PAT Failure Rates
9th July 2010
Test instrument manufacturer Seaward has carried out some research into actual appliance failure rates detected during routine in-service electrical safety testing.
The results of an extensive survey of over 80,000 PAT tests, performed by both in-house test engineers and contract test companies across a wide range of industry sectors, showed an average appliance failure rate of 1.4% - indicating that the presence of over 1,100 potentially dangerous appliances in the sample would not have been discovered if inspection and testing had not been carried out.
The type of failures recorded in premises including offices, schools, universities and factories range from damaged mains cords and enclosures or casings to exposed moving parts and failed earth continuity or insulation resistance tests.
Within different sectors the results also confirmed the presence of different levels of risk associated with the type of equipment being used, their patterns of use and the particular working environment.
For example, in a series of tests carried out in local authority, housing association and professional services offices, an average appliance failure rate of 0.7% supports the notion that administrative areas are relatively low risk areas. However, between individual organisations the failure rate ranges from 1.5% to as low as 0.3%.
In industrial environments such as engineering and manufacturing premises the failure rates were much higher at an average of 7.4%, reflecting the damage and mishandling often associated with power tools and other moveable electrical equipment. However in one engineering business test engineers discovered 38 total fails out of 158 appliances tested – a failure rate of over 24%.
Between these two relatively low and high risk environments, a review of tests undertaken in a range of education establishments returned an average failure rate of 1.7% - again with some variation from as high as 3.3% to as low as 0.5%.
Other figures also show the causal effects of faulty portable electrical appliances in fires. According to the official Fire Statistics UK, the fire services attended 136,000 accidental fires in non-residential dwellings in the period 2000 to 2005. The main cause of these fires was faulty appliances and leads which were responsible for 30% (38,100) of the total.
During this same period the Fire Protection Association reported that there were 346 reported fire losses which were electrical in origin in premises excluding dwellings. The reported losses from these fires totalled over £178m – with an average loss per incident of £50,000.
Rod Taylor, managing director of Seaward, said: “The recently announced Government review of health and safety regulations has prompted some to raise concerns over the level of inspection and testing carried out in certain premises.
“These figures show beyond any doubt the extent to which damaged and faulty electrical appliances both pose a danger to users and are also a potential cause of damaging fires.
“Although at first sight the percentages may appear to be low, the true potential impact can be gauged from the massive number of appliances and electrical items used in everyday workplaces.
“These figures prove beyond doubt that periodic inspection and testing identifies many situations where defective equipment could have caused electrocution or fire.
“Clearly the preventative measures to be adopted need to be in proportion to the risk, but in the majority of cases the costs of adopting sensible inspection and testing regimes are lower than those involved with other forms of risk assessment.”
To help those responsible for maintaining safety in the workplace, Seaward has introduced a free new booklet which is also being supported by a series of seminars.
‘A Common Sense Approach to Electrical Safety in the Workplace’, describes the importance of implementing inspection and testing measures that are appropriate to the particular working environment and which are in keeping with the specific risks posed.