Editing Kill switch (section)

==Machine tools==
Emergency stop functions are frequently used on [[Machine_tool|machine tools]], including equipment like wood and metal [[Saw|sawing machines]], [[Grinding_machine|grinding machines]], [[Drill|drilling machines]], [[Milling_(machining)|milling machines and machining centres]] and [[Lathe|lathes]]. The emergency stop [[Functional_safety|safety function]], and general requirements for emergency stop devices are set out in ISO 13850. <ref name="ISO_13850">{{cite web |title=ISO 13850:2015 Safety of machinery — Emergency stop function — Principles for design |url=https://www.iso.org/standard/59970.html |website=iso.org |publisher=International Organization for Standardization |access-date=14 April 2022}}</ref> Machine specific (type-C) standards often include specific requirements for the emergency stop functions, but in the absence of a relevant type-C standard, the [[risk assessment]] should be used to determine whether or not an emergency stop function would be useful in avoiding or limiting harm. The ISO machinery safety standard types are defined in ISO 12100,<ref name="ISO_12100">{{cite web |title=ISO 12100:2010 Safety of machinery — General principles for design — Risk assessment and risk reduction |url=https://www.iso.org/standard/51528.html |website=iso.org |publisher=International Organization for Standardization |access-date=14 April 2022}}</ref> and this nomenclature is used by other standards development organizations, like [[American_National_Standards_Institute|ANSI]] in the US, and [[CSA_Group|CSA]] in Canada.<ref name="ANSI_B11-0">{{cite web |title=ANSI B11.0-2020 Safety Of Machinery |url=https://webstore.ansi.org/Standards/AMT/ANSIB112020 |website=ansi.org |publisher=American National Standards Institute |access-date=14 April 2022}}</ref><ref name="Z432-16">{{cite web |title=Z432-16 (R2021) Safeguarding of machinery |url=https://www.csagroup.org/store/product/Z432-16/ |website=csagroup.org |publisher=Canadian Standards Organization |access-date=14 April 2022}}</ref>

===Complementary protective measure===
[[File:Homemade Mollyguard.jpg|thumb|An emergency stop button with a custom-made plastic molly guard to prevent it from being pressed accidentally]]
A machinery's emergency stop control is considered a complementary protective measure<ref name="ISO_12100"/> because it is intended to complement the primary safeguarding measures like [[Machine_guarding|fixed guards, movable interlocked guards or safeguarding devices]]. The primary safeguarding measures prevent injury automatically, either by enforcing distance between a hazard and a person, or by eliminating the hazard by stopping hazardous motion or switching off a source of hazardous energy.

By contrast, an emergency stop requires a deliberate action on the part of a person who must first recognize that some hazardous condition is about to arise or is arising, and who then must activate the emergency stop function by pressing the emergency stop button or activating another emergency stop device such as a pull-cord switch.