The Occupational Safety and Health Administration (OSHA) is in the final stages of updating the existing standard on electric power generation transmission and distribution (1910.269 and Subpart V) related to electrical protective equipment. In many aspects, the standard is long overdue, considering that the existing construction standard dates back to 1971. Many safety-related work practices have changed in the last 40 years, and certainly, electrical protective equipment has evolved. However, some of the proposed changes are directly in line with electrical line construction industry safety-related practices and technological advances, so in many regards, the carriage is well ahead of the horse. These areas are where conflicts lie.

The proposed updates to this standard are important because they make the general industry (1910.269) and the construction industry standards (Subpart V) more consistent. In fact, the provisions of 1910.269 were last modified in 1994, while the construction standard (Subpart V) has gone unaddressed with the exception of some amendments that occurred in the early ’90s.

The change process
The Advisory Committee on Construction Safety and Health made a formal recommendation to OSHA in May 2004 that (1) the construction standards for electric power transmission and distribution work should be the same as the general industry standards for the same type of work, (2) requiring some safety-related communications between host employers and contractors was necessary, and (3) employees need to be protected from hazards posed by electrical arcs through the use of flame-resistant clothing.

The regulatory review process for this standard started on Dec. 6, 2005, spending nearly seven years in the rule-making process. Certainly there have been safety advances that might be in direct conflict with the proposed rule because the rule-making process is not as dynamic as industry practices. Out of this process, there are certain changes the industry is most likely to see, and certain current electrical construction industry best practices might serve as meeting the spirit of each rule. Examining them should help alleviate some tension the electrical line construction industry is experiencing as it awaits official development. One may at least take comfort in knowing in advance that many of the proposed changes are already in line with current industry practices.

Overall, the revisions will include requirements relating to enclosed spaces, working near energized parts, grounding for employee protection, work on underground and overhead installations, working in substations, applicable emergency procedures, and other special conditions and equipment unique to the transmission and distribution of electric energy.

A closer look at what will change
Most electrical line contractors have historically used 1910.269 as the source for safety-related work practices, so the publication of Subpart V will not cause most of these contractors to experience sweeping changes.

As mentioned above, Subpart V covers utility-related construction work. As used in Subpart V, the term “construction” includes the erection of new electric transmission and distribution lines and equipment. It also includes the alteration, conversion and improvement of existing electric transmission and distribution lines and equipment.

Host and contract employer provisions
This section is controversial because it discusses performance. The proposed language will require host employers to inform contract employers of known hazards that might affect contract employers’ work. Access to information about the installations that the contract employer must be provided to allow them to make the hazard assessments required by this subpart and the reporting of unsafe (violation of this provisions) acts to the contract employer.

In short, this section provides some direction for what the host and contract employers are expected to ensure safe working conditions for affected employees. The exchange of information this section requires, in many aspects, already occurs at meetings, such as the contractors safety kick-off or project initiation meetings.

Protective clothing
Most important, the standard directly addresses the host employer and the contract employer’s responsibilities relative to performing the arc flash hazard assessment. As many are already aware, this hazard assessment is vital in determining the anticipated risk posed by exposure to electrical currents.

The portion related to protective clothing is broken into two parts: the hazard assessment and the flame-resistant clothing requirement. The hazard assessment is required to be performed if the employer anticipates that his or her employees could be potentially exposed to flames or electric arc hazards.

While OSHA does not endorse a specific method of assessment, Subpart V provides a list of various methods to determine an estimate of the anticipated heat energy values. These methods can be found in Appendix F, Table 7, of the proposed rule in Subpart V.

The following are some of the methods mentioned:

  1. Standard for Electrical Safety in the Workplace NFPA 70E 2004 Annex D “Sample Calculation of Flash Protection Boundary”
  2. Doughty, R.L.; Neal, T.E.; and Floyd, H.L., II: “Predicting Incident Energy to Better Manage the Electric Arc Hazard on 600 V Power Distribution Systems”
  3. Guide for Performing Arc Flash Hazard Calculations, IEEE 1584 2002
  4. Heat Flux Calculator, free software created by Alan Privette
  5. ARCPRO, commercially available software developed by Kinectrics, Toronto, Ontario, Canada

The standard requires that the employer reasonably estimate the maximum available heat energy to which employees are expected to be exposed.

Once the hazard assessment is performed and evidence of potential exposure to the flame and electric arc flash hazard exists, the protective clothing requirements are triggered. If the determination is made that employees are expected to be exposed to flames and electric arc flash, the employer must ensure that those employees wear flame-resistant clothing. The flame-resistant clothing rating required must be greater than or equal to the heat energy estimates. Clothing that can melt onto skin or that could ignite when exposed to flames and electric arcs are strictly prohibited. Remember, while the contract employer performs the hazard assessment, the host employer must provide the information needed to perform the hazard assessment.

The ground-breaking approach that OSHA has taken in this rule is that, due to the protective characteristic of flame-resistant clothing, it will now be interpreted as meeting the personal protective equipment (PPE) definition.

Training requirements
While training requirements applicable to Subpart V appear as new, 1910.269 had already provided performance language back in 1994. Electrical line constructors should expect a synergistic approach to bring the Subpart V closer in line with 1910.269.

Subpart V now will now require all employees to be trained in safety-related work practices, safety procedures and other requirements pertaining to their job. Those requirements include emergency procedures, such as pole and manhole rescue. Electrical line constructors are expected to train employees to the degree of risk that they may be exposed to.

The issue of qualifying employees to work on energized equipment under Subpart V will be identical to 1910.269.

A qualified employee must have training and prove competency in the following areas: distinguishing live parts from other electrical equipment, knowledge in determining the nominal voltage of exposed parts, minimum approach distances, special precaution techniques, PPE, and insulating and shielding material. OSHA considers employees meeting these training requirements to be qualified.

Supervision and annual inspections
Here is an area where OSHA, through the rule-making process, provides a system of checks and balances to validate the effectiveness of employer-provided safety training and guidance.

Continual reinforcement of this initial guidance must be provided to ensure employees actually use the procedures they have been taught. This reinforcement can take the form of supervision, safety meetings, prejob briefings or conferences, and retraining. Therefore, additional training requirements would be required if supervision indicates employees are not complying with the safety-related work practices.

This section has two requirements: it requires or acknowledges supervision as a source of training evaluation, and it mandates retraining in the case where the institution of safe work practices has not been effective.

Job briefing
This section addresses job briefing requirements that historically have been standard practice in the electrical line construction industry. One key point to consider is that the provisions of this section are not to be confused with training requirements. Training requirements are covered under a separate provision. The job briefing has everything to do with the planning of the work.

The main items that meet the intent of this rule and that should be included in a job briefing are hazards associated with the job, work procedures involved, special precautions, energy sources and PPE.

While a brief discussion will suffice if the work involved is routine, longer discussion should be allowed if the task is nonroutine. Detailed discussion should be allowed if work is complicated, particular hazards are present or the employee cannot be expected to recognize hazard avoidance. OSHA clarifies that, regardless of how short the discussion is, the briefing must still touch on all the topics listed above.

An employee working alone is not expected to conduct a job briefing. However, the employer shall ensure the tasks are performed in the same fashion as if briefing were required.

Minimum approach distances (MAD)
The original proposed tables from 2005 have changed. On Oct. 22, 2008, OSHA published a Federal Register notice to reopen the record on a limited basis for a period of 30 days. The technical committee responsible for revising IEEE Standard 516 stated that, in its view, there was an error in the calculations of phase-to-phase minimum approach distances for nominal voltages 230 kilovolts (kV) and higher.

The equation used to calculate the electrical component of the minimum approach distance for voltages over 72.5 kV included a term that represented the saturation factor for transient overvoltage. The minimum approach distances for phase-to-phase exposures were calculated using a factor corresponding to the phase-to-ground transient overvoltage rather than for the higher phase-to-phase transient overvoltage.

The minimum approach distances in OSHA’s 2005 proposal were based on the same equations that were questioned by the IEEE technical committee; therefore, the same issue potentially affected the minimum approach distances in OSHA’s proposal. The industry expects that OSHA will adopt the National Electrical Safety Code 2009 version of MAD. In many regards, the final suggested language included in this provision is still unknown. However, OSHA has stated that, “The minimum approach distances in this proposal are more protective as well as more technologically sound.”

In summary, the majority of the proposed revisions to the rule have existed in 1910.269 for the last 17 years. Electrical line constructors most likely already have adopted some of the safety-related work practices proposed in this rule. Some of the newer and more controversial changes include the protective clothing requirement, hazard assessments (although they are defined in other OSHA rules), and host/contractor responsibilities. In any event, existing contractor and customer requirements have driven the adoption of more efficient safety-related work practices and the use of technologically advanced PPE.


RIVERA is NECA’s director of safety. Reach him at jr@necanet.org. TODD, CSP SGE, is a certified safety professional with more than 25 years of experience in the electrical power transmission and distribution industry. Reach him at suntodds1@bellsouth.net.