Moisture damage 101 – What is moisture damage?

In the first of several of guides, we lift the lid on the world of moisture prevention. Moisture 101 introduces beginners to the basics and how to get them right. But we hope it’s also a helpful refresher for those of you with more experience. Enjoy!

If you’re shipping rubber ducks then you can stop reading now. Go outside, enjoy yourself, live in the moment, the world’s your oyster etc.

But for everyone else and almost every other cargo, we need to know our enemy: Moisture. And it’s a sneaky enemy too, causing all kinds of damage to goods – directly through corrosion or mould etc. and even indirectly by ruining packaging that protects against scratches, scrapes or squashes … wait, is it too late to get the rubber duck guys back? They’re gone? Oh well.

In this blog article, we’ll cover the different types of moisture damage, including those that can affect the goods you are most interested in. We hope it’ll be a useful guide to the risks you should be aware of and protect against. And, by minimizing these risks, it should also save yourself and your business a lot of extra cost and hassle.

Why is relative humidity so important?

Before we start looking at the most common types of moisture-related damage, first an explainer for a term that always comes into play: Relative humidity. Relative humidity or RH describes how much moisture is in the air at a certain temperature. And this is what you need to keep an eye on as it’s when relative humidity reaches a certain percentage in a container that it will cause damage to goods – and that damage can increase exponentially when RH goes even higher.

Corrosion

Metal parts can corrode and rust, which can weaken metal, cause discoloration or, in the case of expensive electronics, make them utterly useless. An RH of around 45% or less shouldn’t be a problem. But at 60% or more, your metal goods and any metal parts will probably be in trouble.

Mould and mildew | Bad or changed smell | Bad or changed taste

Mould and mildew can affect all cargo and its packaging. And that’s a particularly nasty problem for organic cargo like food or agricultural commodities. To make matters worse, moisture damage can also affect the smell and taste of food. Which even less fussy eaters tend to get picky about.

A relative humidity over 75% means that mould can grow in any temperature between -5 °C and +55 °C – and mould’s favourite temperature is a very normal 20-30 °C! Research also shows that mould could even be a problem with an RH as low as 50%. So anyway you look at it, if you want to protect cargo, especially organic goods that aren’t deep frozen, you will need to ensure lower levels of moisture in the container

Damaged packaging | Collapsed Packaging | Peeling labels

As we mentioned at the top, moisture also causes indirect damage to goods by compromising packaging. Basically, traditional wood-fibre cardboard and similar want to absorb moisture from the air. If you want to impress friends and family, this quality is called hygroscopic.

Anyway, moisture damage to packaging means it can collapse and goods risk physical damage. Or with nice attractive packaging on the shelf being a key part of selling products in stores, the value of the product is greatly reduced and/or it may need to be returned for repackaging, which will waste a lot of time, money and good will throughout the supply chain.

Similarly, moisture can damage labels so they peel off from glass bottles and cans of food. And the market for random sauces and mystery cans of meat isn’t so hot at the moment.

Powder caking

Dry goods like powders are often hygroscopic – well, you’re an expert now – and will attract moisture. This moisture damage appears as caking or clumping. Which often means the powder won’t flow or mix as intended in use or during later stages of manufacturing. The result? An entire shipment may have to be scrapped or at least re-processed at great cost.

Clearly, this is just the basics of moisture damage. But it’s important to have them top of mind to protect your goods, your business and the entire supply chain from totally unnecessary and excessive delays, hassle and costs.

Talk to us

And if you want to dig deeper into the specifics of your particular shipments, and find out where the biggest moisture damage risks lie and how to take the most effective and cost-effective prevention measures, then give us a call. Yes, even if you’re shipping rubber ducks…