Hot work

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The process of joining two pieces of metal or plastic together through an electrode.{{Cite news |title=Welding 101: A Supervisor's Guide |url=https://www.canadianmetalworking.com/canadianfabricatingandwelding/blog/welding/welding-101-a-supervisors-guide |archive-url=http://web.archive.org/web/20240703031052/https://www.canadianmetalworking.com/canadianfabricatingandwelding/blog/welding/welding-101-a-supervisors-guide |archive-date=2024-07-03 |access-date=2025-03-11 |language=en}} Several forms of welding exist, including:

• Shielded Metal Arc Welding (SMAW) or Stick Welding
• Gas Metal Arc Welding (GMAW) or Magnesium Inert Gas Welding (MIG)
• Flux-Cored Arc Welding (FCAW)
• Gas Tungsten Arc Welding (GTAW) or Tungsten Inert Gas Welding (TIG)
• Submerged Arc Welding (SAW)

Welding temperatures vary depending on the type of electrode, but is typically higher than soldering.{{Cite book |last1=Humpston |first1=Giles |url=https://books.google.com/books?id=cQ6khQScBF4C&dq=soldering&pg=PR1 |title=Principles of Soldering |last2=Jacobson |first2=David M. |date=2004 |publisher=ASM International |isbn=978-1-61503-170-2 |language=en}}

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Soldering is the same type of joining process as welding but uses different filler material called solder and operates at under 450 degrees Celsius. Soldering is commonly used in circuit boards and copper pipes in plumbing.

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Brazing is used in applications to join close fitting members in the range of 0.001 to 0.005 inches.{{Cite web |date=2014-02-27 |title=Understanding Brazing Fundamentals |url=https://www.aws.org/wj/amwelder/9-00/fundamentals.html |url-status=dead |archive-url=https://web.archive.org/web/20140227064624/http://www.aws.org/wj/amwelder/9-00/fundamentals.html |archive-date=2014-02-27 |access-date=2025-03-11 }} Brazing operations are conducted at temperatures above 450 degrees Celsius.

Cutting processes that produce sparks fall under the category of hot work. Examples include sparks produced from saw cutting and grinding. {{Cite web |last1=Mcdonald |first1=Timothy |last2=Rummer |first2=Bob |date=June 2010 |title=Temperature variations and spark generations from rock contact in hot saws |url=https://www.researchgate.net/publication/239522336 |access-date=2025-03-10 |website=ResearchGate}}{{Cite journal |last1=Guillen |first1=Anthony |last2=Goh |first2=Fang |last3=Andre |first3=Julie |last4=Barral |first4=Amaury |last5=Brochet |first5=Clement |last6=Louis |first6=Quentin |last7=Guillet |first7=Thibault |date=2019 |title=From the microstructure of steels to the explosion of sparks |url=https://emergent-scientist.edp-open.org/articles/emsci/full_html/2019/01/emsci180006/emsci180006.html |journal=Emergent Scientist |language=en |volume=3 |pages=2 |doi=10.1051/emsci/2019001 |issn=2556-8779}}

The hazards presented with hot work vary greatly, depending on the type of hot work used, the space and surroundings that the work is performed, and how to evaluate the best solution for the hazards present. While nearly every job involving hot work is unique in some way, there are some general steps that can be taken to help mitigate risk:{{Cite news |title=A Health and Safety Guide to Welding |url=https://www.canadianmetalworking.com/canadianfabricatingandwelding/article/welding/a-health-and-safety-guide-to-welding |archive-url=http://web.archive.org/web/20210629181309/https://www.canadianmetalworking.com/canadianfabricatingandwelding/article/welding/a-health-and-safety-guide-to-welding |archive-date=2021-06-29 |access-date=2025-03-24 |language=en}}{{Cite web |title=Safety in gas welding, cutting and similar processes - HSE |url=https://www.hse.gov.uk/pubns/indg297.htm |access-date=2025-03-24 |website=www.hse.gov.uk}}

• Evaluate the workplace for potential hazards before performing the work
• Consider moving the workplace to a safer location if possible or removing hazardous materials
• In areas where there is particularly high danger, utilize a fire watch

• Ensure everyone in the area is aware of the hazards present and where they are
• After finishing work, keep a watch as the work piece cools to ensure nothing ignites

Personal Protective Equipment (PPE) is also an important part of safety in hot work. Many worksites cannot have the hazards eliminated or utilize components of the hierarchy of controls. Therefore, it is important for employers to emphasize the importance of PPE and for workers to utilize PPE in these conditions to mitigate risk wherever possible.{{Cite web |last=Government of Canada |first=Canadian Centre for Occupational Health and Safety |date=2024-08-14 |title=CCOHS: Hazard and Risk - Hierarchy of Controls |url=https://www.ccohs.ca/oshanswers/hsprograms/hazard/hierarchy_controls.html |access-date=2025-04-21 |website=www.ccohs.ca}}{{cn|date=April 2025}}

When performing hot work, welders must assess the risk of fire in the work area and implement certain safety precautions if a threat is detected. The establishment of a fire watch is the most important precaution a welder can take against an accidental fire on a job site. Either the welder himself or an appointed laborer must become designated for a fire watch and stay in the area of the hot work for no less than 2 hours after the last of the hot work has been completed. This designated fire watch person must have a fire extinguisher and access to phone in case of a fire.{{Cite journal|last=Hedrick|first=Steve|title=Fire prevention during hot work|url=https://www.canaweld.com/wp-content/uploads/2019/07/Fire-Prevention-During-Hotwork.pdf|journal=Weld World}}

In some countries, such as the UK and Canada,{{Cite web |date=14 February 2022 |title=Welding - Hot Work : OSH Answers |url=http://www.ccohs.ca/oshanswers/safety_haz/welding/hotwork.html}} a hot work permit is required for hot work.{{Citation |last1=Hughes |first1=Phil |title=Introduction to health and safety at work: the handbook for the NEBOSH national general certificate |page=84 |year=2005 |url=https://books.google.com/books?id=F-3XDSCSWKoC&pg=PA84 |edition=2nd |publisher=Butterworth-Heinemann |isbn=978-0-7506-6623-7 |last2=Ferrett |first2=Ed}}. The purpose of a hot work permit is to effect "the employer's written authorization to perform hot working operations".Occupational Safety and Health Administration, [https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.146 1910.146 - Permit-required confined spaces], accessed 7 December 2019 The UK's Health and Safety Executive suggests that a hot work permit should specify:

• what work will be done;
• how and when it is to be done;
• what safety and health precautions are needed;
• who is responsible for checking it is safe for the work to start;
• who will check that the work is done safely;
• who is responsible for confirming that work is complete and there is no longer a risk from, or to, the people doing the work.Health and Safety Executive, [https://www.hse.gov.uk/pubns/indg297.pdf Safety in gas welding, cutting and similar processes], INDG297, published May 2012, accessed 7 December 2019

File:Confined spaces team keeps manhole work safe 160226-F-EB935-003.jpg

Confined spaces present a unique challenge with hot work for several reasons. Hot work performed in storage tanks, pipelines, and sewers present a risk of explosion due to the presence of flammable gasses.{{Cite web |last=productioneditor |date=2024-10-23 |title=Improving worker safety in confined space entry and hot work operations: Best practices for high-risk industries |url=https://gsjournals.com/gjarr/content/improving-worker-safety-confined-space-entry-and-hot-work-operations-best-practices-high |access-date=2025-03-24 |website=Global Journal of Advanced Research and Reviews |language=en}} Physical and chemical hazards in confined spaces are:

• Limited access points make entering and exiting difficult
• Poor ventilation and limited airflow can lead to the buildup of toxic and flammable gasses
• Gasses such as Carbon Monoxide can buildup from hot work in confined spaces
• Workers can face entrapment when physical barriers or equipment fails

In the united states, OSHA requires confined spaces where hot work is done to acquire a permit for hot work. {{Cite web |title=Confined Spaces |url=https://www.osha.gov/confined-spaces |access-date=2024-03-24 |website=Occupational Safety and Health Administration}} General requirements for hot work include:{{Cite web |title=1910.146 - Permit-required confined spaces |url=https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.146 |access-date=2024-03-24 |website=Occupational Safety and Health Administration}}

• The employer shall post danger signs or other effective means of the existence, location, and danger posed by permit spaces
• The employer must have a written permit confined space program available for inspection by employees

There are several specific circumstances in which an employer may qualify for exemptions from parts of the regulation, such as when the hazard present is solely a hazardous atmosphere and forced ventilation is utilized.

Most countries in the world use their own rules and regulations that have different responsibilities for both the employer and employee regarding safety and risk mitigation in the workplace, while some countries lack these rules or struggle to enforce them. The International Fire Code Chapter 35 presents a general framework for countries to adopt and utilize in the building of their own safety regulations regarding hot work.{{Cite web |title=CHAPTER 35 WELDING AND OTHER HOT WORK - 2021 INTERNATIONAL FIRE CODE (IFC) |url=https://codes.iccsafe.org/content/IFC2021P2/chapter-35-welding-and-other-hot-work |access-date=2025-03-24 |website=codes.iccsafe.org}}

In the United States, OSHA maintains regulations for hot work in the marine industrial setting. The following regulations apply:

• [http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10220 Hot Work. - 1915.14]
• [http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10416 Welding, cutting and heating (hot work). - 1917.152]
• [http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=12976 Precautions for hot work. - 1915.503]
• [https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.251 Welding, Cutting, and Brazing definitions - 1910.251]
• [https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.252 Welding, Cutting and Brazing General Requirements - 1910.252]
• [https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.253 Oxygen-fuel gas welding and cutting - 1910.253]
• [https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.254 Arc Welding and cutting - 1910.254]
• [https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.255 Resistance Welding - 1910.255]
• [https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.350 Gas Welding and cutting - 1926.350]

Other relevant literature is:

• API RP 2009 : Safe Welding, Cutting, and Hot Work Practices in the Petroleum and Petrochemical Industries, published by the American Petroleum Institute (API).API, [https://www.api.org/oil-and-natural-gas/health-and-safety/refinery-and-plant-safety/occupational-safety/rp-2009 RP 2009: Safe Welding, Cutting, and Hot Work Practices in the Petroleum and Petrochemical Industries], accessed 18 March 2020

• Oil Industry Safety Directorate

{{Reflist}}

• *[http://www.osha.gov/SLTC/etools/oilandgas/general_safety/hot_work_welding.html Hot Work / Welding - OSHA]

Category:Welding safety

Category:Occupational hazards

Category:Fire protection