Mosquito-repellent textiles are a part of protective textiles which help in protection from the species that are prone to cause diseases like malaria and dengue fever. This study explored the possibility of natural extract (alcoholic) from peppermint leaves, stems, and garlic cloves to use as a mosquito-repellent finish material on knit fabric. Accordingly, different concentration (5%, 15%, 25%, and 35%) of PGE (Peppermint Garlic Extract) solution was prepared and applied to the developed fabric using an exhaust dyeing process to assess the mosquito (Aedes Aegypti L.) repellency performance. Following WHO (World Health Organization) standard (cone bioassay) and a self-modified cage technique from literature survey, mosquito protection and repellency tests have been performed for characterization. The findings revealed that the PGE-treated fabric samples C (25% PGE) and D (35% PGE) had the highest mosquito mortality (50.00% and 76.67%, respectively) and repellency (78.6% and 85.6%, respectively) rates. Moreover, this study evaluated the prepared PGE formulations’ shelf-life performance and colorfastness properties of PGE-treated fabrics, including the impact of washing cycles on the treated fabrics. There was no fungal growth, and the fabric showed excellent colorfastness properties. However, the efficacy of treated fabrics decreased with an increasing number of washes.

Fire smoke, rich in toxic ultrafine particles and polycyclic aromatic hydrocarbons (PAHs), poses significant health risks to first responders and vulnerable populations. In this study, a reproducible combustion–smoke simulation platform was developed to mechanistically quantify fire behavior, particle emissions, and PAH toxicity under controlled heat flux and oxygen conditions. Consistent combustion and smoke emissions were achieved by measuring heat release rate, particle mass, particle number concentration, and PAH concentration, with an overall average coefficient of variation below 15%. Systematic experiments with representative biomass (pine, oak) and plastics (PVC, polystyrene) demonstrate that fuel composition, heat flux, and oxygen availability jointly govern particle formation and PAH partitioning. Regardless of the combustion factors, ultrafine particles dominated the particle number concentration (55.5–86.2%). Plastic combustion generated 7 to 59 times particle mass, up to 260 times higher PAH emissions, and up to 58,500 times greater PAH toxic equivalent quotient (PAH-TEQ) than wood. Oxygen-deficient and smoldering regimes shifted emissions toward fine and ultrafine particles enriched in high-molecular-weight PAHs, revealing a coupled physical–chemical hazard not captured by bulk PM metrics alone. These results establish a quantitative framework linking combustion regime, particle size, and PAH toxicity, providing critical insight for exposure assessment, PPE design, and mitigation strategies in ventilation-limited and mixed-fuel fire scenarios.

Lithium-ion battery fires present complex aerosol hazards that vary substantially with oxygen availability; however, the effects of oxygen depletion on particulate emissions, soot transformation, and contamination pathways remain poorly characterized. Here, LiNi₀.₈Mn₀.₁Co₀.₁O₂ (NMC811) 18650 cells (2.5 Ah) were tested across a 12-condition state-of-charge–oxygen matrix (0–70% SOC; 20.95%, 7%, and 0% O₂) under 50 kW/m² radiant heating. Reducing O₂ decreased peak heat release rate by 47–71% but increased total particulate matter by 22–158% and particle number concentration by 84–134%. Ultrafine particles (≤100 nm) dominated particle emissions, accounting for 80–94% of total counts. Airborne metal emissions exhibited a non-monotonic oxygen response, reaching 11.90 ± 0.68 µg/m³ at 7% O₂ and 70% SOC, representing a 65% increase relative to normoxic (20.95% O₂) conditions. Multi-technique soot characterization (HRTEM, Raman spectroscopy, and XPS) revealed increased carbon ordering under oxygen depletion, evidenced by reduced D1/G ratios (0.386→0.261), decreased fringe tortuosity (1.37→1.13), and substantially lower oxygenated surface carbon. Soot–metal aggregate particle diameters increased from 47 ± 9 to 61 ± 11 nm. SEM–EDS identified Ni- and Co-rich particle deposition throughout firefighter PPE layers under reduced or absent flaming conditions. These results demonstrate that oxygen depletion shifts NMC battery-fire emissions toward enhanced ultrafine particle loading, persistent metal-containing aerosols, and more ordered soot structures, providing source-characterization data for battery-fire hazard assessment and for future validation of mitigation, exposure-control, and PPE-contamination protocols.