Figure 1.

Natural logarithm of the fractional decay of BPA as a function of OH exposure averaged over multiple experiments for BPA (circles) and BPA + NaCl (triangles). The slope of the exponential fit was a parameterization from Davies and Wilson et al. (large dashed line).⁴⁴ The slope of the linear fit (small dashed line) of the decay up to 6.1 × 10¹¹ molecules s cm^–3 of OH exposure represents the second-order heterogeneous reaction rate constant for reactive OH uptake by BPA aerosol. The top axis corresponds to the equivalent amount of aging in days assuming an ambient steady-state OH concentration of 1.5 × 10⁶ molecules cm^–3.