tbo-regulatory? recommendation? grace period?

[Da Vinci]

can anyone quote law that it is illegal to fly past a tbo? i was real sure about it until the chief said -naw, that's a recommendation... now i think i know better but he's making me think twice. the plane is already about 100hrs over and their asking me to fly it for about a 120hr mission. i'm thinking if i accept and fly it, i'm illegal, unsafe and will the actually the company could prob sue me if something happened. basically i'd be responsible for ANYTHING!! is that right??? is there a 10% grace period on tbo's?? any grace period? thanks to whoever might know this answer. refusing the trip will prob equal "fired!"

 

[Da Vinci]

sorry put this in the wrong forum...moved it to the FAR's/regulations forum.