Welding Safety Signs
The intense heat of welding and sparks can cause burns. Contact with hot slag, metal chips, sparks, and hot electrodes can cause eye injuries. • Excessive exposure to heat can result in heat stress or heat stroke. Welders should be aware of the symptoms - such as fatigue, dizziness, loss of appetite, nausea, abdominal pain, and irritability. Ventilation, shielding, rest breaks, and drinking plenty of cool water will protect workers against heat-related hazards.
Visible Light, and Ultraviolet and Infrared Radiation • The intense light associated with arc welding can cause damage to the retina of the eye, while infrared radiation may damage the cornea and result in the formation of cataracts. • Invisible ultraviolet light (UV) from the arc can cause “arc eye” or “welder’s flash” after even a brief exposure (less than one minute). The symptoms of arc eye usually occur many hours after exposure to UV light, and include a feeling of sand or grit in the eye, blurred vision, intense pain, tearing, burning, and headache. • The arc can reflect off surrounding materials and burn co-workers working nearby.
About half of welder’s flash injuries occur in co-workers who are not welding. Welders and cutters who continually work around ultraviolet radiation without proper protection can suffer permanent eye damage. • Exposure to ultraviolet light can also cause skin burns similar to sunburn, and increase the welder’s risk of skin cancer.
Welding Safety Section
Welding, cutting, and brazing are hazardous activities that pose a unique combination of both safety and health risks to more than 500,000 workers in a wide variety of industries. The risk from fatal injuries alone is more than four deaths per thousand workers over a working lifetime.
Welding, cutting, and brazing are addressed in specific standards for the general industry, shipyard employment, marine terminals, and construction industry
The main types of welding are oxyacetylene gas welding and arc welding (wire welding). Both involve the joining of metals at high temperatures. Cutting metals using these techniques involves the separating of metals at high temperatures. Welding and cutting pose a serious fire hazard as fragments of metal at high temperature are produced and if these hot metal fragments come into contact with a combustible material they may act as an ignition source and start a fire.
Cutting metals is much more of a fire hazard than welding, because during cutting operations many more sparks of hot metal shower from the work, providing a potential ignition source for a fire.
General Welding Safety Rules
1. Arc rays from the welding process produce intense visible and invisible (ultraviolet and infrared) rays that can burn eyes and skin. Sparks fly off from the weld. 2
2. Wear a welding helmet fitted with a proper shade of filter to protect your face and eyes when welding or watching (see ANSI Z49.1 and Z87.1 listed in Safety Standards).
3. Use protective screens or barriers to protect others from flash, glare, and sparks; warn others not to watch the arc.
4. Wear body protection made from durable, flame−resistant material (leather, heavy cotton, wool). Body protection includes oil-free clothing such as leather gloves, heavy shirt, cuffless trousers, high shoes, and a cap.
5. Before welding, adjust the auto-darkening lens sensitivity setting to meet the application
6. Stop welding immediately if the auto-darkening lens does not darken when the arc is struck. See the Owner’s Manual for more information.
7. Arc rays from the welding process produce intense visible and invisible (ultraviolet and infrared) rays that can burn eyes and skin. Sparks fly off from the weld.
8. Use impact resistant safety spectacles or goggles and ear protection at all times when using welding helmet.
9. Inspect the auto-lens frequently. Immediately replace any scratched, cracked, or pitted cover lenses or auto-lenses
10. NOISE can damage hearing. Noise from some processes or equipment can damage hearing. Wear approved ear protection if noise level is high.
Welding Safety Issues
Welding can be dangerous and unhealthy if the proper precautions are not taken. However, using new technology and proper protection greatly reduces risks of injury and death associated with welding. Since many common welding procedures involve an open electric arc or flame, the risk of burns and fire is significant; this is why it is classified as a hot work process. To prevent injury, welders wear personal protective equipment in the form of heavy leather gloves and protective long sleeve jackets to avoid exposure to extreme heat and flames.
Additionally, the brightness of the weld area leads to a condition called arc eye or flash burns in which ultraviolet light causes inflammation of the cornea and can burn the retinas of the eyes. Goggles and welding helmets with dark UV-filtering face plates are worn to prevent this exposure. Since the 2000s, some helmets have included a face plate which instantly darkens upon exposure to the intense UV light. To protect bystanders, the welding area is often surrounded with translucent welding curtains. These curtains, made of a polyvinyl chloride plastic film, shield people outside the welding area from the UV light of the electric arc, but cannot replace the filter glass used in helmets.
Welders are often exposed to dangerous gases and particulate matter. Processes like flux- cored arc welding and shielded metal arc welding produce smoke containing particles of various types of oxides. The size of the particles in question tends to influence the toxicity of the fumes, with smaller particles presenting a greater danger. This is because smaller particles have the ability to cross the blood brain barrier. Fumes and gases, such as carbon dioxide, ozone, and fumes containing heavy metals, can be dangerous to welders lacking proper ventilation and training.
Exposure to manganese welding fumes, for example, even at low levels (0.2 mg/m3), may lead to neurological problems or to damage to the lungs, liver, kidneys, or central nervous system. Nano particles can become trapped in the alveolar macrophages of the lungs and induce pulmonary fibrosis. The use of compressed gases and flames in many welding processes poses an explosion and fire risk. Some common precautions include limiting the amount of oxygen in the air, and keeping combustible materials away from the workplace
Controlling Hazardous
Fume and Gases during Welding Welding joins materials together by melting a metal work piece along with a filler metal to form a strong joint. The welding process produces visible smoke that contains harmful metal fume and gas by-products. This fact sheet discusses welding operations, applicable OSHA standards, and suggestions for protecting welders and coworkers from exposures to the many hazardous substances in welding fume.
Welding Disasters
July 1994 Boston Harbor Tunnel fire. Welders were cutting bolts from a bearing housing and these hot bolts and nuts then fell into the shaft. On coming in contact with the conveyor belt, the hot metal bits then started a fire which could have been avoided had a fire resistant tarp been suspended beneath the work area.
April 1991 fire in the US embassy in Moscow. The fire was caused by hot sparks dropping down from welding that was being done in the elevator shaft. Had a fire resistant tarp been suspended beneath the welders, this fire too, could have been avoided.
Fighting the Fire
Even after precautions are taken to reduce the risk of a fire occurring, a fire may still occur. It is important to be prepared in case this does happen. Before commencing the work, it is important to establish that the appropriate firefighting equipment is available and ready for use, and that staff are properly trained in using such equipment.
Fire protection systems
Depending on the nature of the work, various types of firefighting systems should be present. Before any work commences, it should be established that these systems are functioning, and will continue to function during and after hot work operations.
You have to wait 30 seconds here.
To establish that fire protection systems are not malfunctioning, various checks should be carried out. For example control valves for fixed protection systems should be fully opened. As well as a fire extinguisher, a bucket of dry sand and a pair of water buckets should be at hand. These are used in addition to other firefighting equipment to fight certain types of fires. Sand is effective in smothering fires of flammable liquids such as oil, petrol, paint, etc. (class 6 fires). The only to fight fires in which wood, paper, clothing (class A fires). Buckets of water should be used and similar materials are burning
Hot work permit system
A hot work permit is required before any welding or cutting is carried out in a ‘hazardous situation’. It is the responsibility of property and plant management to oversee the permit issuance system. The Responsible Officer issues the hot work permit after they are satisfied that certain precautions have been followed and the hot work may proceed safely.
The hot work permit covers aspects of the work such as the times the work may be carried out, the equipment to be used and the precautions which have been taken. Once work has been approved as safe, the hot work permit is filled out and signed by the Responsible Officer. The permit is then posted at the worksite. It is signed again at the completion of the work, and filed for documentation.
Welding on Containers
Containers of flammable materials should never be welded or cut with a torch, even if the container has been completely empty and sitting empty for a long time, as vapors and flammable materials can still permeate the metal. An example of what can occur when such containers are welded on occurred in the early 1990s when a welder in the USA was cutting 55-gallon oil drums in half. As his cutting torch pierced the metal of one of these drums, the drum exploded and the welder was blown through the shop’s roof, 50-feet up in the air.
Vapors from flammable liquids are explosive and should be handled with extreme care. Vapors from non-flammable liquids can also be explosive under certain conditions. If welding b to be carried out on vessels of flammable or combustible materials, the vessel should be drained, cleaned, purged and tested for flammable vapors before the work begins. The transfer piping should also be drained, purged and blanked.
As a rule, only welders who are properly trained to do so should weld or cut a container that has held flammable or hazardous materials.