Complex sentence: Once produced, astatine must be used quickly, as astatine-211 decays with a half-life of 7.2 hours; however, this is long enough to permit multi-step labeling strategies.
Split into simpler sentences: Once produced, astatine must be used quickly, as it decays with a half-life of 7.2 hours. This is, fortunately, long enough to permit multi-step labeling strategies.