Several brands of leather shoes in Shanghai contain excessive levels of formaldehyde, according to the Shanghai Quality and Technical Supervision Bureau.
It said results from tests on 50 batches of shoes revealed that 37 contained formaldehyde, a known carcinogenic, while four of those had levels deemed excessive.
Among those brands found to contain excessive amounts were women's shoes made by Shanghai Yingshi Shoes Co under the "Ray" brand, as well as and men's shoes by Shanghai Huaihai.
In addition, some women's shoes made by Shanghai Falali Shoes Co and men's shoes by Nanjing Meilihua had large amounts of poisonous compound hexavalent chromium, the bureau added. And shoes from Shanghai Dengyun and Fusheng Shoes Co in Fujian Province had aromatic amines, another carcinogenic, all of which can cause inflammation, allergies and cancer.