Touch safe office equipment testing

[Dave A]

I've got a client that seeks regular testing of their electric/electronic office equipment to ensure it is touch-safe (no or limited risk of electrical shock).

My questions are:
What would be the appropriate tests for this?
Are there relevant standards that need to be met?

I've got a sneaking suspicion that testing for continuity of something like the equipemt's metal chassis back to the main earth point of the installation isn't always going to help, and testing for earth-to-touchable-metals voltage might not always be reliable either.

Any thoughts?