ATP hygiene test result for a wooden pallet, recording 11,833 RLU and failing hygiene thresholds. The reading indicates significant organic contamination on the upper deck surface, highlighting the potential contamination risks associated with porous pallet materials used within food and pharmaceutical supply chains.
Food and pharmaceutical manufacturers are being urged to scrutinise their cold chain pallet infrastructure after ATP swab testing revealed significant hygiene differences between wooden and sanitised plastic pallets
In a recent assessment at a customer’s facility, Hydropac conducted ATP (adenosine triphosphate) hygiene testing on wooden pallets that had entered the facility through the wider supply chain and from a cross section of suppliers.
One pallet returned a reading of 11,833 Relative Light Units (RLU), compared with 300 RLU for a sanitised plastic pallet subjected to the same testing process. This revealed the plastic pallet was more than 38 times cleaner based on ATP measurements.
ATP testing is widely used across food manufacturing and pharmaceutical environments to identify the presence of organic contamination, and in many food production settings, readings of around 11,500 RLU would indicate heavy organic contamination, typically triggering further investigation or cleaning procedures.
While businesses continue to invest heavily in temperature control, packaging integrity, environmental monitoring and sanitation procedures, pallet infrastructure frequently receives less scrutiny.
Hydropac believes the findings highlight a potential contamination blind spot within food and pharmaceutical supply chains, where pallet hygiene is often assumed rather than verified despite being a key foundation of contamination control.
Sanitised Plastic Pallet. ATP hygiene test result for a sanitised plastic pallet, recording 300 RLU and achieving a pass rating following a controlled wash process. Non-porous plastic surfaces can be cleaned, sanitised and hygiene-verified before re-entering the supply chain.
Francisco Azeredo, Commercial Manager at Hydropac and specialist in cold chain and temperature-controlled packaging for food and pharmaceutical supply chains said,
"Pallets are often overlooked despite being one of the first surfaces products and packaging come into contact with. If organisations are serious about contamination control, every item entering a controlled environment should be subject to the same level of scrutiny."
“Wooden pallets remain widely used across logistics networks, but their porous structure can absorb moisture and retain organic matter, making them more difficult to clean and sanitise effectively. In contrast, non-porous plastic pallets can be washed, sanitised and validated before being returned to service.”
"The challenge with wooden pallets isn't that they're inherently unsafe. It's that their history is largely unknown. You don't know where they've been, what they've been exposed to, or what contaminants may be embedded within the material," continued Francisco.
Hydropac also notes that wooden pallets can present additional operational and safety concerns, including splinters, exposed nails, damaged boards and debris generation, all of which can create housekeeping and workplace safety challenges within production and warehouse environments.
Beyond the ATP results themselves, Hydropac warns that contamination risks associated with wooden pallets may extend far beyond the visible surface. As pallets move throughout the supply chain, any organic contamination present has the potential to be transferred to warehouse floors, food handling areas, equipment and even operatives' hands and footwear.
"Plastic pallets offer manufacturers a different level of control because they can be washed, sanitised and verified before re-entering the supply chain," added Francisco.
As food manufacturers, pharmaceutical companies and logistics providers continue to strengthen quality assurance programmes and contamination control measures, Hydropac believes greater visibility around pallet hygiene standards could help organisations reduce risk, improve audit readiness and support compliance with increasingly stringent industry requirements.