This article originally appeared on ABACUS Apple and Xiaomi are being accused by a consumer group in China of selling phone cases with toxic substances -- but Xiaomi is crying foul. The Shenzhen Consumer Council says phone cases from Apple, Xiaomi, Tiya, Yuening and Q-Guo contain harmful substances exceeding European safety standards. Xiaomi pushed back, saying the safety standards in question were inappropriate because they were meant for children’s tableware and utensils. But the consumer watchdog insisted they were relevant, because some consumers were worried that children might bite phone covers. One of the cases sold in Xiaomi’s online store is said to contain plasticizers -- a substance linked to genital birth defects in boys and hormone disruptions in men . Xiaomi said in a statement to the South China Morning Post that even though there are no equivalent safety standards for phone covers in China, its products were made under strict quality control. One iPhone case purchased from Apple’s online store is said to contain polycyclic aromatic hydrocarbons (PAHs) at nearly 50 times the safety limit. The chemicals -- often found in car exhaust and cigarette smoke -- have been linked to cancer, as well as eye and liver problems. The iPhone cases in question are still being sold in Apple’s online stores in Asia, including China , Hong Kong , South Korea and Japan . Apple did not respond to a request for comment on Monday. Shenzhen, a southern Chinese city bordering Hong Kong, is home to some of the country’s biggest tech companies -- including Tencent, Huawei and DJI. Together with foreign giants like Apple, many rely on nearby factories to make their products. The most famous one is operated by Foxconn, which has been assembling iPhones for years. The city churns out 70% of phone cases sold in China, according to the Shenzhen Consumer Council. For more insights into China tech, sign up for our tech newsletters , subscribe to our Inside China Tech podcast , and download the comprehensive 2019 China Internet Report . Also roam China Tech City , an award-winning interactive digital map at our sister site Abacus .