Ozone in indoor environments: Research progress in the past 15 years

•A review on chemistry and concentration of ozone in indoor environment was reported in Weschler (2000).•A review of what succeeding 15 years, after Weschler (2000), has taught us, was provided in this paper.•This paper is concluded by suggesting future research directions for the next 15 years.

Presence of ozone in indoor environment has implications on creation of sustainable indoor environment. A material mass balance model is used to summarize outcome of the review exercise that was conducted to understand what 15 years has taught us, with regards to the chemistry and concentration of ozone in indoor environment, since after a similar review effort by Weschler in the year 2000. Additionally, key knowledge gained on the impact of ozone and its initiated chemistry products on human health and comfort are summarized. This paper is concluded with recommendations for future research directions.