Mountains of dumped styrofoam lunch boxes look likely to remain a familiar feature, because environmentally friendly alternatives are too expensive, it was claimed yesterday. Peter Wong Hong-yuen, chairman of the Advisory Council on the Environment,said it was unlikely a ban would be considered because of the cost of alternatives and lack of research into substitutes. 'China, who imposed a ban, have had to defer it because it has been unworkable. 'It is, of course, a concern,' he said. A discussion paper prepared for yesterday's council meeting said 'very careful consideration to alternative strategies would have to be considered before introducing legislation'. Styrofoam is composed of chlorofluorocarbon chemicals, which are said by scientists to be responsible for the destruction of the ozone layer.