What can be done to allow the safe dispersal of static charges (ESD)?
The two main types of danger from ESD are areas that contain (albeit only occasional or briefly) explosive vapours (eg. hospital operating areas or chemical laboratories) or areas containing electronic equipment (eg. computer rooms, control rooms etc.). Such rooms should have conductive floors installed so that the charges on people or trolleys can be dispersed.
Specific work areas on benches etc. should have conductive mats installed. These are directly connected to earth. If the floors are adequately conductive, then as we move around, the static charges are constantly dispersed and do not build up to dangerous levels. Most conductive floors are made with either copper sheet or strip under conductive PVC or other plastic sheeting, which allows for adequately fast, but not surging, dispersal.
We offer conductive (commonly known as “anti-static”) non-marking wheels in 75mm (3″), 100mm (4″) and 125mm (5″) diameters that can be assembled into our M series castors. These wheels are designed for use in ESD (Electrostatic Discharge) environments as part of an effective ESD Control Program.
Our wheels have conductivity of <106 (exceeding the requirement of ANSI/ESD S20.20-1999 for Mobile Equipment in Protected Areas – which nominates 109 as the maximum level of resistance).
When used with plastic expanding adaptors (codes ER/ES – see Fitting Options) provisions for electrical continuity between the castor and trolley will be required.
Further technical notes follow. These notes are summaries of complex matters originally prepared as background material for the internal use of Fallshaw staff. In allowing others to access them without charge we assume no legal liability.