For automatic powder coating installations, explosive atmospheres may occur during operation. Due to this the user should ensure that:

• Areas where hazardous explosive atmospheres may occur are classified into zones based on their likelihood and persistence.
• Areas classified into zones are protected from sources of ignition by selecting equipment and protective systems meeting the requirements of the Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations 1996, although equipment already in use before 1 July 2003 can continue to be used indefinitely provided the risk assessment shows it is safe to do so;
• Where necessary, areas classified into zones are marked with a specified "EX" sign at their points of entry;
• Where employees work in zoned areas they are provided with appropriate clothing that does not create a risk of an electrostatic discharge igniting the explosive atmosphere;
• Before coming into operation for the first time, areas where explosive atmospheres may be present are confirmed as being safe (verified) by a person (or organisation) competent in the field of explosion protection. The person carrying out the verification must be competent to consider the particular risks at the workplace and the adequacy of control and other measures put in place.

Guidance on the classification and zoning of areas where potentially explosive atmospheres may occur, and the selection of equipment for use in those areas can be found from the HSE here and also here.