Reefer Trailer Washout: Cleaning Food-Grade Trailers Under FSMA

A reefer trailer washout should remove all food residue and odor, sanitize where the load requires it, and leave the trailer dry before it is pre-cooled and loaded. Under FDA's Sanitary Transportation rule, carriers who take on sanitary responsibility need written procedures for cleaning, sanitizing and inspecting trailers. Hot water speeds up the job on fats and proteins, and the wash water has to be captured, not sent down a storm drain.

What does FSMA require for trailer cleaning?

FDA's Sanitary Transportation of Human and Animal Food rule, part of FSMA, puts responsibility on shippers, loaders, carriers and receivers to keep food from becoming unsafe in transit. When a written agreement makes the carrier responsible for sanitary conditions, the carrier must have written procedures that "specify practices for cleaning, sanitizing if necessary, and inspecting vehicles and transportation equipment" (21 CFR 1.908).

The same section says carriers must pre-cool refrigerated compartments as the shipper specifies, and a carrier offering a bulk vehicle must tell the shipper about its most recent cleaning if asked. In practice, that means your washout has to be repeatable and documented, not just done when a trailer looks dirty.

What makes reefer trailers hard to clean?

Reefer interiors collect food residue, blood, grease, produce juice and floor debris in the grooves of ducted floors, along walls and around door seals. Residue that sits warm turns into odor and biofilm fast. Shippers of meat, dairy and produce often reject a trailer at the dock for smell alone.

Cold water moves loose debris but struggles with fats and proteins. Hot water softens them so detergent can lift them, which is why most dedicated trailer washes use heat. Our comparison of hot water vs. cold water pressure washers explains the difference.

What are the steps of a good reefer washout?

Step	What to do	Why it matters
1. Dry clean	Sweep out pallet debris, stretch film and loose product	Keeps solids out of drains and filters
2. Pre-rinse	Low-pressure rinse from nose to doors	Loosens residue before detergent
3. Detergent wash	Apply detergent, wash with hot water	Removes fats, proteins and film
4. Rinse	Clean water rinse, floor grooves and seals included	Clears detergent and soil
5. Sanitize (if required)	Apply food-contact sanitizer per label	Meets the load or shipper's requirement
6. Dry and inspect	Squeegee, air out, inspect and record	Wet trailers can't be loaded or pre-cooled properly

Work from the nose toward the doors so dirty water always moves out of the trailer. Pay special attention to floor channels, rear door gaskets and the bulkhead, where residue hides.

How much pressure and flow do you need?

Interiors don't need extreme pressure. Moderate pressure protects wall liners, door seals and the reefer unit's components, while enough flow carries residue out the back. Heat does most of the work. If you're sizing a washer for a trailer yard, our guide to PSI vs. GPM walks through the trade-offs, and specifying a fleet wash rig covers burners, tanks and reels.

Where does reefer washout water go?

Not into a storm drain. Washout water carries food waste, grease, detergent and sanitizer, and most cities prohibit wash water with soaps or pollutants from reaching storm drains. Our article on fleet wash water rules covers what cities in Texas, California and elsewhere require.

Typical options:

• A wash bay that drains to the sanitary sewer through a grease and solids trap, with the utility's permission.

• Recovery and holding at yards without a sewer connection, then disposal at an approved point.

• Recovery with recycling, filtering the water for reuse in the pre-rinse and wash steps to cut water use and disposal volume.

Grease is the main enemy of both sewer connections and recycling systems, so separate it early.

Should you wash in-house or send trailers out?

Fleets that run their own reefers often bring washouts in-house to control timing and records. A dedicated hot-water wash rig lets a yard crew turn trailers between loads without waiting on an outside wash. Smaller carriers may use a contract washer. Either way, ask to see the written procedure and the cleaning record that goes with each trailer.

If you're comparing equipment, our buying guide on what a pressure washer trailer costs and the Slider Skid for washing without a trailer are good places to start.

Frequently asked questions

Does FSMA require reefer trailers to be sanitized after every load?

Not automatically. The rule requires written procedures for cleaning, sanitizing if necessary, and inspecting, when the carrier has taken on that responsibility. Shippers often set the sanitizing requirement in their contracts.

Is hot water required for reefer washouts?

No rule requires it, but hot water removes fats and proteins much faster than cold water and leaves less residue and odor.

Can washout water go down the storm drain if I use a food-safe detergent?

Generally no. Most city stormwater rules prohibit wash water containing soaps or pollutants from entering storm drains. Send it to a sanitary connection or capture it.

What records should I keep?

Keep your written washout procedure and a log of each trailer's cleaning, sanitizing and inspection. Shippers can ask about a bulk vehicle's most recent cleaning.

Set up a washout that passes the dock

We build hot-water pressure washer trailers and skids with wash water recovery and recycling, delivered nationwide. Text us through the "Text us" button on this site or call 800-897-7515 to plan your washout setup and get a quote.