Section 1 · Definition SSPasteurization time + temperature
| Method | Temperature | Time |
| Batch (vat) | 145°F (63°C)* | 30 min |
| HTST | 161°F (72°C)* | 15 s |
| HHST | 191°F (89°C) | 1.0 s |
| HHST | 194°F (90°C) | 0.5 s |
| HHST | 201°F (94°C) | 0.1 s |
| HHST | 204°F (96°C) | 0.05 s |
| HHST | 212°F (100°C) | 0.01 s |
| Eggnog, vat | 155°F (69°C) | 30 min |
| Eggnog, HTST | 175°F / 180°F | 25 s / 15 s |
* Add 5°F (3°C) if fat is 10% or more, total solids 18% or more, or the product contains added sweeteners. PMO p. 11 PMO p. 12
Definitions III + EEUltra-pasteurized + aseptic
| Item | Requirement |
| Ultra-pasteurized (UP) | ≥ 280°F (138°C) for ≥ 2 s |
| UP holding tube | Verified by the Regulatory Agency to a calculated hold of at least 2 s PMO p. 98 |
| Low-acid aseptic / retort | aw > 0.85 and pH > 4.6; regulated under 21 CFR 108, 113 and 117 |
| Aseptic processing | See Appendix S PMO p. 402 |
PMO p. 15 PMO p. 7
Section 7 · Table 1 + Item 17pTemperature standards
| Product | Requirement |
| Raw milk, on farm | ≤ 50°F (10°C) within 4 h of starting milking, then ≤ 45°F (7°C) within 2 more hours. Blend after later milkings ≤ 50°F |
| Raw milk, at the plant | ≤ 45°F (7°C) until processed |
| Pasteurized + UP | ≤ 45°F (7°C), maintained |
| Concentrated (condensed) | ≤ 45°F unless drying starts immediately |
| Whey for condensing/drying | ≤ 45°F or ≥ 135°F (57°C), except acid-type whey |
| Condensed whey | ≤ 50°F during crystallization, within 72 h of condensing |
PMO p. 35 PMO p. 36 PMO p. 110
Section 7 · Table 1Bacterial + chemical limits
| Product | Test | Limit |
| Raw, individual producer | Bacteria | ≤ 100,000 /mL |
| Raw, commingled | Bacteria | ≤ 300,000 /mL |
| Raw, individual producer | Somatic cells | ≤ 750,000 /mL* |
| Pasteurized + UP | Bacteria | ≤ 20,000 /mL or g |
| Pasteurized + UP | Coliform | ≤ 10 /mL (100 bulk tanker) |
| Pasteurized | Phosphatase | < 350 mU/L |
| NFDM + dry milk | Bacteria / coliform | ≤ 10,000 / ≤ 10 per g |
| All | Drug residues | No positive results |
* Goat milk 1,500,000 /mL. Exceptions for cultured and other products are listed in M-a-98. PMO p. 35 PMO p. 36
Items 12p + 16pEquipment + cleaning rules
| Item | Requirement |
| Storage tanks | Cleaned when emptied; emptied at least every 72 h (clock starts when milk first enters) PMO p. 74 |
| Silos + tanks > 24 h | 7-day temperature-recording device PMO p. 75 |
| Milk tank trucks | Clean + sanitize before first use; re-sanitize if more than 96 h pass before first use PMO p. 75 |
| Holding tube slope | ≥ 0.25 in/ft upward (2.1 cm/m) PMO p. 98 |
| Regenerator / booster pump | Pasteurized side ≥ 1 psi (6.9 kPa) above max booster pump pressure PMO p. 103 |
| Batch airspace | ≥ 5°F (3°C) above minimum pasteurization temperature during hold PMO p. 94 |
| Indicating thermometers | ± 0.5°F (0.2°C) PMO p. 251 |
Section 7Other heat treatments
| Item | Requirement |
| Whey (from cheese milk heat-treated, not pasteurized) | ≥ 147°F for 21 s, or ≥ 153°F for 15 s |
| Heat-treated for separation (bulk cream, skim, reduced/lowfat) | One time, > 125°F and < 161°F; labeled heat-treated |
| Heat-treated cream (enzyme deactivation) | < 166°F (75°C), then cooled to ≤ 45°F |
PMO p. 34
Appendix D, V + Appendix GWater standards: reclaimed water categories
Water reclaimed from milk and milk products, and from heat exchangers or compressors, may be reused in a milk plant under three categories. PMO p. 179
Category IPotable water purposes, including culinary steam
- Meets Appendix G bacteriological standards, and total plate count ≤ 500/mL
- Sampled daily for 2 weeks after approval, then at least every 6 months (daily for 1 week after repairs)
- From milk: turbidity < 5 units, or conductivity correlated to organic content < 12 mg/L (COD or permanganate test)
- From milk: automatic fail-safe monitor diverts out-of-spec water to sewer
- No off-flavors, odors or slime; tested organoleptically weekly
- Chemicals (e.g. chlorine) or UV added automatically before storage; daily chemical testing
- Separate distribution system, no cross-connections
- Water from raw milk membrane processes needs pasteurization-equivalent heat treatment first
PMO p. 179 PMO p. 180
Category IILimited purposes
- Culinary steam production
- Pre-rinsing product surfaces (pre-rinse not used in product)
- Cleaning solution make-up water
- Non-recirculated heat exchange media against raw milk or acid whey
- Non-recirculated heat exchange media against pasteurized product (per Item 15p.(B)9)
Must also meet Category I items 3–11 (items 5–11 for heat exchanger or compressor water), plus one of these:
- No carry-over day to day, or
- Held at ≤ 45°F or ≥ 145°F automatically, or
- Approved chemical or UV treatment before storage, or
- Appendix G standards and plate count ≤ 500/mL
Lines labeled “limited use reclaimed water.” No permanent connection to product vessels without an air break and controls.
PMO p. 180 PMO p. 181
Category IIIWater not meeting Category I or II
- Boiler feed water (not for culinary steam)
- A thick, double-walled, enclosed heat exchanger
PMO p. 181
| Water rule | Requirement |
| Bacteriological standard (water supplies, reclaimed + recirculated cooling water) | Total coliform < 1.1 MPN/100 mL, or < 1/100 mL by membrane filter or P/A PMO p. 217 PMO p. 218 |
| Water sampling (individual supplies, Category I + II) | At initial approval, at least every 6 months, and after any repair or alteration PMO p. 68 |
| Air gap | At least 2 × the diameter of the largest supply pipe, never less than 1 in PMO p. 68 |
| UV disinfection | Reduction equivalent dose ≥ 40 mJ/cm² at 254 nm, fail-safe divert or shut-off valve PMO p. 178 |
| Reclaimed water in a raw milk heat exchanger | Water side ≥ 1 psi above raw milk side; water rises ≥ 12 in above any raw milk before opening to atmosphere PMO p. 180 |
| Evaporator barometric leg | At least 35 ft vertical, or an automatic safety shut-off valve on the condenser feed PMO p. 68 |
About this pageSource + edition
Everything here comes from the Grade "A" Pasteurized Milk Ordinance, 2025 Revision (U.S. FDA / NCIMS). Page numbers are the PMO's printed page numbers, and each button opens the official text to that page.
This is a convenience summary, not legal advice. The official PMO, the M-memoranda and your Regulatory Agency govern. Check for newer revisions on FDA's NCIMS page.
Summary of the 2025 Grade "A" PMO for convenience only, not legal advice. The official PMO, FDA memoranda and your Regulatory Agency govern.