Energy Absorbing System 1 : A material, suspension system, or combination thereof incorporated into the design of the helmet to attenuate impact energy
NFPA 1971 Standard on Protective Ensemble for Structural Fire Fighting, 2000 ed. https://www.nfpa.org/Assets/files/AboutTheCodes/19 71/1971-A2006-ROC-Preprint.pdf, (Std: Prot Ens for Stru Fr Fight - Amer) {428 NFC}