Compatibility
Product compatibility with legacy products listed on the Qualified Products List (QPL) is a mandatory requirement of both Federal and State wildland fire agencies. The 5100-304d Long-Term Fire-Retardant (LTFR) specification is currently being revised following the failure of the magnesium chloride product and the subsequent investigations by the NTSB and NIST.
Working in close collaboration with the National Institute of Standards and Technology (NIST), the USFS has introduced three new test requirements to ensure the successful integration of new aerial LTFRs. These requirements include crevice corrosion, galvanic corrosion, and compatibility testing. This partnership between the USFS and NIST has restored trust within the wildland firefighting community. We applaud their efforts to strengthen the integrity of the LTFR specification, a critical step toward restoring competition in the LTFR market.
We are excited to announce that Kaiterra GPP-F has successfully passed all testing required under the 5100-304d specification, and has been evaluated for compliance with proposed 5100-304e updates. Below is a quote from the National Technology Development Program office, dated May 12, 2026, regarding the compatibility of our product.
"Kaiterra products were evaluated for compatibility with other legacy long-term QPL retardants containing similar ammonium phosphate base retardant salts. They did not demonstrate any clumping, pH swings, color/physical changes or precipitation of solids when cross-mixed with other QPL legacy products. These products meet all burn testing criteria as outline in the specification and are expected to behave very similarly to other ammonium phosphate-based legacy products on the QPL."