Street sellers particularly in developing countries, supply large amounts of food【H1】people on low incomes. This sector also employs some 6%～25% of the work force, mainly women, in developing countries, and provides markets for agricultural and other produce. In many countries【H2】, the authorities are not willing to recognize it【H3】a formal sector of the food supply system, they may ignore it in food control programs or even try to put an end to【H4】. There are tow possible contaminants: pathogenic micro-organisms;【H5】hazardous chemicals: As【H6】as micro-organisms are concerned, there is apparently no convincing evidence that street foods are more involved in the transmission of infection【H7】foods obtained in, e. g. hotels. Studies in Egypt and else- where have found street foods to compare not unfavorably with hotel【H8】in respect of contamination with micro-organisms--some street foods were found to be contaminated with pathogens, but so also were foods from four-and five-star【H9】in the same area. Hazardous chemicals have【H10】found in street foods, and food exposed for sale on roadsides may become contaminated by lead from vehicle exhausts. Health dangers may arise【H11】purchase of raw food of poor quality; improper storage, processing, and cooking, leading to reuse of water; limited piped drinking water; lack【H12】refrigeration; and unsatisfactory waste-disposal facilities; inexperienced or personal cleanliness. The authorities should take【H13】account the potentials of different categories of food for transmitting disease, and should control appropriately for the different【H14】-sellers of bottled drinks require less control than those of food.Dry foodstuff, dried grains, and sugared foods are less likely to transmit disease than gravies, cooked rice, and low-acid milk, egg, and meat products. Similarly foods which are thoroughly cooked and eaten at【H15】are safer than precooked food kept at high temperatures for several hours. 【H1】