I need a little help from anyone capable... My company is looking to ship 1000s of the packages around the US, the problem is as follows: The packages contains pods in pic related - they have liquid in them, and sometimes during air travel, the difference in pressure causes them to leak. We can send them ground, but the cost is more than triple They are only 6oz packages so if we use first class USPS, its very cheap. However we need to address the issue of leaking. Is there anyway to protect the pods from being exposed to this - such as using a shrink wrap machine to wrap the box - we have one, and the plastic on it is quite thick. As far as what Ive found, the pressure in cargo is approx 8000ft, or around 10 psi, so there is a difference of 5. Will the plastic seal, if air-tight, prevent this, the plastic shouldnt burst because it is thick.... or is there some other way I should consider?