A huge Melbourne warehouse blaze is expected to burn for days, spewing toxic fumes over the city’s west and polluting waterways.

Schools and child care centres were set to reopen on Friday, a day after the fire broke out in the asbestos-ridden West Footscray factory which housed aerosol cans and 44 gallon drums containing grease, oil and acetone residues.

The blaze was declared under control late on Thursday night after more than 17 hours, but a watch and act warning remains in place for 19 suburbs in Melbourne’s west.

Large machinery will be brought in to pull apart the site and extinguish the blaze, which Emergency Management Commissioner Andrew Crisp expects to burn for “two, three, four days”.

About 60 firefighters remained at the scene overnight after the alarm was raised around 5am on Thursday.

The Environment Protection Authority was called in to monitor air quality and run-off into waterways as people were urged to stay inside, bring their pets indoors and seal their windows and doors to keep out the toxic smoke.

Eleven public schools, 38 child care centres and eight Catholic schools were closed.

But the MFB on Friday said air monitors were confident conditions were safe for the community.

“There was a large plume yesterday which hung quite high in the atmosphere, and that protected the community for most of the day,” the MFB’s Trent Curtin told reporters at the scene.

“There were some very short periods where some smoke came to the ground, but overnight conditions have improved significantly.”

Water run-off into Stony Creek remained a “significant issue” and people should stay away from it, Mr Crisp said.

“There’s a lot of material that’s gone in there and that’s actually where people will pick up the smell of the acetone that’s come out of the building.”

A steel recycling company was in the process of moving into the tin and asbestos warehouse when it caught fire.

It is not yet safe for investigators to go into the building but there is nothing to indicate the blaze was suspicious, Mr Crisp said.

-AAP