Outer shell layer seam assemblies where rupture could reduce the protection of the garment by exposing the inner layers such as the moisture barrier, the thermal barrier, the wearer's station/work uniform, other clothing, or skin
NFPA 1976 Standard on Protective Ensemble for Proximity Fire Fighting, 2000 ed. https://www.nfpa.org/assets/files/AboutTheCodes/19 76/TIA1976-00-1.pdf, (Std: Prot Ens for Proximity Fr Fight - Amer) {430 NFC}