Heavy metal contents of various finished leathers

In this study, an investigation was made into the heavy metal content of leather articles. The metals concerned were cobalt, chromium, copper, zinc, lead and nickel as these metals may be subject to restrictions in some products because of their toxic characteristics. Insole leathers, upper leathers and garment leathers were studied as likely contaminating sources because of their extensive contact with the human body. Total amounts of heavy metals were initially measured by digestion. In addition, the possible amounts of heavy metals which would easily be extracted in use were extracted in aqueous and artificial perspiration solutions and analyzed using ICP-AES. It was concluded that the heavy metal content of finished leathers depended mainly on the chemicals used in production, and in particular high chromium contents in leather goods were determined. Also, small amounts of cadmium, zinc, lead, cobalt and copper were detected due to chemical and physical reactions during dyeing and finishing processes. The results of heavy metal contents were compared with limit values for leather and textile articles.