NFPA 11: 2021 Edition makes the following recommendations:
- “Different types of foam concentrates shall not be mixed for storage.” (Para. 220.127.116.11)
- “Different brands of the same type of concentrate shall not be mixed unless data are provided by the manufacturer ... to prove that they are compatible.” (Para. 18.104.22.168)
In accordance with NFPA 11: 2021, quality foam concentrates of the same type from different suppliers can be mixed, provided that the supplier presents a Certificate of Compatibility (C of C).
Compatibility testing consists of:
- Freeze / thaw ageing
- Physical property evaluation
- Fire Tray performance testing
To be given a C of C, the foam concentrate should show no reportable adverse reactions.
For further information or to request a copy of any of our Certificates of Compatibility, please contact us.
- Quality foam usually refers to those tested and accredited to International Standards such as UL 162 or ICAO Level B.
- We recommend that Alcohol Resistant (AR) foams are never mixed.
- In order to maintain EPA 2010/15 compliancy, it is recommended that C6 foams are not mixed with any other foams.