Contamination of Food Cooked or Stored in Contact with Nickel-Chromium-Iron Alloys
Authors: Titus, AC; Elkins, HB; Finn, HG; Fairhall, LT; Drinker, CK
HERO ID: 4843806
Alloys of nickel (7440020), chromium (7440473), iron (7439896), and in some cases molybdenum (7439987) . . .
Alloys of nickel (7440020), chromium (7440473), iron (7439896), and in some cases molybdenum (7439987) used in cooking utensils were studied with regard to corrosion, weight loss, and contamination of food during cooking. The three alloys examined contained 65.3 to 74 percent iron, 17 to 18 percent chromium, 8 to 15 percent nickel, and 0 to 3.7 percent molybdenum. Alloy strips were cooked with various foods for 1 hour. Weight loss of the strips after cooking was determined, and degree of tarnish was assessed. Food cooked for 1 hour in alloy containers was analyzed for metal content before and after cooking to determine metal uptake. The weight loss of the alloy strips did not differ significantly between alloys and ranged from 0 to 9.6 milligrams (mg) per 4 square decimeters per hour. Weight loss was not affected by food pH. Degree of tarnishing also did not differ between alloys and was not affected by food pH. Uptake of metal by 400 grams of food in contact for 1 hour with 4 square decimeters of alloy ranged from 0.01 to 4.20mg iron, 0 to 1.40mg chromium, 0 to 0.24mg nickel, and 0 to 0.05mg molybdenum. Fish and corn showed the most contamination. The alloy containing 67 percent iron, 18 percent chromium, and 15 percent nickel produced the least contamination, averaging 2.56mg iron, 0.12mg chromium, and 0.16mg nickel. The authors conclude that the alloys tested are hygienically safe for cooking purposes.