Antistatic materials, ESD control and electrical insulation: key differences

Understanding the differences helps you select appropriate product-protection measures and personal protective equipment for the assessed hazards.

What do these terms mean, when do they matter, and how should protection be selected?

1. Antistatic materials

Antistatic describes behaviour that limits charge generation or accumulation. It does not mean that a material can never become charged.

Contact and separation of materials, including clothing, the body and chair upholstery, can generate electrostatic charge.

Charge accumulation must be controlled through suitable materials, bonding, grounding and other measures. Dissipation should follow a controlled path; simply discharging as fast as possible is not the objective. Removing a sweater is a familiar example of charge generation and discharge.

A discharge spark can ignite a flammable atmosphere if the conditions are suitable. Controls must be selected through an assessment of the actual fire and explosion hazards.

Controlling static-related fire and explosion risks

• Select protective clothing suitable for the assessed hazard and applicable requirements, such as EN 1149-5 where relevant. Conductive fibres or treatments can support charge dissipation when the complete clothing and grounding system is used correctly.
• Select suitable footwear and verify its markings, electrical properties and intended conditions of use. An antistatic designation alone does not establish suitability for every explosive atmosphere or for protection against electric shock.
• Where electronic equipment is used in a hazardous atmosphere, verify the appropriate equipment protection and approval for that area; do not treat an ATEX designation as a general synonym for antistatic PPE.

2. ESD: electrostatic discharge

Distinguish the following terms:

• ESDS: an electrostatic-discharge-sensitive device or item.
• ESD: electrostatic discharge, the transfer of charge between objects at different electrical potentials.

ESD is an event; an ESDS item is something that can be damaged by that event. The terms are not interchangeable.

ESD control limits charge generation and potential differences using suitable materials, bonding, grounding and, where needed, ionisation.

ESD product protection does not automatically provide protection against electric shock. Equipment intended as PPE must separately meet the requirements for the hazards faced by the wearer.

For example, even a discharge too small for a person to notice can damage sensitive microelectronic components.

Protecting ESD-sensitive items

• Select and use ESD garments as part of the applicable programme, such as ANSI/ESD S20.20 or IEC 61340-5-1. Verify the garment’s electrical properties and its intended grounding arrangement.
• The original article cites a footwear resistance value below 1.0 × 10⁹ ohms. Do not use that isolated value as the complete acceptance criterion: verify the person-footwear-flooring system and the applicable test requirements.
• ESD glove test methods do exist, including ANSI/ESD SP15.1. Select and test gloves for their actual use; antistatic PPE requirements and ESD product-protection requirements are not interchangeable.

3. Electrical insulation

An insulating material strongly resists current flow and charge movement. Electrical insulation used for personnel protection must be designed, rated and maintained for the relevant electrical hazard.

Before electrical work, isolate the supply, secure it against reconnection and verify that it is de-energised using an appropriate procedure. Work near or on live parts requires competent personnel, a specific risk assessment and suitable controls; putting on insulating PPE is not a substitute for isolation.

An electrician may use electrically rated mats, footwear and other protective equipment as specified by the work procedure. Ordinary rubber products must not be assumed to provide electrical protection.

Protecting people against electric shock

• Select a helmet explicitly rated for the electrical hazard and follow its standard, markings and manufacturer’s limits. Do not infer a universal working-voltage rating from a marking quoted without context.
• Select insulating gloves of the correct class and voltage rating, inspect them and perform the specified periodic tests. Thickness alone does not establish electrical protection.
• Select electrically insulating footwear rated for the task and its environment. Verify the complete product, applicable standard, AC/DC working limits, condition and manufacturer’s instructions; ESD or antistatic footwear is not a substitute.

Conclusion

The three concepts serve different purposes:

• Antistatic measures limit charge generation or accumulation and, with suitable grounding and other controls, help manage discharge risks.
• ESD control protects sensitive products by controlling electrostatic charge and potential differences. ESD itself is the discharge event.
• Electrical insulation resists current flow. Properly rated insulating protective equipment forms one part of an electrical-safety system.

EOS/ESD Association - basic control procedures and materials

HSE - electrical safety guidance

EOS/ESD Association - glove test method SP15.1

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ESD smock testing procedure

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ESD S20.20 electrostatic-discharge control training at Goertek Vina