A Shenzhen court has begun hearing a Hong Kong woman's 70,000 yuan compensation claim against a beauty salon, which she says sold her a face cream that gave her severe mercury poisoning. Cao Hui , a Hunan native now living in Hong Kong, said she told Longgang District People's Court on Monday she visited a branch of the Shenzhen Mermaid Cosmetology Company in February last year and paid 2,000 yuan for Franne Skin Whitening Cream bearing the company's logo. Ms Cao said her face turned white several days after she used the product but she also began to experience side effects including numbness of the tongue, breathing difficulty, breast discomfort and a painful face swelling. She stopped using the cream in May and then went deaf in the right ear. She said she had the cream assessed by the Shenzhen Academy of Metrology and Quality Inspection, and tests revealed it had 180,000 times the national maximum level of mercury for cosmetics. The salon has denied selling unsafe cosmetics to Ms Cao and said the poisonous cream was a counterfeit product. The case comes after Shenzhen Fuhua Hospital was shut down in May amid claims that it used a toxic gel in breast implants.