Another product has been added to the list of unsafe Chinese exports, but consumers can breathe a sigh of relief because unlike ginger, cooking oil, milk powder and rice, this one is not to be ingested.
At least half of the silk products on sale in China's capital do not meet safety and quality standards, according to a Beijing Consumers Association study, with most cases finding that the product contained little or no silk at all. The study tested 40 types of silk products bought from local retailers, department stores and online stores including Wal-Mart, Wumart, Sogo and e-commerce site Jingdong Mall.
The silk products were tested for levels of formaldehyde, pH, biodegradable capacity, carcinogens and other safety indicators, but at least 19 of them failed to meet the regulatory standards, the Beijing News reported  on Monday.
The products tested ranged from “a few hundred yuan to several thousand yuan”, the report said.
Product labelling was found to be inaccurate in most of the cases. At least eight of the products tested contained discrepancies in terms of purported silk content on their labels and the actual silk content.
One brand, Shengwei, labelled a quilt as having a “50/50” cotton-and-silk blend as filler, when the real amount of silk was closer to 20 per cent.
According to the study, there were also products that claimed to be made with silk, but had no silk content at all. Quilts that claimed to be filled with 100 per cent silk, including one sold under a licensed Pierre Cardin label, contained mostly synthetic polyester and viscose, the study found.
Under a microscope, polyester and synthetic fibres usually appear brighter in colour and have uniform thicknesses. Pure silk, however, appear more lustrous, are irregularly shaped and most of the fibres have varying thickness.
Brands of products reported to have used faulty silk have been removed from store shelves over the weekend, the Beijing News said.
National standards require textiles marketed or labelled as "silk products" to contain at least 50 per cent silk in their fibre blend.
The study comes weeks after tests revealed that hotpot restaurants in Shanghai  were using rat meat but selling it as mutton or lamb.