USCG Accepts Aluminum Flammable Liquid Storage Cabinets

Overview

The U.S. Coast Guard has issued new guidance allowing aluminum flammable liquid storage cabinets to be accepted on the weather decks of inspected towing vessels operating on domestic voyages.

This update gives vessel owners and operators a new option for storing flammable and combustible liquids while still meeting safety and compliance expectations. When built and installed correctly, aluminum cabinets may now be accepted as providing an equivalent level of safety to traditional steel cabinets.

Why This Update Matters

For years, flammable liquid storage cabinets approved under existing standards were made of steel. While steel cabinets meet fire protection requirements, many operators have experienced rapid corrosion and deterioration when these cabinets are exposed to weather, salt spray, heat, and humidity on deck.

In some cases, steel cabinets have deteriorated in as little as two years, creating added cost and maintenance concerns. Industry feedback led the Coast Guard to evaluate whether aluminum cabinets, when properly designed and installed, could provide the same level of safety while better withstanding harsh marine environments.

What the Coast Guard Is Allowing

The Coast Guard has determined that aluminum flammable liquid storage cabinets may be accepted in place of steel cabinets if they meet specific construction and placement requirements.

This acceptance applies only to:

• Inspected Towing Vessels (ITVs)

• Domestic voyages only

• Weather deck installations

The cabinet must still meet the intent of existing fire safety regulations by protecting contents from ignition sources and giving crews time to respond in an emergency.

Key Requirements for Aluminum Cabinets

To be accepted, aluminum storage cabinets must meet all of the following criteria:

• Installed on the weather deck

• Located as far as practical from:

  • Machinery spaces

  • Exhaust stacks

  • Escape routes

• Kept away from ignition sources

• Constructed of at least ¼-inch aluminum (frame and shell)

• Fully welded construction

• Equipped with:

  • A latching door

  • A raised door sill at least 2 inches high to contain spills

• Maximum cabinet size: 30 cubic feet

• Permanently marked:

  • “FLAMMABLE, KEEP FIRE AWAY”

  • Lettering at least 2 inches tall

• Properly secured to the vessel

• A 40-B portable fire extinguisher located nearby

• Maximum storage quantity:

  • Only what is necessary for the vessel’s mission

  • No more than 120 gallons per cabinet

• Repaired or replaced if deemed unserviceable by the local OCMI

The final installation and arrangement must be acceptable to the local Officer in Charge, Marine Inspection (OCMI).

What This Does Not Change

• This guidance does not apply to SOLAS vessels

• It does not remove the need for proper marking, securing, or fire protection

• Approval is still subject to local OCMI review

• Cabinets outside these criteria require separate Coast Guard approval

FAQs

Does this mean steel cabinets are no longer required?
No. Steel cabinets are still acceptable and compliant. This guidance allows aluminum cabinets as an alternative when all requirements are met.

Can this be used on all vessel types?
No. This applies only to inspected towing vessels on domestic voyages.

Can aluminum cabinets be installed indoors?
This guidance is specific to weather deck installations.

Do aluminum cabinets have the same fire resistance as steel?
Aluminum does not perform the same as steel in fire conditions. However, the Coast Guard determined that when additional safety measures are used, aluminum cabinets can provide an equivalent level of safety for this application.

Does this eliminate the need for a fire extinguisher nearby?
No. A properly rated 40-B fire extinguisher must still be located near the cabinet.

Who approves the installation?
The local OCMI must approve the cabinet’s construction, location, and installation.

What happens if the cabinet becomes damaged or corroded?
If deemed unserviceable, the cabinet must be repaired or replaced with a cabinet that meets these requirements or the standard steel requirements.

Final Takeaway

This update gives operators more flexibility while maintaining safety. Aluminum cabinets may reduce corrosion issues and replacement costs when used correctly, but compliance still depends on proper design, placement, labeling, and approval.

If you’re considering installing or replacing flammable liquid storage cabinets, it’s important to review these requirements carefully and coordinate with your inspection authority.