Field And Laboratory Emission Cell Research Articles

Emissions of acetic acid and other volatile organic compounds from different species of solid wood

The emission of volatile organic compounds (VOC) from wood and wood products are important in evaluating the impact on the indoor environment from different materials. The results from analyses of emissions from nine different wood species are presented in this article. The measurements were made with Field and Laboratory Emission Cell (FLEC) and with Head-Space (HS) analyses and the results from the different methods are discussed. The main emissions are terpenes from softwood and acetic acid from hardwood.

Characterization of the field and laboratory emission cell—FLEC: Flow field and air velocities

Abstract The Field and Laboratory Emission Cell (FLEC) has been designed for VOC emission testing of material surfaces. Knowledge about the air flow field in the cell compartment is highly desired, as the air velocity at the sample surface may considerably influence the emission behaviour. A simple mathematical approach of flow theory predicted an unevenly distributed air flow into the FLEC. This could be confirmed by air velocity measurements using a self-constructed hot-wire anemometer. With a total flow of 250 ml min −1, air velocities measured at the surface ranged from ⩽ 0.1 to 0.9 cm s −1. A surface area of very low air velocities was detected in the FLEC centre with a radius of ≈20 mm. A VOC emission test using a simulated punctual source yielded different emission rates at different locations in the cell compartment.

Toluene in Rotogravure Printed Brochures: High Speed Emission Testing and Comparison with Exposure Data

Abstract Residual solvent in rotogravure printed brochures has given rise to complaints and injury reports among postal workers in Denmark. A method has been developed for a fast determination of the emission of toluene from rotogravure printed brochures by use of the field and laboratory emission cell (FLEC). Emitted compounds were identified by gas chromatography-mass spectrometry. Toluene head space concentration in packs of brochures was measured by use of a photoionization detector. The emission decay was monitored by use of the FLEC with photoionization detection or with sampling on Tenax TA. Highly time-resolved personal exposure measurements were performed during simulated mail handling in a 41-m3 test chamber using a newly developed photoacoustic infrared detector, paralleled by personal sampling on Tenax TA. Toluene constituted about 99 percent of the emission. Head space concentrations up to 2145 ppm were measured. The FLEC-photoionization detector measurements showed toluene emission decay curves rapidly decreasing during the first 1 to 3 minutes. Areas under the curves correlated with FLEC-Tenax measurements. The FLEC-photoionization detector method was repeatable and seemed to be reproducible. Highly time-resolved personal exposure measurements during simulated mail handling showed frequently repeated peak exposures exceeding the Danish occupational exposure limit. There was a fair correlation between personal exposure measurements, toluene head space measurements, and FLEC measurements. The FLEC-photoionization detector method yields a rapid determination of toluene emission and is recommended for on-line production quality control.

A new approach for indoor climate labeling of building materials—emission testing, modeling, and comfort evaluation

A labeling system for building materials' primary emission of volatile organic compounds (VOCs) according to their impact on comfort and health has been developed and introduced in Denmark. The system unifies chemical emission testing over time (months), modeling (including a standard room and mathematical modeling of the emission profile, when necessary), and health evaluation. As a first step, the Danish system focuses on comfort, i.e. odor annoyance and mucous membrane irritation, because of their preponderance in the sick building syndrome reporting and the absence of other relevant data on indoor air related health effects. Two design criteria have been set: the labeling system shall be easily comprehensible and at the same time operational and dynamic. The principle is to determine the time value, t( C m), required to reach the relevant indoor air value, C m (presently, based on odor and mucous membrane irritation thresholds), in a standard room. Odor thresholds are used because they generally are at least one order of magnitude lower than mucous membrane irritation thresholds. t( C m) is a measure of the period of time during which a new building material may cause indoor air quality problems, unless special precautions are made. The system may also be used for singular VOCs of which a specific health endpoint has been reported. The Danish labeling system is illustrated with the emission testing and comfort evaluation of two sealants using the Field and Laboratory Emission Cell (FLEC)

Application of the Field and Laboratory Emission Cell "FLEC" - Performance Study, Intercomparison Study, and Case Study of Damaged Linoleum in an Office#

The Field and Laboratory Emission Cell (FLEC) has been tested and evaluated for qualitative and quantitative emission testing of volatile organic compounds (VOCs) from building products. An air supply control unit has been developed and its performance is reported in the range of 100 to 500 mllmin airflows. The recovery in the FLEC has been tested with a new performance test kit with dodecane and 2-ethylhexanol, respectively. Additionally, five VOCs emitted from a liquid floor wax were measured in the FLEC and in a small climate chamber. The first order rate constants (k1) and the initial emission rates (R0) obtained from the time versus concentration data measured over 24 hours proved to be comparable. The application of FLEC in a complaint case of malodorous linoleum in an office building showed that artificial wetting of the linoleum had a marked influence on the qualitative offgassing of odorous VOCs such as fatty acids, glycol ethers, and 2-decenal.

Documentation Of Field And Laboratory Emission Cell "FLEC": Identification Of Emission Processes From Carpet, Linoleum, Paint, And Sealant By Modeling

Time versus concentration data of selected volatile organic compounds (VOCs) emitted from four pre-conditioned building materials were measured in the Field and Laboratory Emission Cell (FLEC) at three air exchange rates, 171, 342, 684 h−1, respectively, during a period of 240 hours. The materials were a carpet, a linoleum, a water-borne paint, and a sealant. Modeling of the time versus concentration data for two air exchange rates showed that the emission of VOCs from the carpet were best described with a diffusion model in which the diffusion coefficient depends on the concentration gradient for all data (exponential diffusion model), while a reduced data set eliminating initial events also could be described with a first order decay incorporating a sink effect. The paint emission data of the polar semi-VOC, Texanol, could be described with a first order decay model incorporating a sink effect for all three air exchange rates. The emission rate constant doubled by doubling the air exchange rate. The emission data for VOCs from the sealant were best described for all three air exchange rates by the exponential diffusion model. The best model correlation fit was obtained for hexane, but satisfactory results were also obtained for 2-ethylhexanol and dimethyloctanols. The decay results of linoleum did not allow for modeling leading to the conclusion that an internal concentration gradient had not yet been established under the experimental conditions

Comparison Of Volatile Organic Compounds From Processed Paper And Toners From Office Copiers And Printers: Methods, Emission Rates, And Modeled Concentrations

The emission of volatile organic compounds (VOC) from nine toner powders and eleven types of processed paper from photocopying machines (6), laser (3) and matrix printers (21, and one carbonless copy fm has been measured. A total of 61 VOC from toner powders were identified by heating (185 °C) the powder for three minutes for thermal desorption and by gas chromatography followed by the use of low and high resolution EI and CI mass spectrometry. VOC from processed paper were analyzed by headspace sampling on Tenax TA from nylon bags. Thirty-one VOC with a wide range of volatility and persistency were identified from processed paper. The total VOC emission from the various types of paper differed substantially. Using the field and laboratory emission cell (FLEC), the calculated initial emission rate of styrene was 5 μg m−2h−1 from a freshly processed paper The VOC emission from machines and the processed paper can be reduced by proper choice of o m e equipment. However, an evaluation should consider all potential pollutants.