ARB Research Seminar

This page updated April 5, 2017

Air Quality Impacts of Low Vapor Pressure-Volatile Organic Compounds

Photo of David Cocker, Ph.D.

David Cocker, Ph.D., Professor, Chemical and Environmental Engineering, Bourns College, University of California, Riverside.

May 16, 2017
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA

Research Project


Low vapor pressure-volatile organic compounds (LVP-VOCs) are a set of VOCs currently exempted for VOC content based on a combination of boiling point, vapor pressure, and/or elution time from a GC-column.

This work explores evaporation rates and secondary pollutant formation from a series of individual LVP-VOCs associated with consumer products, select generic consumer products that include these LVP-VOCs, and several hydrocarbon solvents. Evaporation rates, a critical parameter for ascertaining atmospheric availability for individual LVP-VOCs and in complex mixtures, are evaluated. Next, the ozone and secondary organic aerosol (SOA) formation from the select individual LVP-VOCs, hydrocarbon solvent mixtures, and generic consumer products is explored in detail using large, indoor environmental chambers located at the University of California, Riverside. The exploration includes a detailed characterization of chamber wall effects with losses of LVP-VOCs within this study found to be negligible and SOA formation impacted only for LVP-VOCs with low nucleation intensity or generally low SOA. The Atmospheric Chemical Mechanism SAPRC-11 is evaluated for the LVP-VOCs studied and found to predict well the gas-phase chemistry and ozone formation from the individual LVP-VOCs studied. SOA formation, including aerosol mass formation as well as chemical and physical characterizations of the SOA, will be presented for each system. SOA formation from compounds ranges widely with n-Heptadecane, Benzyl Alcohol, Diethylene Glycol Monobutyl Ether generally forming the most aerosol, and Propylene Glycol, Diethylene Glycol, and TexanolŽ forming only minimal SOA.

A case study of SOA formation as it relates to molecular structure for glycol ethers as well as SOA formation as a function of oxidant concentration from all precursors will be discussed.

Speaker Biography

David Cocker, Ph.D., is a professor of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, Riverside (UCR). Professor Cocker has been on the faculty at UCR since 2001. Dr. Cocker's research interests include secondary organic aerosol formation, emission characterization, and aerosol-related health impacts. Dr. Cocker has published over 100 peer-reviewed journal articles. He received his Ph.D. (2001) and M.S. (1998) in Environmental Engineering Science from the California Institute of Technology and his B.S. in Environmental Engineering and Chemistry (1996) from UCR. .

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