How dangerous is welding?
The world is full of 60-year-olds who regret not protecting their health when they were younger. And so it is with welders. It's well-documented that many long-term health problems associated with the profession are preventable. But, because the causes and incremental effects can be invisible, literally, they tend to be ignored, that is until welders grow older and the impact of that disregard can be ignored no longer.
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What makes welding dangerous?
Gas metal arc welding
Gas metal arc welding is the most often used version of arc welding in use. In the process, a wire electrode melts under a shielding gas cover. The gas protects the arc, the joinings and the welding seam from ambient air. If active gas is used (e.g. carbon dioxide), we speak of metal active gas welding (MAG). However, if the steel is welded using an inert gas such as for example argon, we speak of metal inert gas welding (MIG). The procedure is versatile. Nearly all weldable materials can be joined this way.
In gas metal arc welding, the danger due to electric current is relatively high. Unlike many other electronic devices, electrode welders are not fully protected against direct contact. The insulation is interrupted at the welding point so that the electrical circuit can be closed to smelt the metal. The voltage used can cause a life-threatening injury.
A further aspect is arc radiation. The welding arc emits visible, infrared and ultraviolet rays which are more intensive and dangerous than in the case of, for example, gas welding. The invisible short-wave ultraviolet rays can burn the skin and cause inflammation of the outer eye. The higher the current and current density, the higher the radiant intensity. During the process, the welder must wear an appropriate safety helmet and also watch out for reflections on stainless steel or aluminium surfaces.
How does electric shock happen?
Electric shock is one of the most serious and immediate risks facing a welder. Electric shock can lead to severe injury or death, either from the shock itself or from a fall caused by the reaction to a shock.
Electric shock occurs when welders touch two metal objects that have a voltage between them, thereby inserting themselves into the electrical circuit. For instance, if a worker holds a bare wire in one hand and a second bare wire with another, electric current will pass through that wire and the welding operator, causing an electric shock. The higher the voltage, the higher the current and, thus, the higher the risk for the electric shock to result in injury or death.
The most common type of electric shock is secondary voltage shock from an arc welding circuit, which ranges from 20 to 100 volts. Bear in mind that even a shock of 50 volts or less can be enough to injure or kill an operator, depending on the conditions. Due to its constant change in polarity, alternating current (AC) voltage is more likely to stop the heart than direct current (DC) welders. It is also more likely to make the person holding the wire unable to let go.
To avoid secondary voltage shock, welding operators should wear dry gloves in good condition, never touch the electrode or metal parts of the electrode holder with skin or wet clothing and be sure to insulate themselves from the work and ground, keeping dry insulation between their body and the metal being welded or ground (such as a metal floor or wet surface).
Welding operators also should inspect the electrode holder for damage before beginning to weld and keep the welding cable and electrode holder insulation in good condition, because the plastic or fibre insulation on the electrode holder prevents contact with the electrically "hot" metal parts inside. Always be sure to repair or replace damaged insulation before use. And remember, stick electrodes are always electrically hot, even when welding is not being done, and the voltage is the highest.
An even more serious shock, initial voltage shock, may occur when a welder touches electrically "hot" parts inside the welder case or the electric distribution system to which the welder is connected. This action can lead to a shock of 230 or 460 volts.
When not in use, but still turned on, most welding equipment have a voltage that ranges from 20 to 100 volts at the welding circuit and voltages inside the welding equipment may range from 120 volts to more than 575 volts, all of which pose a risk for electric shock. Only qualified repair technicians should attempt to service or repair welding equipment.
Why is TIG welding delicate?
In the case of Tungsten Inert Gas Welding (TIG), an electric arc burns between a tungsten electrode and the part. However, the electrode does not smelt in the process. If material needs to be added, this is done by hand using welding rods or mechanically as wire using a feeding device. A nozzle is installed around the tungsten electrode concentrically through which inert gas is emanated to protect from the atmosphere. Usually, argon is used as a protective gas.
Compared with other processes, TIG welding seems to be the most low-emission at first glance, since minimum visible welding smoke builds. Nevertheless, it can be dangerous to health: Due to high electric arc temperatures, ozone and nitrous gas (nitrogen oxide) are produced. These irritant gases can cause nausea, headaches and severe lung damage. During welding of chrome-nickel-steel joins, cancer-causing hazardous substances are produced which are not noticeable with the naked eye.
When working with tungsten electrodes containing thorium oxide, the danger of exposure to radiation appears, since the electrodes contain radioactive thorium oxide. This applies above all to TIG welding using alternating current – such as for example, with aluminium materials. Safe work using the TIG welding technique can be guaranteed only with the use of powerful extraction systems and particle filters.
It turns out those fumes inhaled through the years may cause serious medical complications. Those noises that didn't seem so loud actually were, potentially destroying your ability to hear. The parts that didn't seem so heavy may trigger shoulder problems. The constant kneeling can lead to knee troubles. All too often seemingly insignificant job-related activities can compound and lead to illness in later years. The good news is you can reduce the risk of these ailments significantly by forcing yourself to make a few simple changes to your daily routine.
What to do to avoid gases and fumes?
Sometimes you receive specific warning signs after inhaling gases and fumes. For example, if you breathe enough zinc fumes while welding on galvanized metal, you later may experience metal fume fever. Symptoms include night sweats, chills, and stomach pains. Or you may exhibit shortness of breath or headaches after breathing certain fumes.
However, you might inhale many gases and fumes over the span of your career that do not provide any obvious warnings. Even though air testing may determine these fume exposures are within current regulatory occupational limits, those limits are simply a guideline to help benchmark the airborne concentration. They should not be considered an absolutely safe level of exposure.
Welding fumes are a combination of various metals. For instance, mild steel is mostly iron, but it also contains manganese, which has received a great deal of attention recently in terms of its effect on health. Stainless steel also contains iron, as well as nickel and chromium. Each compound may have different health effects.
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The nose typically filters and collects much of the smoke, fumes, and grinding dust welding machines create. But some welding fume particles are very small in size and can pass through the nose, the sinus cavity, down the throat, and into the lungs. Most people never even notice an irritation. After years of inhaling welding fumes, you begin to exhibit signs. Symptoms can be as benign as breathing heavily after walking up a flight of steps, but the underlying problems can be much more severe.
Being attentive to conditions and taking simple, preventive measures can greatly reduce the risks presented by gases and fumes. Here are some steps you can take to protect yourself:
What are the safety measures to keep your face out of the welding fumes?
If there is a natural breeze blowing through the building, stand to the side, so the breeze pushes the fumes away from your face. Don't block the airflow.
Whenever possible, use a cooling fan to blow away fumes when there is no natural breeze in the building. Remember, you cannot be close to a large fan because the air current will remove the shield gas around the arc. Move the fan until you notice a very slight breeze. The breeze will not cool you, but it will help dissipate the smoke and fumes.
Weld-on clean metal whenever possible. Grind away coatings and paints from the area to be welded because they burn up and smoke, creating offensive odours and gases.
Use local exhaust ventilation systems properly. Position the hood close to the weld, and set up your workstation to allow the ventilation controls to do the job they were intended to do.
If you cannot use a cooling fan or exhaust ventilation system to capture the fumes, wear a respirator to protect your lungs.
Other safety considerations
Welders should also be aware of other safety considerations within the work environment. For example, those working in a confined space or in an elevated area need to take extra precautions. In any welding situation, welding operators should pay close attention to safety information on the products being used and the material safety data sheets provided by the manufacturer and work with their employer and co-workers to follow appropriate safety practices for their workplace.
How can welders protect themselves?
Simple steps can minimize exposure:
- Wear a respirator.
- Don't stand in before airflow pushing fumes away from your workspace.
- Position your face as far from fumes as possible.
- Use a small cooling fan if no airflow moves fumes from your workspace.
- Use any provided ventilation systems.
- When possible, remove any coatings and paint from the metal prior to welding. This will avoid the production of other toxic gases that may be produced under the fusion of those coatings.
- If welding in confined spaces with no extraction ventilation system or if welding fumes cannot be avoided, wear a respirator with proper filtration.
Choosing a welding respirator
To eliminate the possibility of inhaling welding fume, there are two main ways of supplying air to a respirator:
- A powered air-purifying respirator (PAPR) is a battery-powered filter unit that mounts on a belt and supplies air to your respirator. If welding in a large, open space with no airflow, this is a good option because it is fully portable. As it's positioned on your back, a PAPR does not draw air from the fume zone.
- A supplied air system uses a compressor outside the work zone to draw air through a larger filter to your helmet via an air supply hose and flow control valve. When welding in a confined space, it is paramount to use this system.
Both systems filter particulates, not gases. The air going to the respirator must be of a quality that meets the regulation set in the user manual. Always be aware of the quality of air being supplied to your respirator. Gas detection devices monitor air quality and alert you to unsafe levels of dangerous gases.
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How to protect your ears from the sound of welding?
As odd as it sounds, fumes you breathe actually may harm your hearing. Multiple health studies show a strong correlation between certain chemicals and audio-nerve damage. For example, breathing high levels of carbon monoxide gas affects how much oxygen gets into the blood. If the oxygen level in the blood supply to auditory nerve cells is lowered, they become stressed, posing a higher risk for damage.
The more obvious threat to hearing is the noise welding generates. Noise is a health hazard that many welders ignore. The same people who might wear earplugs or earmuffs when grinding metal will shun that protection when welding, simply because it doesn't seem loud—at least not to the point of being painful. However, welding is loud enough to cause minor nerve cell damage, and minor damage on a daily basis adds up over the years.
Even moderately loud noise, such as that produced by welding, leaves auditory nerve cells affected permanently. Damaged cells do not mend, and new ones don't grow. The long-term result is a loss of hearing. To prevent auditory nerve damage now, wear ear protection. It's never too late to start, but like saving money, the younger you are when you begin, the better off you'll be later on.
What are the important tips in welding?
Years of repetitive kneeling or lifting heavy parts can take their toll on the body. Chronically bad backs, knee joints, and shoulders are common ailments among aging welders.
When you're young, it might seem easier and faster to work in an uncomfortable position instead of moving the part to a table and working at a comfortable height. Even if you decide to move the part, it might seem easier to lift a heavy object to a bench manually than to use a mechanical hoist.
Both actions are akin to winning the battle but losing the war. You might save some time, and you might not feel any pain from the squatting or the lifting, but over time, all of that kneeling and hauling can catch up with you. Be smart about your working situation. Use lifts, get help from others to move heavy pieces, don't stay in one position too long, and try to be as comfortable as possible as much as possible. This is not a sign of weakness. It's a simple acknowledgment that your health in the future is shaped by the actions you take today.
Remember, what doesn't hurt you today may harm you tomorrow.
Does it explode and cause a fire while using welding?
The welding arc creates extreme temperatures and may pose a significant fire and explosions hazard if safe practices are not followed. While the welding arc may reach temperatures of 10,000 degrees Fahrenheit, the real danger is not from the arc itself, but rather the intense near the arc and the heat, sparks and spatter created by the arc. This spatter can reach up to 35 feet away from the welding space.
To prevent fires, before beginning to weld, inspect the work area for any flammable materials and remove them from the area. Flammable materials are comprised of three categories: liquid, such as gasoline, oil and paint; solid, such as wood, cardboard and paper; gas, including acetylene, propane and hydrogen.
Know where the fire alarms and extinguishers are located, and check the extinguisher's gauge to make sure it is full. If an extinguisher is not available, be sure to have access to fire hoses, sand buckets or other equipment that douses fire. And, know the location of the nearest fire exit.
If welding within 35 feet of flammable materials, have a fire watcher nearby to keep track of sparks and remain in the work area for at least 30 minutes after finishing welding to be sure there are no smouldering fires. Put a fire-resistant material, such as a piece of sheet metal or fire-resistant blanket, over any flammable materials within the work area, if you can't remove them.
In an elevated location, make sure no flammable materials are beneath you and watch out for other workers below you in order to prevent dropping sparks or spatter on them. Even high concentrations of fine dust particles may cause explosions or flash fires. If a fire starts, don't panic – and call the fire department immediately.
What happens if you do not have PPE?
Personal protective equipment (PPE) helps keep welding operators free from injuries, such as burns – the most common welding injury – and exposure to arc rays. The right PPE allows for freedom of movement while still providing adequate protection from welding hazards.
Thanks to their durability and fire resistance, leather and flame-resistant treated cotton clothing is recommended in welding environments. This is because synthetic material such as polyester or rayon will melt when exposed to extreme heat. Welding leathers are especially recommended when welding out of position, such as applications that require vertical or overhead welding.
Avoid rolling up sleeves or pant cuffs, as sparks or hot metal will deposit in the folds and may burn through the material. Keep pants over the top of work boots – don't tuck them in. Even when wearing a helmet, always wear safety glasses with side shields or goggles to prevent sparks or other debris from hitting the eyes. Leather boots with 6-to-8-inch ankle coverage are the best foot protection; metatarsal guards over the shoelaces can protect feet from falling objects and sparks. It will not be pleasant if a hot piece of spatter finds its way inside your clothing or shoes.
Heavy, flame-resistant gloves should always be worn to protect from burns, cuts and scratches. As long as they are dry, they also should provide some protection from electric shock. Leather is a good choice for gloves.
Helmets with side shields are essential for protecting eyes and skin from exposure to arc rays. Make sure to choose the right shade lens for your process – use the helmet's instructions to help select the right shade level. Begin with a darker filter lens and gradually change to a lighter shade until you have good visibility at the puddle and weld joint but it is comfortable and does not irritate your eyes. Helmets also protect from sparks, heat and electric shock. Welder's flash from improper eye protection may cause extreme discomfort, swelling or temporary blindness, so don't take any risks – wear a helmet at all times during welding.
To protect ears from noise, wear hearing protection if working in an area with high noise levels. Doing so will protect your hearing from damage, as well as prevent metal and other debris from entering the ear canal. Choose earplugs or earmuffs to protect the ears.
Good common sense is also key. If opening cans of an electrode, keep hands away from sharp edges. Remove clutter and debris from the welding area to prevent tripping or falling. And never use broken or damaged equipment or PPE. To keep up with the most modern safety practices, welding operators should utilize resources from the American Welding Society (AWS), OSHA and welding manufacturers, such as Lincoln Electric's online Interactive Safety Guide. By following these safe practices and using common sense, operators can stay safe and keep production moving with no lost-time accidents.