Mexican Official Standard NOM-118-STPS-1995, Rubber gloves for electrical use.
ASTM F496-20 governs the manufacture, testing and use of dielectric gloves for electrical protection. The standard includes detailed procedures for evaluating the effectiveness of gloves in high-voltage situations.
Dielectric glove testing is essential to ensure that gloves designed to protect workers from electrical hazards maintain their insulating capability under electrical stress.
Electrical Withstand Test (High-Voltage Test)
1. Objective: Verify the ability of the gloves to withstand electrical voltages without failing or allowing current to pass.
2. Procedure: The gloves must be subjected to a high-voltage test in which a voltage much higher than the glove’s protection level is applied.
The test consists of applying this voltage under controlled conditions and making sure that the glove shows no current leakage or visible defects during the process.
This voltage must be applied for a specific period to make sure the glove maintains its insulation.
High-voltage gloves are tested at voltages that vary according to the glove class (Class 00, 0, 1, 2, 3 or 4).
3. Result: If the glove shows signs of electrical failure or allows current to pass through it, it does not meet the standard and must be discarded.
The gloves must withstand the applied voltage without allowing current to flow, which indicates that their insulation is still effective.
Example test voltages:
- Class 00 (500 V working voltage, 2,500 V proof test)
- Class 0 (1,000 V working voltage, 5,000 V proof test)
- Class 1 (7,500 V working voltage, 10,000 V proof test)
- Class 2 (17,000 V working voltage, 20,000 V proof test)
- Class 3 (26,500 V working voltage, 30,000 V proof test)
- Class 4 (36,000 V working voltage, 40,000 V proof test)
Test Frequency
- New gloves: They must be tested before initial use.
- Gloves in use: Periodic tests must be performed depending on local regulations or frequency of use. It is generally recommended to test every 6 months or whenever there is suspicion that the glove has been exposed to adverse conditions (for example, impacts, cuts or exposure to chemicals).
- Visual inspection: Must be performed before each use to make sure there is no visible damage.
Electrical Tests
Gloves in use, according to Mexican Official Standard NOM-118-STPS-1995, must be electrically tested under the following criteria:
- Gloves in storage and not in use must be tested at least every 12 months.
- Gloves in use, at least every 6 months.
In summary, dielectric glove testing is crucial for safety in work with electrical hazards, and must be performed in accordance with specific standards to ensure its effectiveness.
