A suspicious fire at a battery factory at Campbellfield in Melbourne's north has created an environmental hazard.

The blaze destroyed 20 pallets of batteries.

Acid from the batteries contaminated nearby stormwater drains.

The MFB's (Metropolitan Fire Brigade) Luke Kline says firefighters did what they could to prevent the runoff getting into the water system.

He says the Environment Protection Authority will monitor the clean up.

"The EPA's been called to assist us with the contaminated water run-off," he said.

"We've blocked the drains and we've doing testing on the water that's in the drains and that'll be recovered."