Unit4
C hanges in the 2018 edition of NFPA 7 0 E : St an d ard for Electrical S a f e t y i n the Work-
place continue the direc- tion established in 2015, w h i c h i n t e n d e d t o change how st a ke - h o l d e r s e v a l u a t e and mitigate risk f rom el e c t r i c a l hazards. Some changes involve better alignment with occupational health and safety and man- agement systems (OHSMS) standards and other standards that address hazards and risk. Other changes are intended to help clarify intent and simplify application of long standing requirements in the standard.
These changes, coupled with knowledge con- dens ed in the informative annexes, will help stakeholders identify opportunities for ongoing improvement in reduction of risk for injuries and fatalities from electrical hazards. As in previous editions, a summary of the major changes to the standard is provided in the forward of NFPA 70E – 2018. For most stakeholders, reading the for- ward is a good place to start to compare existing electrical safety programs to the continuing evolu- tion in NFPA 70E and its aim toward eliminating electrical injuries and fatalities.
For those responsible for informing the man- ufacturing team on requirements in the 2018 edition, paying close attention to changes and additions to the informative annexes, the trans- formation of informational notes, and the illus- tration on the front cover may hold the key to
achieving real progress in reducing risk of injuries and fatalities.
The changes to the requirements in the standard are supplemented with annexes and informational notes that are included for informational purposes only. Revisions and additions to the informative annexes and informational notes are the latest enhancements to link and align the standard with proven concepts in occupational health and safety management standards.
The 2009 edition of NFPA 70E included the first reference to OSHMS with an informational note added to Article 110.3, Electrical Safety Program. Prior revisions included the statement, “Safety- related work practices are just one component of an overall electrical safety program.” Informational Note 2 added in the 2009 edition expanded on this by pointing to ANSI Z10: Standard for Occupa- tional Safety and Health for a framework to estab- lish a comprehensive electrical safety program as a component of an occupational safety and health program. ANSI Z10 is one of several OHSMS stan- dards that have roots in systems safety.
Systems safety is the application of engineering and management principles, criteria, and techniques to
By H. Landis “Lanny” Floyd, PE, CSP, CESCP
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22 • October 2017 PLANT ENGINEERING www.plantengineering.com
Systematic safety NFPA 70E updates brings the hierarchy of control measures to the forefront.
Personal protective equipmentPersonal protective equipmentPersonal protective equipmentPersonal protective equipmentPersonal protective equipmentPersonal protective equipment
Administrative controlsAdministrative controlsAdministrative controls
AwarenessAwarenessAwareness
Engineering controlsEngineering controlsEngineering controlsEngineering controlsEngineering controlsEngineering controls
SubstitutionSubstitutionSubstitution
EliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationEliminationElimination
achieve acceptable mishap risk as low as reasonably practicable throughout all phases of a system or facility life cycle. Systems safety emerged in the early 1940s as aircraft designers, manufacturers, and pilots were pushing the envelope in military aviation technology.
As airplanes became more sophisticated, the cost of mishaps escalated.
The aviation industry recognized the common practice of analyzing mishaps after that fact was becoming unacceptable in terms of human safety and financial loss. At the same time, scientists were harnessing nuclear energy for military and
civilian use. Systems safety methodology quickly matured as it was applied to the risk of nuclear
accidents having consequences more cata- strophic than any other technology devel-
opment in history. Considering that modern militar y aircraft can cost $1 billion each and
a nuclear accident can render a large portion of a continent uninhabit-
able for generations, the concept of preventing a mishap has
extraordinary value. The pri- mary goal in system safety
is to identify and mitigate risk before a mishap occurs. Central to system safety are risk assess- ment and risk reduction. Thought leaders and researchers in safety management are providing evidence that risk management techniques with demonstrated results in managing technologies with catastrophic consequences can be effectively applied to common occupational risks.
A 2014 RAND study comparing occupational fatalities in the U.S. and United Kingdom showed that the occupational fatality rate in the U.K. is one-third that of the U.S. Fatalities from electrical hazards in the U.K. is one-quarter that of the U.S. One factor contributing to this difference is that the safety management culture in the U.K. places more emphasis and resources on risk assessment and application of a hierarchy of controls than the safety management culture common in the U.S.
The first safety management system standard to document system safety methodology was U.S. Military Standard 882, Standard Practice for Sys- tem Safety, published in 1969. Since then, indus- try consensus standards including OHSAS 18001, Occupational Safety and Health Management Sys- tems – Requirements, ANSI Z10, Occupational
Health and Safety Management Systems, and CSA Z1000, Occupational Safety and Health Manage- ment have adapted the methodology for managing occupational safety and health risk.
Scheduled for publication in 2018, ISO 45001, Occupational Health and Safety Management Sys- tems – requirements of implementation and use, will be the latest OHSMS standard to reinforce robust risk assessment coupled with the hierarchy of controls to reduce the risk of injury to as low as reasonably practicable.
Hierarchy of control measures Common to all OHSMS standards is the concept of a hierarchy of control measures. NFPA 70E first made reference to the hierarchy of controls in an informational note in Article 110.1(G) in the 2015 edition. The 2018 edition elevates the use of the hierarchy of controls from an informational note to a requirement in Article 110.1(H) and includes a graphic illustration on the cover.
OHSMS standards rank effectiveness of the control measures in preventing injury and in life cycle value.
The top control me asures have t he hig hest effectiveness and lifecycle value and the bottom control measures are less effective and contribute to lower lifecycle value. In applying a hierarchy of controls, the outcome should be that risk for which the probability of an incident or exposure occurring and the severity of harm that could result are as low as reasonably practicable.
For most situations, a combination of risk con- trol measures is necessar y to achieve acceptable risk. The expectation is that consideration will be given to each control in a descending order. There should be reasonable attempts to eliminate hazards or reduce their associated risks through
www.plantengineering.com PLANT ENGINEERING October 2017 • 23
“ These changes, coupled with knowledge condensed in the informative annexes, will
help stakeholders identify opportunities for
ongoing improvement in reduction of risk for
injuries and fatalities from electrical hazards.”
steps higher in the hierarchy before lower steps are considered.
A lower step in the hierarchy of controls should not be selected until the preceding level or levels are considered. The top three control measures, elimination, substitution and engineering con- trols, are more effective because they are applied during design and redesign of a facility life cycle. Risk reduction in facility design results in a more inherently safe installation that is less dependent on error-free human performance.
Lifecycle value is created by reducing depen- dence on administrative controls and personal protective equipment (PPE), which are costly to maintain. The bottom three control measures, warnings, administrative controls, and PPE, are typically applied during construction, operation, maintenance, and demolition phases of a facility lifecycle. They are highly dependent on human performance, not just for the worker at risk, but also for supervision and other support personnel.
The six categories of hazard control measures are:
MIL Standard 882E Systems Safety states that when a hazard is eliminated, a mishap (i.e., inci- dent, injur y, property damage) is “incapable of occurrence for the life of the item.” In the ideal situation, hazards would be identified appropri- ately and considered in the initial design and subsequent redesign processes so that there is no risk to be eliminated in an organization’s con- struction, operational maintenance, and ultimate dismantlement phases of the installation’s life- cycle. Elimination is most effective early in the design process, when it may be inexpensive and simple to implement. It is more difficult to imple- ment for an existing process, when major changes in equipment and procedures may be required.
We live in an electrical world, and elimina- tion of hazardous electrical energ y completely by modifying the design may be rare. More often the goal is to modify the design so that the likeli- hood of human errors and the need for PPE is at a practical minimum.
For example, when siting an equipment receiv- ing and storage yard for a large industrial con- struction project, locate the yard, access road- ways, material storage and handling areas, and areas with cranes or other mobile lifting equip- ment a sufficient distance from overhead electric lines. Then the electric lines will not be close enough to be a concern. Elimination is 100% effective, with no residual risk.
If the hazard cannot be eliminated, substi- tution of less hazardous equipment, materials or energ y can result in reducing frequenc y or potential severity of exposure. Substituting 24 V control for 120 V control is an example of selecting a less hazardous energy. Replacing 120 V cord-powered tools with battery-powered tools is another example of substitution. In this case, risk of electric shock when handling the battery powered tool is significantly reduced, however the hazard of electric shock associated with bat- tery charging stations is not eliminated and must be addressed with administrative controls.
Engineering controls are design choices that function to reduce frequency or consequences of exposure to a hazard. Passive engineering con- trols function automatically, without any action by personnel, A ground fault circuit interrupter (GFCI) is an example of a passive engineering control that automatically reduces severity of an electric shock exposure. Passive engineering controls may have risk of loss of function which must then be addressed by lower order controls.
For the GFCI example, administrative con- t rols, including maintenance insp e c t ion and testing, are required to address risk of loss of its shock protection function. Touch safe ter- minals in component design is an example of a
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2. Substitution
3. Engineering controls
1. Elimination
passive engineering control that does not depend on maintenance to assure its function as a bar- rier, automatically reducing likelihood of finger contact. An isolation switch is an example of an active engineering control.
Action is required by workers to achieve isola- tion. The switch must be coupled with lockout/ tagout procedures, an administrative control, in order to accomplish energ y isolation.
Warnings are used to alert workers of hazards that were not reduced to acceptable levels during design processes. Warnings may be temporary or permanent, audible or visible. Signs, labels, lights, barriers, barricades, and alerting personnel are examples of warnings.
Warnings are highly dependent on adminis- trative controls such as training, installation in appropriate locations, and maintenance of leg- ibility and visibility. Effectiveness of warnings is vulnerable to errors in human performance in understanding the warning and responding appropriately.
OSHA Recommended Practices for Safety and Health Programs describes administrative con- trols as those measures that require employers or workers to do something to reduce risk of injury. Examples of administrative controls include safe work practices, standard operating procedures, maintenance programs, personnel selection, train- ing, work scheduling, permitting systems, lockout/ tagout procedures, and audits.
For many organizat ions it is common t hat administrative controls comprise the primar y approach to risk management. Effectiveness of administrative controls is highly dependent on human performance and operational discipline
of supervision and support personnel throughout the organization.
The worker at risk of injur y is dependent on administrative controls being properly designed, maintained, and implemented by other personnel. Administrative controls typically require signifi- cant resources in order to maintain continuing levels of effectiveness over long periods of time.
Administrative controls are highly dependent on management and super vision commitment to providing visible leadership and res ources to maintain the controls, worker competency in understanding the controls, and worker discipline in compliance with expected behavior.
This control measure requires the worker at risk to wear something. The proper use of PPE relies heavily on multiple administrative controls including, but not limited to, quality assurance of facility design and installation, hazards assess- ment, worker training on hazards recognition, maintenance of equipment critical to electrical safety, and selection, fitting, training, inspection and maintenance of PPE to help assure PPE is available when needed, the worker recognizes the need, and it is used properly.
Although an important element in injur y pre- vention, use of PPE is considered the least effective control measure because of vulnerability of error in human performance in designing, implement- ing, and monitoring the administrative controls noted above, as well potential errors in hazard recognition and errors in proper selection and use by the worker at risk. PE
H. Landis “Lanny” Floyd, PE, CSP, CESCP, Life Fellow IEEE, is a member of Plant Engineering’s Editor ial Adv isor y Board. Lanny is an adjunct professor in the Advanced Safety and Engineer- ing Management graduate engineering program at the University of Alabama at Birmingham. He retired from DuPont in 2014 after a 45-year career devoted to prevention of electr ical injur ies and fatalities.
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4. Warnings
5. Administrative controls
6. Personal protective equipment
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