Welding, Cutting, Brazing and Soldering
Welding, Cutting, Brazing, and Soldering Quick Links
Welding, Cutting, Brazing, and Soldering Scope
This program provides information regarding health and safety concerns associated with welding, cutting, brazing, and soldering.
This program applies to employees who perform welding, cutting, brazing, or soldering while on the job. It does not apply to home use; however, the safety information provided is beneficial to anyone performing this type of work regardless of location.
Welding, cutting, and other hot work applications can present serious fire, health, and physical hazards leading to significant property damage, injury, and/or loss of life. The hot work performed may be in occupied buildings, which increases the risk of personnel injuries even more. Information on these pages is intended to increase awareness of such hazards and controls; not to teach personnel how to weld/cut. Personnel performing welding and cutting must be suitably trained in the safe operation of their equipment and the safe work practices of the welding/cutting processes.
Departments that have personnel welding, cutting, brazing, soldering must ensure that:
- The equipment provided in is good condition.
- Personnel are trained and familiar with the proper and safe use of welding and cutting equipment (including previous training or experience), and the associated hazards and controls.
- Required documentation, such as a Hazard Communication Plan and relative Safety Data Sheets, are maintained and employees must receive Right-to-Know level training.
- Appropriate personal protective equipment is provided to personnel.
The supervisor is responsible for securing or issuing a Hot Work Permit prior to the start of welding/cutting operations, including ensuring fire protection and extinguishing equipment availability. Supervisors must attend Hot Work Supervisor training and be approved to issue permits.
Supervisors are responsible for the safe handling of welding/cutting equipment and the safe work practices involved in the processes. The work area must be inspected for combustible materials and hazardous areas present, or likely to be present, in the work area. If combustibles are present where welding or cutting will be performed, the supervisor shall ensure that the combustibles are protected or moved, the work is moved to another location, and that work is scheduled around operations that may pose a concern.
Supervisors must ensure that relative information regarding welding and cutting operations is conveyed to the individuals involved. Location of Safety Data Sheets and relative information regarding hazards must be reviewed with employees prior to beginning work.
Personnel performing hot work must:
- Attend safety training on welding/cutting hazards and controls.
- Attend Portable Fire Extinguisher training.
- Follow recommended practices described in this program.
- Attend Hazard Communication RTK (Right-to-Know) training.
- Review relative information, such as Safety Data Sheets, prior to beginning work.
- Wear appropriate personal protective equipment for the task.
Welding, Cutting, Brazering, Soldering Safety
Hot work processes
Welding involves joining two or more pieces of metal together to form a single piece. Molten metal is generated through an intense heat source, such as oxygen and fuel gas or an electrical arc. Common welding processes using an electrical arc include Shielded Metal Arc Welding, Gas Metal Arc Welding, and Gas Tungsten Arc Welding.
Unlike welding processes which join two pieces of metal, cutting processes involve separating or severing a piece of metal through intense heat generated to melt the metal. Cutting processes include oxygen and fuel gas and electrical arc gouging.
Gas welding, or oxy/fuel welding as it is commonly referred to, is slower and easier to control than arc welding. This method unites metals by heating - the heat source being a flame produced by the combustion of a fuel gas, such as acetylene, methylacetylene (MAPP gas), or hydrogen. Temperatures can reach up to 6,000 deg. F. This process sometimes includes the use of pressure and filler material. Gases commonly used are oxygen and either acetylene, hydrogen, propane, or propylene. These gases are commonly supplied in compressed gas cylinders, which can pose additional handling and transport hazards.
In arc welding, the intense heat needed to melt metal is produced by an electric arc. The arc is formed between the actual work piece and an electrode (stick or wire) that is manually or mechanically guided along the joint. The electrode can either be a rod, with the purpose of simply carrying the current between the tip and the work, or it may be a specially prepared rod or wire that not only conducts current but also melts and supplies filler metal to the joint. Power sources for arc welding can be either alternating (AC) or direct (DC) current. The work cable connects to the work piece and the electrode cable creates an arc across the gap when the energized circuit and the electrode tip touches the workpiece and is withdrawn (yet still in close contact). The arc produces a temperature of about 6,500 deg. F at the tip. This heat melts both the base metal and the electrode, producing a pool of molten metal. Metals at high temperatures can react chemically with elements in the air (oxygen and nitrogen). Oxides and nitrides form, which destroy the strength of the weld. A protective shield of gas, vapor, or slag is used to cover the arc and molten pool to prevent or minimize contact or molten metal with air.
Shielded Metal Arc Welding (SMAW) is commonly known as "stick" welding. A flux-covered electrode is used to form a gas shield around the molten weld pool. The flux coating quickly forms a protective "slag" during welding, which produces a gas shield that decreases exposure to oxygen. The electrode is consumed as it moves down the length of the weld joint and the "slag" must cool and later be chipped away.
Gas Metal Arc Welding (GMAW) is commonly known as "MIG" welding. A continuous-feed electrode (i.e. wire) from a spool is used to supply filler metal directly from the torch tip to the weld. As arcing occurs, the electrode instantly melts and a shielding gas, such as argon, carbon dioxide, or helium, is supplied through the torch tip.
Gas Tungsten Arc Welding (GTAW) is commonly known as "TIG" welding. An electric arc between a tungsten electrode and the base metal is created. A separate filler rod is fed into the molten base metal if needed. A shielding gas (i.e. commonly argon, helium, or carbon dioxide) also flows around the arc to minimize atmospheric interactions. Water is often used to cool the torch and cables.
Plasma Arc Welding (PAW) is similar to TIG welding in which an arc, shielded by an inert gas, creates the necessary heat to melt the metals involved. The electrode is not consumed in PAW; however, the primary means of transferring heat to the workpiece is by a hot ionized gas (i.e. "plasma"). Temperatures can reach up to 30,000 deg. F, which is substantially hotter than those produced by an arc only. Commonly, PAW is a fully automatic process. Filler metal may be used, and plasma and shielding gases include argon, argon/helium, and argon/hydrogen.
Brazing is a process similar to welding in that a liquid filler metal is heated and flows between two or more metal surfaces to be joined. It is very flexible in that any number of metals may be joined. However, brazing occurs at lower temperatures than welding, typically around 840 deg. F. A braze metal is heated to a liquified state and is spread over the surface to be joined, rather than both the base metal and filler metal being heated to a molten state as in welding. Parts to be joined must be very clean, often using mechanical methods such as sanding, grinding, abrasive blasting, or the use of chemical solvents. There are several types of brazing based upon the source of heat. Brazing is commonly used to seal or join pipes and the associated hazards are similar to those of welding. Reviewing Safety Data Sheets for the metals, cleaning agents, fluxes, and filler metals is very important in identifying associated health hazards and implementing appropriate hazard controls.
Soldering is similar to welding in that both the base metal and the filler metals are heated to melting and then solidify to form a joint; however, soldering temperatures are typically 840 deg. F or less. Soldering typically involves smaller components to be joined and "softer" metals such as lead/tin or silver. Manual soldering processes use a hand-held iron to heat the components to be joined and the filler metals. Often the filler metal is in the form of a flux-cored wire with additional flux added to assist with wetting (i.e. flow). Always review the Safety Data Sheet for the materials involved. Where possible, lead-free solder should be used to avoid potential exposure to lead.
There are several relatively new heat sources for welding and cutting, such as friction, ultrasonics, and lasers. Each of these special heat sources requires guarding and safe practices, and is beyond the scope of this program. Follow the manufacturer's recommendations for safe and proper use of equipment.
Fire/explosion hazards and controls
Hot Work Permits are required for all permanent and temporary areas where such work is being performed. Permits are issued for permanent areas by Environmental Health & Safety or designated departmental Hot Work Permit Coordinators who have attended Environmental Health & Safety training, after an inspection of the area had been made. Permits are issued by the designated departmental hot work permit coordinator for all temporary areas.
Hot work shall not be performed on used containers until they have been cleaned thoroughly of any potentially flammable material and/or vapor. Pipelines or connections to the drum or vessel shall be disconnected or blanked. All hollow spaces, cavities, or containers shall be vented to permit the escape of air or gases. Purging with an inert gas may be necessary.
If hot work will be performed in a confined space, additional precautions must be taken. Thoroughly testing the atmosphere for explosive gases (i.e. LEL) is critical prior to beginning welding/cutting processes. In addition to testing the top, middle, and bottom areas with a calibrated air monitor, subcompartments must also be tested for the presence of flammable gases or vapors. Under normal applications, the LEL must not exceed 10% for entry to occur. When welding or cutting will be conducted in a confined space, it is best practice for the LEL to be at 0%.
Fire blankets are made from a chemically treated material, commonly fiberglass, to render it flame-retardant. Blankets are generally used to protect other equipment, materials, or combustible building construction from sparks and slag. Overhead work where such equipment or material cannot be removed from the immediate area is one common situation where flame-retardant fire blankets are used.
Hot work, such as welding, cutting, brazing, torch-applied roofing, grinding, and soldering, produces open flames or heat which can ignite flammable and combustible materials in the vicinity. Stray sparks and hot slag can smolder for hours before igniting. Chemical pipelines, storage areas, and certain areas are of special concern where fire and/or explosion hazards may occur.
A thorough inspection of the area and scope of work should be performed prior to beginning work. Consider the following:
- Are there flammable or combustible solids or liquids on-site?
- Could flammable gases or vapors be present in the space or container?
- Is airborne combustible dust (ex. grain, wood, aluminum, or coal dust) present in the space or vessel?
- Is welding/cutting equipment free from leaks that could result in leaking oxygen or flammable gases?
The use of a hot work permitting process is one of the main controls used to reduce the risk of fire/explosion
Health hazards and controls
There are many health effects associated with welding and cutting operations, including fumes from heating various metals, gases generated during the processes, gases used in the processes, and contaminants released from paint coatings. All metals, electrodes, and gases used in welding and cutting processes must be included in the department's Hazard Communication Plan.
One common illness related to welding and cutting is Metal Fume Fever. Flu-like symptoms may be experienced, such as coughing, fever, chills, chest pain, nausea, vomiting, and difficulty breathing. Once the person has been removed from the exposure, recovery generally occurs without intervention within 24 to 48 hours. Other adverse health effects associated with welding and cutting are specific to the source, such as the metal involved, shielding gases used, coatings that may be present, or gases generated during the process.
- Metals: Whenever metal is heated, fumes are released. Fumes are breathed in by the welder/cutter and may result in acute or chronic adverse health effects. Many metals are regulated by OSHA and have a Permissible Exposure Limit (PEL), which an employee must not exceed. For more information, click here.
- Compressed gases: Common gases used in welding/cutting include acetylene, argon, carbon dioxide, helium, hydrogen, and MAPP gas. These gases are either flammable or inert. Always consult the Safety Data Sheet for the specific gases used.
- Coatings: Coatings, such as paint, on metal may contain a variety of contaminants, such as lead, chromium, and zinc. Safety Data Sheets should always be reviewed to identify hazards and recommended controls prior to removal.
- Gases generated: Welding and cutting processes generate a number of contaminants, such as carbon monoxide, fluorides, nitrogen dioxide, and ozone that may adversely affect employee health.
Appropriate and effective ventilation is the most important engineering control for eliminating or sufficiently reducing potential exposure to toxic substances, such as welding fumes.
If engineering controls are being used, such as effective ventilation or non-hazardous metals, electrodes, coatings, etc., exposure is not expected. However, if engineering controls are not functioning properly, have not been employed, or do not appear to be sufficient, air monitoring may be warranted. Environmental Health & Safety offers hazard monitoring for welding and cutting applications. Contact Environmental Health & Safety at 540-231-5985.
Employees exposed to welding and cutting fumes may be required to enroll in EHS's Occupational Health Assurance Program. The Occupational Health Assurance Program (OHAP) was established by Environmental, Health & Safety in 1981 to comply with regulations that require medical surveillance for employees exposed to occupational health hazards. Employees at risk are provided medical examinations, laboratory analysis, or immunizations as required by the regulations. These services are provided at no cost to employees and participation is during normal business hours, whenever possible.
Electrical hazards and controls
Welding machines are generally grounded through their electrical connections via a third grounding wire. Mobile engine-driven generator welding units should be grounded by connecting a cable to a ground stud on the machine to a metal stake driven into the ground. Always follow the manufacturer's instructions for properly grounding the particular model that will be used.
Auxiliary receptacles on welding machines may or may not be ground-fault circuit-interrupter (GFCI) protected. GFCI adapters, or "pigtails" should be used in wet or damp locations. Tools, extension cords, or equipment plugged into these receptacles must be grounded or double insulated.
When grounding the workpiece to the welding table, make sure that the table is also grounded (typically a cable from the table leg to the building structure). Avoid grounding to a building structure that is a great distance from the weld. Never use pipelines carrying flammable liquids, and never use electrical conduit as a ground.
Cables should be inspected prior to use for cuts, burns, or damage to the insulation and uniform flexibility throughout. Inflexible sections of the cable can indicate fusing of the copper filaments probably caused by a current leak. Cables with splices within ten feet of the electrode holder shall not be used. Connections should be tight, clean, and dry. Do not use worn, damaged, undersized, or poorly spliced cables. Check lugs and fittings on the equipment to ensure they are tight.
The electrode holder should hold the electrode tightly and the insulators around the electrode lead should be uniform and free of damage. Electrodes should be discarded when about two inches from the holder in order to prevent damage to the insulators. Consuming the electrode all of the way up to the holder will burn away the insulation and increase the likelihood of electric shock as the arc jumps into the electrode holder, or the holder may be damaged by intense heat.
- Never use electrode holders with missing insulators.
- Do not dip the holder in water to cool it.
- Do not lay the holder on conductive surfaces.
- Do not touch holders connected to two welding machines at the same time.
- Do not touch people with the holder or electrode.
Electric shock from welding and cutting equipment is significant enough to result in death, severe burns, or secondary injury from falls. The electrode and work circuit is electrically energized when the output is "on". The input power circuit and machine internal circuits are also electrically energized when the power is "on". When stick welding, the metal jaws, screws on the holder, and the electrode are all electrically energized. When wire welding, the wire, wire reel, drive rolls, and all other metal parts touching the wire are electrically energized.
Some situations can increase the risk of electrical shock during welding/cutting. Such electrically hazardous conditions include welding/cutting in damp locations, while wearing wet clothing, on metal structures, such as floors, gratings, or scaffolds, or in cramped positions, such as sitting, kneeling, or lying down.
Always review and follow the manufacturer's instructions for the specific welding equipment used.
Primary "input" voltage shock (220-480 volts) - For example, touching a lead inside the welder with the power to the welder "on" while part of your body or a hand is on the welder case or other grounded metal. Remember, turning the welder power switch "off" does not turn the power off inside the welder! To turn the power inside of the welder "off", the input power cord must be unplugged or the power disconnect switch turned off. You should never remove fixed panels from the welder. Electric shock hazards associated with arc welding may be divided into two categories:
- Secondary "output" voltage shock (20-100 volts) - For example, touching a part of the electrode circuit such as a bare spot on the electrode cable at the same time another part of your body is touching the metal upon which you're welding (i.e. the workpiece). To receive a shock, your body must touch both sides of the welding circuit - the electrode and the work (or welding ground) - at the same time. Remember, the voltage at the electrode is highest when you are not welding (i.e. open circuit voltage). Safe work practices and habits, such as keeping everything as dry as possible, maintaining and using equipment in good condition, and preventing accidental contact with equipment when not in use.
Physical hazards and controls
Electric arcs and gas flames produce ultraviolet (UV) and infrared (IR) radiation that can be harmful to the eyes and skin upon continued or repeated exposure. Ultraviolet rays can result in a "sunburn" to the eyes, which is painful and disabling, but usually only temporary. Exposed skin is also subject to sunburn and potential long-term effects such as skin cancer. Sunburns are typically not noticed at the time of exposure, but rather at night. A sensation of having sand in the eyes, along with great discomfort, typically results in a trip to the emergency room where salve is prescribed. Ultraviolet rays are common in gas-shielded arc welding where the shielding gases can double the intensity of the radiation. Intensity can be 5-to-30 times greater where greater current densities are needed, as with covered electrode and gas-shielded metal arc welding.
Infrared radiation may cause permanent eye injury if the worker looks directly into a powerful arc without eye protection, or is in close proximity to the heat. Infrared radiation heats the tissue and can adversely affect exposed body parts.
Appropriate dress is the first consideration. As much of the body as possible should be covered with natural fiber clothing, such as cotton or wool. Long-sleeve shirts buttoned at the neck (or the use of a bandana or high neckline shirt underneath), long pants, and closed-toed shoes should be worn underneath flame-retardant personal protective equipment. In order to avoid slag or sparks getting caught in creases and burning through clothing to the skin, follow these recommendations:
- Shirt-tails should not be tucked into the pants.
- Pants with a cuff should be avoided.
- Leather workboots without shoelaces are recommended.
- Welding caps to cover hair should be worn under the welding helmet when welding overhead.
- Clothing should be dark to avoid reflection.
The proper selection and use of personal protective equipment is required for all personnel performing welding and cutting operations, such as:
- Safety glasses;
- Welding/cutting goggles;
- Welding helmets with filtered lens;
- Flame-retardant sleeves, aprons, and chaps; and
- Leather gauntlet style gloves.
Compressed gas cylinders may pose a variety of hazards if handled, used, stored, or transported in an unsafe manner. Personnel using welding/cutting gasses should attend Compressed Gas Cylinder Awareness level training so that hazards are understood and appropriate precautions are taken.
Repetitive motions and poorly designed workstations may result in worker fatigue and be the start of potentially larger injuries, especially in the wrists. The weight and design of the tools, the position of the work, and various other activities and factors such as lifting, turning, reaching, and vibration can all add up and result in stress to a particular body part. Pain, numbness, and burning sensations are all symptoms of a potential problem. Early detection is the key to recovery.
Frequently Asked Questions
Is training mandatory? If so, when? Yes. Departments that perform welding, cutting, brazing, torch cutting, soldering, and similar open-flame operations must designate a hot work coordinator and implement a hot work permit program.
Class length: 1 hour.
Available online: Yes.
When is refresher training required? Never.
Please see the online class schedule for more information.
If proper protective equipment is worn during welding and cutting operations, such as welding helmets or goggles with filtered lenses, it is acceptable to wear contact lenses. One exception would be where the welding process may produce gas or vapors that could be harmful to employees wearing contact lenses.
Go to the OSHA letter of interpretation.
If leaded solder cannot be replaced with lead-free solder, soldering in a fume hood or use of local exhaust ventilation (i.e. snorkels or tabletop fume extractors) should be used to divert fumes away from the breathing zone.
Robin McCall-Miller, Occupational Safety Program Manager