Wildfire smoke composite — the defining pattern.
The January 2025 Palisades Fire exposed every property in the corridor — whether it burned or not — to weeks of active fire smoke, ash, and ember activity. HVAC systems pulled wildfire smoke composite (burned structures, plastics, vehicles, and household contents mixed with wildland fuels) into every home. Its chemistry is more aggressive than wildland-only smoke, and it keeps off-gassing indefinitely without full remediation.