I get a steady trickle of emails from all over the world from people suffering from static shocks. For some it can seemingly become a real problem. For example, getting a shock every time you touch someone can be a problem for personal relationships! I used to get so many of these emails that I wrote my on-line article "Static shocks, and how to avoid them ". This seems to help many people and attracts many visitors to our web site.
There are many possible factors and so it is not possible to say for sure what causes shocks in any particular situation without doing a first-hand analysis. However two factors are very commonly important - shoes and floor materials. Over the last 50 years or so big changes have happened in these materials - nowadays floor materials and the soles of shoes are often made from insulating materials - often plastics.
The strange thing is that not all shoes and floors give the same charge build-up problems even if they are equally highly insulating. Why should this be? The answer lies in the charge generation characteristics of the particular combination of materials. Some materials generate much more charge when rubbed together than others do. The charge build-up is the balance of charge generation rate and charge dissipation rate - if the charge is generated much more quickly than it can escape, static charge build-up occurs. If it is generated less quickly than it can escape, no build-up of static electricity is found.
A dissipative materials is one which allows the charge to escape slowly, within a few seconds. If manufacturers of shoes and flooring always made their products out of dissipative, rather than insulating materials, we would suffer far less static shocks than we do now.