Energy Isolation in a chemical process is a “complex LOTO”

Under most circumstances, where servicing or maintenance is to be conducted during only one shift by a small number of persons, the installation of each individual’s LOTO device on each energy isolation device would not be a burdensome procedure. However, when complex equipment is being serviced or maintained, when there are many sources of energy, and/or when servicing/maintenance work extends over more than one work shift, OSHA permits employers to utilize an alternative procedure to each employee locking or tagging out each energy-isolating device. Consideration must be given to the procedure’s organizational structure in order to ensure the safety and control of EACH of the employees involved. For example…

In the servicing and maintenance of sophisticated and complex equipment, such as process equipment in petroleum refining, petroleum production, and chemical production, there may be a need for the adaptation and modification of normal group energy control procedures in order to ensure the safety of employees. To permit the implementation of a pragmatic system while accommodating the special constraints of the standard’s requirement for ensuring employees a level of protection equivalent to that provided by the use of a personal lockout or tagout device, an alternative procedure may be implemented. Lockout/Tagout, blanking, blocking, etc., is often supplemented in these situations by the use of safe work permits.

In evaluating whether the equipment being serviced or maintained is so complex as to necessitate a departure from the conventional group lockout/Tagout procedures, the following factors (often coinciding) are among those that must be evaluated:

1. Physical size and extent of the equipment being serviced/maintained;
2. The relative inaccessibility of the energy isolating devices;
3. Number of employees performing the servicing/maintenance;
4. Number of energy isolating devices to be locked/tagged out; and
5. Interdependence and interrelationship of the components in the system or between different systems.

Once the equipment is shut down and the hazardous energy has been isolated, maintenance/servicing personnel, together with operations personnel, must test the machinery or equipment to verify that the isolation of the equipment’s energy source(s) is effective. The employees may walk down the LOTO to verify isolation. If there is a potential for the release or re-accumulation of hazardous energy, verification of isolation must be continued. The servicing/maintenance employees may further verify the effectiveness of the isolation by the procedures that are used in doing the work (e.g., using a bleeder valve to verify depressurization, use of combustible gas test instruments to check for the presence of flammable vapor/gases; flange-breaking techniques, etc.). Throughout the maintenance and/or servicing activity, operations personnel normally maintain control of the equipment.

The following procedures are presented as examples to illustrate the implementation of a group energy control procedure involving many energy-isolating devices and/or many servicing/maintenance personnel. Specific issues related to the control of hazardous energy in complex process equipment are described below. This discussion is intended only as an example and is not anticipated to reflect operations at any specific facility.

1. Complex process equipment, which is scheduled for servicing/maintenance operations, is generally identified by plant supervision. Plant supervision would issue specific work orders regarding the operations to be performed.
2. In many instances where complex process equipment is to be serviced or maintained, the process equipment operators conduct the shutdown procedure. This is generally due to their in-depth knowledge of the equipment and the need to conduct the shut-down procedure in a safe, cost-effective and orderly sequence.
3. The operations personnel normally prepare the equipment for LOTO as they proceed with the shutdown and identify the locations for blanks, blocks, etc., by placing “operations locks and/or tags” (Job Locks) on the equipment. The operations personnel can be expected to isolate the hazardous energy and drain and flush fluids from the process equipment following a standard procedure or a specific work permit procedure.
4. An employer representative or an authorized employee notifies affected employees prior to applying LOTO devices.
5. Upon completion of the shutdown, the operations personnel would review the intended job with the servicing and maintenance crew(s) and would ensure their full comprehension of the energy controls necessary to conduct the servicing or maintenance safely. During or immediately after the review of the job, the servicing and maintenance crew(s) would install locks, tags and/or special isolating devices at previously identified equipment locations following the specified work permit procedure.
6. Line openings necessary for the isolation of the equipment would normally be permitted only by special work permits issued by operations personnel. (Such line openings should be monitored by operations personnel as an added safety measure.)
7. All of the previous steps must be documented by a master system of accountability and should be retained at the primary equipment control station for the duration of the job. The master system of accountability may manifest itself as a Master Tag, which is subsequently signed by all of the maintenance/servicing employees protected by the master tag if they fully comprehend the details of the job and the energy isolation devices actuated or put in place. Signing by the respective employees further establishes that energy isolation training relative to this operation has been conducted.
8. After the system has been rendered safe, the authorized employees verify the effectiveness of energy controls in controlling hazardous energy.
9. Specific work functions are controlled by work permits, which are issued for each shift. Each day each authorized employee assigned must sign in on the work permit at the time of arrival to the job and sign out at departure. Signature, date, and time for sign-in and sign-out would be recorded, reviewed and retained by the applicable crew supervisor who, upon completion of the permit requirements, would return the permit to the operations supervisor. Work permits could extend beyond a single shift and may consequently be the responsibility of several supervisors.
10. Upon completion of the tasks required by the work permit, the authorized employees’ names could be signed off the Master Tag by their supervisor once all employees have signed off the work permit. The work permit is then attached to the Master Tag so that the accountability of exposed employees is maintained.
11. As the work is completed by the various crews, the work permits and the accountability of personnel are reconciled jointly by the primary authorized employee and the operations supervisor.
12. During the work progress, inspection audits are conducted.
13. Upon completion of all work, the equipment is returned to the operations personnel after the maintenance and servicing crews have removed their LOTO devices, including all completed work permits and/or special isolating devices, following the company procedure.
14. At this time, all authorized employees who were assigned to the tasks are again accounted for and verified to be clear from the equipment area.
15. After the completion of the servicing/ maintenance work, operations personnel remove the LOTO devices originally placed to accomplish energy isolation.
16. After the LOTO devices have been removed, notify affected employees that the control devices have been removed. [This notification must be given prior to the starting of a machine or piece of equipment to alert affected employees that the equipment is capable of being started up.]
17. Operations personnel then begin inspection and testing of the equipment prior to its being returned to production service.

In summary, the use of the work permit and/or master tag system, combined with the verification of hazardous energy control, work procedures, and walk-through, is an acceptable approach to compliance with the group LOTO and shift transfer provisions, as long as the control and accountability procedure provides a level of protection equivalent to each individual authorized employee affixing her lockout device to the energy isolating device. Work authorization permits, when used, must be included as a component of the company’s energy control procedure and would additionally require that the company procedure clearly contain, in conjunction with other energy control procedures, the specific requirements detailed in paragraph 1910.147(c)(4) of the standard.

NOTE: A work authorization permit system fulfilling the Personal Tagout (Accountability) Device definitional requirements is considered a Tagout

Device and, as such, all of the tagout provisions of the standard must be met if this system is used. This includes additional employee training and additional periodic inspection requirements. Furthermore, as the preceding example procedure illustrates, each employee must sign on/off the permit, and the crew leader (Principal Authorized Employee) must present this permit documentation to the person responsible for coordinating group LOTO activities (Primary Authorized Employee). The crew leader signs off the master tag only after all crew members are accounted for and after all of the crew member signatures (i.e., sign-offs) are obtained on the work permit. To ensure a system of continuous employee accountability, the crew leader gives the completed master tag (with a signed permit) to the primary authorized employee who is responsible for the overall group LOTO procedure coordination. This work permit example is an extension of and meets the Master Tag definition because the crew leader utilizes the work permit as a satellite control and accountability mechanism. This is similar to the previously described master and satellite lock-box (Type C) example, except that it employs a system of administrative control and continuous employee accountability through a master tag and work permit system instead of personal LOTO devices on satellite- and master-lock boxes.