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Electrical Safety Gloves: Inspection and Classification

Quick Tips #262

Rubber insulating gloves are among the most important articles of personal protection for electrical workers. To be effective, electrical safety gloves must incorporate high dielectric and physical strength, along with flexibility and durability. To help ensure safety and performance, they should meet and/or exceed the requirements of ASTM D120-14a – Standard Specification for Rubber Insulating Gloves. Gloves should also be electrically tested following ASTM D120-14a and International Standard IEC 60903:2014.

Glove System

A glove system consists of:

Rubber insulating gloves – Classified by the level of voltage and protection they provide.

Liner gloves – Reduce the discomfort of wearing rubber insulating gloves. Liners provide warmth in cold weather and absorb perspiration in the warm months. They can have a straight cuff or knit wrist.

Leather protector gloves – Worn over rubber insulating gloves to help provide the mechanical protection needed against cuts, abrasions and punctures.


Employees who work in close proximity to live electrical current may require a variety of electrically insulating protective equipment. The Occupational Safety and Health Administration (OSHA) outlines this in its electrical protective equipment standard 29 Code of Federal Regulations (CFR) 1910.137, which provides the design requirements and in-service care and use requirements for electrical insulating gloves and sleeves as well as insulating blankets, matting, covers and line hoses.

Electrical safety gloves are categorized by the level of voltage protection they provide and whether or not they’re resistant to ozone.

Class of Equipment Maximum Use Voltage (AC) Proof Tested
Proof Tested
00 500 2,500 10,000
0 1,000 5,000 20,000
1 7,500 10,000 40,000
2 17,000 20,000 50,000
3 26,500 30,000 60,000
4 36,000 40,000 70,000

Rubber is susceptible to the effects of the ozone, which can cause cracking and compromise the integrity of the glove. If the gloves are used in an environment where the levels of ozone are high due to pollution, ozone resistance is critical. Ozone resistance is covered by the “Type” designation. A Type I glove is not ozone-resistant; Type II is ozone-resistant.


Once the electrical safety gloves have been issued, OSHA requires that “protective equipment be maintained in a safe, reliable condition.” This requires that the gloves be inspected for any damage before each day’s use. Gloves must also be inspected immediately following any incident that may have caused damage. OSHA also requires that insulating gloves be given an air test along with the inspection.

The air testing method is described in ASTM F496-14a Standard Specification for in-Service Care of Insulating Gloves and Sleeves. The glove is filled with air, either manually or with a powered inflator, and then checked for leakage. The leakage is detected by listening for escaping air or by holding the glove against the tester’s cheek to feel air releasing. In accordance with ASTM F496-14a, gloves and sleeves should be expanded no more than 1.5 times their normal size for Type I, and 1.25 times normal for Type II during the air test. The procedure should then be repeated with the glove turned inside out.

Since sleeves cannot be inflated, they should be inspected along the edge as they are rolled. Rolling will stretch the sleeve along the edge, making cuts, tears and ozone cutting more visible. After the outside of the sleeve is inspected, the procedure should also be repeated with the sleeve turned inside out.

Before each use, gloves and sleeves should be inspected for holes; rips or tears; ozone, cutting or ultraviolet damage; and signs of chemical deterioration per ASTM F1236-14, Standard Guide for Visual Inspection of Electrical Protective Rubber Products. Gloves and sleeves should also be examined to determine if they show any damage as a result of chemical contamination, particularly from petroleum products. The first sign of chemical exposure is swelling in the area of contamination. Should any glove or sleeve be exposed to chemical contaminants or suspected of any other physical damage, they should be retested per ASTM D120-14a requirements.


In addition to the daily inspection, OSHA requires electrical safety equipment to be subjected to periodic electrical tests as specified in 29 CFR 1910.137(c)(2)(viii). Rubber insulating gloves must be tested before first issue and every six months thereafter; upon indication that the insulating value is suspect; after repair; and after use without protectors. If the insulating gloves have been electrically tested but not issued for service, they may not be placed into service unless they have been electrically tested within the previous 12 months.

An alternating glove color program is suggested to help ensure all gloves in use are in the proper test cycle. This program creates a visual reminder of the proper test cycle by using one color for the first six months and a different color for the following six months.


To help ensure the integrity of the gloves and worker safety, gloves need to be stored properly when not in use. Proper storage means that gloves must not be folded and need to be kept out of excessive heat, sunlight, humidity, ozone and any chemical or substance that could damage the rubber.

Commonly Asked Questions

Q: Can I just use the rubber glove only, and not buy the leather part? A: A leather protective glove should always be worn over rubber insulating gloves to provide the needed mechanical protection against cuts, abrasions, and punctures.

Q: Would retesting be needed if I don't use the electrical safety gloves very often and visually see no damage? A: Yes. Retesting is still needed to help verify the integrity of the material and to ensure electrical safety is maintained for the user.

Q: If I find a hole, can I just "patch it," like a tire inner tube? A: Per 1910.137(c)(2)(x)(D), “Rubber insulating gloves and sleeves with minor physical defects, such as small cuts, tears, or punctures, may be repaired by the application of a compatible patch. Also, rubber insulating gloves and sleeves with minor surface blemishes may be repaired with a compatible liquid compound. The repaired area shall have electrical and physical properties equal to those of the surrounding material. Repairs to gloves are permitted only in the area between the wrist and the reinforced edge of the opening.” Repaired insulating equipment must be retested before it can be used.


To view a copy of the OSHA standard, visit 29 CFR 1910.137

The ASTM standards can be purchased at

North American Independent Laboratories for Protective Equipment Testing (NAIL for PET):

NAIL Accredited Laboratories. (Find by State):

OSHA 29 CFR 1910.137(b)(2)(iii)(B)a: Ozone cutting or ozone checking (the cutting action produced by ozone on rubber under mechanical stress into a series of interlacing cracks).

International Standard IEC 60903:2014

(Rev. 7/2015)

Find even more information you can use to help make informed decisions about the regulatory issues you face in your workplace every day. View all Quick Tips Technical Resources at

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Please Note:
The content in this newsletter is intended for general information purposes only. This publication is not a substitute for review of the applicable government regulations and standards, and should not be construed as legal advice or opinion. Readers with specific compliance questions should refer to the cited regulation or consult with an attorney.

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