Regulations (Preambles to Final Rules) - Table of Contents Regulations (Preambles to Final Rules) - Table of Contents
• Record Type: Control of Hazardous Energy Sources (Lockout/Tagout)
• Section: 5
• Title: Section 5 - V. Major Issues


V. Major Issues

The evidence submitted to the record is summarized and evaluated in the following discussion of each major issue and in the Summary and Explanation of this Final Rule. The numbers in brackets refer to specific written comments (Ex.___) and to the transcript page number of the testimony presented at the public hearing (Tr. p. (W for Washington, DC and H for Houston, TX) -- ).

1. Should OSHA require the use of locks, locks and tags, or tags alone to control potentially hazardous energy?

The most vigorously contested issue was over the need to use locks or tags as the primary means to prevent operation of energy isolating devices, such as electrical disconnects, hydraulic or pneumatic valves. The proposed standard did not establish definitive criteria for employers to use in making their choices of control measures, that is, the use of locks, tags or a combination of the two.

In general, a strong preference was evidenced in the comments and hearing testimony for lock& Many parties to this proceeding (Ex. 2-2, 2-12, 2-27, 2-29, 2-42, 2-44, 2-57, 2-63, 2-66, 2-67, 2-79, 2-98, 2-99, 2-103, 2-104, 2-106, 49, 50, 58, 59, 60, 62, 63, Tr. pg. W1-68, W1-71, W1-85, W1-138, W1-141, W1-143, W1-185, W1-192, W1-233, W1-241, W1-249, W2-80, W2-91, H30, H69, H96, H129, H136. H142, H149, H153) stated that the use of locks was the only acceptable means to control hazardous energy. Some of these commenters (Ex. 2-2, 2-44, 2-63, 2-79, 2-98) argued that the use of tags alone did not afford a minimum acceptable level of protection for employees since, as opposed to locks, they could be carelessly bypassed without major effort. Several commenters (Ex. 2-27, 2-29, 2-63, 2-104, Tr. pg. W1-75, H-225) stated that the unrestricted use of tags as the primary means of safeguarding employees during maintenance or servicing of machines and equipment would seriously erode the gains which had been achieved through past labor-management negotiations. Other commenters (Ex. 2-44, 2-57, 2-63, 2-79, 2-98, 2-99, Tr. pg. W1-71, W1-72, H-226) stated that tags were susceptible to being lost or damaged in use due to environmental conditions in the workplace or by contact by employees, materials or equipment moving or being moved about the workplace. These commenters stated that tags only "warn" and that they are a label, not a safety device. Other commenters (Ex. 2-06, Tr. pg. W1-72) stated a view that, the use of tags also promotes a false sense of security among employees and that the accident rate when tags alone are used is higher than when not using any safeguard.

One participant, an employee of Armco Steel (Tr. pg. W2-91), stated that his employer had discontinued the use of tags in favor of locks. He contended that the Company realized that the use of tags alone was not effective in preventing accidents.

Finally, several commenters (Ex. 2-42, 2-79, 2-98, 2-106, Tr. pg. W1-72, W1-138, W1-140, H98, H129, H163) stated that tags can be easily defeated by negligence or ignorance and that the use of tags will not deter the willful misconduct of the employee who would ignore the message of the tag, that is, not to reenergize or restart a machine or piece of equipment.

The record contains a significant body of evidence which indicates that the "one person, one lock, one key" concept enjoys wide acceptance across industry lines. For example, the United Auto Workers provided comments (Ex. 2-24, 20) and testimony (Tr. pg. H215-354) on the use of this concept in the automotive industry. Monsanto Company stated (Ex. 3-52, attachment II) that this form of lockout protection represented their basic approach to lockout/tagout. Monsanto indicated that tagout is only used in situations "where the work is relatively low hazard and the person is in control of the energy source," such as light switches, some valves, and some plug and cord connected equipment. Monsanto also noted that group lockout is used for equipment which requires a relatively large number of servicing workers, with a large number of points to be locked out.

On the other hand several commenters (Ex. 2-33, 2-55, 2-94, 2-96, 2-102, 2-105, and Tr. pg. W1-144, H197) stated that their companies utilize a system of tags to ensure that equipment which has been shut down will not be reenergized or restarted. One of these commenters (Tr. pg. H198) stated that the tagout system utilized by his company is "well understood by all employees. In fact, we feel so strongly about our red/danger tag procedures that we require mandatory discipline for its violation." The company submitted its safety record as support for its assertion that its tagout program is effective. The employees of this company have worked over 488 million hours between January 1980 and September 1988 with only 130 lost time accidents. Of those 130 accidents, only one occurred which was marginally related to tagout. That one accident occurred because there was no valve to guard against the transfer of heat through another closed and tagged valve. Finally this commenter stated, "The key to safety is not in a specific device, be it tag or lock. [Safety] rather, lies in good procedures and careful training combined with assurance of accountability. If these three principles are in place, a system which uses tags only will adequately protect employees. A lockout requirement in addition to tagout will not assure greater safety." (Tr. pg. H199.)

Even 2 commenters (Ex. 2-67, Tr. pg. W1-75, W1-167), who spoke out against the use of tags admitted that there might be instances in which lockout would be either impractical or impossible. However, one commenter (Tr. pg. W1-97) stated that problems, such as the loss of computer memory by shutting off automated equipment, could be overcome. Retention of the computer memory could be accomplished by providing a separate energy source for the computer so that the energy used to power the movable portions of the mechanism could be shut off and locked out without affecting the computer memory. This commenter stated that other innovative means are possible for solving other similar problems.

Other commenters (Tr. pg- W1-139, W1-157) stated that there is no data available on accidents which have occurred when machines or equipment are tagged out.

Several commenters (Tr. pg. W1-105, W1-139, W1-164) suggested tagging should be used only with an increased emphasis on training, supervision, controlled access and employer commitment.

Much of the testimony and comment received in this rulemaking has focused on whether the standard should require lockout as opposed to the proposed approach of allowing lockout or tagout. In a sense, it was unfortunate that attention was focused more on a single aspect of the standard, though it is certainly an important one, than on the standard taken as a whole. The proposed standard was intended to specify that the employer provide a comprehensive set of procedures for addressing the hazards of unexpected reenergization of equipment, and the use of locks and/or tags was intended to be only a single element of the total program. In order to provide adequate protection to employees, the Final Rule requires employers to develop and utilize a comprehensive energy control program consisting of: procedures for shutting down and isolating machines and equipment and locking or tagging out the energy isolating devices; employee training; and periodic inspections of the energy control procedure to maintain its effectiveness.

It should be noted that locks and tags by themselves do not control hazardous energy. It is the isolation of the equipment from the energy source and the following of the established procedures for deenergization and reenergization of the equipment that actually controls the energy. Locks and/or tags are attached to the disconnects and other energy isolating devices after the machine or equipment has, in fact, been isolated, in order to prevent them from being reenergized before the work has been completed. If the equipment has not been properly deenergized, and if proper procedures have not been followed, neither a lock nor a tag will provide protection.

The treatment of lockout vs. tagout presents OSHA with a difficult regulatory dilemma. On the one hand, if the issue were simply whether a lock or a tag will be better able to prevent equipment from being reactivated, there is no question that a lock would be the preferred method. Locks are positive restraints which cannot be removed (except through extraordinary means such as by the use of bolt-cutters) without the use of a key or other unlocking mechanism. By contrast, the limitations of tags used alone are self-evident: They do not serve as positive restraints on energy isolating devices, but are only warnings to employees that the equipment is not to be reenergized. Tags not fastened with a strong material can become detached from the energy isolating device by wind or other environmental conditions, and the legend on some tags can be rendered illegible if the tag becomes wet. Tags may not provide protection if there are affected employees who do not read English or who have not been properly trained in the tagging system and its implementation.

However, the issue in this rulemaking is not merely on the use of lockout vs. tagout, but rather the use of locks and/or tags in a comprehensive program of energy control. As was noted in the preamble of the proposed rule (53 FR 15496, April 29, 1988), OSHA is aware of workplaces in which tagout systems are used with great effectiveness. In particular, various electric utilities and chemical plants report that they have used tagout in lieu of lockout successfully for many years (Tr.pg. H194-214, W2-3 to 2-39). In evaluating these industries, OSHA has determined that there are several factors which have contributed to their successful use of tagout programs: first, these companies have implemented detailed energy control procedures which are quite similar to those set forth in both the proposed and final lockout/tagout standard; second, they have established and utilized extensive training programs to teach their employees about their energy control procedures, including the use of tags and the importance of obeying them; third, these companies reinforce their training periodically. However, it is the fourth common element, discipline, which appears to be the most critical to the success of these programs; the companies with effective tagout programs apply disciplinary action to both supervisors and employees who violate the tagout procedures.

OSHA believes that an effective tagout system needs all four of these elements to be successful. However, it is the fourth element, discipline, which is the most difficult to incorporate into a regulatory approach in the Final Rule. Not surprisingly, it also reflects the most serious limitation of tagout which does not arise with lockout. Because a tagout program does not involve positive restraints on energy control devices, it requires constant vigilance to assure that tags are properly applied; that they remain affixed throughout the servicing and maintenance of equipment; and that no employee violates the tag by reenergizing the equipment, either intentionally or inadvertently, before the tag is removed. By contrast, a lockout device, once applied, cannot inadvertently be removed, and cannot be removed intentionally by an unauthorized person except by the use of force.

In the Final Rule, OSHA has determined that lockout is a surer means of assuring deenergization of equipment than tagout, and that it should be the preferred method used by employees. However, the Agency also recognizes that tagout will nonetheless need to be used instead of lockout where the energy control device cannot accept a locking device. Where an energy control device has been designed to be lockable, the standard requires that lockout be used unless tagout can be shown to provide "full employee protection," that is, protection equivalent to lockout. These requirements will be discussed in detail in the summary and explanation of the standard, below.

The Agency believes that except for limited situations, the use of lockout devices will provide employees with a more secure and more effective means of assuring that equipment will not be reenergized while they are working on it. To the extent that equipment is capable of being locked out during servicing or maintenance, OSHA believes that it should be locked out. It should be noted, in this regard, that a number of General Industry standards, such as 1910.305(j)(4) in Subpart S-Electrical, presently require electrical disconnects to large motors to be capable of being locked out.

According to OSHAs Regulatory Impact Analysis, approximately 90% of all electrical energy isolating devices (disconnects) and about -- of all energy control valves are currently capable of being locked out. As previously discussed, the capability for lockout does not necessarily mean that the equipment has an actual hasp or other physical attachment point for a lock. For example, the use of chains can be an effective means of enabling lockout of many types of valves, even if the valve does not have a specific locking point. Many examples of equipment which was made lockable with minor modifications have been provided to the record. For equipment of this type, OSHA believes that the lockout capability should be used in order to maximize the protection afforded by this standard.

OSHA acknowledges that certain types of energy isolating devices currently in place are not capable of being locked out. Some equipment would need to be replaced or modified significantly to accept lockable-type energy isolating devices. This equipment constitutes a relatively small percentage of all equipment to be covered by this standard, and will primarily involve valves rather than electrical disconnects. OSHA believes that where equipment replacement and major equipment modification would be necessary for the equipment to accommodate a lockout device, such efforts are most effectively achieved when done during machine or equipment replacement, major repair, renovation or modification or when new equipment is installed rather than retrofitting existing equipment within a set time frame established in this standard. OSHA believes that it is much more cost-effective and protective to design a locking capability into equipment than it is to perform a major retrofitting of that equipment solely to incorporate lockout, for several reasons. First, there are situations in which locking out of equipment can create other, and sometimes greater, hazards to employees. Second, retrofitting of existing equipment may not be technologically or economically feasible. The retrofitting of such equipment for the sole purpose of incorporating a lockout capability would not necessarily deal with the additional hazards. By contrast, the incorporation of a lockout means into the design of new equipment is far less costly than modifying equipment which was not designed to be locked out. Third, incorporating a lockout capability into either new or overhauled equipment is a far less complex task from a technological standpoint, since the locking aspect is a small part of the overall design.

Surprisingly, although there was considerable evidence submitted on equipment for which lockout is currently being used, this rulemaking provided OSHA with little new information on the costs or feasibility of extending lockout requirements to equipment which is not currently capable of being locked out. Therefore, OSHA is unable to conclude with any degree of certainty that a requirement to retrofit all such equipment would be feasible, nor is the Agency able to determine the amount of time or resources that would need to be expended to achieve compliance. For such equipment, OSHA will allow employers to use the tagout program as prescribed by (c)(2)(i), but only until the equipment is replaced, or has major repair, renovation or modification performed on it. At that time, the new, renovated or modified equipment must be equipped with lockable energy isolating devices, and the energy control procedure must be revised to make use of that capability, except when the employer can demonstrate that the tagout program in use provides full employee protection.

OSHA is confident that this standard is a cost-effective approach to providing protection against the restarting of machines or equipment and the release of hazardous energy. It recognizes that lockout is, in general, preferable to tagout as a method of assuring that deenergized equipment is not inadvertently or accidentally reenergized. It requires that the employer develop and utilize an energy control program consisting of written procedures, employee training and periodic inspections for servicing and maintenance of machines and equipment, using lockout or its equivalent on the great majority of energy isolating devices, namely those which are capable of being locked out. For energy isolating devices which do not yet have a lockout capability, the standard allows the interim use of tagout, but lockout-capable energy isolating devices must be installed when that equipment is replaced or overhauled. The standard is written in performance-oriented language, providing considerable flexibility for employers to tailor their energy control programs and procedures to their particular circumstances and working conditions. OSHA is confident that this standard will greatly reduce the toll of injuries and fatalities which occur each year from the failure to control hazardous energy in general industry workplaces.

A critical element of this standard is the determination of whether an energy isolating device is "capable of being locked out." In its most limited sense, a device would be considered to be "capable of being locked out" either if it was designed with a hasp or other integral part to which or through which a lock could be affixed, or if it has a locking mechanism built into it. However, OSHA's use of the term for the purposes of this standard is somewhat broader, without being overly expansive. OSHA considers equipment to be capable of being locked out if the use of a locking mechanism will not require the employer to dismantle, rebuild, replace, or alter in a permanent way the energy control capability of the isolating device. For example, although some valves and other energy isolating devices are not designed with an integral means of being locked, they can be secured with chains, blocking braces or wedges, which then can be locked. Because extensive equipment modification is not needed in this situation, OSHA views this type of lockout to be both technologically and economically feasible. However, a specific energy isolating device is not considered as having the capability of being locked out if the device is installed within a cabinet, enclosure or cutout box containing several other energy isolating devices or valves and the only means of preventing access to the energy isolating device or valve is to lock the doors of the cabinet, enclosure or box. In this instance, tags must be used and must be attached to the specific energy isolating device and not simply attached to the cabinet or enclosure door or cover. By contrast, as noted earlier, some types of valves and disconnect would require total or partial replacement in order to provide the equipment with a lockout capability.

2. Should OSHA require employee participation in the development of lockout procedures and the training programs required by this standard?

There was considerable comment on the part of labor unions [Ex. 2-29, 2-44, 2-63, 60) and other commenters (Ex. 2-92, 2-97) that OSHA should require that employees and employee representatives participate in the formulation and implementation of lockout programs (compliance plans, procedures, persons to conduct inspections, education and training programs and materials). These commenters also stated that any comments by employee representatives should be incorporated into the training programs. One commenter (Ex. 2-63) stated, "The standard does not prescribe worker participation in program design and training which is essential to an effective program." Another commenter (Ex. 2-97) stated, "Procedures cannot be written in a vacuum and must be accepted by employees, training must be appropriate and up-to-date for the situation." Finally, one commenter (Ex. 2-97) stated, "An effective lockout program must provide for employee participation and their representatives in program design and training."

OSHA has determined that a specific provision dealing with employee participation in the development of the employer's lockout or tagout procedure is not necessary for the effective implementation of the Final Rule. For standards dealing with exposure to toxic substances and harmful physical agents which were promulgated under section 6(b)(5) of the OSH Act, section 8(c)(3) of the Act spells out specific requirements for employee observation of monitoring activities and access to records of monitoring. By contrast, there is no such specific statutory mandate for the present standard. Although OSHA agrees that active employee involvement may enhance understanding and cooperation, the Agency believes that it would be inappropriate to require such involvement in this standard. The standard sets out the procedures and steps which the employer must take to establish and implement an effective procedure for controlling hazardous energy, and under the OSH Act, it is the employer who is responsible for complying with the standard.

Note: The following paragraphs highlight preamble selections for the Hot Topic: 1910.147 and 1910.269, 1910.333.

3. Should OSHA change the scope and application statements of this standard in this Final Rule to cover construction, maritime. agriculture, electric utility. and oil and gas well drilling industries?

In the Notice of Proposed Rulemaking for the standard on the control of hazardous energy sources (Lockout/ Tagout) (53 FR 15496, 29 April 1988), OSHA proposed exempting the construction, maritime and agricultural industries. In the preamble of the proposed rule, OSHA explained that the exemption of these industries was based upon their unique situations and work practices which would unduly complicate the development of a generic energy control standard for general industry. For example, the longshoring and the construction industries are generally characterized by casual (short term) employment which may last just until the project for which the employees were hired is completed. The project may involve the erection of a single building or the loading or unloading of a single vessel. Even on longer duration construction projects, the various tasks, such as steel erection or brick laying, are usually of relatively short duration. One commenter (Ex. 2-80), in discussing the need for regulation of the construction industry, pointed out the difficulty of providing adequate training of a transient workforce. Likewise, the agricultural industries can be characterized as ones which have more rapidly changing employment. For example, agricultural harvesting (and its employment of migrant workers) and the use of harvesting machines are limited to those times when crops are ready to be harvested.

Of additional concern in the imposition of regulations in the construction industry is the uniqueness of the earthmoving equipment, such as lattice boom mobile cranes, front-end loaders, bulldozers, scrappers and dump trucks. As opposed to maintenance on automobiles, buses and over-the-road trucks where removal of the ignition key usually ensures that the engine can not be started and the vehicle may be worked upon, some of the maintenance of the above mentioned earthmoving equipment involves the positioning of components, such as buckets, blades and vehicle body parts, which present extraordinary hazards to maintenance or servicing personnel. These hazards and the means to minimize the potential for injury to employees involve additional considerations, which were not adequately addressed during the course of the rulemaking proceeding.

Because of the unique nature of these industries, their respective workforces and working conditions, OSHA believes that this Final Rule might need considerable modification in order to provide optimal protection to employees. In particular, OSHA is concerned with the effectiveness of the basic approach of this standard when applied to a workforce which is highly transient. The energy control procedure may vary widely from one workplace to another, and an employee in construction, for example, may find him/herself in several workplaces during the course of a single year. Similarly, the Agency will evaluate means by which the training requirement of this standard could be modified to reflect these conditions.

The Agency currently intends to consult with the Advisory Committee for Construction Safety and Health (ACCSH) on a proposed lockout-tagout standard for construction under section 107 of the Construction Work Hours and Safety Standards Act (Construction Safety Act), 40 U.S.C 333. In addition, for the maritime industry, OSHA intends to present these matters to the Shipyard Employment Standards Advisory Committee (SESAC) for consideration as part of that Committee's review of shipyard standards in part 1915.

OSHA has determined that the Final Rule will cover General Industry, but will not be expanded to cover construction, maritime and agriculture at this time. The Agency has inadequate information at this time on both the hazards of lockout or tagout and the appropriateness of this standard's approach in those industry sectors. However, the Agency will continue to review information on these sectors and will evaluate the need to initiate further rulemaking and will consider whether this Final Rule, or an appropriate modification of same, should be used as the basis for a proposal for construction, maritime and agriculture.

There are several commenters (Ex. 2-27, 2-49, 2-57, 2-76, 2-79, 2-99, 2-106, 60), who were opposed to exempting any industry. Their concern was that the hazards associated with failure to lockout during the maintenance or servicing of machines or equipment were not restricted to a single industry or group of industries. It is their contention that this standard should have universal application. On the other side of the question, there was one commenter (Ex. 2-58) who agreed with the exclusion of these industries.

It should be noted that OSHA's electrical standards for construction (29 CFR part 1926, subpart K), which were revised on July 11, 1986 (51 FR 25318), currently contain various requirements for deactivating equipment, deenergizing electrical circuits, and limiting employee access to energized parts in construction work (e g., 1926.403(j), 1926.416, 1926.417). Similarly, OSHA's shipyard and marine terminal standards (29 CFR parts 1915 and 1917, respectively) include many provisions which address deenergization of equipment during servicing of equipment on vessels and in marine terminals (e.g., 1915.162-.165, 1915.181, 1917.48(i), 1917.151(b)).

Based on its experience in regulating construction and maritime employment, OSHA believes that a generic energy control standard would likely be applied quite differently in these areas than in general industry. Further, the interrelationship between a generic rule and the specific provisions currently applicable to these industry sectors must be considered. In its consultations with its advisory committee on construction and shipyard employment, OSHA will seek guidance on whether a generic rule would be appropriate for these industries; on what areas such a rule should differ from the general industry standard being issued today; and on the reasons for any such differences.

OSHA is no less concerned with the safety of these other employees. However, delaying the promulgation of this generic, general industry standard to examine all the unique aspects of these other industries would further delay the promulgation of this standard. There were five commenters (Ex. 2-22, 2-26, 2-45, 2-52 and 2-81) who recommended the exclusion of the natural gas transmission industry from the scope of this standard. Their contention was that OSHA would be preempted under section (4)(b)(1) of the Act from enforcement of this standard since the U.S. Department of Transportation has regulations affecting the gas transmission industry. Section (4)(b)(1) of the Act states:

Nothing in this Act shall apply to working conditions of employees with respect to which other Federal agencies and State agencies, acting under section 274 of the Atomic Energy Act of 1954, as amended (42 U.S.C. 2021), exercise statutory authority to prescribe or enforce standards or regulations affecting occupational safety or health.

OSHA recognizes the possibility that its lockout or tagout standard may be preempted under section (4)(b)(1) of the OSH Act by other Federal agency actions, such as regulations issued by the Department of Transportation's Division of Pipeline Safety. Section (4)(b)(1) provides that when another Federal agency exercises statutory authority to prescribe or enforce standards or regulations affecting occupational safety or health, that exercise of authority will preempt OSHA from covering those same working conditions. However, OSHA declines to incorporate a specific provision on preemption into this standard for two reasons: first, whether or not preemption takes place for a given working condition is a matter of law, to be evaluated in a case-by-case basis. Second, even in the event that preemption takes place, if the preempting agency were to choose to revoke its regulations or other exercise of authority, there would no longer be any preemption. Inclusion of a preemption provision by OSHA in a particular safety or health standard would inappropriately prevent OSHA from asserting its authority under the OSH Act in that situation.

There were five commenters (Ex. 2-21, 2-36, 2-40, 2-46 and 2-50-20), who discussed the application of this standard to the petroleum industry. Four of those commenters (Ex. 2-21, 2-36, 2-40 and 2-46) stated that OSHA should not try to "force fit'' a machinery standard to process systems and piping networks; that OSHA should not expand the scope of the consensus standard; and that, if necessary, OSHA should develop a separate standard for process piping. (There was universal agreement on the part of these industry commenters that this standard did properly apply to the machinery elements of the process piping systems.) On the other hand, one commenter (Ex. 2-50) spoke out in favor of this OSHA standard applying to piping systems."

There were two commenters from the petroleum industry (Ex. 2-21 and 2-46) and one commenter from the chemical industry (Ex. 2-59) who objected to the use of a written lockout or tagout procedure as specified in the proposed Standard. These commenters stated that they use a work permit or work authorization system. The safe work permit checklist enclosed with one comment (Ex. 2-59) has provisions for the use of blinds and disconnecting pipes, and for extensive post isolating cleaning and testing. At the Houston segment of the hearing, the representative of the American Petroleum Institute acknowledged that the work authorization system was not inconsistent with the procedures set forth in the proposal. (Tr. p. H64). (OSHA agrees that a work permit checklist system or work authorization system could serve as the required written procedure as long as it meets the criteria for a procedure spelled out in this Final Rule.)

In their comments to the record, the American Petroleum Institute (API) restated their view that the lockout/ tagout rule was not designed to regulate piping networks and process systems (Ex. 2-36). OSHA recognizes that the energy sources and control methods used in process hazards management are often quite different from those encountered with machinery and mechanical equipment. However, the Agency considers the basic approach of this standard to be appropriate for the control of all hazardous energy sources, including those discussed by API. Indeed, many, if not all, of the elements covered in the standard are addressed by the "work authorization procedures" commonly used throughout the petroleum and chemical industries. These procedures, which focus upon the issuance of work permits or permits for safe entry into piping systems, were acknowledged at the hearings to be consistent with the procedures set forth in the proposed rule. The primary area which warrants further explanation involves the different means used to isolate the energy in piping and process systems, and how they relate to the lockout or tagout requirements of this standard.

According to one commenter (Ex. 20) the procedural steps required for safe performance of process system maintenance are: (1) Deactivation, (2) removing contents, (3) isolation, (4) decontamination, (5) restraining, (6) verification, (7) control and (8) communication. In contrast, this standard set forth five steps for lockout or tagout: (1) Equipment shutdown, (2) isolation, (3) lockout or tagout application, (4) stored energy restrictions, and (5) verification. However, these five steps encompass all elements of process system deenergization as well. For example, deactivation of a process system is analogous to equipment shutdown. Similarly, removing the contents of the piping system and isolation of the energy source can be compared to isolation and lockout or tagout of a machine or equipment, and decontamination and restraining in piping systems is essentially the same as restraining or minimizing the stored energy of machines and equipment. Finally, verification of the success of prior steps of a piping system isolation is the same as verification of proper implementation of the energy control program. OSHA acknowledges that when there are additional steps specific to the preparation for maintenance of piping systems, these steps would also need to be included in an employer's energy control program.

Based upon the foregoing comparison, OSHA believes that the imposition of the requirements of this standard (particularly the need for a standardized procedure) is not a "force fit" but the logical "tailoring" of the steps to a different type of equipment. Based upon the generic nature of this standard, OSHA recognizes that some modifications or "tailoring" of the requirements of this standard may be necessary, but the basic procedural provisions of the standard are designed to be used throughout general industry, in a wide range of applications.

Two commenters (Ex. 2-21 and 57) pointed out that some of the items listed in the definition of energy isolating devices (notably the blank flange and bolted slip blind) can require at least as much effort to remove as locks. These commenters pointed out that removal of these devices, when they are properly bolted in place, requires wrenches to disassemble the nuts and bolts holding the blank flange or blind. The use of these wrenches is comparable to using bolt cutters to remove a lock. Although the wrenches used for removing the nuts and bolts from the flanges may be more readily available with a piping system than a pair of bolt cutters in the average workplace, the time to remove the nuts and bolts would surpass the time to remove a lock. OSHA believes that this type of bolted system will provide comparable security against the release of hazardous energy in the system, even though a "lock" is not used. Based upon the above rationale, OSHA will consider bolted blank flanges or slip blinds to be an acceptable type of lockout/tagout device. As with all devices, these bolted systems must be wed as part of a standardized, documented procedure, and they must meet the other requirements of the standard for lockout or tagout devices (that is, they must be durable, standardized, substantial and identifiable.)

If bolted flanges or slip blinds are used, a means must be devised so that each authorized employee can be identified as a participant in the project when he/she is working on it. For example, individual identification can be achieved by each authorized employee hanging his/her tag on the blank flange or the slip blind when he/she starts work and removing his/her tag when he/she stops work. The tag, in this case, supplements the blank flange or blind by identifying the employees performing the maintenance, thereby establishing a method of continuous individual accountability for the employees. An effective system of administrative control, such as the use of a single master tag with provision for individuals to sign in and out as they begin or end their work on the machine or equipment, would satisfy this requirement.

The applicable consensus standard (ANSI Z244.1)(Ex. 9) has been reviewed for its applicability to process systems. It is clear from this review that this consensus standard was intended to apply to machines, equipment and processes. The definition of energy isolating device contains examples which include slip blinds, blank flanges, line valves and similar devices. These are devices used for energy isolation in piping systems.

OSHA believes that the employees working on the piping portions of processes deserve no less protection than when those same employees work on the mechanical components of the same systems. The advantage of writing this OSHA standard in performance language is to allow flexibility of compliance for all systems in which hazardous energy is or may be present. OSHA has used this approach to the formulation of this standard because of the wide range of energy control situations encountered throughout general industry.

OSHA also proposed to exclude from coverage of this standard certain installations under the exclusive control of electric utilities, as well as oil and gas well drilling operations. These industrial sectors were proposed to be exempted from this standard because lockout will be uniquely addressed for these industries in other proposed standards. In both cases, OSHA is actively working on projects to cover the special safety needs of these industries. (See 54 PR 4974, January 31, 1989 for the Proposed Standard on Electric Power Generation, Transmission, and Distribution.)

Note: More preamble sections that highlight the Hot Topic: 1910.147 and 1910.269, 1910.333 are available.

4. Should OSHA state the requirements of this final standard in performance language?

There were two commenters (Ex. 2-27, 2-29, and 2-91) who objected to the use of performance language in the proposed standard. Their objections were based upon the fact that, without specific requirements, employers would be allowed too much discretion in the means or methods that they utilize in complying with the standard.

There were 11 commenters (2-31, 2-34, 2-36, 2-37, 2-39, 2-46, 2-55, 2-57, 2-59, 2-62, 2-69, and 2-87) who favored the use of performance language in the standard. These commenters pointed out that the standard covers a vast segment of industry (both in size and type of companies) and type of operations. It is their contention that the use of performance language allows a degree of latitude to employers to "tailor" the required procedures, training requirements, and inspection parameters of the standard to fit the individual conditions present in their workplaces.

OSHA concurs with those commenters who stressed the need for flexibility in the standard. For example, the detail into which a procedure may have to go may vary depending upon the type of power the machine or equipment may utilize, or the means used to isolate or block the machine or equipment from the source of power. The amount of detail in a procedure for shutting down a simple conveyor with a single source of power, and single feed and discharge points, could be much less than the procedure for shutting down a long assembly line conveyor with multiple feed and discharge points and multiple power sources. The use of multiple sources of power applied to the machine or equipment at multiple points would necessarily cause the complexity of the procedure to be enhanced.

Finally, the OSH Act, in discussing the promulgation of standards, states in the second sentence of section 6(b)(5), "Whenever practical, the standard promulgated shall be expressed in terms of objective criteria and of the performance desired."

Based upon the foregoing, OSHA has decided to retain the performance language in this final standard.


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