The rapid increase in population worldover has forced the mankind to increase food production and also search for ways to increase the shelf life of the food produced so that it may be transported to far of places and also stored for long duration so that it may be utilised in lean seasons. The need for increasing the shelf life of the food produced has led to the adoptation of several food preservatives which are produced artificially and most of them are chemicals which inhibit the growth of the food spoiling microorganisms. In this list sodium metabisulphite is a important and commomnly used food preservative. This chemical although beneficial in increasing the shelf life of the food products is very toxic. Most countries have specific laws governing the use of this preservative and also prescribing the maximum limit of its use in the food products. This work makes an effort to evaluate the cytotoxic and genotoxic effect of this preservative in Allium cepa test system. The concentrations used are far below the prescribed maximum limits and the results demostrates that it is very harmful in terms of its toxicity and efforts need to taken to search for bio-based preservatives.