Electrostatic is an unwelcome yet ubiquitous feature of many workplaces. The result of contact between two materials – one positively and the other negatively charged – transfer of static charge is all but unavoidable and responsible for a range of reactions from low-level irritation through to catastrophic outcomes.
Most people are familiar with minor shocks experienced when touching something metallic like a door handle. The likelihood of this increases in low humidity conditions and when the individual is wearing, walking on, or otherwise exposed to conducive materials. Though not necessarily pleasant, minor static shocks are generally benign. The stakes are higher in environments that incorporate sensitive electronic components or explosion hazards, where electrostatic build up and discharge can cause considerable harm to both workers and sensitive electronic equipment components.
There are two key spheres in which operations and safety managers aim to mitigate the adverse effects of static in the workplace;
- Electrostatic discharge (ESD) in and around sensitive electronic components and equipment and;
- Prevention of explosion from static discharge in volatile environments or applications, generally referred to as ATEX (ATmosphères Explosives)
WHAT IS ESD?
ESD stands for electrostatic discharge – the sudden flow of electricity between two electrically charged objects. It is caused by contact, an electrical short or dielectric breakdown (current flowing through an insulator). It is an issue in workplaces that incorporate sensitive electronic equipment and parts — this includes environments such as cleanrooms used in the production of electronics, nanotechnology, and semiconductors. Transfer of electrostatic charge to sensitive components damages the electrical characteristics and can cause equipment malfunction and failure.
Static poses significant problems in many or industries or workplaces but is especially detrimental in environments where delicate electronics are found.
How does ESD damage happen?
ESD damage is facilitated by transfer of electrostatic charge between an ESD-sensitive device and a human body or other ESD-sensitive device. For example, when a person walks on the floor, their body can become charged, and that charge is released when they touch a device. Equally, an ESD-sensitive device can become charged while on a conveyor belt or other processing surface and subsequently release this charge when it contacts another device or a human body.
Why is it an issue?
Beyond the immediate effects, failing to adequately control ESD can be expensive, especially in cleanroom environments used in the production of electronics, nanotechnology, and semiconductors. Damage to electronics caused by static charge can quickly increase manufacturing costs and lower production yields, potentially decreasing overall profitability.
How can it be avoided?
From a safety and operations perspective, employers will generally utilise personal protective equipment (PPE) designed to minimise any charge transfer between staff and ESD-sensitive equipment or components. In most cases, this will incorporate a hand protection solution. Utilising the correct glove will not only eliminate or minimise static, but also prevent contamination caused by particle attraction to the natural oils from a workers’ hands.
WHAT IS ATEX?
ATEX stands for ATmosphères Explosives. Uncontrolled electrical discharge in ATEX zones is even more problematic than ESD. ATEX environments feature risk of explosion due to the presence of flammable or otherwise volatile materials. Because ESD often manifests as a spark, it holds potential for extensive harm in these conditions. Applications defined under ATEX call for equipment, footwear and clothing that will not give rise to ESD which could lead to explosion.
Potentially explosive environments are governed by the ATEX Directive, which comprises two European Union directives; one of which focuses on equipment manufacturers and the other on equipment users. ATEX derives its name from the French title of the 94/9/EC directive and is the generally accepted term encompassing requirements for the safe design and use of products utilised in potentially explosive environments.
What are the explosive risks in an ATEX zone?
Solvent or dust concentration in an area may contribute to or create the risk of an explosion. Areas where such risks are present are therefore classified as an ‘ATEX zone’.
Examples of actions that present explosive risks may include the following;
• Handling over compounding tanks in fine chemistry or
• Sampling from solvent tanks
• Transferring flammable substances from a tanker lorry
• Cleaning with solvents
• Packing, filling hoppers or weighing powders
• Manufacturing explosive products
How can these risks be avoided?
In an ATEX zone, objects that charge and discharge static electricity may produce a spark and can therefore cause an explosion. Under the directive, any object that enters an ATEX zone must be designed, constructed and utilised in a manner that will not accumulate static electricity. This is referred to as ‘static dissipative’ or ‘conductive’ and often incorrectly as ‘antistatic’.
What are the requirements?
Workers in ATEX zones must wear clothing and footwear that ensures they are permanently earthed and therefore not able to discharge static electricity through movement. Both the ATEX and PPE Directives stipulate the use of hand protection solutions designed and constructed so that they will not give rise to electrostatic discharge. This requirement means opting for protective gloves that meet with the EN16350 standard and are designed specifically for ATEX applications, incorporating conductive yarns in the textile liner and conductive fillers in the elastomer compound. General or chemical protective gloves constructed from neoprene or nitrile are not a suitable alternative for this type of application.
HOW CAN WORKERS STAY SAFE?
As with any PPE selection process, there are additional factors that influence identification of the ultimate protective glove choice. These factors may include the presence of secondary hazards, such as risk of cut injury or chemical exposure.
To overcome the confusion consider using a service like AnsellGUARDIAN®, a personalised assessment that matches glove materials and choices to your specific application and environment, removing the guesswork and ensuring optimum worker safety.
Contact Us to ask for a personalised AnsellGUARDIAN® Safety Assessment here.