Renault team boss Eric Boullier is among a number of Formula One personalities to express fears that plans to make cars run electrically in the pits from 2014 is too dangerous.
The proposal that "the car must be run in electric mode (no ignition and no fuel supply to the engine) at all times when being driven in the pit lane" was included in the governing FIA's new 2014 regulations published last week.
Other environmentally-friendly ideas were also adopted but some teams feel they were not adequately consulted on the changes by the governing body.
"The concept is intriguing but... the cars would not make noise and that could be very dangerous," Boullier told reporters at the German Grand Prix.
"I think there are aspects of the rules published by the FIA which should be looked at again."
Formula One is due to switch to a new 1.6 litre turbo V6 engine with energy recovery systems from 2014. The sport currently uses V8 units.
Boullier is also keen on an extra practice session rather than just two on a Friday from 2012 while teams continue to talk with the FIA about a return to some form of in-season testing from next year.
