“He attempted to extinguish it, but sustained burn injuries,” Mak said, adding that three of the worker’s colleagues managed to escape unharmed from the building before emergency personnel arrived.

The Fire Services Department sent a total of more than 160 firefighters and paramedics, with 38 fire engines and five ambulances, to the scene. Fire hoses up to 700 metres (2,300 feet) long were laid to reach the water source.

Samuel Wong Chun-on, the department’s acting New Territories North divisional officer, said the factory “housed a large quantity of plastic hoses that caused dense smoke”.

He added that the blaze, which covered an area measuring 20 metres by 40 metres and hit extremely high temperatures, was upgraded to a No 3 alarm fire at 1am because of its intensity. Fires in the city are rated on an alarm scale of one to five according to their seriousness.

About 140 firefighters were sent to fight the fierce blaze, which was upgraded to a No 3 alarm fire. Photo: Facebook

Firefighters battled the blaze with three water jets, bringing it under control at 3am and putting it out at around 3.30am. They had to remain on site and wait for the area to cool down in case any flames were rekindled.

The cause of the fire is still being investigated. Police said there was currently “no evidence indicating any criminal involvement in the incident”.

The injured worker was sent to Tuen Mun Hospital and later transferred to Prince of Wales Hospital in Sha Tin for treatment.