Unfortunately this sounds like a very poor quality fan. I have fans that have been left running for literally years. Make/model/manufacturer?? I've never heard of such a thing. J
most fans are guaranteed a certain number of hours or rotations. If there's a fire hazard warning...well it's a cheap fan. what did you pay for it?
lol this is fine, the most trouble you'll run into is if it stops running. and i'm assuming you'll check your plant everyday anyway..so no worries man
they have to put it on the box cause i bet you one was left unattended and cause a fire but its probly very rare it just covers the company feom being sued id rather leave a fan on than risk lights getting too hot or baking my plant it should be baking me not the other way round