Safety requirements for cutting and welding operations

Welding, cutting and brazing are hazardous activities that pose risks to more than 500,000 workers; the risk of fatal injuries is more than four deaths per thousand workers over a working lifetime. 

The potential hazards present a unique combination of both physical and chemical risks to the worker. Potential exposures to metal fumes and non-ionizing radiation exist along with burns, eye damage, electrical shock, cuts, crushed toes and fingers. But as is always the case, many of these risks can be controlled with proper work practices and personal protective equipment (PPE).

Physical hazards

Welders can be exposed to fire, ultraviolet (UV) and infrared radiation as well as visible light. What is particularly dangerous about these exposures is that often workers may not perceive that they are being exposed, and if close enough to the source, the damage can happen almost instantly. It only takes seconds for radiation to cause burns to the cornea as well as thermal burns to the eye and skin. Burns to the eye create a sensation like having sand in the eye.

Before cutting or welding begins, the area should be inspected by an individual charged with the responsibility of authorizing cutting and welding operations. This individual should designate precautions to be followed and preferably these procedures are written down in a safety plan. 

Cutting and welding should always be conducted in areas that have been made fire safe by removing combustibles or protecting combustibles from ignition sources. If the object to be welded or cut cannot be moved and if all the fire hazards cannot be removed, then guards must be used to confine the heat, sparks and slag and protect the immovable fire hazards.

If welding or cutting is taking place out of doors, be aware of how dry the environment is. Where I live in Texas, we’ve been experiencing a drought for two years and if welding and cutting is conducted in a dry grass area a fire watch should be present. Fire watches must have fire extinguishing equipment readily available and be trained in its use. They must be familiar with the procedures for sounding an alarm and must be trained to know which fires can be extinguished with the available equipment or otherwise when to sound the alarm. A fire watch must be maintained for at least half an hour after completing the welding or cutting to guard against smoldering fires.

Other safety provisions to avoid fires include using a nonflammable tarp under the area where the welding is occurring or better still, if possible move the welding operation so it doesn’t have to take place over vegetation. If welding outdoors in dry conditions, it’s a good idea to notify the local fire authority. They may give safety advice over the phone or they may even dispatch an inspector to the site to limit the fire risk

One of the most common occupational injuries in welding comes from general burns from touching hot surfaces and not using PPE. These avoidable burns can get expensive for the business owner with workers taking time off, workers compensation expenses, medical claims and lower productivity.

Another physical hazard to be aware of is electrical shocks. High voltages and ampage present risk of electrocution as well as thermal burning.

Chemical hazards

Always ensure and never assume that the welding surface is free of chemicals, greases and non-combustible materials before welding begins. When welding on different types of metals, different compounds are produced. A number of potentially hazardous materials are used in fluxes, coatings, coverings, and filler metals used in welding and cutting or are released to the atmosphere during the process. Metals themselves, or oxides of metals, or different types of chemical gases can be released.

These include, but are not limited to, nitrogen oxides that are produced as a result of heat releasing a combination of nitrogen and oxygen into the air. Carbon monoxide, ozone and nitrogen are consequences of the intense heat the arc produces. Phosgene gas can be produced by welding on materials contaminated with chlorinated solvents, which should always be avoided. Fluorine gas can result from different kinds of fluxes used in welding and the welding rods and metal can also release fumes.  Exposure to lead and mercury is possible as both are used to coat metals. Cadmium is used on steel and Beryllium can be derived from some alloys. Zinc is contained in some brass galvanized metals and alloys.

Confined spaces

Plenty of ventilation, and open space should be provided to keep the amount of toxic fumes, gases and dusts derived from compounds and metals below the maximum allowable concentration as specified by OSHA.

All welding and cutting operations carried on in confined spaces must be adequately ventilated to prevent the accumulation of toxic gasses, the possibility of fire or explosion or even oxygen deficiency. This applies not only to the welder but also to helpers and potential rescuers. There is a high probability of catastrophe when welding and cutting are conducted in confined spaces without the proper safety measures in place. All companies, even small businesses, engaged in this activity should consult OSHA's confined space standards as well as general industry recommendations.

Consequences

The consequences of welding and cutting without taking the appropriate safety measures can be extremely serious and can result in chemical exposures to the upper respiratory tract, nose, throat and eyes. Short term exposures can lead to pulmonary edema, lung irritation, chemical pneumonia, other respiratory illnesses, and in rare cases, even death. Some studies suggest that occupational exposures to welding fumes may pose the risk of neurological and reproductive effects and lung cancer.

Exposure to zinc fumes can cause metal fume fever, the symptoms of which are very similar to the flu with fever and aches, chills, nausea, cough, fatigue and weakness. The symptoms generally disappear within 24 hours, but workers are more susceptible after the first attack.

OSHA requires that employers identify worker exposure to these compounds. This requires sampling during the welding operation in order to quantify and qualify the exposure and to make a determination if the exposure is acceptable or unacceptable. If unacceptable, the employer must institute controls to bring exposures to acceptable levels. Bringing in an expert to initially assess and control hazards lowers risk and can be a good return on the initial investment.

PPE

Employees exposed to hazards created by welding, cutting or brazing operations must be protected by PPE in accordance with OSHA requirements. Appropriate protective clothing required for any welding operation will vary with the size, nature and location of the work to be performed. However, welding PPE may include welding hoods, goggles, nonflammable shirts and pants, welding gloves and steel-toed boots.

Ensuring respiratory protection from the compounds produced during the welding process, through the use of a respirator or positive pressure hood, is a very good idea. Again, refer to OSHA’s respiratory protection standards.

Training

Management has an obligation to insist that cutters or welders and their supervisors are suitably trained in the safe operation of their equipment and understand the risks associated with welding, cutting and brazing. This includes training in PPE use and function, the ability to make decisions about when to use PPE, and also the effective use of fire extinguishers and fire prevention methods. Refresher safety training should also be required.

Anticipating health and safety issues and taking action to prevent them is a long-term and profitable investment for companies. For more information on industrial hygiene and methods for promoting health and safety in the workplace, as well as a listing of industrial hygiene consultants, please visit the American Industrial Hygiene Association Web site at www.aiha.org.

Michael Larrañaga, PhD, PE, CIH, CSP, is associate professor and department head of the School of Fire Protection and Safety at Oklahoma State University.

Applicable Standards
ANSI Z49.1 Safety in Welding and Cutting
OSHA 29CFR1926.351 Arc welding and cutting
OSHA 29CFR1926.352 Fire Prevention
OSHA 29CFR1926.353 Ventilation and protection in welding cutting and heating (confined spaces, metals of toxic significance)
OSHSA 29CFR1926.354 Welding cutting and heating in way of preservative coatings
OSHA 1926.350 Gas welding and cutting