The answer of an auditor:
Yes, we do and should check the lockers on the items named by gfdoucette07.
However in some countries this can be seen as an insult on privacy.
- I check the lockers that are left open by the workers;
- walks in the changing rooms around the breaks and ask the employees if I can check their lockers;
- ask if their is a master key and if the plant manager is allowed to open the lockers;
- ask the staff that is accompanying me to open their lockers;
- ask if they ever check the employee's lockers by their selves.
I think the last point is important.
Like Charles said, sometimes some unpleasure surprises are found in the lockers.
Companies around here, that do check the lockers, do it:
- in present of the user of the locker.
They are looking for:
- company owned items (theft);
- food and other contamination risks.