Executive brief
Appendix II of USDA Handbook 669 reprints the load compatibility groups from Marketing Research Report 1070 (Lipton & Harvey, 1977). They remain the industry’s shared language for mixed produce: commodities in the same group share transit temperature, humidity, ethylene, and ice tolerance closely enough to ride together under normal practice.
Five factors before the chart
- Required commodity temperature
- Required relative humidity
- Emission of physiologically active gases (ethylene)
- Odor-absorbing characteristics
- Modified-atmosphere requirements
HB 669: desired transit temperatures of co-loaded products should be within a reasonably close range — mature-green tomatoes at ~55°F do not share air with lettuce at 32°F.
Group cheat sheet
| Group | Transit °F | RH | Character |
|---|---|---|---|
| 1 | 32–34 | 90–95% | Apples, stone fruit, berries*, pears… high ethylene; ice never in contact |
| 2 | 55–65 | 85–95% | Avocados, bananas, mangoes, green tomatoes, many tropicals |
| 3 | 36–41 | 90–95% | Cantaloupes, cranberries, many oranges/tangerines/lemons* |
| 4 | 40–45 | ~95% | Snap beans, okra, peppers, summer squash, pink tomatoes* |
| 5 | 40–55 | 85–90% | Cucumbers, eggplant*, late potatoes, winter squash; ginger ≥55°F |
| 6a | 32–34 | 95–100% | Leafy greens, lettuce, herbs, sweet corn, many roots |
| 6b | 32–34 | 95–100% | Cole crops; generally compatible with 6a (exceptions: figs/grapes/mushrooms) |
| 7 | 55–65 | 85–90% | Early potatoes, sweetpotatoes, ginger |
| 8 | 32–34 | 65–75% | Garlic & dry onions — dry + odor isolation |
*See handbook footnotes: origin-specific citrus temps; grape SO₂ rules; multi-group commodities (watermelon, eggplant, pink tomato, etc.).
Non-negotiables
- Group 1 ↔ 6a/6b: no (ethylene).
- Ice contact: never for most fruit/berries/mushrooms; acceptable for many cole crops / some 6-class items per notes.
- Grapes: only with others if not SO₂-fumigated in the vehicle / no SO₂-releasing packs that conflict.
- Group 8 onions/garlic: odor taints nearly everything; keep isolated.
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FAQ
Is this official USDA guidance?
No. These are educational modernizations of public USDA handbooks (AH-66 and HB 669) by ProspectSentinel / Sentinel Labs. Always consult the primary sources and your contracts.
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Where are the interactive tools?
Sources & interactive tools
- USDA AH-66 — The Commercial Storage of Fruits, Vegetables, and Florist and Nursery Stocks (2016)
- USDA AMS HB 669 — Protecting Perishable Foods During Transport by Truck
- Federal rules (eCFR): 7 CFR Part 46 — PACA regulations · 49 CFR Part 370 — Principles and practices for the investigation and voluntary disposition of loss and damage claims
- Cold Chain Index — 200+ commodity storage/transit matrix + co-load checker
- Produce Shipper Transit Guide — dock setpoints, mix load, checklist
- Reefer Precool Time Estimator — half-cooling-time style estimator
- Perishable Claim Analyzer · PACA Good Arrival Calculator · Produce Truck Rate Explorer
- Freight claim package checklist · Claim / Carmack deadline calculator
Important notice
This publication modernizes and explains public USDA guidance and, where noted, points to public federal regulations on eCFR.gov for educational use by shippers, brokers, carriers, and operators. It is not an official USDA or DOT document, and it is not legal, insurance, PACA advocacy, food-safety certification, or professional claims advice. Always verify current commodity specifications, contracts, and the current eCFR text with the controlling authority and your counsel.
Primary sources: USDA-ARS Agriculture Handbook 66 (2016); USDA-AMS Handbook 669, Protecting Perishable Foods During Transport by Truck (1995, reprinted 2008), including Load Compatibility Groups from USDA Marketing Research Report 1070 (Lipton & Harvey, 1977). Selected federal regulation entry points: 7 CFR Part 46 (PACA); 49 CFR Part 370 (freight claims).
Full series
- 00 Cold Chain Operating System
- 01 The Reefer Is Not a Precooler
- 02 Colder Is Not Safer
- 03 Ethylene: The Invisible Load Killer
- 05 Airflow, Load Patterns & Multi-Temp Zones
- 06 Commodity Setpoint Desk Guide
- 07 Protein, Dairy & Eggs on the Same Trailer
- 08 CA, MAP & When Gas Matters
- 09 From Temperature Log to Claim
- 10 Seasonal Produce Desk
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