PPE for Electrical Safety. Anti-static, Electrostatic or Insulating?
February 11, 2020
Electricity is a commodity in our modern life. Some people work with electricity directly – engineers, electricians, electronic technicians, to mention a few. And others work with it indirectly.
Approximately 350 electrical-related deaths occur on the job in the US, every year, according to OSHA. Therefore, choosing the right electrical safety protection is crucial. And making the right choice starts with understanding the risks.
Find out how to choose the right electrical safety equipment for your workers.
What is static electricity
It is a phenomenon that is commonly produced both in a natural environment and in industrial facilities. Static energy charges appear due to physical or chemical changes, or processes of dynamic nature, and can be a direct effect of our activity.
Static charges are regularly produced by the friction of your clothes with another surface when you move – your body, garments or the upholstery of a chair. You have certainly experienced static charge in your every-day life when taking off your sweater by pulling it over your head.
In a working environment, the accumulation of these charges can be dangerous, as a potential discharge may cause sparks, which can be life-threatening in explosion-risk areas. They can cause lots of different disturbances: fire explosions, technological disturbances of the production processes or disruptions in the functioning of the equipment.
Static discharge explosions
All potential sources of ignition should be eliminated in explosive atmospheres following electrical safety procedures. Personal protective equipment (PPE) such as industrial safety helmets, eye and face protection or footwear may be a cause of dangerous spark discharges themselves, thus, a source of ignition.
Therefore, PPE for electrical safety, verified in terms of electrostatic properties, should be used in areas of explosion risk. Very special attention should be paid to the materials the electrical safety PPE is made of and if they can be subject to dangerous charges with static electricity. Secondly, electrical safety PPE should be verified if when being put on and off, they can cause dangerous static electricity.
Antistatic work shoes reduce the amount of static electricity accumulated from walking by dissipating static electricity from the body to the ground, thus minimizing the chance of ignition from a static electric spark. They need to have a low electrical resistance between 0.1 and 1000 MegaOhm (MΩ).
The antistatic and ESD features of electrical safety PPE are based on conductivity. They protect by dispersing electrical charges to the ground, preventing a static shock, charge or spark. They are opposite to electrical insulating materials, which protect you from completing an electrical circuit to the ground.
When working with objects that cannot be disconnected from the source of electricity, employees must wear electrical insulation clothing and equipment.
Electrical insulating equipment is made of materials that block the transmission of charges, thus no electricity can go through the material.
Rubber is probably the most commonly used insulator. Putting it in the soles of boots or gloves is the most commonly used way to implement insulators into clothing. Check out our rubber gloves and sleeves.
High resistance electrical insulation clothing is also necessary, especially since a perfect insulator does not exist. Even insulators contain small numbers of mobile charges which can carry current. Clothes made of metal or carbon fibers allow charges to dissipate.
What is an electrostatic discharge (ESD)?
Materials with low electrical conductivity and conductive objects isolated from the ground are subject to accumulating electrostatic charges due to static electricity. Electrostatic discharges (ESD) are created because of an excess of electrical charges.
ESD can cause harmful effects in industrial environments, including explosions in gas, fuel vapor and coal dust, as well as a failure of solid-state electronics components such as integrated circuits. These can suffer permanent damage when exposed to high voltages.
Electronics manufacturers, therefore, establish electrostatic protective areas free of static electricity, using measures to prevent charging. These include avoiding highly charging materials, providing workers antistatic clothing and footwear and controlling humidity.
ESD protection basics
Like antistatic equipment, ESD also aims to dissipate charges as quickly as possible to prevent static discharges. However, ESD protection refers to securing a product or a production process, rather than a person. Therefore, ESD products are not considered PPE.
Safety tips to protect against ESD
1. Choose clothes made of antistatic fibers to stop the accumulation of charges. Thus, you will prevent electrostatic discharge.
2. Wear ESD shoes. Just like antistatic safety shoes, they are conductive safety shoes. ESD shoes protect electrical equipment by conducting electrical charges to the ground, preventing a static shock, charge or spark. ESD safety shoes have an even lower electrical resistance than antistatic shoes, between 0.1 and 100 MegaOhm (MΩ).
3. ESD gloves are designed for use in particle sensitive and low-contaminate environments, protecting workers and the environment around them.
General best practices for electrical safety
Wear a hard hat in working areas where there is the risk of exposure to electrical conductors that can potentially contact the head. Class E hard hats are designed to reduce exposure to high voltage conductors and offer protection up to 20,000 volts.
Insulating rubber gloves are among the most important articles of personal protection for electrical workers. Insulating gloves and sleeves must be rated for the voltage to which a worker will be exposed and marked to indicate their rating [class 00 – resistance up to 500 V alternating current (AC)/proof tested to 2,500 V AC and 10,000 V direct current (DC) – through class 4 – resistance up to 36,000 V AC/proof tested to 40,000 V AC and 70,000 V DC].
Use protective footwear when your feet are exposed to electrical hazards. Insulating boots or dielectric boots prevent charges from passing through your body to the earth. Electrical safety shoes are manufactured with non-conductive electrical shock resistant soles and heels. The resistance of dielectric boots is also tested – class 00 has resistance up to 500 V AC or 750 DC; class 0 has resistance up to 1000 V AC or 1500 V DC. The highest certified level of electrical protection, electrically insulating class 4 boots, protects up to a maximum working voltage of 36000V.
There are big as well as subtle differences between the three types of electrical safety materials discussed. In a nutshell, antistatic materials protect you against sparks and explosions, while ESD materials protect your sensitive equipment, and insulating or dialectical materials protect you against electrical shocks.