Introduction: The California Air Resources Board (CARB) has promulgated a new Airborne Toxics Con... more Introduction: The California Air Resources Board (CARB) has promulgated a new Airborne Toxics Control Measure (ATCM) to reduce formaldehyde emissions from composite wood products that are manufactured, imported, distributed, sold, and fabricated in the state of California. The ATCM sets ceiling limits for the emission of formaldehyde from these products that will go into effect beginning with Phase 1 requirements on January 1, 2009. CARB specifies the use of a large chamber test method (ASTM E 1333) as the reference method for demonstrating compliance. This paper describes an alternate testing approach using smallscale chambers.
Lawrence Berkeley National Laboratory, May 29, 2008
Three volatile nitrogen-containing compounds, 3-ethenylpyridine (3-EP), pyridine and pyrrole, wer... more Three volatile nitrogen-containing compounds, 3-ethenylpyridine (3-EP), pyridine and pyrrole, were investigated as potential tracers for determining the contribution of environmental tobacco smoke (ETS) to concentrations of volatile organic compounds (VOCs) in indoor environments with smoking. The source emission rates of the three tracers and ten selected VOCs in ETS were first measured in a room-size environmental chamber for a marketweighted selection of six commercial cigarettes. The ratios of the emission rates of the tracers to the emission rates of the selected VOCs were calculated and compared among the six brands. The utility of the tracers was then evaluated in a field study conducted in five office buildings. Samples for VOCs were collected in designated smoking areas and adjoining nonsmoking areas, air change rates were measured, and smoking rates were documented. Concentrations of the three tracers in the smoking areas were calculated using a mass-balance model and compared to their measured concentrations. Based on this comparison, 3-EP was selected as the most suitable tracer for the volatile components of ETS, although pyrrole is also potentially useful. Using 3-EP as the tracer, the contributions d ETS to the measured concentrations of the selected VOCs in the smoking areas were estimated by apportionment. ETS was estimated to contribute 57 to 84 percent (4.1 to 26 pg m-3) of the formaldehyde concentrations, 44 to 69 percent (0.9 to 5.8 pg m-3) of the 2-butanone concentrations, 37 to 58 percent (1.3 to 8.2 pg m-3) of the benzene concentrations, and 20 to 69 percent (0.5 to 3.0 pg m-3) of the styrene concentrations. The fractional contributions of ETS to the concentrations of acetone, toluene, ethylbenzene, xylene isomers and d-limonene were all less than 50 percent.
A passive sampling device based on the principle of diffusion has _~~ __ ~ __ ~_ been developed s... more A passive sampling device based on the principle of diffusion has _~~ __ ~ __ ~_ been developed specifically for the determination of formaldehyde in . ~~s ident ial ~~ i ndoor afr~-Tfiedevice-,-whlclr i-s-inexp-enstve---and -easyto-~ use, is capable of measuring one-week time-weighted average concentrations of formaldehyde from as low as 0.018 ppm to over 1 ppm. The sampler was validated by a series of laboratory experiments and a field study conducted in occupied residences and an office. The parameters evaluated in the laboratory and field experiments were: sampling rate; sampling period; detection ~ limit; relative humidity effects; chemical interferences; shelf life; sample stability; overall precision; bias; and overall accuracy. The performance of the passive sampler compared favorably to that of a reference pump/bubbler sampler.
Exposure assessment to e-cigarettes part 2: A pilot laboratory study on formation of volatile carbonyls from propylene glycol – a major e-cigarette carrier solvent
The cost of emissions tests and other factors have discouraged nearly all but the largest product... more The cost of emissions tests and other factors have discouraged nearly all but the largest product manufacturers from obtaining emissions data. Emissions data, where available, require toxicologic evaluation before design professionals and other potential purchasers can use them. The absence of health effects infonnation at the low exposures likely to occur from nonnal indoor uses of most products and materials increases the uncertainty in any such evaluation. The complex mixture emitted by most products poses an additional interpretation problem. A simple screening procedure to identify potentially problematic products has been developed, and preliminary experience indicates it may be suitable for screening or comparing products during selection by design professionals and other consumers. Commercial specimens are tested for emissions in a small, controlled, dynamic test container over a 24-h period after initial screening by headspace analysis. The procedure allows identification of and quantification of dominant compounds that may then be reviewed for odor, irritancy, toxicity, and carcinogenicity. Only significant quantities of such substances likely to cause adverse effects are considered sufficient basis for rejecting a product. The screening procedure is relevant to the uses required for product selection and significantly less costly than current standard environmental chamber tests. A relatively short-tenn test of emissions from office work stations using a large-scale chamber is also presented. This test is conducted at realistic building conditions. The six-day test duration is adequate to characterize emissions rates and provides data that can be used to both compare products and estimate expected concentrations in buildings. Finally, procedures and criteria for evaluating the results of emissions tests with respect to the selection of products are discussed. With these procedures, measured and modeled concentra tions are compared to published values for human toxicity, irritation, and odor and the existing data on indoor concentrations of volatile organic compounds (VOCs).
This report was prepared as a result of work sponsored by the California Energy Commission (Commi... more This report was prepared as a result of work sponsored by the California Energy Commission (Commission) and the University of California (UC). It does not necessarily represent the views of the Commission, its employees, or the State of California. The Commission, the State of California, its employees, and UC make no warranty, express or implied, and assume no legal liability for the information in this report; nor does any party represent that the use of this information will not infringe upon privately owned rights. This report has not been approved by the Commission nor has the Commission passed upon the accuracy or adequacy of the information in this report. The submitted manuscript has been authored by a contractor to the Regents of the University of California/California Institute for Energy Efficiency. Accordingly, The Regents retains a non-exclusive royalty free license to publish or reproduce the published form of this contribution, or allow others to do so, for CIEE's purposes.
Sorption of emitted gas-phase organic compounds onto material surfaces affects environmental toba... more Sorption of emitted gas-phase organic compounds onto material surfaces affects environmental tobacco smoke (ETS) composition and exposures indoors. We have introduced a new metric, the exposure relevant emission factor (EREF) that accounts for sorptive uptake and reemission to give the mass of individual ETS constituents available for exposure over a day in which smoking occurs. This paper describes month-long experiments to investigate sorption effects on EREFs and potential ETS exposures under habitual smoking conditions. Cigarettes were smoked in a 50-m 3 furnished room over a 3-h period 6-7 days per week, with continuous ventilation at 0.3, 0.6, or 2.1 h À1 . Organic gas concentrations were measured every few days over 4-h ''smoking'', 10-h ''post-smoking'' and 10-h ''background'' periods. Concentration patterns of volatile ETS components including 1,3-butadiene, benzene and acrolein were similar to those calculated for a theoretical non-sorbing tracer, indicating limited sorption. Concentrations of ETS tracers, e.g. 3-ethenylpyridine (3-EP) and nicotine, and lower volatility toxic air contaminants including phenol, cresols, and naphthalene increased as experiments progressed, indicating mass accumulation on surfaces and higher desorption rates. Daily patterns stabilized after week 2, yielding a steady daily cycle of ETS concentrations associated with habitual smoking. EREFs for sorbing compounds were higher under steady cycle versus single-day smoking conditions by B50% for 3-EP, and by 2-3 times for nicotine, phenol, cresols, naphthalene, and methylnaphthalenes. Our results provide relevant information about potential indirect exposures from residual ETS (non-smoker enters room shortly after smoker finishes) and from reemission, and their importance relative to direct exposures (non-smoker present during smoking). Under the conditions examined, indirect exposures accounted for a larger fraction of total potential exposures for sorbing versus non-sorbing compounds, and at lower versus higher ventilation rates. Increasing ventilation can reduce indirect exposures to very low levels for non-sorbing ETS components, but indirect routes accounted for B50% of potential nicotine exposures during non-smoking periods at all ventilation rates.
The objectives of this study were to (1) identify the major organic compounds emitted by finish m... more The objectives of this study were to (1) identify the major organic compounds emitted by finish materials; (2) some typical building construction and interior quantify emissions of organic solvents from representative adhesives that have indoor applications; and (3) evaluate methods for the rapid screening of architectural materials for organic emissions. Organic compounds emitted by 15 building construction and interior finish materials and by 15 adhesives were identified by a vacuumextraction screening procedure and gas chromatography/mass spectrometry. A total of 68 major compounds with molecular weights ranging from 94 to 458 were identified in the vacuum extracts of the construction and interior-finish materials. The lowest molecular-weight compounds among these were phenol, alkyl benzenes, naphthalenes and terpenes. The most frequently occurring compounds were plasticizers, dibutyl phthalate and 2,2,4-trimethyl-1,3-pentanediol di-!-butyrate. Toluene, styrene and a variety of cyclic and normal alkanes were identified in the vacuum extracts of the adhesives. The number of volatile compounds varied greatly among the materials: a carpet padding only emitted a single compound, while a synthetic textile wall covering emitted more than 60 compounds. Other wall and floor coverings and several adhesives also emitted relatively large numbers of compounds. Emission rates of toluene and total alkanes from the adhesives were determined using a simple exposure apparatus. Exhaust air from the apparatus was sampled with charcoal tubes, and solvent extracts of the samples were analyzed by gas chromatography. After 9-14 days of drying, iii three solvent-based adhesives had toluene emission rates ranging from 6 6 -1 -1 0. to 0 ~g g h , and two water-based adhesives, used to glue carpets, had total alkane emission rates of 600 to 800 ~g g-1 h-1 • A simple ventilation model, assuming a single, well-mixed chamber, was used to rank the potential indoor air quality impacts of the adhesives. The results demonstrated that the two water-based adhesives can be significant sources of volatile organic compounds.
We have developed a new air sampler for collecting parriculate and gas phase polycyclic aromatic ... more We have developed a new air sampler for collecting parriculate and gas phase polycyclic aromatic compounds (PAC). This sampler was designed to collect a 25 m' volume of air at a constant sampling rate of 34 Ifmin over a I2-hour sampling penod. The 25 m3 sample volume is necessaty to achieve the desired nglm' detection limit for PAC. The 34 Ilmin sampling rate is estimated to cause less than a 5% reduction in the indoor contaminant concenmath. The sampler pump is a 1f4 horsepower vacuum pump in an acoustically shielded fan-cooled enclosure and is relatively quiet. The pump draws air through a 47 mm t e e impregnated glass jibre jilter for collection of partisulate-phase PAC followed by a c a d g e containing XAD-4 resin in front and back sections (2.5 g each) for coUection of gas-phase PAC. In a pilot jield study the mean breakthrough from the front sorbent section to the back section was less than 1% for each of 14 species of gas phase PAC except biphenyl which had a mean breakthrough of 3.7%. The pressure drop increase across the filter is linear up to a W i n g of 6 mg and causes less than a 10% reduction in the sample jluu rate. The sampler was successjidly demonsmated in a pilot jield test with air temperatures as high as 30 "C.
iii Analytical Methods for Oil and Water Samples •• * Reference to any company or product name do... more iii Analytical Methods for Oil and Water Samples •• * Reference to any company or product name does not imply approval or recommendation of the product by the University of California or the U.S. Department of Energy to the exclusion of others that may be suitable.
Barrier materials to reduce contaminant emissions from structural insulated panels
Publisher Summary The use of Structural Insulated Panels (SIPs) to create very tight building env... more Publisher Summary The use of Structural Insulated Panels (SIPs) to create very tight building envelopes helps reducing the environmental impact and energy use of new housing. Typically, SIPs are constructed from oriented strand board (OSB) and rigid foam in multilayered sandwich-like structures. Although environmental and energy advantages make panelized systems very attractive, the tighter building envelopes may result in degraded indoor air quality. The potential release of volatile contaminants from SIPs must also be considered to ensure the reduced energy use. A physically based diffusion model that predicts emissions from a single layer of vinyl flooring has recently been developed and successfully validated. A logical extension of this approach is to apply the model to predict emissions from multilayer systems such as SIPs. A double-layer model is developed to predict the rate of mass transfer from double-layered building material to indoor air. It is assumed that the two layers are flat homogeneous slabs, that internal mass transfer is governed by diffusion, and that the indoor air is well mixed. An analytical solution to the double-layer model is presented and used to demonstrate the potential for a thin surface barrier layer to reduce contaminant emission rates from building materials.
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Papers by Alfred Hodgson