I left Buffer P1 at room temperature after addition of RNase A, what shall I do?
FAQ ID -859

Buffer P1 with RNase A used in QIAGEN Plasmid Purification Kits should be fine at room temperature for a few days. We would expect the enzyme to have some residual activity. However, optimal results cannot be guaranteed after storage at room temperature. If you notice that RNase A activity is substantially reduced, you can add fresh RNase A to your buffer.

We recommend that Buffer P1 with RNase A be stored in the refrigerator (2-8°C). RNase A will be stable for 6 months under this condition.