Dear authors,

Thanks for submitting this manuscript with very interesting and important results to ACP. Thanks for your detailed responses to the reviewer comments.

I would ask whether you consider a few minor comments largely triggered by some of the reviewer comments.

p.1:

Line 18. I think that the metyltetrol sulfates are the most abundant in the boundary layer, but for the overall atmosphere it has been suggested that it may be glycolic acid sulfate (Liao et al. JGR 2015)

Line 23. In line with some of the reviewer comments. The way it is written the readers will at this stage assume that reaction products were observed. I suggest eliminating the reaction products as argument in the abstract. I do not think this detracts from the main finding, which is the rate constant.

Line 27. Also, following up on one of the reviewer comments. The effective rate OH constant is given as it is usually for a gas-phase reaction. It may be useful to explain this in the abstract or provide a context as why it is given as gas-phase when it is a heterogeneous reaction.

Line 28. Please state the assumed OH concentration for this (1.5E6?).

Line 31. “absence of functionalization processes” is a little awkward. One could argue that changing an alcohol to an aldehyde or acid, even if it is just formaldehyde and formic acid, is a functionalization process as it changes the functional groups, so perhaps the phrasing could be improved. I think the important aspect is that the results strongly suggest fragmentation, as stated in the next sentence.

P. 2 Line 11. I may be mistaken, but my impression was that the C5-alkene triols are not direct SOA constituents but rather decomposition products from the analytical techniques.

Dear authors,

thanks for your fast response. Also, thanks for submitting this manuscript which contains much needed information on ageing of IEPOX sulfates. I hope that future studies will be able to elucidate the reaction products, although you make a strong case that deposition is a much more important sink term.

Best Regards,

Frank Keutsch