Firebrake® 415

Firebrake® 415 is a unique proprietary zinc borate compound with multifunctional fire retardant applications in a variety of polymers. Request a sample.

Applications & Benefits

Having a higher zinc to boron ratio and much higher dehydration temperature than Firebrake® ZB, this zinc borate is preferred in applications where the processing temperatures can be up to 415 °C. Improved smoke reduction has also been noted with this zinc borate in PVC.

Firebrake® 415 fire retardant is a unique proprietary* zinc borate compound with multifunctional applications in a variety of polymers. It has an unusually high dehydration onset temperature of >415 °C (780 °F). Therefore it can be used in polymer systems requiring very high processing temperatures. It is a white powder that can be fed to extruders, calenders, or injection molding equipment in the same way as other solid polymer additives.

Firebrake® 415 can be used as a flame retardant and smoke suppressant in a variety of polymers. It is particularly useful in systems such as nylon that require high processing temperatures, where enhanced thermal stability has been noted in some cases. Firebrake® 415 is also an excellent smoke suppressant for systems such as flexible PVC.

Chemical and Physical Properties

Theoretical composition
Boric Oxide, B2O3 16.85%
Zinc Oxide, ZnO 78.79%

Characteristics (typical values)
Refractive Index 1.65
Median Particle Size 5 microns (Laser Diffraction)
Thermal Stability Stable to >415 °C
Weight Loss (TGA) 0.4% max. to 415 °C.
Bulk Density ca. 0.37 g/cm3 (23lb/ft3)
Specific Gravity 3.7

Firebrake® 415 is a fine powder that shows little tendency to cake or absorb significant amounts of moisture when stored under normal atmospheric conditions.

*Protected by US and international patents.


Senior Development Specialist

Fred Ascherl

Fred has worked for Rio Tinto Borates for over 37 years. He currently holds a position as a Senior Development Specialist.