The present invention relates to a food contamination detector associated with a double bar code, given the trademark GILBAR.TM. by the owner of the present invention, that includes coded indicia used to identify the presence of conditions indicative of microbial contamination in food, including toxic contaminants, bacterial metabolites, and other microbial secretions. Of the two bar code symbols associated with the food contamination detector, the first identifies the food product in terms of the type of food, the quantity, the price and the like, while the second bar code symbol is designed to identify the presence of contaminants. When contamination is not detected, the first bar code symbol is scanner readable, whereas the second bar code symbol is not. Once contamination is detected, bars in both bar code symbols can appear or disappear causing the first bar code symbol to become scanner unreadable and the second bar code symbol to become scanner readable.