How many years can a diesel nissan cabstar be on the road?

In account to any emission regulations, how long can a Nissan Cabstar be on the road until it needs to be modified or is not able to be used anymore?|||I have a 41 year old Diesel Land Rover in daily use. No modifications have been made. What exactly are you asking? Is this relative to the LEZ? If so, please iterate it more clearly when you amend your question.|||Depends how well it's been looked after, and also the emissions regs in whatever country it's being used in.|||There is no definite answer to that.