The study investigates the exposure of firefighting personnel to hydrogen cyanide (HCN) during fire suppression operations, with a particular focus on the permeation of HCN through protective clothing. Experiments were carried out on four representative garments – SAND, ROT, BLAU and WALD – covering both indoor and vegetation fire scenarios. The garments were examined in their individual flat textile layers (Versuchsreihe A) and in complete multilayer constructions (Versuchsreihe B). The test protocol involved controlled exposure to HCN‑laden atmospheres, measurement of permeation fluxes, and evaluation of the influence of moisture, mechanical stress and surface impregnation on the barrier performance.
Results show that HCN can penetrate the outer layers of firefighting apparel and reach the skin, especially when the fabric is wet or mechanically deformed. Moisture was found to increase permeation rates markedly; in wet conditions the flux through ePTFE membranes rose by a factor of two compared with dry tests. Mechanical loading, such as bending or compression, further enhanced permeation, whereas the application of a hydrophobic impregnation reduced the flux by up to 30 %. The multilayer garments exhibited the lowest permeation values, confirming that a three‑layer construction with an inner protective membrane provides the best barrier against HCN. In all cases, the permeation rates remained below the acute toxicity threshold for short exposure periods, but the study warns that in fires with very high HCN concentrations the cumulative skin absorption could reach levels associated with acute poisoning. The authors therefore conclude that while the risk of acute cyanide poisoning during typical fire operations is low, it cannot be ruled out in extreme scenarios, and that protective measures should be reinforced accordingly.
The experimental data also reveal that the skin absorption of HCN is a function of both the chemical concentration in the ambient air and the duration of exposure. The study’s reference tests, performed with standard laboratory textiles, confirmed the validity of the permeation measurements and provided baseline values for comparison. Based on the findings, the report proposes several recommendations: use of multilayer garments with hydrophobic coatings, regular inspection of fabric integrity, and consideration of additional respiratory protection in high‑risk environments.
Regarding collaboration, the report does not specify individual institutional partners or funding bodies. It indicates that the research was conducted by a consortium that includes firefighting units and research laboratories, but no explicit names or grant identifiers are provided. Consequently, the exact roles of each participant, the project timeline, and the source of financial support remain unspecified in the document.