Highly Oxygenated Organic Molecules (HOM) from Gas-Phase Autoxidation Involving Peroxy Radicals: A Key Contributor to Atmospheric Aerosol

Research output: Contribution to journalReview article


Highly oxygenated organic molecules (HOM) are formed in the atmosphere via autoxidation involving peroxy radicals arising from volatile organic compounds (VOC). HOM condense on pre-existing particles and can be involved in new particle formation. HOM thus contribute to the formation of secondary organic aerosol (SOA), a significant and ubiquitous component of atmospheric aerosol known to affect the Earth's radiation balance. HOM were discovered only very recently, but the interest in these compounds has grown rapidly. In this Review, we define HOM and describe the currently available techniques for their identification/quantification, followed by a summary of the current knowledge on their formation mechanisms and physicochemical properties. A main aim is to provide a common frame for the currently quite fragmented literature on HOM studies. Finally, we highlight the existing gaps in our understanding and suggest directions for future HOM research.


  • Federico Bianchi
  • Theo Kurtén
  • Matthieu Riva
  • Claudia Mohr
  • Matti P. Rissanen
  • Pontus Roldin
  • Torsten Berndt
  • John D. Crounse
  • Paul O. Wennberg
  • Thomas F. Mentel
  • Jürgen Wildt
  • Heikki Junninen
  • Tuija Jokinen
  • Markku Kulmala
  • Douglas R. Worsnop
  • Joel A. Thornton
  • Neil Donahue
  • Henrik G. Kjaergaard
  • Mikael Ehn
External organisations
  • University of Helsinki
  • Centre de Recherche en Cancérologie de Lyon
  • Stockholm University
  • Leibniz Institute for Tropospheric Research (TROPOS)
  • Jülich Research Centre
  • Aerodyne Research, Inc.
  • University of Washington
  • Carnegie Mellon University
  • University of Copenhagen
  • California Institute of Technology
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Chemical Sciences
Original languageEnglish
Pages (from-to)3472-3509
JournalChemical Reviews
Issue number6
Early online date2019
Publication statusPublished - 2019
Publication categoryResearch