Skip to Main Content

This information is provided free of charge by the Department of Industrial Relations from its web site at These regulations are for the convenience of the user and no representation or warranty is made that the information is current or accurate. See full disclaimer at
Subchapter 7. General Industry Safety Orders
Group 6. Power Transmission Equipment, Prime Movers, Machines and Machine Parts
Article 41. Prime Movers and Machinery
Return to index
New query

§4000. Process Machine Power Control.

(a) Each process machine driven by an individual prime mover shall be equipped with a prime mover stopping device which can be safely actuated from the operator's working position unless the machine is equipped with a clutch which will stop all machine operations.

(b) Where an operator attends one or more process machines not having individual drive each machine shall be equipped with a stopping device which can be safely actuated from the operator's working position at the machine. Such a stopping device may stop an entire group of machines by stopping the prime mover power transmission or it may be a machine clutch, cut-off coupling, or tight and loose pulley with belt shifter which can stop all the machine operations at any time on any machine. Pole or hand shifting of belts is not considered adequate means for disconnecting the power.

EXCEPTION: Where due to the process, machines must be operated in groups, the machine power control may stop the entire group of machines. Such group drives shall be provided with conveniently located, readily accessible, and properly marked or otherwise identified stop stations.

(c) Each process machine simultaneously attended or operated by more than one employee shall be equipped with a machine power control for each employee exposed to point of operation hazards. Said controls shall be interlocked in a manner to prevent operation of machine, unless all controls are operated simultaneously. Controls for more than one operating station shall be designed to be activated and deactivated in complete sets of two operator's hand controls per operating station by means capable of being supervised by the employer.

(d) Machine power controls shall be maintained in safe operating condition and shall be so designed, installed and/or located that they cannot operate from accidental contact with objects or parts of the body.

NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.


1. Repealer and new section filed 10-25-74; effective thirtieth day thereafter (Register 74, No. 43).

2. Amendment of subsection (b) filed 10-9-85; effective thirtieth day thereafter (Register 85, No. 44).

Go BackGo Back to Article 41 Table of Contents