In an attack on the Big Mac and other fast foods enclosed in foam plastic containers, the Berkeley City Council is considering a proposal to ban the non-biodegradable packages. The council tonight is to consider a proposal from the city's Solid Waste Management Commission that it ban foam food packages containing chlorofluorocarbons, or CFCs, immediately and all foam take-out packaging by 1990. Until such an overall ban would take effect, the commission said, local restaurants should be urged to cut their use of the foam packages in half. Commissioner Beverly Kelly said the immediate ban on packaging containing CFCs was requested because it is believed the chemical damages the atmosphere's protective ozone layer. The substance was banned from aerosol spray cans in 1978.