How long do you keep your hotwork permits?

In just about all our audits, we get this question.  We all know that OSHA requires us to maintain our PRCS Entry Permits for one year to be used in our annual program review, but they do not mention HW permit retention.  We always advise maintaining HW permits on a rolling 12-month schedule; however, at some very large facilities, this can take a lot of filing cabinets!  So I am asked by legal “what is officially required,” and that is where I go to one of my most trusted sources… State Fire Code.  I am unaware of any state not having a fire code, even when most adopt the International Fire Code(s).  For example, in my home state of Ohio, we are REQUIRED by our code to keep our hotwork permits for…