The modelling results at 293 K show that in a particle consisting of only the hydrophilic phase, the atmospheric lifetime (e-folding time, τBrC) of BrC is strongly dependent upon the RH, decreasing from 20 h to 5 h between 40 and 95% RH (Fig. ). These results are consistent with the whitening results for the water-soluble component of BrC reported by Schnitzler et al. . At 10% RH, τBrC for the hydrophilic particle is ~ 40 h, arising from the low experimentally-derived value for DR6G at this RH for the hydrophilic phase in Fig. . However, for a BBOA particle that has undergone LLPS, τBrC remains reasonably constant at approximately 1 day for RH 0 -95% (Fig. ), following a similar RHdependency to the pure-hydrophobic case. The difference between a particle consisting of only the hydrophilic phase and a particle that has undergone LLPS illustrates how the presence of the hydrophobic outer phase on the outside of a particle can drastically change the whitening rates by acting as a kinetic barrier to the uptake of ozone. Thus, LLPS can lengthen the potential warming effect of BrC compared to models or experiments that only consider the water-soluble component of BBOA.