BUY a Big Mac anywhere in the world and you will get the same sesame-seed bun, identical slices of beef and exactly the same combination of sauce and salad. But in Hong Kong it will come in a styrofoam box, while elsewhere it might be in cardboard, or wrapped in paper with a card 'collar' to keep pickles and patties in place. In places where styrofoam is banned - or where public pressure against its use is strong enough - McDonald's has been using more environmentally friendly burger wraps for almost a decade. Foam burger boxes were phased out at mainland McDonald's branches a few months ago, but there are no plans to scrap them in the SAR. 'If you have a major multinational that's demonstrating it can use environmental products in some parts of the world and then doesn't use them here, that's inexcusable,' says government adviser Barry Cook. McDonald's insists it is not that simple and that concerns about hygiene, food quality and keeping burgers hot prevent the immediate replacement of foam in Hong Kong, home to some of the company's busiest outlets. This is despite the fact that in countries such as Germany and Australia, such obstacles were overcome in the early 1990s. 'We are always seeking better alternatives for packaging,' says Maye Tang, communications manager of McDonald's Hong Kong. 'We've been working on a lot of initiatives. We look to other countries when they take up good initiatives and we learn from them, but it takes time.' Ms Tang says the styrofoam used by McDonald's is chlorofluorocarbon-free so does not harm the environment if incinerated. She says it helps waste disposal by speeding up combustion of other rubbish in incinerators. McDonald's Hong Kong has reduced the size of its napkins to save paper and made its coffee stirrers lighter to save plastic, she says. Environmentalist Lisa Hopkinson says: 'They'll carry on using the cheapest, most convenient product until consumers stand up and say they want something different.'