Justifying the need to prescribe limits for toxic metal contaminants in food-grade silver foils.
The use of silver foils in various food preparations is a common practice in Middle Eastern and South East Asian countries. The FAO/WHO Joint Expert Committee on Food Additives (JECFA) has included silver in the list of food additives, but specifications were not prepared. Indian food legislation has included food-grade silver foil and laid down a purity requirement of 99.9%. This leaves an unspecified margin of 0.1% or 1000 microg g(-1) for contaminants. Therefore, a study to investigate the levels of metallic contaminants in food-grade silver foil was undertaken. Of 178 foils analysed, 161 (90%) contained silver, whilst 10% were fraudulently made up of aluminium. In the case of silver foils, 46% of the samples adhered to the desired purity requirement of 99.9%, while 54% had a lower silver content. Copper was present in 86.3% of the silver foils, while chromium, nickel and lead contamination was found in over 54% of samples. Cadmium levels were detected in 28% of the silver foils and manganese was present in 6.8% of samples. In silver foils showing metal contaminants, average levels were found for nickel (487 microg g(-1)), lead (301 microg g(-1)), copper (324 microg g(-1)), chromium (83 microg g(-1)), cadmium (97 microg g(-1)) and manganese (43 microg g(-1)), which being appreciable justify the need to prescribe limits for some metals in food-grade silver foil as well as for silver powder used in confectioneries and medicinal preparations. The work reported here should encourage manufacturers to use high-purity raw materials and take suitable precautions to reduce unwarranted exposure of consumers to toxic metal contaminants.
Das
Mukul
M
Food Toxicology Laboratory, Industrial Toxicology Research Centre, MG Marg, PO Box 80, Lucknow 226001, India. mditrc@rediffmail.com
Dixit
S
S
Khanna
S K
SK
D000535:Aluminum / Q000032:analysis; D002104:Cadmium / Q000032:analysis; D002857:Chromium / Q000032:analysis; D003300:Copper / Q000032:analysis; D005506:Food Contamination / Q000517:prevention & control*; D018857:Food Packaging; D007854:Lead / Q000032:analysis; D008345:Manganese / Q000032:analysis; D008670:Metals / Q000032:analysis*; D009532:Nickel / Q000032:analysis; D012834:Silver / Q000032:analysis
D008670:Metals; D002104:Cadmium; D002857:Chromium; D007854:Lead; D012834:Silver; D008345:Manganese; D003300:Copper; D009532:Nickel; D000535:Aluminum