Comprehensive atmospheric modeling of reactive cyclic siloxanes and their oxidation products

Janechek, Nathan J.; Hansen, Kaj; Stanier, Charles O.

doi:10.5194/acp-17-8357-2017

Cited by 42 publications

(87 citation statements)

References 53 publications

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“…These species include methylcyclohexane, emitted indoors by glues, paints, and other materials, 127 and cosmetic component cyclopentasiloxane (D5 siloxane). [85][86][87][88][89][90] From TAG PMF results, we observe a similar trend in both Factors 2-D and 2-ND (Figures 4 and 5, respectively) with window opening, which comprises many of the TAG-measured indoor-originating solvents, plasticizers, and personal care product components.…”

Section: Dilution Of Indoor Speciessupporting

confidence: 54%

“…73,76,77 Although formaldehyde and acetaldehyde are often observed as by-products of cigarette smoking, 78 supplies, 17,18,21,22,84 and siloxanes are ubiquitous in cosmetics and personal care products. [85][86][87][88][89][90] Benzene, toluene, ethylbenzene, and xylene (BTEX) result from fossil fuel combustion and often originate outdoors. However, known indoor sources include building materials, paints, and cleaning products.…”

Section: Windows Closedmentioning

confidence: 99%

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Analysis of indoor particles and gases and their evolution with natural ventilation

et al. 2019

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Although people in developed nations spend up to 90% of their time indoors, 1,2 the chemistry and composition of indoor air remain understudied, especially compared to the outdoor environment. 3 Evaluating air quality in residential dwellings is particularly important for several reasons. First, although building standards (eg, for minimum air change rates and moisture control) have been established over the past several decades, 4,5 many residential structures fail to meet these standards, especially older buildings. Newer buildings, designed to minimize outdoor-to-indoor infiltration for improved energy efficiency, often have higher concentrations of airborne pollutants that are released indoors from materials and activities. 6,7 Concentrations and composition AbstractThe air composition and reactivity from outdoor and indoor mixing field campaign was conducted to investigate the impacts of natural ventilation (ie, window opening and closing) on indoor air quality. In this study, a thermal desorption aerosol gas chromatograph (TAG) obtained measurements of indoor particle-and gas-phase semi-and intermediately volatile organic compounds both inside and outside a single-family test home. Together with measurements from a suite of instruments, we use TAG data to evaluate changes in indoor particles and gases at three natural ventilation periods. Positive matrix factorization was performed on TAG and adsorbent tube data to explore five distinct chemical and physical processes occurring in the indoor environment. Outdoor-to-indoor transport is observed for sulfate, isoprene epoxydiols, polycyclic aromatic hydrocarbons, and heavy alkanes. Dilution of indoor species is observed for volatile, non-reactive species including methylcyclohexane and decamethylcyclopentasiloxane. Window opening drives enhanced emissions of semi-and intermediately volatile species including TXIB, DEET, diethyl phthalate, and carvone from indoor surfaces. Formation via enhanced oxidation was observed for nonanal and 2-decanone when outdoor oxidants entered the home. Finally, oxidative depletion of gas-phase terpenes (eg, limonene and α-pinene) was anticipated but not observed due to limited measurement resolution and dynamically changing conditions. K E Y W O R D Sfield measurements, gas chromatography-mass spectrometry, gas-particle partitioning, natural ventilation, residential air quality, semivolatile organic compounds

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Section: Dilution Of Indoor Speciessupporting

confidence: 54%

Section: Windows Closedmentioning

confidence: 99%

Analysis of indoor particles and gases and their evolution with natural ventilation

et al. 2019

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“…A 13.3 L potential aerosol mass (PAM) OFR chamber (Kang et al, 2007(Kang et al, , 2011Lambe et al, 2011a) was used to oxidize vapor-phase D 5 . The OFR was run in the OFR185 mode where O 3 and OH are generated in situ by photolysis of oxygen and water.…”

Section: Aerosol Generation and Characterizationmentioning

confidence: 99%

“…In this work, aerosols are produced using an oxidation flow reactor (OFR), which is a photochemical flow-through reactor. OFRs are small (liter-sized) reactors that use very high oxidation conditions to oxidize reactants (Kang et al, 2007(Kang et al, , 2011Lambe et al, 2011a). Advantages of using OFRs include the ability to quickly test a range of aging conditions, reach high oxidant exposures (multi-day exposure) in minutes, and deploy easily for ambient measurements.…”

Section: Introductionmentioning

confidence: 99%

Physical properties of secondary photochemical aerosol from OH oxidation of a cyclic siloxane

et al. 2019

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Cyclic volatile methyl siloxanes (cVMS) are highproduction chemicals present in many personal care products. They are volatile, hydrophobic, and relatively longlived due to slow oxidation kinetics. Evidence from chamber and ambient studies indicates that oxidation products may be found in the condensed aerosol phase. In this work, we use an oxidation flow reactor to produce ∼ 100 µg m −3 of organosilicon aerosol from OH oxidation of decamethylcyclopentasiloxane (D 5 ) with aerosol mass fractions (i.e., yields) of 0.2-0.5. The aerosols were assessed for concentration, size distribution, morphology, sensitivity to seed aerosol, hygroscopicity, volatility and chemical composition through a combination of aerosol size distribution measurement, tandem differential mobility analysis, and electron microscopy. Similar aerosols were produced when vapor from solid antiperspirant was used as the reaction precursor. Aerosol yield was sensitive to chamber OH and to seed aerosol, suggesting sensitivity of lower-volatility species and recovered yields to oxidation conditions and chamber operation. The D 5 oxidation aerosol products were relatively non-hygroscopic, with an average hygroscopicity kappa of ∼ 0.01, and nearly non-volatile up to 190 • C temperature. Parameters for exploratory treatment as a semi-volatile organic aerosol in atmospheric models are provided.Published by Copernicus Publications on behalf of the European Geosciences Union.

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“…The bathroom was assumed to have dimensions of 43 These reactions were assumed to form silanols. 42,44 Whelan et al 45 suggested that the cVMS (cyclic Volatile Methyl Siloxane) species had a dry deposition velocity of 0.3 cm s −1 outdoors and also that the silanols were more likely to undergo deposition than the parent siloxanes. Based on the method described by Carslaw et al, 35 the outdoor deposition velocity was divided by 20 to provide an indoor equivalent of 0.015 cm s −1 for the cVMS species.…”

Section: Atmospheric Modelmentioning

confidence: 99%

Simplified speciation and atmospheric volatile organic compound emission rates from non‐aerosol personal care products

et al. 2020

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Indoor Air. 2020;30:459-472. | 459 wileyonlinelibrary.com/journal/ina 1 | INTRODUC TI ON Volatile organic compounds are a diverse class of air pollutants that, in high concentrations, can directly impact human health, 1 and have widespread indirect effects through aiding the formation of secondary pollutants such as ozone and secondary organic aerosols (SOA). Both indoors and outdoors, VOCs are readily oxidized by O 3 and radicals such as OH and can produce both tropospheric ozone andAbstract Volatile organic compounds (VOCs) emitted from personal care products (PCPs) can affect indoor air quality and outdoor air quality when ventilated. In this paper, we determine a set of simplified VOC species profiles and emission rates for a range of non-aerosol PCPs. These have been constructed from individual vapor analysis from 36 products available in the UK, using equilibrium headspace analysis with selectedion flow-tube mass spectrometry (SIFT-MS). A simplified speciation profile is created based on the observations, comprising four alcohols, two cyclic volatile siloxanes, and monoterpenes (grouped as limonene). Estimates are made for individual unit-ofactivity VOC emissions for dose-usage of shampoos, shower gel, conditioner, liquid foundation, and moisturizer. We use these values as inputs to the INdoor air Detailed Chemical Model (INDCM) and compare results against real-world case-study experimental data. Activity-based emissions are then scaled based on plausible usage patterns to estimate the potential scale of annual per-person emissions for each product type (eg, 2 g limonene person −1 yr −1 from shower gels). Annual emissions from non-aerosol PCPs for the UK are then calculated (decamethylcyclopentasiloxane 0.25 ktonne yr −1 and limonene 0.15 ktonne yr −1 ) and these compared with the UK National Atmospheric Emissions Inventory estimates for non-aerosol cosmetics and toiletries. K E Y W O R D S emission inventories, indoor air quality modeling, mass spectrometry, personal care products, siloxanes, VOCsThis is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

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Comprehensive atmospheric modeling of reactive cyclic siloxanes and their oxidation products

Cited by 42 publications

References 53 publications

Analysis of indoor particles and gases and their evolution with natural ventilation

Analysis of indoor particles and gases and their evolution with natural ventilation

Physical properties of secondary photochemical aerosol from OH oxidation of a cyclic siloxane

Simplified speciation and atmospheric volatile organic compound emission rates from non‐aerosol personal care products

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