Toxicological studies show that oral doses of nickel can cause allergic contact dermatitis, and routes of exposure, such as nickel leached from stainless steel cookware are not well characterized. In this study, four variables: grade of stainless steel, cook time, stainless steel seasoning or cooking cycles, and commercial tomato sauces, were tested to for their effect on nickel leaching and their possible effects on human health. Two grades of stainless steel, two, six, and 20 hour cooking times, ten cooking cycles, and four commercially obtained tomato sauces were tested. The stainless steel grades tested were equivalent to those typically found in cookware (grade 316 and 304). We found after a single cooking cycle of six hours, depending on grade of stainless steel, nickel concentrations increased 30 to 60 fold. Increased cook times of 20 hours resulted in additional nickel leaching, about 70 fold higher than tomato sauce cooked in the absence of stainless steel. The first cooking cycle resulted in the largest increase in nickel concentration at 5.8mg/kg. However, with sequential cooking cycles, the total amount of nickel leached was less than in the first cycle. There was no change in the amount of nickel leached between the sixth and tenth cooking cycle. Nickel was still leaching into tomato sauce after 10 cooking cycles about 10 fold higher than the original tomato sauce. After 10 cooking cycles, each six hours in duration, an average of 88μg of nickel was leached per 126g serving of tomato sauce. In addition to dietary intakes, stainless steel can be an overlooked source of nickel, and the amount of additional exposure is dependent on stainless steel grade, cooking time, and repeated usage.