The fire broke out in the area of the ethylene glycol plant of the Sinopec petrochemical complex at around 4 am in the city of Jinshan, the company said in its official Weibo account.
Rescue teams from the Jinshan and Fengxiang districts, as well as the local chemical industrial park, were sent to the scene, according to the Shanghai Fire Department. Rescue operations are underway, he added.
At 9 a.m. local time, the company said the fire was under control.
In a video posted by Shanghai residents on social media and viewed by CNN, at least one explosion occurred at the petrochemical plant while the fire broke out.
In recent years, China has witnessed a series of industrial accidents that have left dozens dead, raising public safety concerns.