| Antifreeze | Max concentration | System type |
|---|---|---|
| Propylene glycol (listed) | 30% by volume | Residential and commercial |
| Glycerine (listed) | 38% by volume | Residential and commercial |
| Factory-premixed listed solution | Per listing | All |
| Sodium chloride brine | Prohibited | — |
| Calcium chloride brine | Prohibited (new systems) | — |
Notes
- Post-2012 NFPA 13 prohibits field-mixed antifreeze; only listed pre-mixed solutions.
Source
NFPA 13 (2022) §7.6.
Cite this page
- APA
- FireTwin AI (2026). Antifreeze concentration limits (NFPA 13). FireTwin AI. https://firetwin.eu/data/antifreeze-limits
- IEEE
- FireTwin AI, "Antifreeze concentration limits (NFPA 13)," FireTwin AI, 2026. [Online]. Available: https://firetwin.eu/data/antifreeze-limits