Machinery that is imported into the USA and/or put into service there is subject to complex specifications that may vary depending on the state or region. Compliance with the testing standards of OSHA (Occupational Safety and Health Administration) or UL is a mandatory requirement for market approval, for example. This applies to new, used and modified or expanded machinery.
So if you sell machinery in the USA as a manufacturer, you must take care that all specifications are already met in the design phase in order to ensure that the process for obtaining an operating permit at the machinery installation site runs smoothly.
Operators of machinery in the USA are in turn obliged to ensure that work on the machinery is safe. This includes creating a LoTo system, among other things.