I opened an ammo can (with a good seal) and broke a seal on a "new" can of IMR 4320. Red dust comes from the powder when I dispense. The powder smells good but I understand this (red dust) may be a sign of old powder and I should not use? I'd sure hate to toss out a can of powder I just opened but I'd rather not waste time and energy trying to develop a load with bad powder. What should I do?