I think the standard you are looking for is b56.1 either asme (American Socity of Mechanical Engineers, or the much more current (and in my opinion, friendly, but I am prejudiced) ITSDF (Industrial Truck Standards Development Foundation) go to ITSDF.org to download the standards for free.
it may also be that you are really considering an aerial lift, such as a boom lift or scissor lift, and those standards are somewhat different, and covered under ANSI A92.6 and SIA (Scaffold industry Association). the dividing line is; does the machine also have to "move goods and material", or -just- personnel?