'''Hazardous energy''' in occupational safety and health is any source of energy (including electrical, mechanical, thermal, chemical, hydraulic, and pneumatic sources of energy) that "can be hazardous to workers", such as from discharge of stored energy.<ref>{{Cite web|url=https://www.osha.gov/SLTC/controlhazardousenergy/|title=Control of Hazardous Energy|website=Occupational Safety and Health Administration|publisher=United States Department of Labor}}</ref><ref>{{Cite web|url=https://www.ccohs.ca/oshanswers/hsprograms/hazardous_energy.html|title=(none)|last=Safety|first=Government of Canada, Canadian Centre for Occupational Health and|website=www.ccohs.ca|language=en|access-date=2018-11-21}}</ref><ref>{{Cite web|url=https://www.ccohs.ca/oshanswers/safety_haz/electrical.html|title=(none)|last=Safety|first=Government of Canada, Canadian Centre for Occupational Health and|website=www.ccohs.ca|language=en|access-date=2018-11-21}}</ref> Failure to control the unexpected release of energy can lead to machine-related injuries or fatalities. The risk from these sources of energy can be controlled in a number of ways, including access control procedures such as lockout-tagout.<ref>{{Cite web |last=Moore |first=Paul |last2=Pizatella |first2=Timothy J. |date=August 1999 |title=Preventing worker deaths from uncontrolled release of electrical, mechanical, and other types of hazardous energy |url=https://stacks.cdc.gov/ |access-date=2026-04-15 |website=stacks.cdc.gov}}</ref><ref>{{Cite journal|last1=Parker|first1=David L.|last2=Yamin|first2=Samuel C.|last3=Xi|first3=Min|last4=Brosseau|first4=Lisa M.|last5=Gordon|first5=Robert|last6=Most|first6=Ivan G.|last7=Stanley|first7=Rodney|date=January 2016|title=Findings From the National Machine Guarding Program|url= |journal=Journal of Occupational and Environmental Medicine|volume=58|issue=1|pages=61–68|doi=10.1097/jom.0000000000000594|issn=1076-2752|pmc=4961089|pmid=26716850}}</ref>
== Types of Hazardous Energy == Hazardous energy in occupational settings exists in many categories, all forms have distinct risks depending on the equipment and work environments. <ref name=":0">{{Cite web |title=eTool : Lockout-Tagout - Hot Topics - Multiple Energy Sources/Multiple Items of Equipment {{!}} Occupational Safety and Health Administration |url=https://www.osha.gov/etools/lockout-tagout/hot-topics/multiple-energy-sources |access-date=2026-04-05 |website=www.osha.gov}}</ref>
Categories include:
* "Electrical energy, which can result in shock, burns or arc flash injuries when workers are exposed to energized conductors or equipment."<ref>{{Cite web |last=Government of Canada |first=Canadian Centre for Occupational Health and Safety |date=2025-08-28 |title=CCOHS: Hazardous Energy Control Programs |url=https://www.ccohs.ca/oshanswers/hsprograms/hazardous_energy.html |access-date=2026-04-13 |website=www.ccohs.ca}}</ref> * "Mechanical energy, consisting of rotating members, reciprocating arms, moving belts, gears, cutting teeth and any parts that impact or shear." <ref>{{Cite web |title=eTool : Machine Guarding - Introduction - Hazardous Motions/Actions {{!}} Occupational Safety and Health Administration |url=https://www.osha.gov/etools/machine-guarding/introduction/hazardous-motions-actions |access-date=2026-04-13 |website=www.osha.gov}}</ref> * "Hydraulic and pneumatic energy, energy stored in the form of pressurized fluid making it application of fluid power. Fluid power is the use of pressurized fluids to generate, control and transfer power."<ref>{{Cite web |title=Pneumatic Hydraulic energy - Energy Education |url=https://energyeducation.ca/encyclopedia/Pneumatic_Hydraulic_energy |access-date=2026-04-13 |website=energyeducation.ca}}</ref> * "Thermal energy refers to energy within a system that's created by the random motion of molecules and atoms. As motion increases more energy is produced this energy is transferred in the form of heat."<ref>{{Cite web |last=Jonker |first=Tom Krantz, Alexandra |date=2024-03-08 |title=What Is Thermal Energy? {{!}} IBM |url=https://www.ibm.com/think/topics/thermal-energy |access-date=2026-04-13 |website=www.ibm.com |language=en}}</ref> * Chemical energy, involving reactions or stored chemicals that may release toxic, flammable, or explosive substances."<ref name=":0" />
== Hazards and Workplace Risks == The number one danger associated with hazardous energy is unexpected startup of machinery or the release of stored energy. Release of energy can happen even when equipment seems to be completely de-energized. These situations can lead to severe injuries, including amputations, electrocution, and fatalities.<ref name=":1">{{Cite web |last=CDC |date=2025-05-20 |title=Hazardous Energy Control Resource Guide |url=https://www.cdc.gov/niosh/manufacturing/hazardous-energy-control/resource-guide.html |access-date=2026-04-05 |website=Manufacturing |language=en-us}}</ref>
Stored energy can stay in systems even after shutdown. For example:
* Electrical capacitors may retain charge after shutdown. * Hydraulic systems may remain pressurized. * Mechanical components may be under tension or gravity load.
Workers performing maintenance and routine cleaning are especially vulnerable. Without proper protection, minor mistakes can result in catastrophic outcomes. Studies and safety agencies have consistently identified failure to control hazardous energy as a leading cause of industrial accidents. <ref>{{Cite web |last=CDC |date=2025-05-19 |title=Hazardous Energy Control |url=https://www.cdc.gov/niosh/manufacturing/hazardous-energy-control/index.html |access-date=2026-04-05 |website=Manufacturing |language=en-us}}</ref>
== Control Methods and Safety Procedures == One of the most popular controls of hazardous energy is commonly achieved through lockout-tagout '''(LOTO)''' procedures. '''LOTO''' is designed to isolate energy sources and prevent machines from being energized during servicing. Under these procedures, energy-isolating devices are physically locked in a safe position and clearly labeled to indicate that maintenance is in progress. Other than '''LOTO''' engineering controls such as machine guarding and interlocks provide more layers of electrical protection. <ref name=":2">{{Cite web |title=eTool : Lockout-Tagout Interactive Training Program {{!}} Occupational Safety and Health Administration |url=https://www.osha.gov/etools/lockout-tagout |access-date=2026-04-05 |website=www.osha.gov}}</ref><ref name=":1" /><gallery widths="400" heights="400"> File:Power Lockout (13421721974).jpg|Lockout-tagout devices applied to prevent accidental energization during maintenance. </gallery>A typical hazardous energy control process includes:<ref name=":2" />
* "Verifying all energy sources that are connected to equipment" * "Completely shutting down the system" * "Isolating energy sources" * "Attaching lockout or tagout devices" * "Releasing or containing stored energy" * "Verifying isolation before maintenance begins"
These procedures are formalized in regulatory standards such as [https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.147 29 CFR 1910.147] which establishes minimum requirements for protecting workers from hazardous energy during maintenance activities. <ref>{{Cite web |title=1910.147 - The control of hazardous energy (lockout/tagout). {{!}} Occupational Safety and Health Administration |url=https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.147 |access-date=2026-04-05 |website=www.osha.gov}}</ref>
== Training and Employee Responsibilities == Correct training is an important component of any hazardous energy control. OSHA demands all workers whom perform servicing on machinery must be trained to understand the dangers of hazardous energy.<ref>{{Cite web |title=Control of Hazardous Energy (Lockout/Tagout) - Overview {{!}} Occupational Safety and Health Administration |url=https://www.osha.gov/control-hazardous-energy/ |access-date=2026-04-15 |website=www.osha.gov}}</ref>
Training requirements most of the time apply to three genres of employees:
* '''Authorized employees''' are workers who "locks out or tags out machines or equipment in order to perform servicing or maintenance on that machine or equipment"<ref name=":3">{{Cite web |title=1910.147 - The control of hazardous energy (lockout/tagout). {{!}} Occupational Safety and Health Administration |url=https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.147 |access-date=2026-04-15 |website=www.osha.gov}}</ref> * '''Affected employees''' "become authorized employees when that employee's duties include performing servicing or maintenance." Affected employees must be trained to understand '''LOTO''' and know they shouldn't try to reenergize the machine.<ref name=":3" /> * '''Other employees''' "whose work operations are or may be in an area where energy control procedures may be utilized, shall be instructed about the procedure, and about the prohibition relating to attempts to restart or reenergize machines or equipment which are locked out or tagged out."<ref name=":3" />
"Retraining shall be provided for all authorized and affected employees whenever a periodic inspection reveals, or whenever the employer has reason to believe, that there are deviations from or inadequacies in the employee's knowledge or use of the energy control procedures."<ref>{{Citation |last=Richard |first=Ennis |title=Stadard Summary Electrical Safety-Related Work Practices 29 CFR Part 1910 |date=2024-11-01 |work=Electrical Safety-Related Work Practices |pages=2–20 |url=https://doi.org/10.1201/9781003575542-2 |access-date=2026-04-15 |place=Boca Raton |publisher=CRC Press |isbn=978-1-003-57554-2}}</ref>
== References == {{Reflist|30em}}
== External links == * Canadian Centre for Occupational Health and Safety, OSH Answers Fact Sheets- [https://www.ccohs.ca/oshanswers/hsprograms/hazardous_energy.html Hazardous Energy Control Programs] * [https://www.osha.gov/Publications/osha3120.pdf Control of Hazardous Energy - Lockout/Tagout.] OSHA Publication 3120, (Revised 2002). This booklet presents OSHA's general requirements for controlling hazardous energy during service or maintenance of machines or equipment. It is not intended to replace or to supplement OSHA standards regarding the control of hazardous energy. * Health and Safety Executive, [http://www.hse.gov.uk/pubns/indg231.htm Electrical safety and you, a brief guide] * [https://www.osha.gov/OshDoc/data_General_Facts/factsheet-lockout-tagout.pdf Lockout/Tagout. OSHA Fact Sheet, (2002)]. Also available in Spanish. * National Occupational Research Agenda- [https://www.cdc.gov/nora/councils/manuf/loto/default.html Hazardous Energy Control (Lockout and other means)]
Category:Energy sources Category:Occupational hazards
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