Most of the victims suffered internal burns from the effects of the corrosive gas. The authorities said there was no danger to the wider population.
The accident took place at Weng’s Cold Storage on Fengxiang Road, and the injured were rushed to Baoshan’s Dachang Hospital.
Some victims had burns to their skin, and a number of those who died had severe facial burns, making identification difficult, said doctors.
More than 200 firefighters in 25 fire vehicles and 100 police were dispatched to the scene, where firefighters sprayed water to dilute ammonia in the air.
This is not the first instance of ammonia leakages in China over the last year.
In June, 121 people were killed and 76 injured in an explosion caused by a liquid ammonia leak in a poultry company in Changchun City of northeast China’s Jilin Province.
And last October, 479 people were poisoned in an ammonia leakage attributed to worn machine parts in Honghu City of central China’s Hubei Province.