WorkSafe, the CFA and Environment Protection Authority are assessing contents of three warehouses after new information was received by WorkSafe.
The sites appear to house bulk containers similar to those being stored at the eight sites found in late December.
Chemical testing will be required to establish the presence of dangerous goods, but 24-hour security has been put in place at each site as a precautionary measure. Air monitoring will also be established at the sites.
In January, WorkSafe announced it would use special powers under the Dangerous Goods Act to lead a government agency taskforce to remove chemicals from the sites in Epping and Campbellfield.
The taskforce, which includes EPA, fire services, Victoria Police and local councils, began removing the first containers from sites in Epping in early February.
Investigations into the circumstances that led the chemicals to be stored at the sites in Epping and Campbellfield are continuing.
Anyone with information or concerns about chemical storage can contact WorkSafe on 1800 136 089.
In the case of an emergency, contact 000.