Chemical characterization and phytotoxicity assay of Novolac phenolic foam resin from healthcare services: Challenging environmental liability

Abstract

Novolac phenolic foam resin (NPFR), a polymer of phenol and formaldehyde, is used in healthcare to ensure thermal stability of cold chain products. Post-use, NPFR is classified as non-hazardous solid waste and disposed of in landfills without prior treatment. However, it contains formaldehyde and phenol, two well-established toxicants, posing environmental and health risks. The full extent of these risks has not been evaluated, raising concerns about NPFR disposal. This study investigates the chemical and toxicological properties of NPFR to assess its environmental implication and the potential consequences of its disposal to support proper management strategies. The SEM-EDS revealed C, O, Ca, Na, Si, S, and K as the main elements. TGA-DSC curves showed mass losses related to dehydration (8.2 % - 180 °C) and organic matter degradation. According to the FTIR spectrum, traces of formaldehyde and phenol were found. GC-FID revealed formaldehyde levels: 660 mg L−1 [σ = 23.72] for solid fraction of NPFR and 441 mg L−1 [σ = 16.20] for a liquid fraction, while the content of phenol was 242 mg kg−1 [σ = 8.30] for a solid fraction of NPFR, and 210 mg L−1 [σ = 9.10] for a liquid fraction. These constituents confer toxicity to the residue. In the Lactuca sativa bioassay, the NPFR extract was considered as toxic at concentrations ranging from 31 to 125 g L−1, indicating a significant risk to plant life and, by extension, to the ecosystem. Based on these results, it may be concluded that the NPFR, classified as an environmental liability, requires a reevaluation of current management practices due to the risks associated with its conventional disposal methods. Furthermore, the current study provides relevant results and can contribute to public solid waste management policies, in accordance with the Sustainable Development Goals.