Wooden Flammable Storage Cabinets – Build Your OwnPaul S
Yes! It’s true… Wood flammable storage cabinets not only meet code, but can provide better protection than metal cabinets as shown in the video. The key is using the materials and construction techniques spelled out in the applicable standards that are cited and linked in the following article.
If you have flammable liquids like aerosol spray paint, adhesives, and oils – OR – containers of flammable finishes, paints, solvents, gasoline, or kerosene, etc., you should keep those liquids in a flammable storage cabinet that meets the fire code. The purpose of flammable storage cabinets is to give people enough time to safely exit a building in case of fire and to identify where the flammables are stored when the fire department arrives. The cabinets must keep the flammable liquids protected from high temperature for at least 10 minutes.
Businesses that store flammable liquids are subject to inspections from their insurance company, the Fire Marshal, and the Occupational Safety and Health Administration (OSHA). If you’re not in compliance, you can be shut down and receive big fines. During the inspections, one of the things they will be looking for is to make sure you are in compliance with the requirements defined by the National Fire Protection Association (NFPA). The NFPA is a nonprofit organization dedicated to the protection of human life and property from the hazards of fire. It publishes over 300 nationally recognized fire codes and standards, as well as fire service training and public education materials. The two standards associated with flammable storage for finishing operations are NFPA 30 and 33.
NFPA 30 is the Flammable and Combustible Liquids Code. It provides the fundamental safeguards for the storage, handling and use of flammable and combustible liquids, including waste liquids. The standard outlines best practices widely used in industry and by insurers. You can read the code for free at this link – NFPA 30: Flammable and Combustible Liquids Code. According to the NFPA, flammable storage cabinets can be constructed using metal or wood.
NFPA 30 – Wooden Cabinet Construction Requirements
NFPA 30, Chapter 9.5.3 states “Storage cabinets that meet at least one of the following sets of requirements shall be acceptable for the storage of liquids;
(1) Storage cabinets designed and constructed to limit the internal temperature at the center of the cabinet and 1 inch (25mm) from the top of the cabinet to not more than 325 degrees Fahrenheit (163 Celsius) when subjected to a 10-minute fire test that simulates the fire exposure of the standard time-temperature curve specified in ASTME 119 shall be acceptable. All joints and seams shall remain tight and the door shall remain securely closed during the test.
(2) This section covers metal storage cabinets…
(3) Wooden cabinets constructed in the following manner shall be acceptable;
a. The bottom, sides, and top shall be constructed of exterior grade plywood that is at least 1 inch (25mm) thick and of a type that will not break down or delaminate under fire conditions.
b. All joints shall be rabbeted and shall be fastened in two directions with wood screws.
c. Where more than one door is used, there shall be a rabbeted overlap of not less than 1 inch 25mm)
d. Doors shall be equipped with a means of latching, and hinges shall be constructed and mounted in such a manner as to not lose their holding capacity when subjected to fire exposure.
e. A raised sill or pan capable of containing a 2 inch (50mm) depth of liquid shall be provided at the bottom of the cabinet to retain spilled liquid within the cabinet.
(4) Listed storage cabinets that have been constructed and tested in accordance with 9.5.3(1) shall be acceptable.”
Venting is Not Required
NFPA 30, paragraph 9.5.4 states that a storage cabinet is not required to be vented for fire protection purposes. Paragraph 18.104.22.168 states if the storage cabinet is vented for any reason, the vent openings must be ducted directly to a safe location outdoors or to a treatment device designed to control volatile organic compounds (VOCs) and ignitable vapors in such a manner that will not compromise the specified performance of the cabinet and in a manner that is acceptable to the authority having jurisdiction.
Label the Cabinet – Code Requirements
NFPA 30, Chapter 9.5.5 states that the Storage cabinets must have the following marking:
KEEP FIRE AWAY
The sub-paragraphs that follow have additional requirements. The color of the words must contrast with the background, be located on the upper portion of the cabinet’s front door or frame, and be in all uppercase letters with a minimum height of 2 inches for the word “FLAMMABLE” and 1 inch for the words “KEEP FIRE AWAY.” Use of other languages, the flame in a triangle symbol, and a burning match in a “no” circle are also permitted.
The Occupational Safety and Health Administration (OSHA) repeats this labeling requirement in their standards. Click on the OSHA link for additional information and free access to the standards.
NOTE: Make sure your flammable storage location and quantities meet the requirements of NFPA 33: Standard for Spray Application using Flammable or Combustible Materials. This standard is also available to read free at this link.
Wooden Flammable Storage Cabinets Are Safe
Take a look at this video from SciMatCo putting their wood cabinet through a live flame test. The wooden cabinet outperformed the metal cabinet by a WIDE margin!
Make Your Own Flammable Liquids Storage Cabinet
If you’re interested in making your own wooden cabinet, check out this video from Tim Johnson at American Woodworker Magazine. He overviews the construction of a wood flammable storage cabinet for a small shop;
On-line Plans for a Wood Storage Cabinet
Want to build you own flammable storage cabinet? Popular Woodworking has plans for one at this link – Finish Cabinet Plans. Use a latex paint on the cabinet (safety yellow is most common) and add 8 ounces of FR-1 fire retardant (available from Benjamin Moore) to each gallon of paint.