Project at a Glance

Title: Air quality impacts of low vapor pressure-volatile organic compounds

Principal Investigator / Author(s): Cocker, David

Contractor: UC Riverside

Contract Number: 13-302

Research Program Area: Atmospheric Processes

Topic Areas: Chemistry & Reactivity


Low vapor pressure-volatile organic compounds (LVP-VOCs) are used in consumer products and currently are exempt from compliance with VOC limits. However, atmospheric emissions of LVP-VOCs from consumer products and their impacts on ozone and secondary organic aerosol (SOA) formation are inadequately understood at this time. This project investigated the ambient evaporation rates of LVP-VOCs both as pure compounds and in consumer products, and conducted environmental chamber studies on selected LVP-VOCs, and products that contain them, to explore ozone and secondary organic aerosol formation from these compounds. Based on measurements of the evaporation rates of LVP-VOCs in evaporation chambers, a semi-empirical formula using the vapor pressure and molecular weight of the LVP-VOC was identified from the scientific literature and found to be sufficient to accurately estimate evaporation rates for the wide range of LVP-VOCs studied within this program. To evaluate the ozone and secondary particle formation from the selected individual LVP-VOCs, hydrocarbon solvent mixtures, and generic consumer products, environmental chamber experiments were conducted at the advanced environmental chamber facility at UC Riverside. An atmospheric chemical mechanism, SAPRC-2011, was evaluated for the LVP-VOCs studied and was found to predict well the gas-phase chemistry and ozone formation from the individual LVP VOCs studied. SOA formation ranged widely between the LVP-VOCs studied. The project provided valuable experimental data and modeling tools to estimate the emission rates of LVP VOCs and their impacts on ozone and SOA formation.

For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753

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