OSHA has overhauled its standards for the construction of electrical transmission and distribution installations, and the general industry and construction standards for electrical protective equipment. The new rules make the construction standards more consistent with the more recent general industry standards, as well as with approved consensus standards already in widespread use.
In addition to electrical utilities, the new rules impact contractors building, repairing, and maintaining electric power facilities, and manufacturing (and other) firms that own or operate their own electrical power generation, transmission or distribution installations as a secondary part of their business operations. Tree-trimming companies will also be affected.
While space does not allow a full examination of the new electrical standards, the primary changes under the new rules fall mostly under four categories: (1) new provisions regarding the passing of information between the “host employer” and “contract employers;” (2) revised provisions on the use of fall protection systems; (3) revised requirements for “MAD,” or minimum approach distances; and (4) new requirements to protect employees from hazards associated with electric arcs. We’ll look at these briefly, in the order listed.
Sharing of information: Under the new rules, the host employer is required to pass on to the contracting employers all information concerning safe work performance related to the design, condition, operation and capacity (fault currents) of all equipment. Each of the contract employers is required, in turn, to pass instructions to their respective employees, based on information received from the host employer.
Each contract employer should contact the host employer, before work begins, of any unique hazards not covered in their conversation. During performance, the contract employer should contact the host employer, within two working days, when unanticipated hazards become apparent.
The host and contract employers are to coordinate work rules, so that all employees are properly protected.
Labeling the calculated fault current on electrical equipment has been an NFPA 70E requirement since 2008, but is not a requirement prescribed under the new OSHA standards. Labeling outdoor, high-off-the-ground equipment is of doubtful utility, but maximum fault current, and maximum clearing time of the upstream protective device in the system, is critical information, which should be included in written or electronic work orders, and documented, in a readily-accessible place, in locations where arc flash incident energy labels are not installed.
Each contract employer should have — and the host employer should make sure that each of them has — supervisory processes to ensure worker compliance with electrical safe work processes. OSHA’s new standards do not require that a pre-job meeting be documented, but we recommend that minutes of such a meeting state, in detail, what information was shared, as well as a summary of what initial and refresher training is contemplated, and what monitoring will be done to ascertain what safety-related information is (and is not) being understood and followed, so that refresher training cycles can be determined accordingly.
Fall protection: Under the new standards, workers climbing poles and elevated 4’ or more off the ground must use fall protection systems, unless the employer can show that doing so is infeasible, or creates an additional or greater hazard. Workers performing covered work can no longer use body belts as part of a fall arrest system; they must use harnesses. (According to OSHA, it’s mainly employees of tree-trimming services that use body belts at present).
Work positioning systems must now be rigged, so that an employee cannot free-fall more than 2 feet. Companies now working under NFPA 70E and 2012 NESC standards must change their training and work rules, as fall protection is now required at 4’ elevations (not 10’) and it’s no longer permissible to be unattached during repositioning activities.
Minimum approach distances: Under OSHA’s new rules, MAD will now be calculated using tables based on engineering principles, including system transient overvoltage and spark-over distances mainly applicable when working on systems greater than 72.5kV. Distances must be appropriate for the particular workplace, not the industry at large.
Companies following NFPA 70E or 2012 NESC need to note, and incorporate into their training and procedures, differences in the definitions of certain terms, as used in the new OSHA standards (e.g., MAD, or minimum approach distance; LAB or “boundary — limited approach;” RAB, or “boundary — restricted approach;” and AFB, or “boundary — arc flash”).
Protection from electric arcs: These new rules are intended, among other things, to afford workers the benefit of clothing made of flame-resistant materials, rated to withstand the incident energy of electrical arc flash exposure, and reduce the likelihood of burns.
Under OSHA’s new rules, employers must estimate the arc flash incident energy to which employees could be exposed. In devising the new rules, OSHA in effect rejects the NFPA 70E tables now widely utilized, in that those tables prescribe appropriate levels of PPE based in part on the likelihood that an arc will occur. OSHA’s approach under the new rules bases the determination of the level of PPE solely on incident energy: if there is a significant likelihood that an arc will occur, then protection against the full incident energy of the arc flash is required.
Where the incident energy calculation exceeds 2.0 cal/cm2 the employer must require that exposed employees wear clothing with a rating equal to or greater than the expected exposure. This will generally need to include rubber insulating gloves and leather protectors (or 12-oz. leather work gloves), heavy-duty work shoes or boots, and a Class E hard hat.
Polypropylene has been added to the list of prohibited fabrics for protective clothing.
Employers must henceforth have written statements in their electrical safety program, prescribing worker attire from the skin out. Compliance with NFPA 70E in determining PPE levels may no longer constitute compliance with the new OSHA rules, especially when working from a bucket, on a pole, or while using a live-line tool.
One aspect of the new rules that threatens confusion and noncompliance is the requirement, above a certain threshold level, for face protection. Many workers find that face protection limits visibility, and are resistant to using it. Also, heat stress mitigation will probably be required where arc-rated clothing must be worn, and it is controversial whether 40 cal/cm2 arc-rated clothing is truly necessary.
Additional subjects addressed in the new rules include job briefings; insulation and working position of employees working on or near live parts; de-energizing transmission and distribution lines and equipment; protective grounding; operating mechanical equipment near overhead power lines; and working in manholes and vaults.
Full documentation concerning the new rules can be found on OSHA’s website, or in the Federal Register.