Hello Lawtons,
Here in the UK, and the EU, we have the PUWER regulations.
Google these.
Of particular interest to you would be BSEN 60204 / IEC 60204 - Safety of Machinery - Electrical equipment of machines.
A manufacturer, Pilz, also produces a useful guide book.
Hope this points you in...
Hello dms074s,
Successfully used forklift and floor scales for warehousing applications.
Major source of errors is inconsistent pallet or container weight.
Focus on sorting tare consistency and regular reference checks.