Concentration-response curves for some common additives. Dose–response curves for 6 additives used in the manufacture of various PC-replacement plastics. Key as for Figure 1. Panels A-F: antioxidants (A-C) tested as individual chemicals; colorants (D), UV stabilizers (E) or inks (F) added to PP bottles or PP plaques. Without the additive, the PP plaques or bottles exhibited no detectable EA (data not shown).