Some top safety experts believe an anti-smog device to be installed on new cars may cause fires in crashes. The EPA is requiring the device, an on-board refueling-vapor recovery (ORVR) canister, to be installed on 40 percent of 1998 model cars; by 2006 the ORVR canister will be required on all new cars and trucks.

The coffee-can-size device is designed to capture gas fumes during refueling.

• Even the smaller, simpler evaporative canisters that have been installed on cars for two decades have been linked to an increase in car fires.

• A 1991 National Highway Transportation Safety Administration study of crashes found 27 percent more fires in vehicles with evaporative canisters than in vehicles without them.

• In 1991 NHTSA warned EPA that the new ORVR canisters would increase fire risk, and a 1993 report found that despite design improvements a "small, unquantifiable safety risk" remained.

The anti-pollution device does not have to pass a federal crash test the way other parts of the fuel system do.