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Summary:

            This article presents results and analysis from laboratory experiments to investigate gaseous and particle emissions from the burning of household solid waste common to South Africa. The authors provide elemental analysis, fuel-based emission factors from smoldering and flaming phases of combustion, and literature comparisons for emissions from the burning of the separated waste products and also combined waste. Generally, this was a very well written and well-structured paper that offers important results on a poorly characterized emission source. The experimental design is well thought out and neatly lays out results from a very complicated and diverse emission source. The use of ash and PM in the carbon mass balance equation and the subsequent calculation of fuel-based emission factors demonstrates the high quality of the experiment and provide, I think, the most important results of the paper, which is that ash and PM have a significant share of the carbon mass balance in smoldering emissions. Finally, the authors do a good job contextualizing the separated burns compared to the combined burns in the discussion section, by suggesting that emission factors from separated burn materials may not perfectly reflect the emissions from combined burns due to different burn conditions. I have very few comments or edit suggestions for this manuscript. The paper covers the globally important topic of emissions from open burning of solid waste and delivers novel results. I recommend this manuscript for final publication in ACP with only a few minor revisions.

Comments: 

Line 74: “However, particle emissions are not often measured in these studies.” What studies do the authors refer to here? Yokelson et al. and Jayarathne et al. both use filter- based particle sampling and Stockwell et al. 2016 makes BC measurements of garbage burning. More context is needed here.

Figure 1: Is there a reason for the order of the categories in the bar graph? Just a suggestion for readability, and not a requirement, but it may help if the categories were sorted by mass %.

Line 85: Can the authors elaborate on if the floor mat is composed of petroleum-based materials (i.e. synthetic) or natural (i.e. cowhide and natural rubber) since these are likely to have different emission factors. The floor mat appears to be synthetic but it should be specified.

Line 172 Carbon is misspelled ‘caron’

Line 189 “…likely formed from re-condensation of evaporated plastic molecules”. Could the authors elaborate on this suggestion on why the aerosol emissions were highest from plastic bottle burning? Wouldn’t condensation of vaporized plastic be true for the plastic bags and synthetic rubber as well? I assume this conclusion comes from the extent of smoldering phase compared to flaming phase?

Figure 4: Can the authors explain why nitrogen oxide emissions are observed from plastic bag combustion and not from plastic bottle burning?

Figure 6: I find it interesting that the OC and EC PM2.5 mass fractions are similar for the plastic bags and combined burning. Does this suggest that when plastic bags are contained in garbage the plastic burning dominates the total emissions? Or does it suggest that when plastic bags are contained in the garbage it increases the higher efficiency flaming emissions of the combined refuse?