Electrical protective equipment requirements

Under 1910.137(a)(1)(i) these items must be produced by a seamless process. Rubber insulating blankets, gloves, and sleeves shall be manufactured without seams to meet the requirement in 1910.137(a)(1)(i).

• Seamless construction reduces stress points and helps ensure insulating integrity.
• Employers should obtain equipment marked by the manufacturer showing compliance, as permitted by 1910.137(a)(1)(ii).

Under 1910.137(a)(1)(ii) each insulating item must be clearly marked with its class (for example, "Class 00", "Class 0", "Class 1", etc.).

• Specific class markings are required by 1910.137(a)(1)(ii)(A)–(F).
• Type markings (Type I for nonozone-resistant and Type II for ozone-resistant) are required per 1910.137(a)(1)(ii)(G)–(H).
• Markings may also include manufacturer ID and size as allowed by 1910.137(a)(1)(ii)(I).

Yes. Markings must be nonconducting and not impair insulating qualities, and glove markings must be confined to the cuff. The standard at 1910.137(a)(1)(iii) requires nonconducting markings applied so they do not reduce insulation, and 1910.137(a)(1)(iv) limits glove markings to the cuff.

• Avoid painted or metallic labels that could create conductive paths.
• Confirm manufacturer marking practices meet these rules before placing equipment into service.

Under 1910.137(a)(2)(i), insulating equipment must withstand the AC proof-test voltages in Table I-1 or the DC proof-test voltages in Table I-2.

• Table I-1 lists AC proof-test voltages and maximum proof-test currents for gloves by size and class (see 1910.137(c) for tables).
• Table I-2 gives DC proof-test voltages for each class.
• The proof test must reliably indicate that the equipment can withstand the voltages involved as required by 1910.137(a)(2)(i)(A).

Under 1910.137(a)(2)(i)(C) and 1910.137(a)(2)(ii)(B), gloves must be water-soaked for 16 hours and, for the AC test, filled with tap water and immersed to the specified water level with equal inside and outside water levels.

• The 16-hour soak is specified before the separate AC proof test to confirm performance after moisture exposure.
• Water level clearances for each glove class are listed in Table I-3 in 1910.137(c).
• The AC proof-test current must not exceed the glove currents in Table I-1 per 1910.137(a)(2)(ii).

Under 1910.137(a)(2)(ii)(A), the permissible proof-test current must be adjusted in direct ratio to the test frequency when the AC proof test is run at a frequency other than 60 hertz.

• For example, if testing at 50 Hz, allowable current = (50/60) × current listed in Table I-1.
• This ensures the test is electrically equivalent regardless of frequency.

Under 1910.137(a)(2)(iii), equipment that has been subjected to a minimum breakdown voltage test may not be used for electrical protection. A breakdown test damages insulation and therefore disqualifies the item from protective service.

• If a protective item fails or is subjected to destructive testing, it must be removed from service and not used to protect employees.

Under 1910.137(a)(2)(iv), Type II (ozone-resistant) insulating materials must pass an ozone test with no visible effects to show they will resist ozone exposure in actual use.

• Visible signs of ozone deterioration such as checking, cracking, breaks, or pitting indicate failure per 1910.137(a)(3).
• Manufacturers commonly follow ASTM ozone test procedures referenced in the Note to paragraph (a) for compliance.

Under 1910.137(a)(3)(ii), certain surface irregularities like indentations, protuberances, or embedded foreign material are acceptable if they meet conditions in (A) and (B): they must blend smoothly when stretched and embedded foreign material must remain in place and stretch with surrounding material.

• Acceptable irregularities are limited to those that do not adversely affect insulating properties and are detectable by required inspections and tests.
• For inspection guidance, employers can use ASTM F1236-96 as noted in the regulation.

Under 1910.137(b)(1), insulating equipment must withstand voltages that may be imposed on it, including transient overvoltages such as switching surges as well as nominal line voltage.

• The note to 1910.137(b)(1) references IEEE Std 516-2009 for assessing transient overvoltages.
• Employers should consider both nominal and transient voltages when selecting protective equipment.

Under 1910.137(b)(2)(i) and 1910.137(b)(2)(ii), equipment used as primary insulation must pass a current test at the highest nominal voltage it will see, and the equipment current may not exceed 1 microampere per kilovolt of phase-to-phase applied voltage.

• This limit covers capacitive, conduction, and leakage currents and ensures insulation performance under AC excitation.
• The rule applies only to primary insulation (see Note 1 to paragraph (b)(2)).

Under 1910.137(c)(2)(ii), insulating equipment must be inspected for damage before each day's use and immediately after any incident that might have caused damage; insulating gloves must also receive an air test in addition to the visual inspection.

• Use ASTM F1236-96 for visual inspection methods as noted in the standard.
• Conducting the air test on gloves helps detect leaks not visible to the eye.

Under 1910.137(c)(2)(iii), insulating equipment may not be used if it has any of these defects: a hole, tear, puncture, or cut; ozone cutting or checking; an embedded foreign object; texture changes like swelling, softening, hardening, or becoming sticky or inelastic; or any other defect that damages insulating properties.

• Remove and test any suspect equipment per 1910.137(c)(2)(iv).

Under 1910.137(c)(2)(vii), protector gloves must be worn over insulating gloves except for limited-use exceptions: Class 0 gloves can be used without protectors under limited-use conditions for fine dexterity tasks, and Class 00 gloves may be used without protectors if voltage does not exceed 250 V AC (375 V DC) under limited-use conditions per 1910.137(c)(2)(vii)(A)–(B).

• If gloves are used without protectors, extra care must be taken during inspection as noted in the standard.
• Other classes may be used without protectors under strict conditions only if the employer demonstrates low possibility of physical damage and the glove used is one class higher than required per 1910.137(c)(2)(vii)(C).

Under 1910.137(c)(2)(vii)(D), insulating gloves that have been used without protector gloves may not be reused until they have been tested under the provisions of paragraphs (c)(2)(viii) and (c)(2)(ix).

• This means such gloves must undergo the periodic electrical test procedures and the reliable test methods specified in 1910.137(c)(2)(viii)–(ix).
• Keep records and markings showing retest dates per the certification requirements in 1910.137(c)(2)(xii).

Under 1910.137(c)(2)(viii) and Table I-5, rubber insulating gloves must be electrically tested before first issue and every 6 months thereafter; rubber insulating blankets must be tested before first issue and every 12 months thereafter. Repaired equipment must be retested per 1910.137(c)(2)(xi).

• Table I-5 in the standard lists the exact intervals for service items.
• Tests must be performed with methods that reliably indicate insulating capability as required by 1910.137(c)(2)(ix).

Under 1910.137(c)(2)(ix), the test method must reliably indicate whether the insulating equipment can withstand the voltages involved; the standard notes that ASTM standards such as ASTM D120 (gloves) and ASTM D178 (matting) are examples of acceptable methods.

• Use consensus ASTM procedures listed in the note, including ASTM D120-09 and ASTM F496-08 for gloves and sleeves.
• Ensure tests follow the test voltages and timing described in Table I-1 through Table I-4.

Under 1910.137(c)(2)(x), insulating equipment that fails inspections or tests may not be used by employees except in limited ways: line hose may be shortened by cutting off the defective part; blankets may be salvaged by severing defective areas if the remaining undamaged area meets size minimums; gloves and sleeves with minor defects may be patched with compatible material; and repaired items must be retested before reuse as required by 1910.137(c)(2)(xi).

• For Class 1–4 blankets the undamaged area must be at least 560 mm × 560 mm (22 × 22 in) per 1910.137(c)(2)(x)(B).
• Repairs must restore electrical and physical properties equal to the surrounding material per 1910.137(c)(2)(x)(C)–(D).

Under 1910.137(c)(2)(xii) employers must certify that equipment was tested in accordance with the listed paragraphs and identify the equipment and test date; these certifications must be made available to OSHA and employees or their representatives. The standard notes marking equipment and maintaining logs as acceptable ways to meet this requirement.

• Certification must identify which items passed and when the test was conducted per 1910.137(c)(2)(xii).
• Keep records of retests after repair or after use without protectors as required by the standard.

Under Table I-4, Class 2 rubber insulating equipment has a maximum use voltage of 17,000 V AC rms, a retest voltage of 20,000 V AC rms, and a retest DC average of 50,000 V per 1910.137(c) Table I-4.

• These values determine both safe working system voltages and the voltages used for periodic electrical retesting.

Under Table I-1, a Class 0 glove must withstand an AC proof-test voltage of 5,000 V rms. For a 410-mm (16-in) glove the maximum proof-test current allowed is 14 mA as shown in Table I-1 in 1910.137(c) Table I-1.

• Always confirm glove size and class markings per 1910.137(a)(1)(ii).

Under Table I-5, rubber insulating line hose and rubber insulating covers must be tested upon indication that their insulating value is suspect and after repair per 1910.137(c) Table I-5.

• There is no fixed periodic interval for line hose and covers in Table I-5—testing is condition-based or post-repair.
• Employers should inspect these items frequently and test immediately if damage or contamination is suspected as required by 1910.137(c)(2)(ii).

Under 1910.137(c)(2)(vi), insulating equipment must be stored to protect it from light, temperature extremes, excessive humidity, ozone, and other damaging substances and conditions.

• Keep items in a cool, dark, dry area away from ozone-generating equipment (like some motors) and chemicals that can degrade rubber.
• Follow manufacturer storage recommendations and rotate stock to prevent long-term degradation.

Under 1910.137(c)(2)(v), insulating equipment must be cleaned as needed to remove foreign substances because contaminants can reduce insulating properties and cause leakage or tracking.

• Clean according to manufacturer guidance and use compatible, non-degrading cleaners.
• After cleaning, reinspect and, if necessary, perform electrical tests before returning to service per 1910.137(c)(2)(ix).

Under the Note to paragraph (a), rubber insulating equipment meeting ASTM D120-09 for rubber insulating gloves and ASTM D178-01 (2010) for rubber insulating matting is deemed to comply with the performance requirements of paragraph (a) per 1910.137(a) Note.

• The Note lists other ASTM standards for various products and tests used to demonstrate compliance with 1910.137(a).
• Using items manufactured and tested to these ASTM standards simplifies demonstrating compliance.

Under 1910.137(c)(2)(x)(D), repairs to gloves are permitted only in the area between the wrist and the reinforced edge of the opening, and repaired areas must have electrical and physical properties equal to those of the surrounding material.

• Repairs must be done with compatible patches or liquid compounds that restore insulating integrity.
• After repair, the glove must be retested per 1910.137(c)(2)(xi).

Under the Note to paragraph (b), plastic guard equipment is deemed to conform to paragraph (b) if it meets and is used in accordance with ASTM F712-06 (2011), making it an acceptable option when the device satisfies that standard's test methods and specifications.

• Employers should ensure plastic guards are certified to ASTM F712-06 and are appropriate for the voltages and tasks involved.