There are a number of requirements and regulations which all organisations must conform to including the Health and Safety at Work Act of 1974, Electricity at Work Regulations of 1989, Provision and Use of Work Equipment regulations of 1998 and the Management of Health and Safety at Work regulations of 1999.
In summary, these laws, enforceable by the HSE, require that an organisation takes reasonable steps to protect the health, safety and wellbeing of its employees, customers and visitors.
This includes properly maintaining, inspecting and testing any electrical equipment.
Whilst there is no law that states appliances require Portable Appliance Testing (PAT testing) per se, completing PAT testing is the easiest way for an organisation to prove compliance with these above legal requirements and regulations.
PAT testing is conducted on all electrical items which are plugged in (i.e. not hardwired into the building's electrical circuits) even if they are heavy and not really portable – such as vending machines, printers and even plant machinery.
PAT testing checks for faults which are potentially dangerous, such as failed insulation, perhaps from damage to power leads resulting in exposed live wires, over-heating caused by incorrect or faulty fuses (which happens alarmingly regularly) and which can lead to internal parts melting and causing short circuits or fires.
Damage can occur to portable appliances even when they aren't used, with dust and dirt building up internally. Equally, regular usage invariably results in physical damage as well as wear and tear.
Once PAT testing is completed but a reputable specialist, you will receive a comprehensive report, listing all of your portable appliance assets, cross referenced with a barcode reference and test-results proving that they are operating safely. You should keep this report in order to provide evidence of compliance with the above legislation.
In addition to testing for safety using specially designed PAT testing equipment, all workplaces should encourage regular visual inspections which can be carried out by the appliance user. A system or process should be in place to enable all employees to report observed damages to the most appropriate person and keep a record of such reports.