Posted By Ron Hunter
The detail on this (for MEWPs) is contained in a British Standard Code of Practice = BS8460.

There are some extracts at the IPAF website.

or Goggle "MEWP British Standard".

Hope this helps.

Posted By Dave Merchant
No. For a start there's no specific "law" on MEWPS - they fall under the general requirements of the WAHR, PUWER and LOLER but none of these makes any ruling on staff numbers. They simply say operators must be competent, the equipment must be maintained in a safe and legal condition, and the risks should be managed.

There are hundreds of MEWP designs that need two or more operators, and there are hundreds that don't - it would be impossible for a law to apply across the board. The 'second operator' concept is usually proposed as an emergency and security system (they can help if the operator is trapped or injured, plus they can stop children stealing the keys while you're up there) but they aren't "operating" the equipment so on a secure site with other workers in the area there'd be no particular need for a dedicated person.

Posted By Dave Wilson
Look here may give you some pointers

http://www.hse.gov.uk/pubns/misc614.pdf