This means it is only slightly harmful when dissolved in water. However, reactions with alkali metals, aluminum, mercury, fluorine or terpentine may increase the risk. Environmental risks may differ between iodine substances. The LD 50 value for rats (oral uptake) is about 14,000 mg/kg.
If you need to get it there fast, your best option is to use USPS's Priority Mail Express service! This is the fastest service offered by the USPS, with a guaranteed shipping time of 1 to 2 days, depending on the destination-or your money back!
USPS does not offer a guaranteed overnight service. Priority Mail Express may be 1-day or 2-day service, depending on destination; the earlier deadline always applies. For example, my neighborhood PO closes at 5:30 p.m., which is also the time of the last pick-up for the collection box outside the door.