Weidong Wang

Volatile organic compounds (VOCs) from furniture and interior furnishing materials have been proven to pose adverse health effects. However, very VOCs (VVOCs) and odors were rarely taken into account. To bridge this gap, emissions of VVOCs and odors from medium density fiberboard (MDF) coated with different lacquers were characterized using gas chromatography coupled with mass spectrometry and olfactometry detection. The results demonstrated that the total VVOC AT THE 28th d (TVVOC28) from the control sample was higher than that of the other three lacquered samples. Alcohol VVOCs were the most abundant chemicals from the control MDF, followed by ketones, esters, and ethers, accounting for more than 90% of the total concentration. Also, they were the major odor-contributing substances with higher odor intensities. Nitrocellulose (NC), polyurethane (PU), and water-based (WB) lacquer paintings had a suppressive effect on the emission of certain VVOCs but promotion of the others. After the lacquer paintings, alcohols and ethers were the major components, accounting for 82.3% ~ 88.0% of the total VVOC. In addition, odors were affected by these three lacquer paintings. Fruity was the dominant odor impression of MDF, NC and PU decoration MDF, with an odor rating of 4.4, 7.1, and 4.9, respectively. A multiodor mixture was the major odor impression of WB decoration MDF, with an odor rating around 4.0. The odor may differ from one lacquer to another. Additionally, a newly added fishy-like odor arose in PU lacquer painting. From the data analysis of this study, PU and WB decoration MDF might be suitable for furniture or decorative materials due to their lower pollutants and odor emissions. Based on the comprehensive evaluation indices, the latter may be more preferred and was highly recommended for indoor applications.

Very volatile organic compounds (VVOCs) are a group of important odor pollutants affecting indoor air quality that have been shown to be harmful to human health. A 15 L environmental chamber, combined with multi-bed tube was used to collect gases. Fifteen very volatile organic compounds (VVOCs), including 12 odor compounds, were identified from veneered medium density fiberboard coated with water-based lacquer (WB-MDF) using gas chromatography–mass spectrometry/olfactometry (GC-MS/O). The total very volatile organic compound (TVVOC) and total odor intensity (TOI) showed a decreasing trend over time, reaching equilibrium on day 28. TVVOC showed an overall slow-fast-slow emission profile, from day 3 to day 7, with a maximum decay rate of 29.7%. TOI showed the greatest rate of decline from day 1 to day 3, at approximately 12%. Alkane and alcohol VVOCs were the more abundant compounds, accounting for at least 60% and even up to 80% of the total. The major odor impression was fruity, with a highest odor rating of 6.6, followed by sweet, with an odor rating of 6.1. Although the odor impression changed from sweet to fruity over time, it seemed pleasant overall. The odor contributors were mainly alkanes, alcohols, esters, and ethers, which had relatively high odor intensities. The main odor-contributing substances were dichloromethane, ethanol, ethyl acetate, 2-methylacrylic acid methyl ester, and tetrahydrofuran. When WB-MDF is used for furniture or other decorative materials, it is strongly recommended that it be stored under ventilation for at least 28 days and the adoption of substitute solvents of lacquers, modified adhesives, and low-odor wood raw materials is recommended. These possible initiatives would contribute to the aim of building an environmentally friendly indoor environment.