Rodolphe Sonnier, IMT Mines Alès (France) summarised over 80 smoke emission tests of polymers, with and without flame retardants, using a cone calorimeter, and comparing smoke density (by laser) to heat release rate (HRR). The relation between smoke and HRR is not always linear, particularly towards the end of tests. In these test well-ventilated conditions, polyolefins generate little smoke at low HRR whereas aromatic polymers generate more. Mineral flame retardants ATH and MDH reduce smoke emission, but this seems to be mainly related to the reduction in HRR. The brominated flame retardant TBBA and the phosphorus PIN FR DOPO did not increase the ratio [smoke release per energy released] in polyethylene, but did cause smoke production to start at a lower HRR.