Since 2006, the CORESTA Cigar Smoking Methods Sub-Group conducts periodic collaborative studies in order to improve repeatability and reproducibility measurement methods of different cigar sizes and types.

The purpose of the 15^th Collaborative Study was to estimate the mean values, repeatability, and reproducibility for NFDPM (tar), nicotine, carbon monoxide and other measures for different sizes and types of cigar products and test pieces and to provide a tool for participating laboratories to prove competence in cigar smoke analysis.

Most of the mean values were in good agreement with the 2020 results with the possible exception of the smoke yields for one of the test items which tended to be ~20 % higher than the 2020 results; however only the CO difference was statistically significant.