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Reefer pre-cooling and temperature records under 21 CFR 1.908

Helm PartnersUpdated Oct 30, 2026Sources checked Oct 30, 2026

This guide is general information, not advice on any policy.

Short answer

Under 21 CFR 1.908(e), when a written agreement makes the carrier responsible for sanitary conditions, the carrier pre-cools each refrigerated compartment as the shipper specifies before offering it. On request it gives the receiver the operating temperature and shows the load stayed in range, for example with load and unload readings or time and temperature data. Written procedures are kept 12 months past use.

In this guide
  • When the carrier duties apply
  • Pre-cooling
  • Showing temperature control
  • Records to keep
  • FAQ

When the carrier duties apply

The carrier duties in 21 CFR 1.908(e) apply when the carrier and shipper have a written agreement that the carrier is responsible, in whole or in part, for sanitary conditions.

Pre-cooling

  • Before offering a refrigerated unit for food that needs temperature control, pre-cool each compartment as the shipper specifies.
  • Record the setpoint, start time and reading when offered.

Showing temperature control

  • On request after delivery, give the receiver the shipper's operating temperature.
  • If the shipper or receiver asks, show the load stayed within it. Ambient readings at load and unload or trip time and temperature data both work if agreed.

Records to keep

  • Written procedures for cleaning, inspection and temperature control, kept 12 months past use (21 CFR 1.912(b)).
  • Training records, kept 12 months after the person stops that work.
  • Pre-cool logs, unit downloads and seal numbers with each load.

Related: the FSMA sanitary transportation rule for reefer carriers, the reefer cargo claim file checklist, reefer unit maintenance records.

Which rules apply: produce vs frozen reefer loads.

FAQ

Who sets the temperature?

The shipper specifies the operating temperature in writing, including pre-cooling when needed (21 CFR 1.908(b)(2)).

Does the rule say how to prove temperature?

It allows any means the carrier and shipper agree on, such as ambient readings at loading and unloading or time and temperature data from the trip.

How long are records kept?

Written procedures for 12 months beyond when they are in use, and training records for 12 months after the person stops doing that work (21 CFR 1.912).

Do small carriers have to follow this?

Motor carriers with less than $500,000 in average annual revenue, adjusted for inflation, are non-covered businesses under 1.904. Check the current figure.

What if the temperature goes out of range?

The food is not sold or distributed unless a qualified individual decides it was not made unsafe (1.908(a)(6)).

This guide is general information, not advice on any policy.

Sources