In this study, we evaluated solid sorbents for their ability to passively control indoor CO concentration in buildings or rooms with cyclic occupancy (eg, offices, bedrooms). Silica supported amines were identified as suitable candidates and systematically evaluated in the removal of CO from indoor air by equilibrium and dynamic techniques. In particular, sorbents with various amine loadings were synthesized using tetraethylenepentamine (TEPA), poly(ethyleneimine) (PEI) and a silane coupling agent 3-aminopropyltriethoxysilane (APS). TGA analysis indicates that TEPA impregnated silica not only displays a relatively high adsorption capacity when exposed to ppm level CO concentrations, but also is capable of desorbing the majority of CO by air flow (eg, by concentration gradient). In 10 L flow-through chamber experiments, TEPA-based sorbents reduced outlet CO by up to 5% at 50% RH and up to 93% of CO adsorbed over 8 hours was desorbed within 16 hours. In 8 m flow-through chamber experiments, 18 g of the sorbent powder spread over a 2 m area removed approximately 8% of CO injected. By extrapolating these results to real buildings, we estimate that meaningful reductions in the CO can be achieved, which may help reduce energy requirements for ventilation and/or improve air quality.

Emissions from volatile chemical products (VCPs) are emerging as a major source of anthropogenic secondary organic aerosol (SOA) precursors. Paints and coatings are an important class of VCPs that emit both volatile and intermediate volatility organic compounds (VOCs and IVOCs). In this study, we directly measured I/VOC emissions from representative water- (latex) and oil-based paints used in the U.S. Paint I/VOC emissions vary by several orders of magnitude by both the solvent and gloss level. Oil-based paints had the highest emissions (>105 μg/g-paint), whereas low-gloss interior paints (Flat, Satin, and Semigloss) all emitted ∼102 μg/g-paint. Emissions from interior paints are dominated by VOCs, whereas exterior-use paints emitted a larger fraction of IVOCs. Extended emission tests showed that most I/VOC emissions occur within 12–24 h after paint application, though some paints continue to emit IVOCs for 48 h or more. We used our data to estimate paint I/VOC emissions and the subsequent SOA production in the U.S. Total annual paint I/VOC emissions are 48–155 Gg (0.15–0.48 kg/person). These emissions contribute to the formation of 2.2–7.5 Gg of SOA annually. Oil-based paints contribute 70–98% of I/VOC emissions and 61–99% of SOA formation, even though they only account for a minority of paint usage.