When choosing a flammables storage cabinet, it might seem natural to choose metal over wood. But it appears that wood deserves a closer look. A reader sent me this video, saying that he found it surprising and thought it might be useful information for the chemistry community. The video shows comparison tests of metal versus and flammables cabinets–and the wooden cabinets appear to do a much better job of protecting their contents from fire than the metal ones. According to SciMatCo, which makes wooden cabinets and produced the video, the temperature inside a metal cabinet rapidly increases more than 1,000 °F, while the interior of a SciMatCo wooden cabinet rises only 8 °F.
Tony Leben, vice president of manufacturing for SciMatCo, says that the difference between how the cabinets perform comes from their inherent material properties: When it comes to heat, metal conducts and wood insulates. The wooden cabinets do burn in the fire, but when NFPA, OSHA, and NL requirements are followed, the cabinets burn slowly enough that they protect the contents long enough for emergency response.
Wooden cabinets constructed in the following manner are acceptable. The bottom, sides, and top shall be constructed of exterior grade plywood at least 1 inch (2.5 cm) in thickness, which shall not break down or delaminate under fire conditions. All joints shall be rabbeted and shall be fastened in two directions with wood screws. When more than one door is used there shall be a rabbeted overlap of not less than 1 inch (2.5 cm). 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. A raised sill or pan capable of containing a 2-inch (5 cm) depth of liquid shall be provided at the bottom of the cabinet to retain spilled liquid within the cabinet.
Leben also says that wooden cabinets are more resistant to corrosion than metal ones. If there’s a small spill, “there could be some degradation in the wood, but it’s got to get through coating and sealant and through 1 inch thick plywood lapped together,” Leben says. “It’s really tough to get through all that stuff.”