Screening of Wood Raw Materials for Low-Odor Fiberboard and Particleboard Production: Analysis and Evaluation Based on Volatile Odor Compounds

Woody raw materials of wood-based panels like fiberboard and particleboard are one of the primary sources of product odor and one of the indicators affecting the comprehensive health risk assessment of wood-based panel products. This study employed Gas Chromatography-Mass Spectrometry-Olfactometry (GC-MS-O) to investigate the odorant composition and odor characteristics, including Total Odor Concentration (TOC), odor intensity (OI), odor activity value (OAV), and risk value (RV), of 22 wood species commonly used in fiberboard and particleboard production in China. This research identified the major odor-active compounds in wood and provided recommendations for selecting wood raw materials suitable for low-odor fiberboards and particleboards produced by integrating RV and toxicity classification data. The results showed that the main compound types influencing wood odor in 22 wood species were predominantly terpenes, aldehydes, and alcohols. Woods of <i>Cinnamomum</i>, <i>Machilus</i>, and <i>Pinus</i> contained a higher number of dominant odor compounds (OAV > 1 and OI ≥ 3). Wood with stronger odor intensity included <i>Cinnamomum</i>, <i>Pinus</i>, <i>Machilus</i>, <i>Bischofia</i>, and <i>Saurauia</i>. The total RV of <i>Cinnamomum</i>, <i>Pinus</i>, <i>Machilus</i>, <i>Cunninghamia</i>, and <i>Bombax</i> wood exceeded one, necessitating special attention when used as raw materials for wood-based panels. Camphor in <i>Cinnamomum</i> and <i>Machilus</i> wood was the most concentrated odorant, followed by 3-Carene in <i>Pinus</i> wood. Odorants with high OAV included Longifolene, δ-Cadinene, Terpinen-4-ol, 2-Nonenal, γ-Terpinene, d-Limonene, 3-methyl-Butanal, Octanal, α-Pinene, Hexanal, D-Camphor, and trans-Calamenene. Odorants with high RV included terpenes, alcohols, aldehydes, and ketones, such as Camphor, 3-Carene, Eucalyptol, α-Terpineol, β-Pinene, α-Santalene, δ-Cadinene, Safrole, Longifolene, and d-Limonene. Focusing on the reduction and control of these odor-active compounds represents a primary approach to mitigating odors in fiberboard and particleboard products. However, addressing health risks associated with product odors requires additional attention to four specific substances: Safrole, Camphor, Eucalyptol, and α-Terpineol. Although the total RV for the five wood species exceeds one, this does not necessarily mean the final wood-based panel product's RV exceeds one, as it also depends on the influence of the production process. Therefore, further research should be conducted to investigate the effects of various process parameters in wood-based panel production on the odor compounds present in the final panels. From a comprehensive perspective, considering the overall odor characteristics of wood volatiles, all 18 wood species (<i>Salix</i>, <i>Populus</i>, <i>Rhaphiolepis</i>, <i>Ligustrum</i>, <i>Prunus</i>, <i>Fagus</i>, <i>Pterocarya</i>, <i>Firmiana</i>, <i>Celtis</i>, <i>Cunninghamia</i>, <i>Bombax</i>, <i>Bischofia</i>, <i>Ficus</i>, <i>Saurauia</i>, <i>Eucalyptus</i>, <i>Aleurites</i>, <i>Melia</i>, <i>Bridelia</i>) are suitable for the production of low-odor fiberboards and particleboards.