Will a sealed plastic bag protect my goods from moisture damage?

Yes. No. Um… maybe?  

Sorry! Life is complex enough and we would love to give you a simple answer so we can all move on. But if you ship goods in plastic you need to hang around for a couple of minutes as we break down what you need to know to address the question. And maybe, right at the end, there is a simple answer: Leave it with us. Because giving you the right solution for your goods — and your unique moisture damage prevention needs — is what we do at Absortech. 

Many goods are shipped with sealed plastic protection. Whether to protect valuable cargo from dust or dripping water. Or also, in the case of electronics, automotive parts and similar, because it is seen as the first line of defense against corrosion by preventing excess moisture from acting on critical metal surfaces and circuitry. 

But to know whether sealed plastic packaging is really protecting your goods from moisture damage, you need to check off the following, smaller questions one by one. Because a plastic bag might be causing more problems than it solves, still leaving you and your shipments exposed to unnecessary and very costly risk. 

2. Are you sealing in excess humidity?

If the relative humidity in the packaging area was high, then the air sealed in the bag already has a high moisture content. Which often means a much higher risk for your product. 

3. Are you sealing in goods that release moisture?

When you’re at the supermarket, you’ve probably noticed that fresh goods like tomatoes or grapes are in plastic bags and containers with holes. This is because these foods are hygroscopic and can release moisture when the temperature goes up. Then, when the temperature goes down again, that moisture would condense within a sealed bag and start to damage the food. Hence the holes to release moisture and not trap it on the inside.  

So putting products and materials with moisture content (not just organic goods like fruit but even things like shirts and shoes that contain moisture) in a sealed plastic bag is asking for trouble. The risk of water condensing, pooling and damaging the goods is just too high. 

5. Do you need to manage container humidity?

A better, more cost-effective solution than desiccant pouches in each bag is often to manage container humidity and remove a major underlying cause. If done effectively enough, you might even avoid using plastic altogether.  

6. Is plastic the most sustainable choice?

Beyond finding the most effective solution, it’s also very important for us and our customers to find the most sustainable solution. The good news is that better performance normally means better for the planet too because less desiccant or plastic can be used. Certainly, there are better and more sustainable alternatives instead of just relying on plastic as your moisture barrier.   

So that’s the simple answer as promised. Just get in touch and have full confidence in your eventual solution – with or without plastic! 

To read more about anti-corrosion protection for electronics, automotive parts or other metal goods, then please download our white papers that really get into the issues and help you compare different solutions. For other industries and other plastic-sealed goods, don’t hesitate to ask us for our experience and any insights.