Key Requirements from NFPA 1970

Definition and Role: The chin strap is part of the helmet's retention system, defined as "the complete assembly by which the helmet is retained on the head," including the chin strap, adjustable liner, and any breakaway devices. It must secure the helmet without restricting movement or causing discomfort.

• Design Specifications:

  • Must be a multi-point system (typically 2- or 4-point configuration) with quick-release buckles or postman's slide closures to allow rapid removal if entangled.

  • Minimum width: Not explicitly stated in 2018 edition, but implied to be sufficient for load distribution (e.g., Nomex webbing for flame resistance).

  • Materials: Flame-resistant (e.g., Nomex or Leather) to withstand heat exposure without melting or degrading. It is important to note that Leather is a permitted material, as it is used in helmets, gloves, belts, scabbards, boots and more. Leather has flame resistance, heat endurance, tensile/load strength, cleanability with mild soap, water and shoe polish.

• Performance and Load Regulations:

  • Retention Load Test: The chin strap must retain a 50 lbf (222 N) dynamic tensile load applied at 14–18 mph (6.3–8.0 m/s) without exceeding 3 inches (76 mm) displacement or breaking. This simulates forces from falls or impacts, ensuring the helmet stays on the head. Video documentation can be found at the bottom of this page.

  • Flammability and Heat Resistance: Materials must self-extinguish within 3 seconds after 3-second flame exposure and show no melting or dripping.

  • Compatibility: Must interface with SCBA facepieces and hoods without slippage.

• Maintenance (NFPA 1851 Integration): Chin straps must be inspected for wear, fraying, or damage; replaced if compromised. Soft goods (including chin straps) are now required to be removable and reinstallable within 20 minutes for cleaning.