The incident at around 3:40 pm (0740 GMT) on Thursday occurred at a chemicals company in Ordos in the Inner Mongolia region, state broadcaster CCTV reported.
An "ejection of high-pressure gas sprayed many staff working at height and caused them to fall", CCTV said.
One person died at the scene but the number of casualties has since risen, according to the broadcaster.
Industrial accidents occur relatively frequently in China, where safety protocols are often lax, especially at more rudimentary sites.
In February, the partial collapse of a coal mine in Inner Mongolia killed 53 people, according to official figures.
Related Links
Bringing Order To A World Of Disasters
A world of storm and tempest
When the Earth Quakes
| Subscribe Free To Our Daily Newsletters |
| Subscribe Free To Our Daily Newsletters |
