Terpene emissions from particleboard and medium-density fiberboard products

Indoor air quality problems resulting from emission of volatile organic com pounds (VOCs) have become an issue of increasing concern. Factors known to affect VOC levels in indoor air include: ventilation rate, occupant activit ies, and emissions from building and furnishing materials. In this research , VOC emissions from particleboard and medium density fiberboard (MDF) were measured in small stainless steel chambers (53 L) during a 4-day period. A protocol was developed to obtain new and representative samples and to min imize contamination of the samples during collection, preparation, and ship ment to the laboratory. Samples were collected from 53 of the 61 U.S. mills that produce particleboard and MDF Each mill identified the predominant tr ee species used to manufacture the panels. The laboratory tests were conduc ted at 45 percent relative humidity and used a gas chromatograph and a mass selective detector to identify and quantify VOC compounds. The predominant compounds identified in emissions from the particleboard and MDF samples w ere terpenes and aldehydes. Small straight-chain alcohols and ketones were also found. This study describes the terpene emission data. Quantified terp enes included alpha- and beta-pinene, camphene, 3-carene, p-cymene, limonen e, and borneol. Terpene emissions accounted for between 7 and 21 percent of the total VOC emissions, calculated as alpha-pinene. The highest terpene e missions were observed from particleboard samples manufactured from pines o ther than southern pine. For particleboard, terpene emissions were largely related to the extractive content of the wood species. The terpenes were al most completely absent in emissions from MDF samples, which indicates that differences in the manufacturing of MDF compared with the manufacturing of particleboard may have considerably affected emissions. After 4 days, the t erpene emissions from all particleboard samples decreased to between 20 and 70 percent of their initial values.