Tests on air purifiers made or sold by companies located in Shanghai found that almost half of them were faulty.
Checked by China's top quality watchdog, they failed tests for noise and purification efficiency as well as being potential hazardous on electricity leakage, officials said.
Six of the 14 batches inspected failed the tests, according to the General Administration of Quality Supervision, Inspection and Quarantine of China.
A batch of air purifiers by Mitsubishi Heavy Industries Air-conditioners (Shanghai) Co Ltd was found to be substandard for formaldehyde purification efficiency. Baomi Information Science and Technology (Shanghai) Co Ltd products had noise problems, while air purifiers branded "Novowater" had poorly protected electric parts.
Two batches of air purifiers branded "ReFinAIR" and "Somputon" also had noise problems, as well as "continuous disturbance voltage," according to the administration.
Purifiers made by Zhejiang Benyuan Appliance Co Ltd and sold by LongYea Environmental Technology (Shanghai) Co Ltd failed for particulate matter purification and continuous disturbance voltage.