Big fire at Coolaroo recycling plant

A huge blaze is burning out of control at a recycling plant at Coolaroo in Melbourne's north in what is the second fire there in a year.

The Metropolitan Fire Brigade has had 12 crews on scene at SKM Recycling in Maffra Street since about 7.30pm.

The fire is in a 100m by 50m shed containing bales of co-mingled recycled material, the MFB says.

Firefighters arrived at the facility within seven minutes of being called and surrounded the shed with jets of water and aerial appliances.

Police, paramedics and three CFA units are also on scene.

The cause of the fire is unknown at this stage and there are no reports of any injuries.

Warnings issued on the Vic Emergency website tell nearby residents they are not in danger but should monitor conditions.

The warnings apply to residents in the northern Melbourne suburbs of Attwood, Broadmeadows, Campbellfield, Coolaroo, Craigieburn, Dallas, Epping, Fawkner, Gladstone Park, Glenroy, Greenvale, Jacana, Lalor, Meadow Heights, Roxburgh Park, Somerton, Thomastown, Westmeadows.

"Wind is from the north, smoke is being blown towards housing estates to the south," it reads.

"If you are sensitive to smoke or you live with someone who is sensitive to smoke you should close windows and doors. Turn off heating and cooling systems."