Massive commercial fire sparks evacuations in Brisbane's north

Firefighters expect to remain overnight at the scene of a huge fire that destroyed a commercial factory in Brisbane's north, sending toxic smoke billowing into the air.

Emergency crews brought the fire at the All Crash Parts warehouse just off busy Sandgate Road at Virginia under control just after 5pm but continued to fight the blaze long after.

A police exclusion zone was reduced about 7.30pm and smoke-affected residents advised they could finally leave their homes after close to four hours inside.

Pritchard Road between Shannon Place and Sandgate Road, remained in the exclusion zone.

An emergency situation has been declared as a ferocious blaze tears through a factory in Brisbane's north, sparking warnings about toxic smoke.

Shoppers and staff were evacuated from businesses and a nearby service station's pumps were shut down as fire crews fight a massive blaze at a nearby business.

The fire at the All Crash Parts warehouse just off busy Sandgate Road at Virginia, broke out about 3.30pm.

It was sending plumes of thick black smoke into the air as firefighters used a crane to try to control the flames, with burnt-out cars apparently visible from a news helicopter.

Police declared an emergency situation at 4.10pm, cutting members of the public off from several businesses in the area.

Staff and shoppers at Officeworks and a nearby pet shop had been evacuated, a police spokesman said, adding that a nearby service station had shut its pumps down because of the threat.

"The fire continues to burn and due to the toxic nature of the smoke, residents in the area are being asked to remain indoors and close windows," police said, in a statement.

"Sandgate Road remains open, however police are requesting motorists to avoid the area if possible due to a build-up of traffic."

A Queensland Fire and Emergency Service spokesman said eight pumping crews were fighting the blaze on Pritchard Road, plus support crews, with 20 crews in total on the scene by 5pm.

Firefighters were equipped with breathing apparatuses as they tried to douse the flames.

Passerby Tim McGarrity, from Redline Emergency Management, said the intensity of the fire seemed to be lessening by about 3.30pm but fire trucks were still arriving.

“At the very beginning, the flames themselves within the smoke would have been 50 to 100 feet (15 to 30 metres) in the air,” he said.

“They were absolutely enormous. The smoke was billowing out at a rate that I haven't seen before.”