TAIPEI - Forty per cent of stainless steel kitchenware samples tested were found to contain over 10 per cent manganese, a metal that could lead to neurological disorders, the Taipei City Department of Health (DOH) said yesterday.
The DOH sampled 20 stainless steel kitchenware products from retail outlets in Taipei in its latest investigation in September. All products were found to contain levels of antimony and lead within the legal limits set by the relevant national ordinance, Sanitation Standards for Food Utensils, Containers and Packages.
Twelve samples, however, did not label the type of stainless steel used, among which five were found to have a manganese concentration of over 10 per cent.
According to the Chinese National Standards (CNS) No. 8497 (for hot rolled stainless steel plates, sheets and strips), the concentration of manganese in stainless steel products made from iron nickel manganese chromium alloys (such as stainless steel type No. 202) should not be higher than 10 per cent, the DOH pointed out.
CNS8497, however, is merely a standard for the definition and grading of stainless steel products. Taiwan currently has no legal limits on the level of manganese in stainless steel products.
Advanced economies such as the US, the European Union, Australia and New Zealand, among others, have also not established leaching test standards specifically for stainless steel products, the DOH pointed out.
The DOH called for stainless steel kitchenware manufacturers to label the type of steel used in their products. According to CNS8497, manganese concentrations for stainless steel type No. 202 range from 7.5 per cent to 10 per cent. The concentrations range for type 201 is 5.5 per cent to 7.5 per cent, below 2 per cent for type 304 and below 1 per cent for type 430.
Over-exposure to manganese can lead to neurological disorders such as the rare biphasic disorder manganism. Chronic exposure in low-doses has been connected to neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease.