The blast took place around 11:25 a.M. At the chemical plant in Hebei province. Thirteen people were working inside the plant at the time of the blast, State-run Xinhua news agency reported.
The blast resulted in the collapse of the roof of the two-story plant. Workshops about 500 meters away from the site of the explosion were also affected with a gate broken and windows shattered.
Investigations into the cause of the accident are underway.
Workplace safety is a major issue in China. Work safety standards in the country lags behind international levels and the rapid growth of the industry has brought increasing challenges.