The plastic pallets are unique to the Dorset-based firm, which in the past had received wooden pallets contaminated with glass, broken bottles, oil, paint, various chemicals, general rubbish and rotting material.
TWC also found that wooden pallets were easily damaged - with splinters from the wood getting into product crates.
Managing director Tom Amery said: "We jump through many hoops in fresh produce to maintain standards of cleanliness, only to place crates of salad onto an unregulated pallet. Wooden pallets are never sterilised or even washed between use - they are, in effect, a bacterial sponge."
The new pallets, produced by Craemer UK, are hardwearing and are made from food-grade high-density polyethylene.
They can be recycled at the end of their five-year life and have a non-slip coating to prevent product crates from slipping off.
Another benefit is that they do not carry any problems with fluctuating tare weights because they do not absorb water.
Amery said: "We have invested in this stock of high-quality, robust pallets with the aim of being market leaders in safety, traceability and product hygiene."
He added: "Most customers have embraced the new plastic pallets, recognising their sturdiness and the improvements in traceability that they allow.
"Though some have taken a more cautious approach, they are still keen to make the change once they have been proven to work on their racking system."