Why is Mold Growing on my Pallet?

Your pallets look clean, your production facility is exemplary, yet once you put your product on the pallet and stretch wrap the unit load, mold starts to appear!

​What's to blame and how can I avoid this from happening?

The perfect storm for mold growth.

The Hunt for Mold

Don't feel bad, people in production facilities all over the world find themselves asking the same questions throughout the year. To find the answer, we'll address 4 variables for the unit load pictured above.
  

1. The wood pallets appear to be clean but...
   As you know, wood comes from a living thing.  Even if it is treated and appears to be free of dirt and mold, every wooden pallet still has some degree of bacteria and moisture present.
     
2. What does my product have to do with mold...
   Does your product come off the line warm? If so, it may be using that heat to draw out moisture from the pallet. So, what if the warm bags are on a slip sheet or a piece or corrugate and they aren’t even touching the pallet? See the next point...
     
3. Wood Pallet + Warm Product + Stretch Wrap = Mold Incubator
   That's right. Warm product combined with a wood pallet that's been sealed tight with stretch wrap can trap the warmth and promote mold growth. Obviously, this can be exacerbated by high summer temperatures (variable #4) which was the case in the picture above.

Well there you have it. It's not one thing causing the mold but instead, it's a combination of 3 or 4 things.

What Happens Now?

In some situations, it may be possible to save your moldy wood pallets. Other times conditions simply don't make for a fair fight. In this particular case (pictured), the facility immediately opted to switch over to plastic pallets to avoid sending mold-damaged product to customers.

Have you experienced similar mold issues on pallets? Tell us what did you do to fix the problem or ask for expert advice in the comments below.
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Post by: Mike Cunneen, Director of Sales & Marketing