The area of a particle barrier is an effective filter for particle sizes from >0,1 μm to >0,2 μm. This means the particle barriers used provide optimal protection against penetration by dangerous harmful substances such as polycyclic aromatic hydrocarbons (PAH). As the saying goes, a chain is only as strong as its weakest link. And the weakest link in these particle barriers are the seams. A sewing needle has an average thickness of 0.9 mm to 1.1 mm (1 mm = 1000 μm). The hole that a sewing needle makes in the particle barrier is thus 10,000 times larger if the filter effect is >0,1 μm. Since the dividing seams on the hoods are almost exclusively executed with flat seams (to prevent pressure marks), the untight points double. The smaller the cut portions which make up the hood are, the more weak points the hood will have. To obtain a sustainable test, TEXPORT® developed a testing device (no laboratory standard), in order to get proof of the tightness of the particle barrier seams quickly and easily. In video c mparison, this is proven quite impressively. 85 % Effectiveness Unsealed seams 99,99 % Effectiveness TEXPORT® with sealed seams Fig. Fire Seal PP 3ly short, O A 10, 004 in combination with Fire Survivor-Jacket, ZA16, 203 (example) The perforated seam hole is in part filled in with thread. This cannot really be called seam-sealing though. On the contrary: If the seams are stretched when taking the hood off or putting it on – which is unavoidable – the seams will be stretched by the pulling force acting on them and the seam hole will open wider. For this reason, the greatest possible attention must be paid to finishing the particle barrier’s seams during manufacturing. In contrast to its competitors, TEXPORT® takes a different road in manufacturing flame-retardant hoods. TEXPORT® is the only manufacturer which seals all seams of the particle barrier with a seam sealant. This assures that the particle barrier of TEXPORT®-flame-retardant hoods guarantee an effectiveness of 99 99 % (NFPA 1971-2018) at the intersecting seams even after 50 washes.