The guest, surnamed Sun, said he and his wife were forced onto their balcony late on September 20 after a strong chemical smell filled their room at the Chateau Star River Pudong Hotel.
Hotel staff later told Sun that the leak came from the minibar fridge, which had been in use for eight years without replacement or inspection. The fridge reportedly emitted ammonia, a water-soluble alkaline gas that can cause skin and respiratory irritation.
Medical records showed Sun suffered corneal abrasions and chemical damage to his airways, while his wife was diagnosed with lung irritation and persistent coughing. The hotel covered the initial hospital examination, and offered to refund their 600-yuan (US$83) nightly room rate.
Guo Jiayi