A new federal law designed to make propane tanks safer takes effect Monday.
Beginning April 1st, all tanks are required to have an OPD, or overfill prevention device.
The valves have been mandatory on all tanks manufactured since 1998. The devices are designed to prevent explosions caused by overfilling.
"They can still use the gas that's left in their old styled tanks. But once it runs out of gas they're going to have to replace it. Either replace the tank or replace the valve in the tank. But they can't have the old styled tanks refilled after April first," propane dealer Ron Smith said.