If your reference is to industrial lift trucks or machinery that requires Falling Object Protective Structures (FOPS) or ROPS (Roll-over), possession of the standard is only of use if you are manufacturing FOPS / ROPS to the standard, or are inspecting frames that have been involved in an event to ascertain whether damage may have occurred to the frame (FOPS / ROPS). Typically, repair of damaged safety frames is not acceptable, and full replacements are required, along with re-certification. In any event a suitably competent and Certified Engineer would need to "sign-off certification that the device meets the standard(s), and such individuals are in short supply in NZ. Certification of safety frames should be visible in the form of a plate fixed to the structure, and specifying the standards it complies with.
A machine owner needs to take practicable steps to assess whether the frame attached to a machine is in original condition, is undamaged, and complies with the standard. Getting a suspect frame inspected by a suitably competent engineer is a practicable first step to take when there is doubt.
Possessing applicable conformance standards for all the plant a business owns / uses isn't, of itself, a necessary investment.