I'm looking particularly at KI and the chelating agents, which are ordinary shelf-stable things. The point of these is to prevent biological absorption of particular elements in fallout, so either you have them available right away, or it's a lost opportunity.

- "Time of treatment initiation: DTPA should be administered as soon as possible after exposure, ideally within the first 24h. If early administration is not possible, therapy can be initiated at any time; however, the efficacy decreases substantially when radionuclides are deposited in the bone and other organs (47, 48)."

- "The optimal period of administration of stable iodine is < 24 h before and ≤ 2 h after the expected onset of exposure."