The Civil Aviation Authority unveiled a series of new flight safety regulations on Thursday in a report following a review into North Sea helicopter operations.
Industry leaders held a meeting in Aberdeen yesterday to discuss the new measures and the implications for the oil industry.
The CAA report stated that from June 1 oil workers will only be able to fly if they are seated next to push-out window emergency exits.
The rule will apply until operators fit side floats to helicopters and equip passengers with emergency breathing systems.
Flights to oil rigs during stormy conditions will be prohibited to reduce the risk of ditched helicopters capsizing.
Oil workers being transported to platforms will only be allowed to fly if they can fit through aircraft windows to make an escape.
Helicopter operators, trade unions and industry leaders discussed the new measures at a Helicopter Safety Steering Group meeting yesterday.
Jake Molloy, regional organiser for RMT union, said the report had raised some concerns, such as the time needed to issue every worker with a breathing apparatus.
He said: "The CAA has put this together in a way that has left us all scratching our heads in some respects about the implications. The seating issue [is] the primary issue, [as] it immediately reduces seating capacity by about 40%. How do you deal with that - do we have to get more helicopters?"
He added: "A lot of these issues were being worked through by the helicopter steering group. The CAA has effectively taken it out of everybody's hands and applied its own time-frame."