Those with a sweet tongue should think twice before grabbing a steamed cake: eating two of them already exceeds recommended levels of weekly aluminium intake. Regular consumers of aluminium-containing food additives - used in steamed bread, bakery products and jellyfish - face health risks including premature delivery and hampered growth. Children and babies should be careful with their diets, the Centre for Food Safety said yesterday. Pregnant women should also be cautious as an excessive aluminium intake could affect their fetus. Tests had shown that an excessive intake over a prolonged period of time could cause changes in the testes, shorten the length of gestation, delay maturation and impair development of the nervous system in animals, the centre said. The centre's consultant, Ho Yuk-yin, said 256 samples, comprising 60 prepackaged and 196 non-prepackaged food items - were tested for aluminium and 97 per cent had the metal. The most aluminium was found in ready-to-eat jellyfish - 1,200mg per kg. Under normal eating habits, jellyfish constitutes 10 per cent of a quota of aluminium intake set by an expert panel on food additives formed by the Food and Agriculture Organisation and World Health Organisation. But a bigger concern in the city is in steamed buns and bakery products, as Hongkongers eat more of those than they do jellyfish. Aluminium additives are common ingredients in baking powder to act as a raising agent for dough. For an adult weighing 60kg, eating just one steamed cake - such as a mai lai sponge cake or a thousand-layer cake - takes up 63 per cent of the weekly quota. Muffins and pancakes/waffles are next: eating one constitutes 47 per cent and 21 per cent of the weekly limit. People with normal eating habits should not worry about eating too much aluminium, the centre said. Exceeding intake levels occasionally, as compared to doing so for a prolonged period of time, would not pose a health risk. Nor should elderly people who often ate at Chinese restaurants worry, as they would be hit less with reproductive or development problems, Dr Ho said. A bakery operator said the government should teach bakery workers what alternatives were available if they were to use less baking powder. Using yeast as the raising agent in the baking process could produce the same effect as aluminium additives, King Bakery chief executive John Chong Yam-ming said. The mixture of flour and water should be put in the fridge the night before. 'Some people are lazy and put more baking powder instead.' Or they might not know the alternatives to baking powder, Mr Chong said. Apart from posing a potential health hazard, excessive bakery powder would make the texture of a bun rougher, he said. Food Council chairman Simon Wong Ka-wo called for clearer guidelines to the food industry. 'I hope the Centre for Food Safety can hand us guidelines,' Mr Wong said. 'When things become clear, residents would feel assured when they eat the food and no panic would be stirred up.' Baking powder had been used for many years and it was believed to be safe, he said. 'If there are problems in using the additive, we will follow new guidelines. But we hope the Centre for Food Safety can give us advice on what alternatives we can use.'