Fig. 2: Chemically speciated PM emission factors for firelighter and solid fuels.
From: Air quality—climate forcing double whammy from domestic firelighters

Emission factors for residential wood, peat, coal, and firelighter burning based on the direct ACSM and AE-33 measurement. Donut pie charts are the relative fraction of the chemical composition of direct particulate emissions from the tested fuels. Error bar stands for one standard deviation for the total EF.