In the current study, the RH-dependent viscosity of four different types of BB-SOA was measured using the poke-flow technique. BB-SOA was generated by the reaction of catechol, guaiacol, and syringol with the hydroxyl radical (OH) in an environmental chamber. In addition, BB-SOA was generated by the dark ozonolysis of catechol. We also developed a novel parameterization for predicting the viscosity of BB-SOA as a function of RH and temperature following a previous approach. Using this parameterization along with RH and temperature conditions in the troposphere, we constructed global viscosity profiles for BB-SOA. Using this information, we also made predictions of the occurrence of glassy BB-SOA particles and the mixing time of organics within them.