There is NO legal requiremet to PA-test anything,,,ever!

Lots of guidance out there re frequency, what to PATest etc. Low voltage stuff would just be subject to a pre plug in check!

Save yourself some money and push for and encourage pre use checks!

Holmezy

If it has a plastic earth pin it does not have an earth and is in all likelihood double insulated as the folks above have said. Double insulation symbol is a wee square in a big square.

Therefore the two electrical tests normally undertaking during In-Service Inspection and Testing (what everyone calls PAT), earth continuity and insulation resistance, cannot be done as
a) there is no earth and
b) the casing and two more layers of insulation surround the conducting parts, these would have to be broken in order to make a contact and take a subsequent reading

If you want to, you can test it to probable destruction with a 3570 Volt dielectric strength test for double insulated products but as Harry Enfield's character used to say "You don't wanna do that!"

JohnJ and holmezy are on the money, pre use visual checks.

This May help
http://www.hse.gov.uk/pubns/indg231.htm

Regards Dave