Editing Welding (section)

==Safety issues==
[[File:Welding booth with local exhaust system.jpg|thumb|A stick welding booth equipped with local exhaust system (LEV) that removes the toxic fumes, gases, vapours and dusts before they can mix with the room air. Besides toxic emissions, the booth also helps protect bystanders from UV light. With a well-ventilated booth, personal protective equipment is still needed for the welder.]]
[[Image:AlfredPalmerwelder1.jpg|thumb|Arc welding with a welding helmet, gloves, and other protective clothing (1942)]]

Welding can be dangerous and unhealthy if the proper precautions are not taken.<ref name="Osha-2025">{{cite web |title=Welding, Cutting, and Brazing |url=http://www.osha.gov/welding-cutting-brazing/hazards-solutions |website=OSHA |publisher=US Department of Labor |access-date=23 February 2025}}</ref> Potential safety risks come from fumes, ultraviolet radiation, heat, electric currents, and vibrations.<ref>{{harvnb|Blunt|Balchin|2002|pp=55, 67-68, 13-20, 12, 72}}</ref> New technology, safe work practices, and proper protection reduce the risks of injury or death from welding.<ref>ANSI/AWS Z49.1: "Safety in Welding, Cutting, and Allied Processes" (2005)</ref>

Since many common welding procedures involve an open flame or electric arc, the risk of burns and fire is significant; this is why it is classified as a [[hot work]] process. To prevent injury, [[welder]]s wear [[personal protective equipment]] in the form of heavy [[leather]] [[glove]]s and protective long-sleeve jackets to avoid exposure to extreme heat and flames. Synthetic clothing such as polyester should not be worn.<ref>{{Cite web|url=https://www.osha.gov/dts/maritime/sltc/ships/hotwork/hazard_burnshock1.html|title=Safety and Health Injury Prevention Sheets (SHIPS) {{!}} Process: Hot Work - Welding, Cutting and Brazing - Hazard: Burns and Shocks |website=Occupational Safety and Health Administration |access-date=2019-10-12}}</ref> Wool is less flammable than cotton, but dense cotton fabrics such as [[denim]] are still sufficient for clothing. However, any molten material that splatters onto synthetic material will melt directly through the fabric resulting in severe burns.<ref>{{harvnb|Blunt|Balchin|2002|pp=68-69}}</ref>

Arc welding produces intense visible and ultraviolet light. Typical gas metal arc welding has an [[irradiance]] of 5W/m<sup>2</sup> for the welder, which is many times brighter than sunlight.<ref>{{harvnb|Blunt|Balchin|2002|pp=67-69}}</ref> This can cause a condition called [[arc eye]] or flash burns, in which ultraviolet light causes inflammation of the [[cornea]], and can burn the [[retina]]s of the eyes. [[Welding helmet]]s with dark UV-filtering face plates are worn to prevent this exposure.<ref>Andrews, Graham. "Welding with Safety ." Practical Arc Welding , Flairnet, 2016, pp. 54–54.</ref> Many helmets include an auto-darkening face plate, which instantly darkens upon exposure to the intense UV light.<ref>{{cite web |title=Selecting the Right Welding Helmet for You |url=https://www.millerwelds.com/resources/article-library/selecting-the-right-welding-helmet-for-you |website=MillerWelds |date=23 February 2010}}</ref><ref>{{cite web |last1=Guerrero |first1=Rafael |title=How Have Welders Influenced Welding Helmet Design? |url=https://www.thefabricator.com/thewelder/article/safety/how-have-welders-influenced-welding-helmet-design |website=The Welder |access-date=23 February 2025 |language=en}}</ref> To protect bystanders, the welding area is often surrounded by 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 they cannot replace the [[filter (optics)|filter]] glass used in helmets.<ref>{{harvnb|Cary|Helzer|2005|pp=42, 49–51}}</ref> The light can also burn exposed skin.<ref>{{harvnb|Blunt|Balchin|2002|pp=67-69}}</ref> Because of the less intense light produced in oxyfuel welding, [[goggle]]s that use less UV filtering and do not protect the entire face are sufficient.<ref>{{harvnb|Finch|2007|p=33}}</ref>

Depending on the type of material, welding varieties, and other factors, welding can produce over 100&nbsp;dB(A) of noise.<ref>{{Cite web |title=Welding: Health Risks from Welding - HSE |url=https://www.hse.gov.uk/welding/health-risks-welding.htm |access-date=2024-08-15 |website=www.hse.gov.uk}}</ref> Above 85&nbsp;dB(A), earplugs should be worn.<ref>{{harvnb|Blunt|Balchin|2002|pp=74-75}}</ref> Long-term or continuous exposure to higher [[decibel]]s can lead to [[noise-induced hearing loss]].<ref>{{Cite web |date=2020-09-24 |title=Do You Know How Loud Is Too Loud? {{!}} NIDCD |url=https://www.nidcd.nih.gov/news/2020/do-you-know-how-loud-too-loud |access-date=2024-08-15 |website=www.nidcd.nih.gov |language=en}}</ref> Processes that produce vibrations sufficient to numb a welder's hands are automated because PPE cannot offer sufficient protection.<ref>{{harvnb|Blunt|Balchin|2002|pp=79}}</ref>

[[File:Chamber for Welding Fumes (8743403735).jpg|thumb|A chamber designed to contain welding fumes for analysis]]
[[File:Welding Helmet Effects on Breathing Zone Exposures.webm|thumb|A video describing research on welding helmets and their ability to limit fume exposure]]

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 [[oxide]]s. 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 can 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.<ref name="Cary5262">{{harvnb|Cary|Helzer|2005|pp=52–62}}</ref> Exposure to [[manganese]] welding fumes, for example, even at low levels (<0.2&nbsp;mg/m<sup>3</sup>), may cause neurological problems or damage to the lungs, liver, kidneys, or central nervous system.<ref>{{Cite web|date=2022-05-04|title=Welding and Manganese 
| author=((National Institute of Occupational Safety and Health)) | work = Center for Disease Control| publisher= US Department of Health and Human Services 
|url=https://www.cdc.gov/niosh/topics/welding/default.html|access-date=2023-02-20}}</ref> Nano particles can become trapped in the alveolar macrophages of the lungs and induce pulmonary fibrosis.<ref>{{cite journal|title=The Significance of Nano Particles in Particle-Induced Pulmonary Fibrosis|author1=James D Byrne|author2=John A Baugh|journal=McGill Journal of Medicine|date=2008|volume=11|pages=43–50|pmc=2322933|pmid=18523535|issue=1}}</ref> 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.<ref name="Cary5262" />

There are several technologies to mitigate dangers from welding fumes. [[Engineering_controls#Local_exhaust_ventilation|Local exhaust ventilation]] (LEV) solutions remove fumes, smoke, and dust directly from the welding area. Forms of LEV include downdraft benches, fume hoods, and fume extraction welding guns. Downdraft benches have exhaust ducts beneath the metal welding table. Fume extraction guns have a vacuum hose that runs down to the welding nozzle. Movable fume hoods can positioned directly over the welding area.<ref>{{cite web |title=Welding - Ventilation |url=https://www.ccohs.ca/oshanswers/safety_haz/welding/ventilation.html |website=Canadian Centre for Occupational Health and Safety |publisher=Government of Canada |date=23 August 2024}}</ref><ref>{{harvnb|Blunt|Balchin|2002|pp=57-62}}</ref> Even with ventilation, there are still respiratory risks that [[respirator]]s  can further reduce. Studies have shown that respirators, especially half-mask [[elastomeric respirator]]s, significantly decrease particulate inhalation.<ref>{{cite journal |last1=Rafiee |first1=Ata |last2=Laskar |first2=Imranul |last3=Quémerais |first3=Bernadette |title=Investigating the field effectiveness of respirators against metal particle exposure in various workplaces: a systematic review |journal=Reviews on Environmental Health |date=27 June 2022 |volume=37 |issue=2 |pages=201–210 |doi=10.1515/reveh-2020-0174 |url=https://pubmed.ncbi.nlm.nih.gov/33991467/ |issn=2191-0308}}</ref>