Ground-up rules

Graham Lewis, Corporate Key Accounts Manager – Colorex, from Forbo Flooring Systems takes a closer look at Electro Static Discharge (ESD) flooring in controlled environments.

With ever-increasing numbers of sensitive electrical items in the workplace, static discharge is becoming more of a problem, as it can cause damage to expensive and in some cases life saving equipment.

Natural phenomenon

Static electric discharge is a natural phenomenon and occurs between two surfaces, particularly when they are pulled apart. This transfer of electrostatic charge between two objects of different polarity is known as a triboelectric charge.

Most people can feel a static discharge of about 3,000 V; however, some electronic components can be damaged at only 100 V. A magnetic reader strip, for example, can be damaged at 20 V or less.

Consequently, there are standards regulating the performance of conductive floors in cleanrooms and associated controlled environments found in several industrial sectors, such as semiconductor manufacturing, pharmaceuticals and life sciences.

Reducing the generation of electrostatic charges is the main scope of comprehensive control measures in ESD protected areas (EPA) and the right floorcovering plays a crucial role here. It not only drains electrostatic charges from personnel and equipment, but it also reduces the generation of charges where they occur, at the interface between the shoe soles and the floor.

Potential damage

The possible consequences of ESD impact can be varied, but can result in anything from damage to or destruction of electronic components, silicon wafers, flat screen substrates, data loss on magnetic data carriers, memory errors, malfunctions, lock-ups, failures on equipment, at the most extreme, fire and explosions.

The applicable tests for ESD measurement are EN1081 and IEC61340-4-1. These two tests describe how to measure an electrical charge, and performance levels and requirements for EPA areas are regulated by IEC 61340-5-1.

ESD is a complex and demanding design consideration for engineers to contend with for the technical application of flooring in a cleanroom environment. For further assistance please visit Forbo Flooring Systems www.forbo-flooring.co.uk/colorex