We use a 4 hour expiration for the syringes.
One big advantage of the syringes over bags is that the neonatal syringes filter the units during the aliquoting process. It is a smaller sized filter than the one in a blood administration set so less blood is "lost" to the filtering process.
We discovered that when we sent blood in bags rather than in syringes, the nursery did not realize that they needed to use a standard blood administration set with filter so they were skipping that important process during the blood adminsitration process. (There are pedi sized blood admin sets available for smaller volumes than the adult sets. Our intensive care nursery now stocks the pedi sized blood admin set for times when blood products are issued in bags.)