Indoor Chemistry Research Articles

Absorption of volatile organic compounds (VOCs) by polymer tubing: implications for indoor air and use as a simple gas-phase volatility separation technique

Abstract. Previous studies have demonstrated volatility-dependent absorption of gas-phase volatile organic compounds (VOCs) to Teflon and other polymers. Polymer–VOC interactions are relevant for atmospheric chemistry sampling, as gas–wall partitioning in polymer tubing can cause delays and biases during measurements. They are also relevant to the study of indoor chemistry, where polymer-based materials are abundant (e.g., carpets and paints). In this work, we quantify the absorptive capacities of multiple tubing materials, including four nonconductive polymers (important for gas sampling and indoor air quality), four electrically conductive polymers and two commercial steel coatings (for gas and particle sampling). We compare their performance to previously characterized materials. To quantify the absorptive capacities, we expose the tubing to a series of ketones in the volatility range 104–109 µg m−3 and monitor transmission. For slow-diffusion polymers (e.g., perfluoroalkoxy alkane (PFA) Teflon and nylon), absorption is limited to a thin surface layer, and a single-layer absorption model can fit the data well. For fast-diffusion polymers (e.g., polyethylene and conductive silicone), a larger depth of the polymer is available for diffusion, and a multilayer absorption model is needed. The multilayer model allows fitting solid-phase diffusion coefficients for different materials, which range from 4×10-9 to 4×10-7 cm2 s−1. These diffusion coefficients are ∼ 8 orders of magnitude larger than literature values for fluorinated ethylene propylene (FEP) Teflon film. This enormous difference explains the differences in VOC absorption measured here. We fit an equivalent absorptive mass (CW, µg m−3) for each absorptive material. We found PFA to be the least absorptive, with CW ∼ 105 µg m−3, and conductive silicone to be the most absorptive, with CW ∼ 1013 µg m−3. PFA transmits VOCs easily and intermediate-volatility species (IVOCs) with quantifiable delays. In contrast, conductive silicone tubing transmits only the most volatile VOCs, denuding all lower-volatility species. Semi-volatile species (SVOCs) are very difficult to sample quantitatively through any tubing material. We demonstrate a system combining several slow- and fast-diffusion tubing materials that can be used to separate a mixture of VOCs into volatility classes. New conductive silicone tubing contaminated the gas stream with siloxanes, but this effect was reduced 10 000-fold for aged tubing, while maintaining the same absorptive properties. SilcoNert (tested in this work) and Silonite (tested in previous work) steel coatings showed gas transmission that was almost as good as PFA, but since they undergo adsorption, their delay times may be humidity- and concentration-dependent.

Real-time evaluation of terpene emissions and exposures during the use of scented wax products in residential buildings with PTR-TOF-MS

Scented wax products, such as candles and wax warmers/melts, are popular fragranced consumer products that are commonly used in residential buildings. As scented wax products are intentionally fragranced to produce pleasant smellscapes for occupants, they may represent an important source of volatile organic compounds (VOCs) to indoor atmospheres. The aim of this study is to evaluate terpene emission factors (EFs) and inhalation intake fractions (iFs) for scented wax products to better understand their impact on indoor chemistry and chemical exposures. Full-scale emission experiments were conducted in the Purdue zEDGE Test House using a variety of scented candles (n = 5) and wax warmers/melts (n = 14) under different outdoor air exchange rates (AERs). Terpene concentrations were measured in real-time using a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS). PTR-TOF-MS measurements revealed that scented candle and wax warmer/melt products emit a variety of monoterpenes (C10H16) and oxygen-containing monoterpenoids (C10H14O, C10H16O, C10H18O, C10H20O), with peak concentrations in the range of 10−1 to 102 ppb. Monoterpene EFs were much greater for scented wax warmers/melts (C10H16 EFs ∼ 102 mg per g wax consumed) compared to scented candles (C10H16 EFs ∼ 10−1 to 100 mg per g wax consumed). Significant emissions of reactive terpenes from both products, along with nitrogen oxides (NO, NO2) from candles, depleted indoor ozone (O3) concentrations. Terpene iFs were similar between the two products (iFs ∼ 103 ppm) and increased with decreasing outdoor AER. Terpene iFs during concentration decay periods were similar to, or greater than, iFs during active emission periods for outdoor AERs ≤ 3.0 h−1. Overall, scented wax warmers/melts were found to release greater quantities of monoterpenes compared to other fragranced consumer products used in the home, including botanical disinfectants, hair care products, air fresheners, and scented sprays.

Influence of Ventilation on Formation and Growth of 1-20 nm Particles via Ozone-Human Chemistry.

Ozone reaction with human surfaces is an important source of ultrafine particles indoors. However, 1-20 nm particles generated from ozone-human chemistry, which mark the first step of particle formation and growth, remain understudied. Ventilation and indoor air movement could have important implications for these processes. Therefore, in a controlled-climate chamber, we measured ultrafine particles initiated from ozone-human chemistry and their dependence on the air change rate (ACR, 0.5, 1.5, and 3 h-1) and operation of mixing fans (on and off). Concurrently, we measured volatile organic compounds (VOCs) and explored the correlation between particles and gas-phase products. At 25-30 ppb ozone levels, humans generated 0.2-7.7 × 1012 of 1-3 nm, 0-7.2 × 1012 of 3-10 nm, and 0-1.3 × 1012 of 10-20 nm particles per person per hour depending on the ACR and mixing fan operation. Size-dependent particle growth and formation rates increased with higher ACR. The operation of mixing fans suppressed the particle formation and growth, owing to enhanced surface deposition of the newly formed particles and their precursors. Correlation analyses revealed complex interactions between the particles and VOCs initiated by ozone-human chemistry. The results imply that ventilation and indoor air movement may have a more significant influence on particle dynamics and fate relative to indoor chemistry.

The chemical assessment of surfaces and air (CASA) study: using chemical and physical perturbations in a test house to investigate indoor processes.

The Chemical Assessment of Surfaces and Air (CASA) study aimed to understand how chemicals transform in the indoor environment using perturbations (e.g., cooking, cleaning) or additions of indoor and outdoor pollutants in a well-controlled test house. Chemical additions ranged from individual compounds (e.g., gaseous ammonia or ozone) to more complex mixtures (e.g., a wildfire smoke proxy and a commercial pesticide). Physical perturbations included varying temperature, ventilation rates, and relative humidity. The objectives for CASA included understanding (i) how outdoor air pollution impacts indoor air chemistry, (ii) how wildfire smoke transports and transforms indoors, (iii) how gases and particles interact with building surfaces, and (iv) how indoor environmental conditions impact indoor chemistry. Further, the combined measurements under unperturbed and experimental conditions enable investigation of mitigation strategies following outdoor and indoor air pollution events. A comprehensive suite of instruments measured different chemical components in the gas, particle, and surface phases throughout the study. We provide an overview of the test house, instrumentation, experimental design, and initial observations - including the role of humidity in controlling the air concentrations of many semi-volatile organic compounds, the potential for ozone to generate indoor nitrogen pentoxide (N2O5), the differences in microbial composition between the test house and other occupied buildings, and the complexity of deposited particles and gases on different indoor surfaces.

Ozone generation and chemistry from 222 nm germicidal ultraviolet light in a fragrant restroom.

Devices using 222 nm germicidal ultraviolet light (GUV222) have been marketed to reduce virus transmission indoors with low risk of occupant harm from direct UV exposure. GUV222 generates ozone, an indoor air pollutant and oxidant, under constrained laboratory conditions, but the chemistry byproducts of GUV222-generated ozone in real indoor spaces is uncharacterized. We deployed GUV222 in a public restroom, with an air change rate of 1 h-1 one weekend and 2 h-1 the next, to measure ozone formation and byproducts generated from ozone chemistry indoors. Ozone from GUV222 increased background concentrations by 5 ppb on average for both weekends and reacted rapidly (e.g., at rates of 3.7 h-1 for the first weekend and 2.0 h-1 for the second) with gas-phase precursors emitted by urinal screens and on surfaces. These ozone reactions generated volatile organic compound and aerosol byproducts (e.g., up to 2.6 μg m-3 of aerosol mass). We find that GUV222 is enhancing indoor chemistry by at least a factor of two for this restroom. The extent of this enhanced chemistry will likely be different for different indoor spaces and is dependent upon ventilation rates, species and concentrations of precursor VOCs, and surface reactivity. Informed by our measurements of ozone reactivity and background aerosol concentrations, we present a framework for predicting aerosol byproduct formation from GUV222 that can be extended to other indoor spaces. Further research is needed to understand how typical uses of GUV222 could impact air quality in chemically diverse indoor spaces and generate indoor air chemistry byproducts that can affect human health.

Jingle bells, what are those smells? Indoor VOC emissions from a live Christmas tree

Every year in the United States conifers are purchased to serve as Christmas trees in homes where they emit volatile organic compounds (VOCs) to the indoor environment. Although many studies have measured the ecosystem-level emissions of VOCs from conifers outdoors (characterizing monoterpene, isoprene, and aldehyde emissions), little is known about VOC emission rates once a conifer is brought indoors. Using a proton transfer reaction-mass spectrometer we characterized the VOCs emitted from a freshly cut Douglas Fir for 17 days in an environmentally controlled chamber. Ozone injections were also performed to analyze indoor chemistry that may occur. Introduction of the tree into the chamber increased the response of 52 mass spectra signals detected by the PTR-MS by at least 500 counts per second (cps) compared to background levels, with concentrations sharply decreasing after the first two days. Monoterpenes were emitted from the tree at a rate of 12.4 mg h−1 the first day and fell to 1 mg h−1 by day three. Overall, monoterpene emissions from this Douglas fir were initially comparable to other strong indoor monoterpene sources (fragranced products and air fresheners) but decayed quickly and, within days, were smaller than other common indoor sources. Addition of ozone to the chamber resulted in decreased monoterpene concentrations that coincided with modest increases in formaldehyde. Four other emitted VOCs were tentatively identified due to their large increase within the first few hours of the tree placed in the chamber, behavior during ozonation, or pattern of accumulation over time.

Books and Other Reviews.

Key Points The war and environment reader — Glenn Suter Science on a mission: How military funding shaped what we do and don't know about the ocean — Glenn Suter Engineering with Nature: An atlas Engineering with Nature: An atlas, volume 2 Engineering with Nature: Supporting mission resilience and infrastructure value at Department of Defense installations Overview: International guidelines on natural and nature‐based features for flood risk management — Glenn Suter Why indoor chemistry matters — Robert Stevenson The best American science and nature writing 2022 — Glenn Suter

A Modelling Study of Indoor Air Chemistry: The Surface Interactions of Ozone and Hydrogen Peroxide

Indoor surfaces play a key role in indoor chemistry, including modification of indoor oxidant concentrations. This study utilises the INdoor CHEmical Model in Python (INCHEM-Py) to investigate the impact of surface transformations and their impact on indoor gas-phase chemistry. INCHEM-Py has been developed to simulate the surface deposition of ozone and hydrogen peroxide onto nine and six individual surfaces respectively in a typical bedroom, kitchen and office for normal indoor concentrations in the absence of household activities. The results show that 91 to 96% of these oxidants are deposited onto indoor surfaces under our simulated conditions. In the bedroom, 38 to 44% of indoor ozone and hydrogen peroxide is deposited onto soft fabric surfaces, with 41 to 54% of ozone deposition occurring on plastic surfaces in the kitchen and office. Total indoor concentrations of straight-chained aldehydes (C1-C10) ranged from ≈ 4 to 5 ppb, with nonanal having the highest individual concentration (1.7, 1.6 and 1.5 ppb in the bedroom, kitchen and office respectively), primarily as a result of emissions from plastics following ozone deposition. Aldehyde concentrations following hydrogen peroxide deposition were often less than 0.01 ppb. Understanding how reactions and deposition on different indoor surfaces impact indoor air chemistry will enable internal surface selection with a view to improving overall indoor air quality.

The fate of organic peroxides indoors: quantifying humidity-dependent uptake on naturally soiled indoor window glass.

Humidity plays an important role in the surface removal and concentrations of indoor pollutants such as ozone; however, the indoor surface dynamics and chemistry of organic peroxides is largely unknown. Organic hydroperoxides (ROOHs) are known to participate in the multiphase chemistry of outdoor aerosols and clouds, suggesting that reactive uptake in condensed grime on indoor surfaces is plausible, particularly in humid homes. Here, the effect of relative humidity (RH) on the deposition velocity (vd) and reaction probability (γ) of a model ROOH to naturally soiled indoor glass surfaces was investigated; specifically, by using authentic isoprene hydroxy hydroperoxide (1,2-ISOPOOH) as the model compound. Glass was soiled in 3 local homes for 1+ years and characterized. The removal of ISOPOOH by soiled and clean glass was measured under 5-6%, 56-58%, and 83-84% RH conditions using a novel flow reactor designed for indoor surfaces coupled to an iodide chemical ionization high-resolution time-of-flight mass spectrometer (I-HR-TOF-CIMS). The vd and γ increased with increasing RH, ranging from 0.001-0.059 cm s-1 and 0.4-4.6 (×10-6), respectively, on soiled glass surfaces. The vd and γ ranged from only 0.001-0.016 cm s-1 and 0.1-0.8 (×10-6), respectively, across RH conditions on clean glass, demonstrating a greater RH effect on soiled materials than clean. Loss rates calculated under humid conditions to soiled glass (∼1-6 h-1) were competitive in scale with ventilation rates in typical residences, indicating the importance of surface uptake for indoor ROOH concentrations. This work provides parameters for predictive modeling of indoor ROOHs. To our knowledge, these are the first direct measurements of the vd of an ROOH to naturally soiled indoor surfaces.

Unanticipated Hydrophobicity Increases of Squalene and Human Skin Oil Films Upon Ozone Exposure.

The C-H and O-H oscillators on the surfaces of thin films of human-derived skin oil and squalene are probed under ambient conditions (300 K, 1 atm total pressure, 40% RH) using second-order vibrational spectroscopy and contact angle goniometry before and after exposure to ppb amounts of ozone. Skin oil and squalene are found to produce different vibrational sum frequency generation spectra in the C-H stretching region, while exposure to ozone results in surface spectra for both materials that is consistent with a loss of C-H oscillators. The measured contact angles show that the hydrophobicity of the films increases following exposure to ozone, consistent with the reduction in C═C···H2O ("πH") bonding interactions that is expected from C═C double bond loss due to ozonolysis and indicating that the polar functional groups formed point toward the films' interiors. Implications for heterogeneous indoor chemistry are discussed.

Partition of phthalates among air, PM2 .5 , house dust and skin in residential indoor environments.

As a group of typical endocrine disrupters, phthalates are simultaneously present in a variety of environmental media and enter human body through multiple exposure pathways. In this study, field monitoring data were used to characterize the skin-air (Klg ), dust-air (Kd ), and PM2.5 -air (Kp ) partition coefficients of DiBP, DnBP, and DEHP. The median values of log(Klg ) in the summer and winter were 7.654 and 7.932, 7.265 and 7.902, 9.419 and 9.015 for DiBP, DnBP, and DEHP, respectively, and Klg was significantly higher in the winter. The median Kd (m3 /mg) in the summer (0.036-0.151 for DiBP, 0.021-0.036 for DnBP and 1.479-4.069 for DEHP) were significantly higher than the counterparts in the winter (0.027-0.065 for DiBP, 0.022-0.245 for DnBP, and 0.140-3.250 for DEHP). In addition, Kd was associated with material of surface and residence time of dust. The Kp values (m3 /μg) of DiBP, DnBP, and DEHP in the summer (0.053, 0.015, and 0.021) were also significantly higher than the counterparts in the winter (0.011, 0.004, and 0.025). The partition of phthalates was influenced by built environment, such as temperature, humidity, ventilation, indoor chemistry, smoking, and building age. Except Klg , there was substantial discrepancy between the estimates of K with empirical equations and the values of K based on field monitoring data in our study.

Why Indoor Chemistry Matters: A National Academies Consensus Study

BACKGROUND AND AIM The indoor environment is a significant contributor to human chemical exposures and health risks, and indoor chemistry plays an important role in driving and modifying exposure to many indoor pollutants. Despite recent developments, much of the chemical complexity and variability of indoor environments remains poorly understood. METHODS The National Academies of Sciences, Engineering, and Medicine (the National Academies) convened an ad hoc committee of 16 experts to conduct a consensus study examining the state of the science regarding chemicals in non-industrial indoor environments. RESULTS This presentation will summarize findings and emerging discoveries related to indoor chemistry and sources, chemical partitioning and reactions, and links between chemical exposure, air quality, and human health. Briefly, thousands of chemicals are found indoors in air, particles, dust, and surfaces, and they partition across phases. Humans can modify indoor chemistry and act as primary sources. Indoor chemicals undergo oxidation, photolysis, hydrolysis, acid-base, and other reactions and can form reaction products with differing properties. Improved knowledge of molecular reaction rates, kinetics, emission rates, building and environmental factors, and human behaviors and time activity patterns along with their uncertainties are needed to refine exposure and health risk models. This presentation will also summarize recommendations regarding: 1) key implications of recent scientific research, including potential near-term opportunities for translating research findings into practice, and 2) opportunities for new scientific research in several priority areas critical to achieving a better understanding of the chemistry of the indoor environment and resulting adverse exposures and health risks. CONCLUSIONS The committee noted opportunities for advancing this field of study by enhancing interdisciplinary collaboration and addressing methodological or technological barriers to research. This scientific foundation will further our understanding of indoor chemistry and its impacts on health and the environment and support regulatory action and guidelines.

Why Indoor Chemistry Matters: A National Academies Consensus Report.

Why Indoor Chemistry Matters: A National Academies Consensus Report.

Understanding Ozone Transport and Deposition within Indoor Surface Boundary Layers

Ozone-initiated oxidation reactions on indoor surfaces meaningfully alter the chemical composition of indoor air and human exposure to air toxins. Ozone mass transport within the indoor surface boundary layer plays a key role in ozone-surface reaction kinetics. However, limited information is available on detailed ozone transport dynamics near realistic, irregular indoor surfaces. This paper presents a research framework to study the underlying mechanisms of ozone reactions with realistic indoor surfaces based on microscope scanning of surface material and detailed Computational Fluid Dynamics (CFD) simulation. The study results show that indoor surface topography can meaningfully affect ozone mass transport within a surface boundary layer, thereby modulating near-surface ozone concentration gradient and surface uptake. The results also reveal that the effective indoor surface area available for ozone reaction varies with indoor air speed and turbulent air mixing within the boundary layer. The detailed dynamic behaviors of ozone reactions with realistic indoor surfaces provide insights into the implications of pollutant-surface interactions on indoor chemistry and air quality.

Henry's Law Constants and Indoor Partitioning of Microbial Volatile Organic Compounds.

Microbial volatile organic compounds (MVOCs) play an essential role in many environmental fields, such as indoor air quality. Long-term exposure to odorous and toxic MVOCs can negatively affect the health of occupants. Recently, the involvement of surface reservoirs in indoor chemistry has been realized, which signifies the importance of the phase partitioning of volatile organic pollutants. However, reliable partition coefficients of many MVOCs are currently lacking. Equilibrium partition coefficients, such as Henry's law constant, H, are crucial for understanding the environmental behavior of chemicals. This study aims to experimentally determine the H values and their temperature dependence for key MVOCs under temperature relevant to the indoor environment. The H values were determined with the inert gas-stripping (IGS) method and variable phase ratio headspace (VPR-HS) technique. A two-dimensional partitioning model was applied to predict the indoor phase distribution of MVOCs and potential exposure pathways to the residences. The findings show that the MVOCs are likely distributed between the gas and weakly polar (e.g., organic-rich) reservoirs indoors. Temperature and the volume of reservoirs can sensitively affect indoor partitioning. Our results give a more comprehensive view of indoor chemical partitioning and exposure.

Temperature and indoor environments.

From the thermodynamic perspective, the term temperature is clearly defined for ideal physical systems: A unique temperature can be assigned to each black body via its radiation spectrum, and the temperature of an ideal gas is given by the velocity distribution of the molecules. While the indoor environment is not an ideal system, fundamental physical and chemical processes, such as diffusion, partitioning equilibria, and chemical reactions, are predictably temperature-dependent. For example, the logarithm of reaction rate and equilibria constants are proportional to the reciprocal of the absolute temperature. It is therefore possible to have non-linear, very steep changes in chemical phenomena over a relatively small temperature range. On the contrary, transport processes are more influenced by spatial temperature, momentum, and pressure gradients as well as by the density, porosity, and composition of indoor materials. Consequently, emergent phenomena, such as emission rates or dynamic air concentrations, can be the result of complex temperature-dependent relationships that require a more empirical approach. Indoor environmental conditions are further influenced by the thermal comfort needs of occupants. Not only do occupants have to create thermal conditions that serve to maintain their core body temperature, which is usually accomplished by wearing appropriate clothing, but also the surroundings must be adapted so that they feel comfortable. This includes the interaction of the living space with the ambient environment, which can vary greatly by region and season. Design of houses, apartments, commercial buildings, and schools is generally utility and comfort driven, requiring an appropriate energy balance, sometimes considering ventilation but rarely including the impact of temperature on indoor contaminant levels. In our article, we start with a review of fundamental thermodynamic variables and discuss their influence on typical indoor processes. Then, we describe the heat balance of people in their thermal environment. An extensive literature study is devoted to the thermal conditions in buildings, the temperature-dependent release of indoor pollutants from materials and their distribution in the various interior compartments as well as aspects of indoor chemistry. Finally, we assess the need to consider temperature holistically with regard to the changes to be expected as a result of global emergencies such as climate change.

Environmentally persistent free radicals in indoor particulate matter, dust, and on surfaces

Long-lived, yet reactive, environmentally persistent free radicals with known human health effects have the potential to influence indoor air quality and chemistry.

Insights into interactions of chlorine-based cleaning products with indoor relevant surfaces

Environmental context The chemistry that occurs in indoor environments and the role that indoor surfaces play have recently received increased attention in the scientific community. Here we have investigated the chemistry of chlorine-based cleaning products and their interactions with indoor relevant surfaces and find that these surfaces react with these cleaning products to yield surface adsorbed chlorine oxides and other surface-bound species. Rationale Indoor chemistry has recently received increased attention in the scientific community due to the fact that there is relatively little known given its unique environment including point combustion sources (candles, gas stoves, etc.) resulting in high aerosol concentrations, high surface to volume ratios and the impact of humans on indoor air quality. Recently, surface-initiated reactions during chlorine cleaning events have been proposed. Methodology In this study, we probe the interaction of bleach headspace gas with high surface area silica as a proxy for window glass – an ‘inert’ and impervious surface – using attenuated total reflectance Fourier Transform infrared (ATR-FTIR) spectroscopy, atomic force microscopy photothermal infrared (AFM-PTIR) spectroscopy and transmission electron microscopy (TEM) to observe surface chemical and physical changes. Results The results suggest chemical transformations occur at the silica surface forming surface adsorbed chlorine oxides (ClOx). Conductivity and ion chromatography methods support the presence of adsorbed chloride after surfaces have been exposed to bleach and HOCl. Discussion Interactions between HOCl and indoor surfaces have not been previously studied with molecular based techniques. The possibility of surface-mediated reactions has been relatively unexplored on indoor surfaces and this study shows the chemistry of chlorine-containing cleaning products on indoor relevant surfaces.

Spatiotemporal characterization of irradiance and photolysis rate constants of indoor gas-phase species in the UTest house during HOMEChem.

We made intensive measurements of wavelength-resolved spectral irradiance in a test house during the HOMEChem campaign and report diurnal profiles and two-dimensional spatial distribution of photolysis rate constants (J) of several important indoor photolabile gases. Results show that sunlight entering through windows, which was the dominant source of ultraviolet (UV) light in this house, led to clear diurnal cycles, and large time- and location-dependent variations in local gas-phase photochemical activity. Local J values of several key indoor gases under direct solar illumination were 1.8-7.4 times larger-and more strongly dependent on time, solar zenith angle, and incident angle of sunlight relative to the window-than under diffuse sunlight. Photolysis rate constants were highly spatially heterogeneous and fast photochemical reactions in the gas phase were generally confined to within tens of cm of the region that were directly sunlit. Opening windows increased UV photon fluxes by 3 times and increased predicted local hydroxyl radical (OH) concentrations in the sunlit region by 4.5 times to 3.2×107 moleccm-3 due to higher J values and increased contribution from O3 photolysis. These results can be used to improve the treatment of photochemistry in indoor chemistry models and are a valuable resource for future studies that use the publicly available HOMEChem measurements.

Heterogeneous Interactions of Prevalent Indoor Oxygenated Organic Compounds on Hydroxylated SiO2 Surfaces.

Oxygenated organic compounds (OOCs) are widely found in indoor environments and come from either the direct emissions from indoor activities or the subsequent oxidation of nonoxygenated OCs. Adsorption and partitioning of OCs on surfaces are significant processes in indoor chemistry, yet these interactions specifically involving OOCs are still poorly understood. In this study, we investigate the interactions of three prevalent indoor OOCs (dihydromyrcenol, α-terpineol, and linalool) on an indoor surface proxy (hydroxylated SiO2) by combining vibrational spectroscopy with ab initio molecular dynamics simulations. The adsorption of these compounds on the SiO2 surface is driven by π hydrogen bonding and O-H hydrogen bonding interactions, with O-H hydrogen bonding interactions being stronger. The results of kinetic measurements suggest that indoor surfaces play a significant role in the removal of these OOCs, especially under moderate and low air exchange. Additionally, indoor surfaces can also serve as a reservoir of OOCs due to their much slower desorption kinetics when compared to other indoor relevant organic compounds such as limonene. Overall, the results gleaned by experiment and theoretical simulations provide a molecular representation of the interaction of OOCs on indoor relevant surfaces as well as implications of these interactions for indoor air chemistry.