Chemical scheme Reference scheme 359 860 species 2 270 159 reactions 345 391 species 1 798 480 reactions 530 species 1 934 reactions Chemical schemes 1 350 species 5 616 reactions 150 species 506 reactions Secondary products → surrogate species Primary species → surrogate species Reduction of the peroxy radical types Chemical Operators Performances of the most reduced scheme tested by comparison with the reference scheme (box model / 8 scenarios from highly polluted to remote conditions) S. Szopa et al. ACPD, 5, 755-794, 2005