Tuesday, November 11, 2008

CP91: 2001 Code of Practice for Lockout Procedure

This code applies to the control of energy during construction, servicing or maintenance of machines.

This code covers the construction, servicing or maintenance of machines where any unexpected energisation or start up of the machines, or release of stored energy could cause injury to employees. It establishes minimum performance requirements for the control of such hazardous energy.

Affected employee - An employee who is required to operate or use a machine on which construction, servicing or maintenance is being performed under lockout, or who is required to work in an area in which such construction, servicing or maintenance is being performed.
Authorised employee - A person who locks out machines in order to perform construction, servicing or maintenance on that machine. An affected employee becomes an authorised employee when that employee's duties include construction, servicing or maintenance covered under this code.
Construction, servicing and/or maintenance Workplace activities such as constructing, erecting, installing, setting up, commissioning, repairing, adjusting, inspecting, modifying, operating, and maintaining and/or servicing machines or equipment. These activities include lubrication, cleaning or unjamming of machines or equipment and making adjustments or tool changes, where the employee may be exposed to the unexpected energisation or start-up of the equipment or release of hazardous energy.

Energy isolating device - A mechanical device that physically prevents the transmission or release of energy, including but is not limited to the following:

  • a circuit breaker

  • an isolating switch

  • a line valve

  • a block

  • any similar device used to block or isolate energy.

NOTE - Push buttons, selector switches, functional switches and other control circuit type devices are not energy isolating devices.

Energy source - Any source of electrical, mechanical, hydraulic, pneumatic, chemical, thermal, or other forms of energy.
Lockout - The placement of a lockout device on an energy isolating device, in accordance with an established procedure, for ensuring that the energy isolating device and the machine being controlled cannot be operated until the lockout device is removed.
Lockout device - A device that utilises a positive means such as a lock, either key or combination type, to hold an energy isolating device in the safe position and prevent energisation of a machine.

Tagging device - A prominent warning device, such as a tag and a means of attachment, which can be securely fastened to an energy isolating device in accordance with an established procedure, to indicate that the energy isolating device and the machine being controlled may not be operated until the tagging device is removed.

Lockout poilcy and procedure
Responsibility of each employer whose employees are engaged in erecting, installing, constructing, repairing, adjusting, cleaning, inspecting, operating, or maintaining the machine, to develop, document and implement a policy and procedure for lockout.

The policy and procedure shall clearly and specifically outline the purpose, responsibility, scope, authorisation, rules, definitions and measures to enforce compliance.
The lockout policy shall require all personnel concerned to comply with the lockout procedure.
The lockout procedure shall specify that prior to the performance of any ctivities where unexpected energisation, start up, or release of stored energy could occur and cause injury, all potentially hazardous energy sources shall be isolated and locked out. The procedure shall also specify the requirements for removal of such devices, transfer of locks, and testing for determination of lockout effectiveness.
Use of locks
Locks shall be provided by the employer and shall be the only authorised device(s) used for the lockout of energy sources. They shall be singularly identified and specifically approved for lockout.

Compliance with this code shall be the responsibility of the employer and the individuals to whom the employer delegates accountability for compliance and authority to enforce compliance. Periodic inspections
Responsibility of the employer to verify, through periodic inspections, the organisation's compliance with this code.
Joint responsibility
The responsibility for obtaining performance in the lockout procedure shall be collaborated between the employer and the employee. The responsibility for compliance is that of the employer, who shall establish, communicate, train in the use of and the enforcement of procedure. The employee shall be responsible for knowing and following the established procedure.

Communication and training
All employees- All employees shall be specifically notified of the requirements for compliance with the employer's policy and made aware of the lockout procedure.
Affected employees- The employer shall ensure that each affected employee is instructed in the purpose and use of the lockout procedure.
Authorised employees- All authorised individuals shall receive training in recognition of the applicable hazardous energy sources and in adequate methods and means for their isolation.

Requirements for lockout devices

The lockout devices used for compliance with this code shall be:
  • Durable
  • Unique
  • Standardised
  • Identifiable
  • Substantial Locks & Tags

Requirements for lockout procedure

  • Survey of energy sources and identification of all energy isolating devices
  • Selection and procurement of protective materials and hardware
  • Assignment of duties and responsibilities
  • Preparation of de-energisation and start up sequence
  • Implementation of lockout procedure

Preparation and steps for lockout

Details on the types of energy that power the machinery, locations of the energy isolating devices, presence of any secondary power supplies and the correct steps to turn off the machine safely must be established in the energy control procedure.

Before the machine is shut down the authorised employee must understand the type and magnitude of the energy he is working with, the hazards of the energy, the means and method to control the energy, verification of effective energy control and the purpose of the procedure to be used.

The following steps shall be taken to achieve a safe energy isolation and machine lockout. The sequence established shall be followed.

  • Announce the shut down.
    Inform all affected employees of the purpose and duration of the lockout application. This notification must be given before the lockout procedure is performed.
  • Machine shut down.
    The machine must be shut down using the operating controls according to the shut down procedure for each individual machine to avoid any additional or increased hazard. This is a safe practice as any attempt to shut down machine under load risks damaging the machine.
  • Machine isolation.
    All energy isolating devices that control the energy to the machine must be operated to isolate the machine from the energy sources. The energy control procedure must also identify the location of all energy isolating devices and energy sources including secondary power supplies. This will ensure the safe and complete de-energisation of the machine.
  • Lockout and tagging device application.
    The authorised employee is responsible for the application of proper lockout and tagging devices to the energy isolating devices of the machine.
    The authorised employee must use his own locks only and nobody is allowed to apply his locks on behalf of another individual, except for group lockout protection.
    The lockout devices must be sturdy and lockout the energy isolating devices in the "off" position. They must also be designed to prevent the operation of the energy isolating devices when they are lockout.
    If more than one person is working on the machine, every member of the crew must attach his personal lock and tag. Secure tags directly to the energy isolating devices where the lockout devices are attached. Each tag must be clearly visible, explaining the purpose of the lockout and warning against the hazard of operating the machine. It must also identify the person who affixed the tag and the date of lockout.
  • Control of stored energy.
    Any residual stored energy in the machine can be equally hazardous to the employee. The authorised employee must ensure that any stored energy is safely released before work begins.
  • The following are examples of ways to control stored energy:
    relieve trapped pressure downstream;
    discharge capacitor and install ground wire;
    release tension on spring, or block movement of spring driven part;
    use block to prevent fall due to gravity; and
    use blank flange to block flow of hazardous materials if valve is not available.
  • Verify the energy isolation.
    The authorised employee must verify the isolation and deenergisation of the machine before work begins. The following actions shall be accomplished after the lockout application to confirm the energy isolation:
    Operate the machine "on/off" switch to verify that the machine is not working and return all controls to the "off" or "neutral" position.
    Use appropriate instrument to verify that the machine is completely de-energised.

Steps for start-up
The procedure for release of lockout is equally important after the construction, servicing or maintenance is completed. The following actions are required for safe start-up of machine to ensure the safety of employees:

  • The machine.
    Before restoring energy to the machine, the authorised employee must ensure that the work area is clear of all non-essential items and all necessary components are operationally intact. For a complex machine, use a checklist to verify that all essential components are operationally intact.
  • Personnel.
    It should be ascertained that personnel are physically clear of the machine. Multiple personnel and energy source situations demand comprehensive measures to ensure that assigned work has been completed and all personnel have cleared the machine.
  • Lockout and tagging devices removal.
    Inform all affected employees when the lockout devices are removed but before the machine is energised. Only authorised personnel who applied the lockout and tags are authorised to remove their own locks and tags. No other employee should attempt to remove another person's lockout. The lockout procedure should also have a provision for the removal of another employee's lockout, in the event that the individual is not present. This provision must ensure that the procedure taken is as safe as if the individual were present to remove his locks.


john said...

It is a good thing that there are now a lot of providers for lockout tagout training as this is one of the jobs out there that really needs trained and experienced workers.

darkforce said...

For your information the CP91: 2001 Code of Practice for Lockout Procedure had been change to SS (singapore standard).
Please update your website