Ground-level (tropospheric) ozone is formed by photooxidation from carbon monoxide, methane and volatile hydrocarbons (VOC) in the presence of nitrogen oxides. Ozone penetrates deep into the lungs and can cause inflammation, coughing, eye irritation, headache, or lung dysfunction.
The formation potential for tropospheric ozone (POCP) is calculated according to the LOTOS-EUROS model (as implemented in ReCiPe). Non-methane volatile organic compounds (NMVOC, volatile organic compounds without methane) are used as lead substances.
For the calculation the EK-JRC characterization factors shall be used: http://eplca.jrc.ec.europa.eu/LCDN/developerEF.xhtml