Hot work
 | The examples and perspective in this 2023-01-19 may not represent a worldwide view of the subject. (January 2023) |
Hot work refers to operations which can produce a flame or spark.[1][2] Common hot work processes involve welding, soldering, cutting, brazing and the use of powder-actuated tools or similar fire producing operations. These processes produce sparks which can ignite flammable materials around the work area or flammable gases and vapors in the workspace. [3]
Types of Hot Work
[edit]Welding
[edit]
The process of joining two pieces of metal or plastic together through an electrode.[4] 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.[5]
Soldering
[edit]Soldering is the same type of joining process as welding but uses different filler material called solder and operates at under 450 degrees Celsius.[5] Soldering is commonly used in circuit boards and copper pipes in plumbing.
Brazing
[edit]Brazing is used in applications to join close fitting members in the range of 0.001 to 0.005 inches.[6] Brazing operations are conducted at temperatures above 450 degrees Celsius.
Cutting
[edit]Cutting processes that produce sparks fall under the category of hot work. Examples include sparks produced from saw cutting and grinding. [7][8]
Safety
[edit]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[9][10]:
- 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.[11]
Fire Watch
[edit]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.[12]
Hot Work Permit
[edit]In some countries, such as the UK and Canada,[13] a hot work permit is required for hot work.[14] The purpose of a hot work permit is to effect "the employer's written authorization to perform hot working operations".[15] 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.[16]
Confined Spaces
[edit]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.[17] 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. [18] General requirements for hot work include[19]:
- 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.
Standards
[edit]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.[20]
In the United States, OSHA maintains regulations for hot work in the marine industrial setting. The following regulations apply:
- Hot Work. - 1915.14
- Welding, cutting and heating (hot work). - 1917.152
- Precautions for hot work. - 1915.503
- Welding, Cutting, and Brazing definitions - 1910.251
- Welding, Cutting and Brazing General Requirements - 1910.252
- Oxygen-fuel gas welding and cutting - 1910.253
- Arc Welding and cutting - 1910.254
- Resistance Welding - 1910.255
- 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).[21]
See also
[edit]References
[edit]- ^ US EPA, OLEM (2019-12-27). "Hot Work Definition and Requirements". www.epa.gov. Retrieved 2025-03-11.
- ^ "1917.152 - Welding, cutting and heating (hot work)[12] (See also § 1917.2, definition of Hazardous cargo, materials, substance, or atmosphere)". OSHA. Retrieved 2025-03-10.
- ^ Luminoso, Lindsay (2020-06-30). "A Health and Safety Guide to Welding". Canadian Fabricating and Welding. Retrieved 2025-03-10.
- ^ "Welding 101: A Supervisor's Guide". Archived from the original on 2024-07-03. Retrieved 2025-03-11.
- ^ a b Humpston, Giles; Jacobson, David M. (2004). Principles of Soldering. ASM International. ISBN 978-1-61503-170-2.
- ^ "Understanding Brazing Fundamentals". 2014-02-27. Archived from the original on 2014-02-27. Retrieved 2025-03-11.
- ^ Mcdonald, Timothy; Rummer, Bob (June 2010). "Temperature variations and spark generations from rock contact in hot saws". ResearchGate. Retrieved 2025-03-10.
- ^ Guillen, Anthony; Goh, Fang; Andre, Julie; Barral, Amaury; Brochet, Clement; Louis, Quentin; Guillet, Thibault (2019). "From the microstructure of steels to the explosion of sparks". Emergent Scientist. 3: 2. doi:10.1051/emsci/2019001. ISSN 2556-8779.
- ^ "A Health and Safety Guide to Welding". Archived from the original on 2021-06-29. Retrieved 2025-03-24.
- ^ "Safety in gas welding, cutting and similar processes - HSE". www.hse.gov.uk. Retrieved 2025-03-24.
- ^ Tagurum, Yetunde O.; Gwomson, Martin D.; Yakubu, Pankyes M.; Igbita, James A.; Chingle, Moses P.; Chirdan, Oluwabunmi O. (2018-06-25). "Awareness of occupational hazards and utilization of PPE amongst welders in Jos metropolis, Nigeria". International Journal of Research in Medical Sciences. 6 (7): 2227–2233. doi:10.18203/2320-6012.ijrms20182808. ISSN 2320-6012.
- ^ Hedrick, Steve. "Fire prevention during hot work" (PDF). Weld World.
- ^ "Welding - Hot Work : OSH Answers". 14 February 2022.
- ^ Hughes, Phil; Ferrett, Ed (2005), Introduction to health and safety at work: the handbook for the NEBOSH national general certificate (2nd ed.), Butterworth-Heinemann, p. 84, ISBN 978-0-7506-6623-7.
- ^ Occupational Safety and Health Administration, 1910.146 - Permit-required confined spaces, accessed 7 December 2019
- ^ Health and Safety Executive, Safety in gas welding, cutting and similar processes, INDG297, published May 2012, accessed 7 December 2019
- ^ productioneditor (2024-10-23). "Improving worker safety in confined space entry and hot work operations: Best practices for high-risk industries". Global Journal of Advanced Research and Reviews. Retrieved 2025-03-24.
- ^ "Confined Spaces". Occupational Safety and Health Administration. Retrieved 2024-03-24.
- ^ "1910.146 - Permit-required confined spaces". Occupational Safety and Health Administration. Retrieved 2024-03-24.
- ^ "CHAPTER 35 WELDING AND OTHER HOT WORK - 2021 INTERNATIONAL FIRE CODE (IFC)". codes.iccsafe.org. Retrieved 2025-03-24.
- ^ API, RP 2009: Safe Welding, Cutting, and Hot Work Practices in the Petroleum and Petrochemical Industries, accessed 18 March 2020