Fire has destroyed a cabinet-making business in Melbourne's outer north, with as many as 70 firefighters, 17 trucks and two water bombers being needed to bring it under control.

Smitty's Kitchens & Cabinets on Williamson Road in South Morang went up in flames shortly after midday on Friday with a worker who was still inside but managed to escape without injury.

A fire has destroyed Smitty's Kitchens & Cabinets in South Morang Credit:Facebook

Country Fire Authority crews, with support from the Metropolitan Fire Brigade, brought the fire under control before 2pm and were expected to be on scene well into the afternoon to fully put it out.

A CFA spokesman said chemicals common in such business, including glues and sprays, were inside the building and about 500 litres of a leaked liquid was controlled before it made it to a nearby drain.