Life cycle assessment (LCA) is a standardized tool (ISO 14040) used to evaluate the environmental impacts of products and processes across their entire life cycle, from raw material extraction to end-of-life disposal or recycling. It has become particularly important in the context of engineering materials, where sustainability considerations are critical. Despite challenges such as data quality limitations, variations in system boundary definitions, and methodological inconsistencies, LCA remains an essential tool for assessing and improving product sustainability. This work presents a foundational overview of LCA principles and describes a systematic, step-by-step procedure for its effective application. Additionally, this article revisits the fundamental concepts of carbon footprint (CF) analysis as a complementary tool for quantifying greenhouse gas emissions associated with products and activities. CF analysis underscores the necessity of adopting low-carbon materials and manufacturing processes to minimize embodied energy and reduce environmental emissions. Low-carbon materials are characterized by attributes such as being lightweight, recyclable, renewable, bio-based, locally sourced, and safe for public health. Their development balances the reduction of raw material and resource consumption during production, with increasing product performance, recyclability, and service life, reflecting a cradle-to-cradle, circular economy approach. The integration of LCA and CF methodologies provides an integral framework for assessing environmental performance and supports decision-making processes aligned with global sustainability targets.

Zinc borate (ZnB) has been used as a flame retardant, a smoke suppressant, and an antitracking agent in several applications. It may show synergistic effects with antimony oxide and metal hydroxides in fire retardant systems. In this work, the effect of ZnB on the flame retardancy of PET (poly(ethylene terephthalate)) woven fabrics was investigated. In order to provide the homogenous application of ZnB to the fabrics, the particle size of ZnB powders was reduced from 9 μm to submicron scale by wet-milling with zirconia balls followed by high shear fluid processing. ZnB dispersion was mixed with low-formaldehyde melamine resin based cross-linking agent and it was applied to PET fabrics by pad dry cure method. ZnB dispersion was then added in different ratios to alkyl phosphonate and organophosphorus compound based commercial flame retardant finishing agents and applied to the fabrics. The effect of zinc borate with phosphorus based flame retardant (FR) finishing agents was examined by cone calorimetry under a heat flux of 35 kW/m², vertical flame test, and limit oxygen index. Thermogravimetric analysis was performed up to 800°C under N₂flow. Test results show that zinc borate can be combined with the organophosphorus based commercial FR finishing agents. Zinc borate could not improve the flammability properties of PET fabrics significantly but decreased mean CO, total smoke release, and total smoke production values.

Kaolinite, sepiolite, and clinoptilolite were used as carriers to develop antibacterial materials. The materials were enriched in sodium by ion exchange. Silver ion exchange by silver nitrate followed by phosphoric acid treatment enabled the controlled release of silver. The antibacterial function of the materials was investigated by halo test and the amount of silver released was investigated by energy dispersive X-ray spectroscopy. The enhanced antibacterial efficiency was obtained by minimizing the silver release which further provided longevity to the material and prevented the health risks posed by excess silver release.

Flame-retardant composite hydrogels provide significant advantages over conventional fire suppressants due to their high water retention, char-forming ability, and mechanical adaptability. However, the current formulations mostly rely on synthetic polymers or nanoparticles which restricts their large-scale application and reduces sustainability. In this work, we developed lignin-incorporated dynamically crosslinked cellulose nanocrystal (CNC) hydrogels and systematically investigated the interrelation between microstructure, rheological behavior, thermal properties, and flame-retardant performance. The incorporation of lignin at moderate concentrations enhanced hydrogen bonding, resulting in a denser and more homogeneous hydrogel network with reduced mesh size. The resulting elastic network enhanced water retention during burning, promoting flame retardancy via substrate cooling and fuel dilution effects. Additionally, lignin facilitated the formation of a compact glassy char layer, effectively serving as a heat and oxygen barrier. Thermal decomposition of dried CNC films resulted in 8.6 % residue at 700 °C, whereas CNC-lignin-borax composites exhibited a significant increase in char yield, reaching 70.5 %. The optimal lignin composition extended burn-through time of wood to 12 min-71 % and 33 % longer than uncoated and neat CNC samples. Our findings highlight the potential of CNC-borax-lignin hydrogels as biorenewable environmentally friendly coatings with superior flame-retardant properties, offering a sustainable approach to fire prevention in wood-based materials.