Why static charge builds up on people

Charge can often build-up on people and reach levels that give uncomfortable shocks, can damage sensitive electronic parts or give fire risks when handling solvents and other flammable materials. Dry air humidity encourages static charge build-up, and under dry external conditions the atmosphere in a building can become even drier. Electrostatic charge build-up can be far worse under these conditions. In the UK the worst case is often in winter (January to March) when cold and dry external air is warmed and brought into the building leading to very dry internal atmospheric conditions.