Identification of odour compounds emitted by wooden boards with the presence of indoor ozone

Indoor volatile organic compounds (VOCs) produce odours that reduce perceived air quality. Furnitures and indoor decoration are the main sources of indoor VOCs. Considering the increase in outdoor and indoor ozone concentrations, ozone, as a strong oxidant, can have an impact on indoor odour. Herein, medium-density fibreboard (MDF) and flame retarded plywood (FRP) were selected as experimental materials, and gas chromatography-olfactory-mass spectrometry (GC-O-MS) was performed to identify the odour compounds emitted by materials with and without 100 ppb ozone. MDF1, MDF2 and FRP emitted 6, 8 and 14 different odour compounds, respectively. MDF2 emitted moderate grassy and sour odours. FRP emitted moderate grassy, fruity, rubber and pine incense odours. After 8 h of exposure to ozone at a concentration of 100 ppb, MDF1, MDF2 and FRP emitted different odour compounds, respectively. The characteristic odours of MDF were aggravated. Except for pine incense odour, the intensity of other characteristic odours of FRP was weakened. Through cluster heatmap analysis and principal component analysis, the characteristic odour compounds of MDF and FRP were further clarified. Introducing a SOI model, the results showed that ozone exposure increased the SOI of MDF1 and MDF2 from 3.34 to 4.22 and from 4.11 to 4.44, respectively, and that the odour intensity of FRP decreased from 3.78 to 3.41. It can be determined that ozone may have opposite effects on the odour emitted by different materials. The results clarify the target pollutants for odour control research on wooden board emissions.