Previous approaches to suppressing fire hazards are concentrated on brominated flame retardants (BFRs) or phosphorus flame retardants (PFRs). However, their chemical hazards to health and environment have not been able to be ignored currently. It is quite urgent to propose a durable and environmentally-friendly fire-safe strategy, which can eliminate migration, release, and environmental hazards of traditional flame retardants during their use, disposal, and recycling. Herein, we design a fire-responsive molecule (FRM) only containing C, H, and O elements based on full-life-cycle consideration and achieve fire safety via the synergy of specifically binding aliphatic fragments and aromatized charring in combustion. The resulting polymer shows low fire hazard with excellent self-extinguish, low organic volatiles/heat/smoke release, and good comprehensive performance. This polymer can be fabricated to fibres with potential applications for textiles, and electronics, etc. Therefore, we achieve a durable fire-safe strategy without flame-retardant chemicals hazard. This approach can fundamentally eliminate the potential chemical hazards associated with the introduction of halogen or phosphorus flame retardants and give a new vision about solving the "flame retardant chemical hazard issues" that are debated, tracked, and evaluated for several decades.