Which of the following is not a typical storage container for foam concentrate?

Extinguishers are typically not designed to serve as storage containers for foam concentrate. They are primarily intended for the quick release of fire suppression agents in emergencies, not for long-term storage. Foam concentrate is usually kept in larger, more robust containers that can accommodate bulk storage and allow for easy transfer to firefighting equipment as needed.

Drums, totes, and fire cans are customarily used to store foam concentrate because they are specifically designed for that purpose. Drums and totes provide larger capacities for storing substantial amounts of concentrate, making them suitable for bulk transfer and use in fire suppression operations. Fire cans are also used but are specific for carrying foam concentrate to the scene when not needing to transport large quantities.

In contrast, extinguishers, due to their size and design constraints, are not practical for this function, thereby making them the right answer to identify as not a typical storage container for foam concentrate.