Welding Safety

Welding is the process of joining two pieces of metal together by applying heat or pressure so that when the melted metal solidifies, the parts become fused. Welding is a prevalent activity in the industrial process, involved in industries as diverse as aerospace to electrical and electronic devices and accessories. During 2014, the Bureau of Labor Statistics (BLS) reported that approximately 357,400 welders, cutters, solderers, and brazers were employed (2). Welders and those who perform welding-related activities are susceptible to many occupational hazards, particularly to their ocular and respiratory health. When exposed to these hazards, welders may sustain injuries that can be temporary or permanent in nature, as well as develop illnesses with acute or chronic effects.

Employers’ Role in Workplace Safety

Generally, welders are required to wear welding helmets and shields, safety goggles and protective clothing to guard against optical radiation to the eyes and skin. Ventilation and respiratory masks are used to dilute and shield welders from harmful fumes produced during the welding process. Although this current strategy minimizes exposure levels, it has many shortfalls. Welders often do not wear welding helmets and shields with their safety goggles due to discomfort, which causes ergonomic problems. Additionally, lenses often fog up during the welding process due to heat and perspiration, decreasing their field of vision. Consequently, welders often remove protective masks for simple welding tasks. Radiation may potentially be reflected into conventional welding helmets and penetrate into the helmets from the tops and the sides, causing unintentional exposure even when preventive measures are taken. Finding more advanced protection may not be feasible in an economic and/or practical sense.

A Better Way

Although current protective strategies are available, the persistence of injuries sustained by the non-use or use of unsuitable equipment call for a different approach. Machine vision and automation provide a proactive solution to addressing welding health risks. Welders are displaced from the hazardous environment, eliminating even the slightest chance of accidents waiting to happen. Additionally, these tools allow for the analysis of welding processes in real time, increasing overall productivity. No dollar figure can truly capture the personal toll that occupational hazards have on injured workers and those around them. Making smart choices in creating a healthy and safe environment is crucial as workplace hazards undoubtedly make a significant dip to your bottom line.

Major Hazards

The severity of these adverse effects are influenced by factors including, but not limited to:

  • Work conditions and practices
  • Exposure period
  • Type of welding
  • Inappropriate use of personal protective equipment (PPE)
  • Genetic predisposition
  • Lifestyle factors
WELDING EYE INJURIES

Welding is the most intense artificial producer of optical radiation. Welding arcs emit radiation over a wide spectrum of wavelengths which includes ultraviolet (UV) radiation, visible light, and infrared (IR) radiation. These electromagnetic waves are absorbed into the cornea, lens, and/or retina of the eye which causes phototoxic trauma through damage to critical ocular membrane and structures. In acute cases, it results in what is commonly referred to as “arc eye”. Symptoms of arc eye often appear hours after exposure, and include pain (which varies from a mild pressure to sharp pains), reddening and watering of the eyes, extreme sensitivity to light, along with a “sand in eye” sensation. With special eye drops, symptoms often disappear within a day or so. Depending on the length of exposure and intensity of the radiation, adverse effects could potentially be permanent and sight-threatening. In more chronic cases, welders experience what is known as the “blue light hazard”, leaving permanent scars on the retina which can potentially result in blindness. Other welders may develop phototoxic maculopathy that is accompanied with metamorphopsia and relative central scotoma, significantly diminishing their visual field. Comparing 40 welders and 40 age-matched non-welder controls in a cross-sectional study, fundus photographs revealed the presence of dark-yellow, round macular lesions in 19 welders, as illustrated in figure 1 (10). Optical coherence tomography (OCT) showed an abnormality in the inner segment/outer segment (IS/OS) layer and the inner portion retinal pigment epithelium (RPE) layer in the eyes of 30 welders (10). It was noted that welders in the study had been wearing personal protective equipment (PPE) and strictly following safety protocol during welding processes.

Screenshot-141

The occurrence of eye-related traumas tops all other occupational injuries in the American workplace (8). It is estimated that over 2,000 individuals incur eye injuries at work each day and that 200 of them will have to miss one or more workdays (7). The Bureau of Labor Statistics (BLS) estimate the financial cost of eye injuries at over $467 million annually, with indirect costs added for a whopping $934 million per year (7). In terms of consumer product related eye injuries, welding remains the second leading cause (5). Eye injuries account for 25% of all compensation claims for welders (5). The average cost of a welding related eye injury is $157, slightly higher than the cost of construction related eye injuries (5). In 2002, the state of Massachusetts reported that average total compensation claims amounted up to about $8,246, with the number rising steadily each year (4). Of this amount about $410 (5.0%) represents the portion of compensation claims where eyes would be the major injury (5).

WELDING RESPIRATORY HAZARDS

Respiratory infections in the U.S. cost employers an estimated $132 billion, including medical costs and time lost from work (1). This number is expected to rise considerably each year. Welding processes release harmful fumes made up of solid particles that are formed when the vaporized metal condenses and oxidizes. These particles travel to and become accumulated in the gas-exchange region of the lungs, where it can produce a range of adverse effects. Canada Occupational Health and Safety Regulations (COHRS) requires that employees be limited from exposure to a concentration of an airborne chemical agent beyond the contaminant’s threshold value as established by the American Conference of Governmental Industrial Hygienist (ACGIH). Screenshot (142)Respiratory hazards should be assessed based on factors such as the amount of each substance produced, if each have similar toxicological effects, as well as their collective effect. Factors that determine the level of fumes produced and the exposure period to workers include the type of process, current/voltage, and arc time. Zinc oxide, magnesium oxide, copper, and aluminum fumes can cause metal fume fever. Similar to symptoms of influenza, individuals experience muscle aches and pains, increased body temperature, chills, nausea, and dizziness. Depending on the type of fume inhaled, symptoms may disappear within a few days in acute cases but can potentially result in death, or more serious illnesses (e.g. emphysema, pulmonary fibrosis, lung cancer, etc.) in chronic cases. Certain types of welding fumes are known for causing occupational asthma (OA), which causes coughing, wheezing, and shortness of breath. Symptoms generally improve with time away from arc welding. Of more serious concern is the changes to welders’ lung functions due to long-term and/or heavy exposure to welding fumes. Many experienced decreased forced expiratory volume in one second and increased specific airway resistance, similar to changes seen in long-term smokers. These effects were seen in welders even with concentration of airborne chemical agents well below their threshold limit values (6). Complications from respiratory diseases have even resulted in death for some welders.

Who is at risk?

These hazards pose threats to all welders, regardless of age, industry, and years of service. However, young apprentice welders are most susceptible to these risks due to vocational inexperience and clear ocular media. Providing accessible and comprehensive educational resources on safety is key to addressing these risks.

 

Bibliography
(1) Birnbaum, H.G., Morley, M., Greenberg, P.E., & Colice, G.L. (2002). Economic Burden of Respiratory Infections in an Employed Population. Chest 122; 603-611.
(2) Bureau of Labor Statistics, U.S. Department of Labor, Occupational Outlook Handbook, 2014-15 Edition, Welders, Cutters, Solderers, and Brazers. Retrieved from http://www.bls.gov/ooh/production/welders-cutters-solderers-and-brazers.htm
(3) Creel, D.J. (2014). The Electroretinogram and Electro-oculogram: Clinical Applications by Donnell J. Creel. Webvision. Retrieved from http://webvision.med.utah.edu/book/electrophysiology/the-electroretinogram-clinical-applications/
(4) Lefkowitz, S.J., & McKinnon, S.G. (2012). Examining costs and trends of workers compensation claims in Massachusetts. Oliver Wyman. Retrieved from http://www.oliverwyman.com
(5) Lombardi, D.A., Pannala, R., Sorock, G.S., Wellman, H., Courtney, T.K., Verma, S., & Smith, G.S. (2004). Welding related occupational eye injuries: a narrative analysis. Injury Prevention, 11, 174-179. DOI: 10.1136/ip.2004.007088
(6) Munoz, X., Cruz, M.J., Freixa, A., Guardino, X., & Morell, F. (2009). Occupational Asthma Caused by Metal Arc Welding of Iron. Respiration: International Review of Thoracic Diseases, 78(4), 455-459. DOI: 10.1159/000235817
(7) Prevent Blindness America, Workplace Eye Safety. Retrieved from http://www.preventblindness.org/safety/worksafe.html
(8) The Compliance Resource Center, A Safety Worker. (2009, March 10). Retrieved from http://www.thecrcenter.com/archives/category/bureau-of-labor-statistics/
(9) Winnipeg Air Testing. (2010). Metals/Welding Fumes. Retrieved from http://www.winnipegairtesting.com/metals-welding-fumes
(10) Yang, X., Shao, D., Ding,X., Liang X., Yang J., & Li, J. (2012). Chronic Phototoxic Maculopathy Caused by Welding Arc in Occupational Welders. Can J Ophthalmol, 47(1), 45-50. DOI: 10.1016/j.jcjo.2011.12.001.