Complying with Tier 3 and 4 in a Class 1 div 2 area

[BB382011]

Is there an exemption in place on meeting Tier Standards and operating in a class 1 div 2 area? We supply skid mounted centrifugal pumps powered by Diesel engines so according to the regs we fall under the Non-Road land Standards. These engines are operated on offshore oil and gas platforms. With all the electronics required on the new tier 3 and 4 engines it has become next to impossible for us to upgrade our fleet and still be compliant with operating in a class 1 div 2 area. Any Help?