Author :
Publisher :
ISBN 13 :
Total Pages : 57 pages
Book Rating : 4.:/5 (683 download)
Book Synopsis Characterization of the Sources and Concentrations of Formaldehyde and Other Volatile Organic Compounds in Four New Manufactured Houses by :
Download or read book Characterization of the Sources and Concentrations of Formaldehyde and Other Volatile Organic Compounds in Four New Manufactured Houses written by and published by . This book was released on 1998 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt: The concentrations of formaldehyde, 52 individual volatile organic compounds (VOCs) and total VOCs (TVOC) were measured in four new manufactured houses on three occasions over a period of approximately nine months following completion of their construction. The houses were furnished, but unoccupied, model homes produced by a single U.S. manufacturer. Several of the houses incorporated interior finish materials with lower VOC emissions than standard materials. One house had a modified ventilation system. Ventilation rates were measured concurrently with the collection of air samples. A steady-state mass-balance model was used to calculate the area-specific emission rates of the target compounds and TVOC. The emissions of formaldehyde and VOCs from a specimen of plywood used as the floor sheeting were additionally quantified. The median formaldehyde concentration in the four houses was 37 parts-per-billion (ppb). The formaldehyde concentrations were all less than the most restrictive guideline for this compound of 50 ppb. The concentrations of many of the target VOCs were low. Thirty-one of the VOCs had median concentrations that were at or below 1 ppb. Seven of the compounds were among the most abundant VOCs in all four houses. These compounds were alpha-pinene, beta-pinene, 3-carene, ethylene glycol, hexanal, 2-butanone, and acetic acid. The concentrations of the aldehydes, hexanal, octanal and nonanal, in the four houses were either near or exceeded their respective odor thresholds. The concentrations of acetic acid increased with time. In the final sampling period, the odor threshold for acetic acid was exceeded in all of the houses. The range of TVOC concentrations in the four houses was 0.8 to 3 mg m−3, with a median value of 1.6 mg m−3. These concentrations were somewhat lower than TVOC concentrations previously measured in several new site-built houses, and the median concentration was only about twice the typical value for existing residences. The house with the modified ventilation system and several lower emitting materials had consistently low TVOC concentrations that were near 1 mg m−3. There were no large decreases with time in the emission rates of the individual VOCs or TVOC during the course of the study. However, the emission rates were often lowest in the final sampling with the notable exception of the acetic acid emission rate that increased with time. The source of the aldehydes was most likely engineered wood products, such as the plywood floor sheeting and possibly other structural or interior components. The source of the acetic acid was uncertain. The effects of the source substitution treatments were measurable but turned out to be relatively minor due to the predominance of other sources.
