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Reactive organic carbon emissions from volatile chemical products

Seltzer, Karl M. and Pennington, Elyse and Rao, Venkatesh and Murphy, Benjamin N. and Strum, Madeleine and Isaacs, Kristin K. and Pye, Havala O. T. (2021) Reactive organic carbon emissions from volatile chemical products. Atmospheric Chemistry and Physics, 21 (6). pp. 5079-5100. ISSN 1680-7324.

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Volatile chemical products (VCPs) are an increasingly important source of anthropogenic reactive organic carbon (ROC) emissions. Among these sources are everyday items, such as personal care products, general cleaners, architectural coatings, pesticides, adhesives, and printing inks. Here, we develop VCPy, a new framework to model organic emissions from VCPs throughout the United States, including spatial allocation to regional and local scales. Evaporation of a species from a VCP mixture in the VCPy framework is a function of the compound-specific physiochemical properties that govern volatilization and the timescale relevant for product evaporation. We introduce two terms to describe these processes: evaporation timescale and use timescale. Using this framework, predicted national per capita organic emissions from VCPs are 9.5 kg per person per year (6.4 kg C per person per year) for 2016, which translates to 3.05 Tg (2.06 Tg C), making VCPs a dominant source of anthropogenic organic emissions in the United States. Uncertainty associated with this framework and sensitivity to select parameters were characterized through Monte Carlo analysis, resulting in a 95 % confidence interval of national VCP emissions for 2016 of 2.61–3.53 Tg (1.76–2.38 Tg C). This nationwide total is broadly consistent with the U.S. EPA's 2017 National Emission Inventory (NEI); however, county-level and categorical estimates can differ substantially from NEI values. VCPy predicts higher VCP emissions than the NEI for approximately half of all counties, with 5 % of all counties having greater than 55 % higher emissions. Categorically, application of the VCPy framework yields higher emissions for personal care products (150 %) and paints and coatings (25 %) when compared to the NEI, whereas pesticides (−54 %) and printing inks (−13 %) feature lower emissions. An observational evaluation indicates emissions of key species from VCPs are reproduced with high fidelity using the VCPy framework (normalized mean bias of −13 % with r = 0.95). Sector-wide, the effective secondary organic aerosol yield and maximum incremental reactivity of VCPs are 5.3 % by mass and 1.58 g O₃ g⁻¹, respectively, indicating VCPs are an important, and likely to date underrepresented, source of secondary pollution in urban environments.

Item Type:Article
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URLURL TypeDescription
Murphy, Benjamin N.0000-0003-3542-5378
Pye, Havala O. T.0000-0002-2014-2140
Additional Information:© Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Received: 26 Oct 2020 – Discussion started: 09 Nov 2020 – Revised: 08 Feb 2021 – Accepted: 09 Feb 2021 – Published: 31 Mar 2021. Data availability: VCPy v1.0 is available from (last access: 11 March 2021) (, Seltzer et al., 2021). All data presented in this manuscript can be retrieved and/or generated by downloading VCPy.v1.0. Guidance on using VCPy v1.0 can be requested by contacting the corresponding author. The supplement related to this article is available online at: Author contributions: KMS and HOTP designed the research scope. All authors participated in data curation and/or analysis. KMS and HOTP drafted the initial manuscript, and all authors contributed to subsequent drafts. The authors declare that they have no conflict of interest. Although this work was contributed by research staff in the Environmental Protection Agency and has been reviewed and approved for publication, it does not reflect official policy of the EPA. The views expressed in this document are solely those of authors and do not necessarily reflect those of the Agency. EPA does not endorse any products or commercial services mentioned in this publication. The authors would like to thank Janice Godfrey, Art Diem, Jennifer Snyder, Rich Mason, Caroline Farkas, Claudia Toro, Alison Eyth, Luke Valin, Mohammed Jaoui, Jim Szykman, Donna Schwede, Christian Hogrefe, Kristen Foley, Jesse Bash, Marc Houyoux, and Cindy Beeler at the U.S. EPA, Kyriacos Kyriacou and Jose Gomez at the California Air Resources Board, and David Cooley at Abt Associates for helpful discussions and/or data acquisition. Comments by Marc Houyoux (EPA), Jim Szykman (EPA), and two anonymous reviewers served to strengthen this paper. Karl Seltzer and Elyse Pennington have been supported by the Oak Ridge Institute for Science and Education (ORISE) Research Participation Program for the U.S. Environmental Protection Agency (EPA). Review statement: This paper was edited by Kelley Barsanti and reviewed by two anonymous referees.
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Oak Ridge Institute for Science and Education (ORISE)UNSPECIFIED
Environmental Protection Agency (EPA)UNSPECIFIED
Issue or Number:6
Record Number:CaltechAUTHORS:20210414-133411328
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Official Citation:Seltzer, K. M., Pennington, E., Rao, V., Murphy, B. N., Strum, M., Isaacs, K. K., and Pye, H. O. T.: Reactive organic carbon emissions from volatile chemical products, Atmos. Chem. Phys., 21, 5079–5100,, 2021
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:108732
Deposited By: Tony Diaz
Deposited On:19 Apr 2021 18:33
Last Modified:19 Apr 2021 18:33

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