Don, that's a good question- and I can hardly accept the answers I've received either!

OSHA specifically requires a dedicated lock for lock-out duty, specifically so employees will NOT use the locks for their toolboxes. It was explained to me that this was to prevent a departing employee from removing the lock, and leaving an unsafe condition for the next shift.
My own take is that 1) if I use my lock I sure won't leave the stuff locked out accidentally, or forget to inform the next shift, and 2) that is often the most convenient lock available- and LOTO is something to be encouraged!

OSHA rules also state that ONLY LOTO equipment supplied by the employer shall be used. While I agree that employers should provide all safety equipment, there is no guarantee that the stuff will be available where you need it, when you need it- even in the best-run places.

So I happily use MY lock on MY devices, on the principle that I'd rather be safe than 'OSHA compliant."

Yet, according to the book, I am an outlaw. Thus this thread- sometimes the rules are simply wrong, and actually create a hazard.

While there is a place for rules, there is also a place for their thoughtful application. Or for casting them aside. That is my view. What say you?