Food may be accidentally or deliberately contaminated by microbiological, chemical or physical hazards. In contrast to microbiologically caused foodborne illness, the link between exposure and effect of chemical hazards in foods is usually complicated by cumulative low doses and the delay between exposure and the onset of symptoms. Chemical hazards include environmental contaminants, food ingredients (such as iodine), heavy metals, mycotoxins, natural toxins, improper storage, processing contaminants, and veterinary medicines. Incidents have occurred because of poor harvesting or storage of grain, use of banned veterinary products, industrial discharges, human error and deliberate adulteration and fraud.[1]