In OSHA 29 CFR 1910.178 there is NO requirement that the operator carry an ID badge or card. However, the EMPLOYER is required to keep certain records that are specified in 1910.178 (l): the section on operator training.
There are other good "non-regulatory" reasons for providing the operator with his or her personal credentials though. Especially, if there is a rigorous test during which the operator has to demonstrate valid, work-related skills, the credential(s) tend to have real meaning to those taking their safe and productive skills seriously. Some employers set the pace for such seriousness by subscribing to forklift safety services that will produce and track the credentials for them. Beware though, if you subscribe to such a service, you are best served to use them only if they bring to you a rigorous set of standards for earning the credentials...and you actually want to use such standards that usually go way beyond simple regulatory compliance.
Best wishes,
Joe
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