The lifetimes of long-lived parent anions formed by nondissociative electron attachment to SF6, C6F6, C10F8, and c-C7F14 are investigated. The ions are created via electron transfer in collisions with K(np) Rydberg atoms and their lifetimes determined by observing their decay using a Penning ion trap. The measured lifetimes vary widely from target to target and range from similar to10 mus for C6F6- to similar to10 ms for SF6-. The present results are compared with values obtained in earlier free-electron studies.