The lifetimes of dipole-bound anions due to photodetachment by thermal background blackbody radiation (BBR) are calculated using a simple analytic model. The calculated lifetimes are in reasonable agreement with those measured experimentally. It is shown that, at low temperatures, the temperature dependence of the ion lifetime is similar to that for BBR-induced photoionization of atoms. (c) 2006 Elsevier B.V. All rights reserved.