This is the second of a two-part update on OSHA’s new rules on electric power generation, transmission, and distribution. This part looks at what’s revised, why, and the cost. Read part one of this article, Are new OSHA rules on electrical safety regular or supersize?
When the U.S. Occupational Safety and Health Administration (OSHA) released its changes to rules that affect electric power generation, transmission, and distribution, it was the culmination of a saga that began with a public release of proposed changes almost nine years ago. Agency rule changes send shockwaves of nervousness through the business sector it regulates. There are four sets of major OSHA changes in the new rules.
|Compliance Date||New or Revised Rule||Standard Reference|
|90 Days After Publication
( July 10, 2014)
Transferring information between host employer and contract employers
|1926.950(c) and 1910.269(a)(3)|
|April 1, 2015||2. Revised:
Provisions on the use of fall protection systems
|1926.954 (b)(3)(iii) and (b)(3)(iv) and
1910.269 (g)(2)(iv)(C), and (g)(2)(iv)(D)
|April 1, 2015||3. Revised:
Requirements for minimum approach distances (MAD)
|July 10, 2014||4. New:
Requirements for protecting employees from the hazards associated with electric arcs
|OSHA issues memorandum to delay enforcement pertaining to the new final rule
OSHA has issued a memorandum to both the construction and maintenance sectors to delay enforcement (hence citations) pertaining to the new final rule issued April 2014. Read Bob's recent blog post to learn more.
1. New: Transferring information between host employer and contract employers
Reason: Lack of communication was identified in several incident investigations. Communication is easy but must be consistent in content and coordination.
What the new rule says (1926.950 (c) and 1910.269 (a)(3) paraphrased):
1. Host employer transfers all information related to the safety of work performance:
e. capacity (fault currents).
2. Contract employer(s) responsibilities are to:
a. instruct their employees from the host employer information
b. contact host employer before work begins of any unique hazards not yet covered in their conversation
c. during work performance contact the host employer within two working days when unanticipated hazards arise (although not specifically mentioned, this would be an excellent place to include a “stop work authority” in the employer’s electrical safety program until a suitable resolution is found).
3. Host and contract employer are to coordinate their work rules so that all employees are protected according to these rules (1910.269 (a)(3)(C)(iii)).
Figure 1. Supervision of workers performing in a work area with overhead lines is a key aspect of safety compliance, regardless of the standard that is used.
These rules are much more prescriptive than the older rules and simply state as regulation a practice that is commonly now in place. NFPA 70E has similar wording in 2012 NFPA 70E, Article 110.1. Although the NFPA 70E does not place a two-working-day timeframe on communicating any deviations from the pre-job plans, it does add another important aspect the new OSHA rules do not. The host employer activities in NFPA 70E retain their responsibility throughout the job performance of some direct oversight and to include any observation of contract worker noncompliance (1910.269 and 1926.950 requires only coordination of each other’s work rules). Given the expected work area with overhead lines, this difference is completely understandable (Figure 1). Nonetheless, supervision of workers performing the work is a key aspect of safety compliance regardless the standard that is used. The 2012 NESC includes the idea of communication responsibility in its entire volume, although with less prescriptive terms.
One major area of both concern and discussion by the rule-making participants was where and how to find the available fault current that may be present on the system at the place of work performance. The electrical contractors following NFPA 70E on utilization equipment have long had the same concerns. New NEC requirements, which began in 2008, require that the calculated fault current be placed on the label at the service equipment. This was more for inspector use but had a very positive secondary effect of helping the electrical contractor know the fault current available when applying 70E hazard/risk categories tables for arc flash hazard analysis. This is a best work practice on each of the first disconnecting equipment connected to the secondary of a power transformer even in a facility installation. Where the fault current value is not known, the worker can go to the transformer feeding the system and quickly calculate a worst-case value by dividing the secondary current of the step-down transformer by the decimal equivalent of the transformer impedance. The preamble of the new rules gives the same suggestion when the electrical system fault is not known. Both NFPA 70E and 1910.269 / 1926.960 (Annex E in both OSHA rules) use a handy table to estimate worker protection. When using any of these tables, a worker must first determine maximum fault current and maximum clearing time of the upstream protective device in the system. This is critical information about the system design, which must be communicated by the host employer to the contract employer.
Final Rule Index: https://www.osha.gov/dsg/power_generation/index.html
Recommended best practices for those companies following NFPA 70E.
1. In the pre-job documented meeting include processes to ensure two-way communication between the host employer representatives and the contract employer and employees.
2. Place timelines and action points in the documents and expectations.
3. Ensure maximum fault currents and tripping times are communicated (documented in a readily accessible place) in places where arc flash incident energy labels are not yet installed.
4. Set up supervisory processes, or ensure the contract employer has such processes in place, to monitor worker compliance to the electrical safe work practices. Refresher training cycles can be better established knowing which information is being misunderstood or ignored.
Recommended best practices for those companies following 1910.269 / 1926.950.
1. Interestingly, the OSHA rules do not specifically prescribe that the meeting between the host and contract employers be documented. Of course, with OSHA, if it’s not documented, it didn’t happen. Document information shared and any expectations from either party involved.
2. OSHA is not requiring labels be placed on electrical equipment, as does NFPA 70E. Actually in 1910.331 – 335, utilization work practices, OSHA does not require labels there either. NFPA 70E has in its recommended work practices detailed key information workers need to ensure their safety. Placing labels on outdoor, high-off-the-ground equipment would likely be an exercise in futility. Including such information in written or electronic work orders and reviewing in the pre-job meetings is a very useful practice.
3. Set up supervisory processes, or ensure the contract employer has such processes in place, to monitor worker compliance to electrical safe work practices. Refresher training cycles can be better established knowing which information is being misunderstood or ignored.
Incorporated into the thought of communication among employers is the need for workers to be appropriately trained. The new requirement in 1910.269 (A)(2)(c) and 1926.950 (b) (iii) calls for training to be determined by the risk to the employee for the hazard involved.
Cost: The cost for implementation is considered negligible. Compliance date is July 10, 2014.
2. Revised: Provisions on the use of fall protection systems
Figure 2. Several injuries and fatalities were investigated by OSHA where workers wearing body belts and either changing positions on the pole or while in aerial lifts were ejected from the lift or fell from the poles.
Reason: Several injuries and fatalities were investigated by OSHA where workers wearing body belts and either changing positions on the pole or while in aerial lifts were ejected from the lift or fell from the poles. A few incidents were reported where the worker was first shocked from high voltage and then fell. It was the fall that caused the fatality and not the electrical shock that preceded the fall (Figure 2). There is a need to bring 1910.269 into alignment with 1926.502 (d) and 1926.954 (b)(3)(iii) for employees working from elevated locations 1.2 m (4 ft) above the ground.
What the new rule says (1926.954 (B)(3)(3)(ii) and 1910.269 (g) paraphrased):
1. Qualified workers who are climbing poles and are elevated above 4 ft off the ground must use fall protection systems (body harnesses), unless the employer can demonstrate that doing so is infeasible or creates an additional or greater hazard.
2. Work positioning systems shall be rigged so that an employee can free fall no more than 2 ft.
3. Workers in aerial lifts performing work covered by 1910.269 can no longer use body belts as part of a fall arrest system but must use harnesses.
OSHA indicates this revised rule will mainly affect tree-trimming services. Most employers are now using full harnesses doing electrical work while in the bucket. Changing positions while climbing or descending a pole is an area where the electrical workers will be affected. This protection is required where workers are 4 ft or more above the ground and arranged to free fall less than 2 ft.
Fall protection is not mentioned with this specificity in NFPA 70E, but 2012 NESC in Part 4, Work Rules, Section 420K.1, mandates fall protection at 3 m (10 ft), and K.2 allows qualified climbers to be unattached during some repositioning activities. Both sections are no longer in compliance with the OSHA rules. Employers must amend both their work rules and training to remain in compliance.
Cost: Since OSHA feels the majority of the noncompliance with the use of harnesses is confined to the tree maintenance employers, it estimates a cost of approximately $69 per worker to comply. Fall protection for the electrical worker is another matter, which OSHA admits it did not include in the cost analysis for upgrading existing equipment. A worker must be protected from all hazards to which they are exposed and the linemen are often exposed to multiple hazards all at once.
1. height — fall protection
2. energized lines — shock protection
3. electrical arc flash — flame-resistant/arc-rated protection.
While working on energized lines and equipment from either a bucket or on the pole, a lineman needs protection from all three hazards. Consequently the fall protection must be able to withstand the arc heat and remain intact. Both 1910.269 (g)(2)(ii) and 1926.954 (b)(ii) indicated performance criteria after a harness has been exposed to a 40 + 5 cal/cm2 incident energy level. Fall protection harnesses are available today in conformance with ASTM F887. My suspicion is that, given both the number needed and the added cost, this will be a large line item in a company’s future budget. OSHA is delaying enforcement of this revised rule until April 1, 2015.
3. Revised: Requirements for minimum approach distances (MAD)
Reason: OSHA revisited the way in which the minimum approach distance tables were established from the original 1994 rules. The new tables are based more on engineering principles, which will now include system transient overvoltage and spark over distances mainly applicable when working on systems greater than 72.5 kV. Most importantly the distances must be appropriate for each workplace rather than for the industry in general. The final rule ensures adequate employee protection, even when tools or conductive objects are present in the air gap. OSHA believes, based on incident reports, that this method will better protect each employee than the existing rule.
What the new rule says (1926.960 (C)(1) and 1910.269 (l)(3) paraphrased):
1. The employer shall establish minimum approach distances no less than the distances computed in one of two tables listed in each rule (1910.269 or 1926.960).
2. For voltages over 72.5 kV, the employer shall either determine the maximum anticipated per-unit transient overvoltage, phase-to-ground, through an engineering analysis or assume a maximum anticipated per-unit transient overvoltage, phase-to-ground in accordance with tables associated with each rule (1910.269 or 1926.960).
Those who follow NFPA 70E or 2012 NESC must understand some basic definition differences between the standards and OSHA rules.
Definition of minimum approach distance (MAD)
1910.269 (x) and 1926.968: the closest distance an employee may approach an energized or a grounded object.
2012 NESC Section 2: the closest distance a qualified employee is permitted to approach either an energized or a grounded object, as applicable for the work method being used.
Definition of boundary, limited approach (LAB)
2012 NFPA 70E: an approach limit at a distance from an exposed energized electrical conductor or circuit part within which a shock hazard exists.
Definition of boundary, restricted approach (RAB)
2012 NFPA 70E: an approach limit at a distance from an exposed energized conductor or circuit part within which there is an increased risk of shock, due to electric arc-over combined with the inadvertent movement, for personnel working in close proximity to the energized electrical conductor or circuit part.
Definition of boundary, arc flash (AFB)
2012 NFPA 70E: When an arc flash hazard exists, an approach limit at a distance for a prospective arc source within which a person could receive a second degree burn if an electric arc flash were to occur.
When applying the definitions, we must understand the following.
1. Minimum approach distance (MAD) is a distance inside which a qualified worker must be using PPE and applying the received training covered by the 1910.269 and 1926 utility rules.
2. Limited approach boundary (LAB) is a distance boundary the qualified worker establishes to ensure the unqualified worker does not enter an area where a shock is possible — just beyond arm’s reach plus additional arc over distance when the voltage is greater than 750 Vac or 1 kVdc.
3. Restricted approach boundary (RAB) is a distance inside which a qualified worker must be using both PPE and applying the training received covered by 1910.333 (utilization work rules).
4. MAD is synonymous in purpose but not always equal in distance to RAB.
With the exception of the LAB, the remaining definitions and distances are applicable to the qualified electrical worker approaching exposed energized lines or equipment. The LAB is really for the untrained, unqualified workers. Due to the lack of the appropriate training to recognize the electrical hazard, they are warned by either a physical barrier, typically a warning tape marked “do not enter,” or an attendant to stay away. OSHA is not altering these distances in the final rule. This is a minimum of 3 m (10 ft) up to 50 kV and 10 cm (4 in.) for each 10 kV over 50 kV for overhead lines. The tables allow lesser distances for enclosed and exposed electrical equipment, which can only be accessed in one direction. The modified distances in the final rule mainly affect the qualified electrical workers while working on or near energized overhead lines. Inside the MAD or RAB, qualified electrical workers must be wearing all the appropriate PPE for the hazard. OSHA ‘s comments in the preamble indicate that working at or near the MAD is not a safe practice and would require two actions to be compliant with the rules.
1. When working outside but near the MAD and not insulated from the energized part or performing live-line bare-hand work, they work from a position where they could not reach into the MAB.
2. Rubber insulating gloves and sleeves must be put on and removed while the employee is outside the MAD and from a position where the employee could not reach into the MAD while unprotected.
Some commenters suggested a 3-m (10-ft) rule where employees would don and doff rubber insulating gloves/sleeves. OSHA expects employers generally will elect bright-line rules (cradle-to-cradle work practices). The concern was more for workers climbing poles than for those in buckets or on the ground. Some expressed concern for employees climbing while wearing the rubber insulating gloves and leather protectors and increased fall hazards. OSHA concluded that there is little risk associated with this practice while climbing. Changes to the fall protection rules will mitigate any increased concern for workers becoming injured from a fall.
OSHA believes that allowing employees to design work rules appropriate for their workforces and work places is a reasonable approach to ensuring workers don and doff rubber insulating gloves and sleeves at a safe distance from the energized hazard. This must then become a detail fully described in an employer’s electrical safety program followed by appropriate training and supervision for compliance.
OSHA has provided Table R-3 in 1910.269 (l) and V-2 in 1926.960 for calculating minimum approach distances. In keeping with new technology, OSHA also provides a handy online calculator where exact values of nominal system voltage, transient overvoltage, and altitude values are entered and the calculated distances populated. The MAD calculator can be found at www.plantservices.com/madcalculator.
To allow employer’s time to react to the revised MAD rule, OSHA will allow them to use legacy tables until March 31, 2015. On April 1, 2015 employers must have in place calculated or confirmed existing distances in compliance with the new rule and must have trained their workforces appropriately. The final rule contains requirements for minimum approach distances that differ substantially from 2012 NESC. For those firms following 2012 NFPA 70E, Table 130.4 (C)(a) for ac and 130.4 (C)(b) for dc, or 2012 NESC Table 441.1 for ac or 441-2 for dc, this will require a thorough review of the existing work practices.
Before we move on, a note about the lowest voltages with distances listed in the tables as “Avoid Contact.” OSHA reports in the preamble of an accident involving an employee working at 120 Vac and wearing only leather gloves as shock protection. The final rule, just like the existing rule, requires employees to avoid contact with energized voltages from 50 V to 301 V. If it is necessary, or even remotely possible, that the employee could contact these voltages they must meet the electrical protective equipment and PPE requirements.
Cost: OSHA believes employers will not incur significant costs beyond costs normally associated with retraining employees. The cost for the employer would be great if misunderstanding or confusion resulted due to lack of appropriate training to these changes.
4. New: Requirements for protecting employees from the hazards associated with electric arcs
Reason: When OSHA promulgated 1910.269 back in 1994, there were no standards for clothing to protect employees from the thermal hazards resulting from electrical arcs. Now there are both standards and clothing available that will adequately protect employees to a predicted level of arc flash incident energy (heat) exposure. This clothing is made of flame-resistant materials that have been arc flash tested and rated to withstand the incident energy of electrical arc flash exposure and reduce the heat felt on a worker’s skin to the 50% probability of the onset of a second degree burn when the incident energy exposure is the same as the arc rating of the clothing worn (reference ASTM F1506 and F1959). Previously OSHA’s wording in these rules was that workers wear clothing “that could not increase the extent of the injury a worker may sustain.” OSHA has issued in the final order rules, which require workers to be protected when exposed to electrical arcs, that flame-resistant, arc-rated clothing adequate for the expected arc flash incident energy must be used.
What the new rule says (1926.960 (g) and 1910.269 (l)(8) paraphrased):
1. Employers must make a reasonable estimate of the arc flash incident energy to which the employee could be exposed,
2. Where the estimated arc flash incident energy exceeds 2.0 cal/cm2 the employer shall ensure employee wears protective clothing equal to or greater than the expected exposure and this protection shall cover the employee’s entire body, but some exceptions exist.
- For hands, the employee can wear either rubber insulating gloves and leather protectors or heavy-duty (12 oz/yd2) leather work gloves that would be anticipated to provide up to 14 cal/cm2 of protection for the hands.
- Heavy-duty work shoes or boots are sufficient foot protection.
- Head and face protection requires Class E hard hat (< 9 cal/cm2 single-phase arcs in open air or 5 ca/cm2 all other arcs). Add face protection when > 8 cal/cm2 single-phase arcs in open air or >4 cal/cm2 all others. Exposures involving single-phase in open air, employee protection may be 4 cal/cm2 less than estimate.
3. Polypropylene was added to the list of prohibited fabrics.
These new rules have opened quite the Pandora’s box of understandable objections from employers across the utility sector. What are mainly in question are two concerns. First, are workers on the pole or in a bucket not familiar with or working easily in the new protection, especially face shields, increasing the hazard levels already encountered? And, second, who will pay for all this new clothing? Let’s attack these new requirements one at a time to consider employer’s compliance today.
Employers must first conduct a survey of their system and do a reasonable estimate of potential incident energy to determine appropriate arc-rated PPE required. These estimates are to consider the system is electrically under normal operating conditions. OSHA has provided four example methods for selecting a reasonable incident energy calculating method in Appendix E of the final rule. The Agency is aware that there will be variations in calculated values using the different methods and asks only that the employer make a reasonable estimate of the incident energy based on the worker’s task exposure. The provided table has reference notes indicating which methods OSHA finds appropriate at one of three voltage ranges (less than 600 V, 601 V to 15 kV, and greater than 15 kV). Additional tables are provided to select a reasonable distance from the employee to the arc. A table is provided to select a reasonable arc gap, or arc length, for the voltage with the assumption that open air has approximately 10 kV dielectric strength per 25.4 mm (1 in.).
Estimating arc flash incident energy will demand some electrical engineering expertise. The employer need not estimate the incident energy for every task. Reasonable assumptions can be made for the entire system, instead of at every point in the system, as long as the estimates represent the maximum exposure for any area and work task. Two useful tables incorporate voltage for the system, maximum fault current and maximum clearing time to indicate four levels of PPE protection at a specified distance. The user is reminded that these are for “arc in open air” only. Any arc exposure while working on switchgear or equipment associated with the electrical system must be calculated using one of the four methods given in the table to determine estimated incident energy. The employer is cautioned that using the listed methods may not result in estimates that fully protect workers from internal faults in transformers and similar equipment or from arc flash events in underground manholes and vaults. The 2012 NFPA 70E Table 130.7 (C)(15)(a) and 2012 NESC table 410-1 might be useful for estimation in some cases involving equipment and specific work tasks. Additional tables in 2012 NESC are similar but not exact to the values given in the new OSHA tables and are limited to open air arcs, as well.
2012 NFPA 70E has very helpful tables for common tasks on common electrical system characteristics. Where maximum fault current and maximum clearing time is not exceeded, these hazard/risk category classifications have become the industry gold standard for determining worker protection for that task when incident energy analyses are not completed. It appears to OSHA when reviewing the 70E tables that the NFPA 70E committee chose to reduce the amount of protection based on the likelihood that an arc would occur. OSHA based the determination for the level of PPE in tables under the final rule solely on incident energy and not the probability of an incident occurrence. If there is a reasonable likelihood that an electric arc will occur, then protection against the full incident energy of the arc flash is required. The agency concluded that the risk-based foundation of the 70E tables is not a reasonable method in estimating incident energy and did not reference the NFPA 70E tables in Appendix E in the final rule. For those employers who are covered under the final rule, following NFPA 70E tables in areas common with 70E equipment such as switchgear and panel boards of the supporting electrical systems might find themselves out of compliance to the final rule.
Once the estimated incident energy is determined, OSHA encourages employers to use methods such as moving the worker farther away by means of equipment such as live-line tools or evaluating the electrical system overcurrent protective scheme to decrease the time of a fault. 2012 NFPA 70E and the 2014 NEC both have mandatory requirements when instantaneous trip settings are not used to decrease the intensity of the incident energy.
Let’s summarize these rules before we proceed. The employer:
- determines work task to be done
- selects work practice to be utilized
- estimates incident energy at work task location
- determines if reducing incident energy is possible or practical
- either uses this information to select employee PPE or gives this information to contract employer for selecting their worker’s level of protection.
OSHA makes it clear that compliance with any national consensus standard, even those referenced in the final rule, does not ensure compliance to the final rule. Those employers following NFPA 70E for determining PPE levels may be thinking they are already in compliance, which is likely true, except when working from a bucket, on a pole, or while using a live-line tool. Those following 2012 NESC have a better chance of already following the new rule except where head and face protection are involved. Workers are screaming all over the country that they cannot work with any face protection, which limits their visibility. Thus many are not. Some are saying there is no way they could work in the daily heat while wearing 40 cal/cm2 or greater arc-rated clothing (NFPA 70E Cat. 4). And likely it is not needed.
Utility workers, especially line workers, are exposed to sunlight and heat on a daily basis and in many cases all day long. Any change in clothing must be evaluated for its effect on overall heat retention while working. Arc-flash protection is always based on the incident energy on the person’s face and body at the working distance, not at the hands or arms. OSHA presumes that electric power work is equivalent to the metabolic rate of heavy labor. Wearing 8 cal/cm2 clothing does not interfere with heat loss significantly more than normal, non-flame-resistant work clothing. Employers with employees who are in clothing with arc ratings between 8 and 25 cal/cm2 will need to ensure heat stress mitigation strategies where ambient temperatures warrant such action.
The final rule requires employers to provide protection from the heat of an electrical arc when the estimated incident heat exceeds 2.0 cal/cm2. Although this seems at odds with the accepted rationale of NFPA 70E that an incident energy of 1.2 cal/cm2 is likely to produce a blistering (second degree) burn, OSHA does not. OSHA explains, “Untreated cotton clothing will reduce a 2.0 cal/cm2 exposure below the 1.2 to 1.5 cal/cm2 level necessary to cause burn injury, and this material should not ignite at such low heat levels.” The final rule does require the outer layer of clothing to be flame resistant under three conditions, even when the estimated incident energy is less than 2.0 cal/cm2:
- employee exposed to circuits above 600 V
- flammable material in the area that could ignite during an arc (for example, an oil-filled transformer)
- molten metal or arcs from faulted conductors in the work area.
With these guidelines a reasonable conclusion would be: “Where an arc flash is possible, only flame-resistant, arc-rated clothing is allowed.” OSHA added to the list of prohibited clothing a material that has become commonly worn today due to its comfort in both hot and cold climates. Polypropylene is specifically added to this prohibited fabric list. Employers must have written statements in their electrical safety program detailing worker attire from the skin out.
The rule-making participants had many comments for clarification on what OSHA considers PPE. Since these non-melting fabrics worn as under layers (cotton, wool, or silk) do not provide protection from the arc, they are not considered PPE. This is not to say they are not critically important to the worker protection if the outer flame-resistant layers cannot resist break-open. These under layers should be worn for that secondary protection. OSHA issued a letter of interpretation in November 2007 explaining that the Agency considers FR clothing to be PPE and that the employer must purchase this PPE. Employers then must set up policies and procedures for training about its use and limitations of protection, maintenance, and retention when an employee leaves their employment.
Figure 3. Face protection in the form of either an arc-rated hood or hard hat and arc-rated face shield with arc-rated balaclava combination is required.
After clearing the hurdles of estimating arc-flash incident energy and the heat stress potentially caused by the selected level of FR clothing, what remains is how to comply with the final rule’s requirement: “This protective equipment shall cover the employee’s entire body.” The final rule gives clear guidance on hand and feet protection and made statements in the preamble that injuries to employees’ hands and feet in past incident reports were either very minimal or nonexistent. An employee’s face is another matter altogether. The potential of life-altering injuries to the eyes or life-threatening injuries by inhaling the arc vapor are just too great. Face protection in the form of either an arc-rated hood or hard hat and arc-rated face shield with arc-rated balaclava combination is required (Figure 3). Although the values given in the final rule Appendix E tables were selected to match NFPA 70E thresholds, there is a major departure from the NFPA 70E guidance that the combination of hard hat and arc-rated face shield with arc-rated balaclava is only acceptable for exposures not greater than 12 cal/cm2. The final rule allows this combination or the use of an arc-rated hood at any incident energy level . The determination to require face protection in the final rule is couched where all the following criteria are considered:
Robert S. LeRoy, CESCP - A recognized subject matter expert in the NFPA 70 (NEC), 70B/NETA-MTS (Recommended Maintenance Practices) and 70E (Workplace Electrical Safety), Mr. LeRoy is an electrical safety and compliance consultant to industrial clients worldwide. Mr. LeRoy is a master electrician, certified electrical inspector, certified electrical safety compliance professional performing electrical safety and compliance consultanting to clients worldwide. With 42 years in the electrical industry he is a licensed master electrician and electrical inspector. As the past Director of Electrical Programs for a major international training company he has consulted with and trained thousands of workers for clients in the US, Canada and 17 other countries around the world. He is an active member of NFPA, IAEI, IEEE and ASSE. Mr. LeRoy is the author of numerous articles, training manuals and curriculum as well as a sought after conference speaker focusing on safety training and compliance.
1. when calculated, estimated incident energy is always considered to be at the worker’s chest
2. in open-air, single-phase arcs drop heat inversely proportional to the distance
3. there is no enclosure to reflect the convective heat to the back of the worker’s head as with enclosed electrical equipment
4. therefore the expected incident energy at the worker’s head should be 30% lower than the estimated incident energy at the worker’s chest..
Due to these same criteria, the final rule also allows for exposures involving single-phase arc in open air, that the head and face protection may be 4 cal/cm2 less than the estimated value.
The Agency has concluded that most exposures on overhead lines and equipment, where employees perform much of the work covered by this final rule will be no higher than 12 cal/cm2. It does not believe there are many tasks, if any at all, that, when using a live-line-tool, would expose an employee to 40 cal/cm2. OSHA agrees that wearing arc-rated head and face protection is likely to cause more problems for overhead line workers than for in-plant work. The Agency does not believe these potential problems will create a greater hazard, even for workers when climbing a pole. As a result the employer will then need to add to the training scenarios that involve real-world situations while wearing all the required PPE to ensure worker confidence and satisfactory performance.
Cost: OSHA estimates that the cost of flame-resistant/arc-rated shirt and pants to be $192/set at current prices, excluding laundering and maintenance. The estimate on longevity for each set is four years. The number of sets per worker will depend on employer policy and procedures. The Agency estimated eight sets would be the average. Add to this the cost of the arc-rated face shield and arc-rated balaclava combination or arc-rated hood.
- Employers must make reasonable estimates on incident energy is Jan. 1, 2015.
- Employees must be wearing appropriate outer layer of clothing based on the incident energy estimates when estimate is above 2.0 cal/cm2 by April 1, 2015.
- Employees must be wearing arc-rated equipment (arc-rated face shielding and arc-rated balaclavas or arc-rated hood) by April 1, 2015.