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 dielectric properties and physical strength, along with flexibility and durability. To help ensure safety and performance, they should meet and/or exceed the requirements of the ASTM International ASTM D120-14a – Standard Specification for Rubber Insulating Gloves. Gloves should also be electrically tested following ASTM D120-14a and the International Electrotechnical Commission IEC 60903:2014 standard.

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. Ozone cutting/checking is a series of interlacing cracks produced by the action of ozone on rubber under mechanical stress. 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 for air that is escaping. 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/check 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: 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: 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. However there are some exceptions highlighted in OSHA’s electrical protective equipment standard 1910.137 (c ) 2 (vii) (A) – (C). If the voltage is 250 volts AC, or 375 volts DC, protector gloves need not be used with Class 00 gloves, under limited-use conditions, when small equipment and parts manipulation necessitate unusually high finger dexterity. It also states that protectors need not be used with Class 0 gloves under the same limited-use conditions. Persons inspecting rubber insulating gloves used without protectors need to take extra care when visually examining them. Employees using rubber insulating gloves under these conditions need to take additional caution when handling sharp objects that could nick or cut the glove. Any other class of gloves may be used without protector gloves, under the same limited-use conditions if the class of gloves is one class higher than that required for the voltage involved. Rubber insulating gloves that have been used without protector gloves may not be reused until they have been retested.

Q: How do I size my leather protector that is worn over my rubber insulating glove? A: It is suggested to select the same size leather protector as the rubber insulating glove. For length, the insulating glove cuff must be longer than the leather protector glove and the distance is specified by class. Use the following guidelines:

Class 0, 00 Gloves -1/2"
Class 1 - 1"
Class 2 - 2"
Class 3 - 3"
Class 4 - 4"

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): International Standard IEC 60903:2014

International Standard IEC 60903:2014

(Rev. 11/2016)

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 information contained in this publication is intended for general information purposes only and is based on information available as of the initial date of publication. No representation is made that the information or references are complete or remain current. This publication is not a substitute for review of the current applicable government regulations and standards specific to your location and business activity, and should not be construed as legal advice or opinion. Readers with specific questions should refer to the applicable standards or consult with an attorney.

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