By Luis Lopez, AI transportation consultant, CEO of Go Hub.io Holdings Corp and subsidiaries, and host of the Freight Guru Podcast
Most cargo damage claims involve something physical: a crushed carton, a dropped pallet, a punctured case. Contamination claims are different. The freight may arrive looking intact, but it has absorbed an odor, been stained by a leak, or picked up residue from something it should never have been near. When one product damages another inside a trailer, the question of who pays becomes more complicated.
This article covers how contamination happens in mixed loads, how liability is typically analyzed, and what documentation and prevention steps make the biggest difference.
How Contamination Happens
Contamination in mixed freight usually falls into a few patterns:
- Odor transfer: products that absorb smells, such as paper goods, textiles, packaged food and some plastics, can pick up odors from strong-smelling freight like solvents, fragrances, chemicals or certain cleaning products.
- Leaks from neighboring freight: a container, drum or bottle on another shipper’s pallet leaks and soaks into adjacent freight.
- Chemicals near food goods: chemicals, pesticides or other non-food items loaded near food can make the food unsellable even without a visible leak.
- Dust or residue from prior loads: a trailer not cleaned after a dusty or powdery load leaves residue on the next shipment.
- Pests or debris: a dirty trailer floor can transfer debris or signs of pests to packaging.
The Legal Starting Point
For interstate motor carrier shipments, the Carmack Amendment at 49 U.S.C. 14706 makes the carrier liable for actual loss or injury to the property it transports. Contamination counts as injury to the property if it reduces the value of the goods or makes them unsellable. See our overview of the Carmack Amendment and cargo liability for the basics.
To make a claim, the claimant typically must show that the goods were in good condition when tendered, that they were damaged or contaminated at delivery, and the amount of damages. In contamination cases, each element can be contested, because contamination is often less visible than physical damage.
Carrier Defenses in Contamination Cases
The commonly recognized carrier defenses include act of God, public enemy, act or default of the shipper, public authority, and the inherent nature of the goods. Two come up most often in contamination claims.
Act or default of the shipper
If the shipper loaded incompatible goods together, packed a leaking product poorly, or failed to disclose that its freight could damage other freight, the carrier may argue the damage was caused by the shipper. This is especially relevant when the shipper loaded and sealed the trailer. Our article on shipper’s load and count explains why that notation affects the evidence.
Inherent vice
In general terms, if the product itself was likely to deteriorate, absorb odors, or degrade under ordinary conditions, the carrier may argue the damage came from the nature of the goods rather than from transport.
Neither defense is automatic. The facts decide, and that is why documentation matters so much in contamination cases.
LTL Commingling
LTL shipments travel with freight from many shippers, moving through terminals where they are unloaded, sorted and reloaded. The shipper does not control what ends up next to its freight. That makes the carrier’s loading practices more central, since the carrier decides how freight is arranged on its trailers and docks.
When a shipper’s goods are contaminated in an LTL network, the claim usually goes against the carrier under Carmack, and the carrier may pursue its own recovery from whoever’s freight caused the problem. The same logic applies to consolidated shipments. For more on how consolidation works, see our guide on freight consolidation.
Who Loaded What
In truckload freight, the loading question is often decisive. If the shipper loaded the trailer, put its own incompatible products together, and sealed it, the carrier has a stronger argument that the shipper caused the damage. If the carrier or a terminal handled the freight and placed incompatible goods together, the carrier is more exposed.
For multi-stop loads with freight from different shippers, records showing who loaded what, where and in what order become essential evidence.
Shipper Duties and Carrier Duties
In general terms, shippers are expected to package goods so they do not leak or damage other freight, to describe the goods accurately on the bill of lading, and to disclose handling requirements, including when goods should not be loaded with certain other freight. Hazardous materials have their own separate rules.
Carriers are generally expected to provide equipment suitable for the freight, keep trailers in reasonable condition, and follow handling instructions they have accepted.
Food shipments
For food, the FDA Sanitary Transportation of Human and Animal Food rule under FSMA, at 21 CFR Part 1 Subpart O, covers shippers, loaders, carriers and receivers moving food by motor or rail vehicle in the U.S. It requires vehicles and equipment to be kept in sanitary condition, practices that prevent contamination, including from non-food items or prior loads, training of carrier personnel, and written procedures and records. Confirm the specific requirements that apply to your operation with FDA guidance.
Documentation That Decides Contamination Claims
Because contamination is often invisible at a glance, documentation carries the claim:
- Load diagrams: records of where each pallet was placed in the trailer, and what was next to it.
- Photos: images of the empty trailer before loading, the loaded trailer before sealing, and the freight at delivery.
- Bill of lading descriptions: accurate descriptions of the goods, including anything with a strong odor or that could leak.
- Compatibility instructions: written handling instructions, such as do not load with chemicals or keep away from odorous freight.
- Trailer inspection records: notes on odor, residue, moisture and floor condition before loading.
- Delivery exceptions: specific notations on the proof of delivery describing odors, stains, residue or leaks.
- Disposal records: if contaminated goods are destroyed, documentation of how and why.
When filing, remember that 49 CFR 370.3 requires a written claim that identifies the shipment, asserts liability, and claims a specified or determinable amount. Keep contaminated goods and packaging available for carrier inspection until the carrier confirms it does not need them. Our guide on how to file a freight claim that actually gets paid covers the full process.
Prevention
Most contamination claims are preventable. Practical steps include:
- Inspect every trailer before loading for odor, residue, moisture and debris, and refuse equipment that is not suitable.
- Write compatibility restrictions into your shipping instructions and routing guides.
- Put handling restrictions on the bill of lading so they are part of the shipment record.
- Package liquids and odorous products to prevent leaks and vapor.
- Avoid mixing food and chemicals in the same load wherever possible.
- Train dock staff to recognize incompatible products.
- Photograph the trailer before and after loading.
Contamination claims are harder to prove and harder to defend than ordinary damage claims. The party with better records usually has the advantage, whether shipper or carrier.
For more conversations on freight and AI, subscribe to the Freight Guru Podcast.
About the author: Luis Lopez is a Miami-based AI transportation consultant and logistics entrepreneur, the CEO of Go Hub.io Holdings Corp and subsidiaries, and host of the Freight Guru Podcast.
This article is general information for the freight community, not legal advice. Talk to a transportation attorney about your specific situation.
