I found this, as I was wondering myself, and didn't know if I should keep it on or take it off, if I did would I lose the pin, if I didn't, would I be sorry in the event of an emergency.
Our fire extinguisher seals are tamper evident seals that allow you to tell at a glance if the seal has been compromised, yet are easy to break in an emergency. Standard pull-tite seals are a common safety feature for use on fire extinguishers so you know if the extinguisher has been used – don't take the chance that someone has tampered with the fire extinguisher and exhausted it, leaving it empty in the event of an emergency.
This polypropylene fire extinguisher security seal with has an average break strength of 13.5 lbs and 9.5" in overall length. Usable strap length is 7" and the diameter is 2.6 mm (0.1"). The flag is 0.8" by 1.3". Custom printing is available on all fire extinguisher seals with fast turnaround: print names, numbers or custom logos on the seal with no minimum quantity.