rags or a wall cavity can smolder unseen for a long time before it reaches flaming combustion, so the most dangerous period is often after the crew has packed up and left. For that reason the fire watch is maintained for a defined period after the work stops, and the watcher must be trained to use the available extinguishing equipment, know how to sound the alarm, and remain outside any confined space so contact with those inside is never lost.

    Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes, and NFPA 51B, Standard for Fire Prevention During Welding, Cutting, and Other Hot WorkReport a problem with this question

18. 18. A shop is asked to weld a bracket onto a 55-gallon drum whose label says it held a flammable liquid; it has stood open and drained for weeks. How is this treated?

    • A.It cannot be welded at all, because a drum that once held a flammable liquid can never be made safe for hot work.
    • B.It stays unsafe until prepared and declared safe for hot work by a qualified person, whatever the label says.✓ Answer
    • C.It may be welded once the welder has rinsed it out with water, since rinsing removes the residue that could ignite.
    • D.It may be welded if it is filled with water to the weld line, which the welder may do without other preparation.

    Every container is treated as unsafe for welding or cutting until it has been prepared and either rendered safe or declared safe by a person qualified to do so, because liquid residue soaked into seams and scale keeps producing vapor long after a drum looks and smells empty. Cleaning, inerting or filling with water are recognized methods, but only when carried out under the established procedure, and even containers that held nothing flammable, such as water tanks, can hold explosive hydrogen generated by internal corrosion.

    Source: AWS F4.1, Safe Practices for the Preparation of Containers and Piping for Welding, Cutting, and Allied ProcessesReport a problem with this question

19. 19. A welder must do GMAW repairs inside a large tank entered through a manhole. Where do the shielding gas cylinder and the welding power source belong, and what else applies?

    • A.The cylinder goes inside and the power source outside, so a leak can be heard by the welder at once and shut off.
    • B.Both stay outside the tank, and a trained attendant outside keeps in communication with the welder inside.✓ Answer
    • C.Both go inside with the welder to keep the leads short, and the attendant works alongside passing tools in and out.
    • D.The power source goes inside and the cylinder outside, so the welder can adjust the machine without leaving the tank.

    Gas cylinders and welding power sources are kept outside a confined space because a leak inside can displace or enrich the atmosphere faster than ventilation can correct it, and because the equipment adds ignition and shock hazards where escape is slow. The attendant stays outside so communication and rescue capability are never lost, and when the gun or torch is left unattended it is removed from the space with the gas shut off at a point outside.

    Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes, and ANSI/ASSP Z117.1, Safety Requirements for Entering Confined SpacesReport a problem with this question

20. 20. Before entering a pit where argon-shielded welding will be done, how must the atmosphere be handled?

    • A.Test only at the top of the opening, because argon is lighter than air and collects at the highest point in the pit.
    • B.Rely on the shielding gas flow to sweep the pit clear and test afterward only if the welder starts to feel lightheaded.
    • C.Purge the pit with oxygen so it is sure to be breathable, then test once at the rim before the welder climbs down.
    • D.Ventilate with air, test low in the pit before entry and during the work, because argon settles and displaces air.✓ Answer

    Argon, carbon dioxide and propane are heavier than air and settle into pits, tank bottoms and other low areas, where they displace the air and can leave a lethal oxygen-deficient pocket that gives no warning, while helium and natural gas rise and collect at the top; the test point must match the gas involved. Ventilation and purging are done with air only, never with oxygen, because an oxygen-enriched atmosphere makes clothing and other materials burn with extreme violence, and the atmosphere is tested before entry and again during occupancy since conditions change as welding continues.

    Source: ANSI Z49.1, Safety in Welding, Cutting, and Allied Processes — confined space ventilation, atmospheric testing, and the prohibition on purging with oxygenReport a problem with this question

Practice questions based on the AWS SENSE Level I (Entry Welder) written modules, ANSI Z49.1 safety practice, and AWS A2.4 welding symbols. This bank covers the KNOWLEDGE half of entry-level welding only — the workmanship and welder performance qualification tests are hands-on and cannot be practised here, and this is not preparation for the separate, performance-based AWS Certified Welder credential. AWS, SENSE, and NCCER are marks of their respective organizations; this site is not affiliated with or endorsed by them. Work from your program's current materials, and follow the welding procedure and drawings on your own job rather than any number you remember. About AWS SENSE →