Some products from China’s most popular footwear brands were found to contain excessive amounts of a toxic chemical, the Shenzhen Consumer Council said Tuesday.

Slippers from three domestic brands — Warrior, Kuailu, and Jimei — used unhealthy doses of a chemical known as phthalate, which makes plastic products more flexible and durable. The phthalate levels were 195-313 times higher than European Union standards, according to the council.

Phthalate is found in everyday household products such as cosmetics, containers, textiles, and toys. Researchers have linked it to health problems including asthma, breast cancer, obesity, and type 2 diabetes. Some studies have also indicated that the chemical may affect reproductive tract development in male infants, though experts say more research is required to determine its toxicity to humans.

The Shenzhen Consumer Council’s report has raised public health concerns, especially given that Warrior is one of China’s most popular and reputable footwear brands. Founded in 1927, the company sells 80 million pairs of shoes annually.

Substandard slippers from the three brands were available on major online retailers such as Tmall, Taobao, and JD.com, the Shenzhen Consumer Council report noted.

This is not the first time excessive phthalate has been detected in products sold in China. In January, a random test by China’s State Administration for Market Regulation found that 16.7% of children’s footwear tested — including products from Warrior — exceeded recommended phthalate levels. The brand said at the time that it had already put out a recall for the products in question.

In 2017, multiple children’s products including toys, clothing, and even snacks were found to be substandard, resulting in several companies recalling their goods from the domestic market.

Editor: Bibek Bhandari.

(Header image: Slippers on display at a supermarket in Shenzhen, Guangdong province, April 18, 2015. Zou Bixiong/IC)