What is the difference between a UL Class 125 and UL Class 150 fireproof cabinet?

UL Class 125 and Class 150 are fire protection ratings for media and data storage, where the number represents the maximum internal temperature in Fahrenheit allowed during the test period. Class 125 (maximum 125°F interior) is designed for magnetic media — magnetic tape, floppy disks, and some hard drives lose data above 120°F–150°F. Class 150 (maximum 150°F interior) is designed for flexible film, optical media, and some digital storage. Both are significantly more protective than Class 350 (for paper) where the interior is allowed to reach 350°F — paper chars at 451°F, but digital media fails well below that. If you're storing electronic media, a Class 125 or Class 150 cabinet is necessary. FindOfficeFurniture.com — call 888-719-4960 for media-rated options.