POLICE are baffled as to how thieves were able to steal hundreds of litres of a deadly industrial chemical - worth up to $4 million if sold as a party drug - from a factory in Melbourne's southeast.

Police fear the toxic solvent could fall into the hands of unsuspecting schoolies who believe it to be the depressant GHB, as the chemical can have a similar effect to the illegal drug.

The substance can be lethal if ingested, and its effect takes up to 20 minutes to kick in, potentially causing unaware users to take a second hit and rapidly overdose.

Police believe several 200L drums of the chemical were taken during a break-in at a Cheltenham factory, located near Moorabbin Airport, which occurred sometime between last Friday and Tuesday.

Investigators would not reveal the substance, only that it is a colourless and odourless liquid.

Kingston CIU, assisted by the drug taskforce, will investigate any possible links to bikie gangs and whether the heist was in inside job.

Southern Metro Region Acting Inspector Tim Day said police were yet to determine how many thieves were involved or recover any CCTV footage.

media_camera A drug called Blue Nitro, which industrial solvent is an ingredient.

He was concerned by the apparent ease with which the theft was carried out, and said the factory's security measures would be examined.

The vague time frame for the crime could also hamper investigators efforts to establish suspects and rule out abilis.

The haul could return a potential street value of up to $4 million if sold as GHB.

Acting Insp Day said thieves could also colour the substance and market it under the name 'Blue Nitro' to make it more attractive to young people.

"Our particular concern is that if it is marketed as GHB, which in itself is insidious and dangerous, that there may be a misapprehension by people who have previously used GHB that it has the same effect," Acting Insp Day said.

"It is a toxic, potentially lethal solvent. It is not GHB."

He said GHB was attractive to teens because it is cheap.

The inspector urged partygoers to be wary of substances they were offered, and warned the thieves that any repercussions were on them.

"If any of our young people ingest this industrial solvent and are hospitalised or die from it, ... it rests squarely on their shoulders," he said.

Police are urging anyone with information about the burglary or the onselling of the chemical to call Crime Stoppers on 1800 333 000 or visit crimestoppers.com.au.

samantha.landy@news.com.au