Direct Measurements of Vapor Pressures of Chlorinated Paraffin Congeners from Technical Mixtures

02 April 2021, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Chlorinated Paraffins (CPs) are a complex group of manmade chemicals detected widely in the environment. To predict their environmental fate and effects, it is important to understand their physical-chemical properties including vapor pressure. In this study, the first direct measurements of the vapor pressure for CP congener groups (C10–16Cl4–11) are presented. Vapor pressure was measured above three industrial CP mixtures with different congener distributions between 20 and 50°C using a gas saturation method. The measured saturated vapor pressure (P*) decreased with increasing carbon chain length and Cl content. ΔHvap ranged between 73 and 122 kJ mol-1, consistent with data from the literature and model prediction. The experimental log P* at 25°C agreed well with predictions from an empirical regression model in the literature (R2 = 0.97; RSME = 0.25) and with those predicted from the COSMO-RS-trained fragment contribution model (R2 = 0.95; RSME = 0.35). A new empirical model was calibrated with the P* data for 35 congener groups measured in this study. Predicted log P* values correlate well with field-measured gas/particle partition coefficients and may therefore be used for estimating the environmental fate and pathways of a broad range of CPs in the environment.


Gas Saturation
Congener groups
Enthalpy of vaporization

Supplementary materials

CP Vapor Pressure Supplementary data Full


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.