The Control of Hazardous Energy (lockout/tagout) standard regulates the servicing and/or maintenance of chemical process systems and associated piping, even though the energy sources (e.g., chemical and thermal energy) and control methods used in process hazards management are somewhat different from those encountered with machinery and mechanical equipment.
Typically, the procedural steps required for the safe performance of the process system and piping network maintenance or servicing are:
- deactivation,
- removal of contents,
- isolation,
- decontamination,
- restraining,
- verification,
- control, and
- communication
The primary difference, relative to typical machinery energy control practice, is the means used to isolate (e.g., blank flanges, slip blinds) the energy in the process and piping network system.
NOTE: Bolted blank flanges, slide gates, or slip blinds are considered piping energy isolating devices and also are acceptable as lockout devices if they are used as part of a standard, documented procedure. If bolted flanges or slip blinds are used, the equipment must be shut down in an orderly fashion not to create additional or increased hazards to employees.
For example, without proper isolation and de-pressurization of the hazardous energy, employees opening pipelines to install blinds may be exposed to pressure-related and/or fire-safety hazards.
These devices MUST meet the other standard requirements for lockout devices (e.g., they must be DURABLE, STANDARDIZED, SUBSTANTIAL, and IDENTIFIABLE).
The deactivation of a process system is equivalent to equipment shutdown. Similarly, removing the contents of the piping system and isolation of the energy source is equivalent to isolation and lockout or tagout of a machine or equipment, and the use of decontamination and restraining in piping systems is equivalent to the restraining or dissipating of stored energy in machines or equipment. Finally, verifying effective isolation is essential for the chemical process, piping network systems, and other machines or equipment.
For example, companies augment generic LOTO procedures with work authorization permit systems to detail the job-specific hazardous energy control measures before employees perform servicing and maintenance work activities in the chemical process and petroleum refining industries. It is recognized that the comprehensive use of such a system is more efficient and relevant to the daily tasks that would a cookbook-type procedure, which might not fully account for a specific situation that might have occurred around the time of the servicing and maintenance activity.
However, if a company uses a work permit authorization system, each permit MUST identify the following:
- equipment to be serviced/maintained,
- types and unique energy characteristics that may be encountered, and
- specific safe work procedures to be used to effectively control hazardous energy associated with the permit’s scope of work.
Ultimately, however, the quality of any hazardous energy control effort, and ultimately employee safety, is dependent upon the hazard analysis, which in turn is dependent upon the knowledge and skill of the individuals – e.g., operations personnel, engineering support – that identify the tasks, the energy-related hazards, and appropriate control measures for the specific servicing operation.
NOTE: Work authorization permit system procedures must, in part, specify that employees are required to perform their work in accordance with the terms and limitations of the work permit and include the means to enforce employee compliance with the work permit provisions. Chapter 4, Section VI of this manual also contains information on the use of work authorization permits as employee accountability devices in group LOTO (control and accountability) procedures.
With the understanding that the standard is flexible and performance-oriented, many procedural items may be incorporated into a generic plant-wide policy (when supplemental means are used) or incorporated without revision into each energy control procedure, regardless of the type of machine or equipment, the type of energy, or the energy control devices associated with the control of the hazardous energy. For example, an employer may decide that it is better to address the purpose and use of the procedure, as well as other general issues, in their generic procedure’s policy sections. The following are some general policy issues that may be capable of being developed and contained in the generic portion of the company’s energy control procedure:
- Who is authorized to perform LOTO?
- Who will notify affected employees of the application and removal of LOTO devices?
- What method (e.g., lockout versus tagout, including, where appropriate, full employee protection measures) will be used for securing energy isolating devices?
- What types of energy isolation (e.g., electric disconnects) and control methods will be employed in the facility?
- How will energy control devices be removed and by whom?
If the employer contemplates removal by others in situations permitted under the LOTO standard, what are the specific procedural steps for the removal of the authorized employee’s LOTO device by someone other than the person who applied the device?
- How will the removal of control devices and re-energization be performed?
- How will the implementation of these energy control procedures be supervised and enforced?
- Where groups perform servicing or maintenance work, how will the group LOTO activities be performed and coordinated?
- Where the servicing or maintenance exceeds a single shift or there is a personnel change, how will authorized employee responsibility be transferred during shift and personnel changes (e.g., job locks)?
- Where contractor employees may be affected by hazardous energy, how will outside personnel (e.g., contractors) be informed of energy control procedures?
Some issues that an employer may need to incorporate in its supplemental sections, such as a checklist, include:
- What equipment is being serviced/maintained and what is the scope of work?
- What are the specific (types and magnitude) hazardous energy sources associated with the system and the specific method and sequence of activities required to control these hazards?
- How is a safe and orderly shutdown of the system performed?
- Where (if not readily apparent) and how does the isolation or blocking of energy occur?
- How is stored energy in the system released?
- Are there precautions (e.g., use of a test instrument) necessary to monitor for hazards associated with energy re-accumulation?
- How do authorized employees test and verify that de-energization and isolation have been accomplished?
- How are LOTO devices removed and what are the steps to re-energize the system?
- How do employees safely test and position machine components?
Source: CPL 02-00-147 The Control of Hazardous Energy – Enforcement Policy and Inspection Procedures