<prompt> Shelf life of gamma irradiated pRBC is21 days28 days35 days42 days  <response>: Irradiation reduces RBC storage shelf life to not 28 days postirradiation depending on the time of irradiation relative to collection. Irradiation followed by refrigerator storage causes a higher concentration of in the product. To avoid wastage of RBC units, irradiation prior to issue is optimal. Ref baley and love 27 pg 17-18 