Grade A milk and the PMO
Definition
Section titled “Definition”The Grade “A” Pasteurized Milk Ordinance (PMO) is the model regulation, published by FDA, that sets the sanitary standards for Grade A milk and milk products shipped in the US. Changes are proposed and voted on through the National Conference on Interstate Milk Shipments (NCIMS), and FDA publishes a revised PMO after each conference. States adopt the PMO by law or rule and enforce it through their regulatory agency (usually the state department of agriculture or health). Only milk from permitted Grade A farms can go into Grade A products such as fluid milk.
What the PMO requires of a dairy farm:
- Permit: a farm must hold a permit from the regulatory agency to sell Grade A raw milk. The permit can be suspended or revoked.
- Inspections: routine farm inspections by the regulatory agency (or a certified industry inspector), using the PMO’s Item list for dairy farms: milking barn or parlor, cow housing, milk house, water supply, toilets, equipment cleaning, cooling, drug storage and labeling, and more.
- Raw milk standards for each producer’s milk (below), checked by regular official sampling.
- Drug residue control (Appendix N): tanker screening, and farm trace-back and permit action on a positive. See drug residue avoidance.
How to pull it in DC305
Section titled “How to pull it in DC305”Mostly not in DC305. The evidence is:
- the farm permit and inspection reports from the regulatory agency;
- official sample results (SCC, bacteria, temperature, drug residue) from the processor, cooperative or regulatory lab, often in the milk-buyer portal; see bulk tank pickup data;
- tank temperature records (recording thermometer or electronic logger);
- water test results for the farm well.
DC305 can help manage what drives the numbers: individual-cow SCC from DHI test
days (see somatic cell count) and
treatment and withhold records that keep residues out of the tank. Item and
event names vary by herd: see the herd’s private dc305-vocab mapping.
Typical range
Section titled “Typical range”Herd context: US Grade A cow-milk producers; PMO standards as of November 2026 (2025 PMO revision, Section 7, Table 1). States may set stricter limits, and processors and cooperatives often pay premiums at much lower SCC and bacteria counts.
| Standard (Grade A raw milk for pasteurization, cow) | PMO limit |
|---|---|
| Somatic cell count, individual producer | ≤ 750,000 cells/mL |
| Bacteria (SPC), individual producer, before commingling | ≤ 100,000 cfu/mL |
| Bacteria, commingled milk before pasteurization | ≤ 300,000 cfu/mL |
| Cooling | ≤ 50°F (10°C) within 4 hours after the milking starts, then ≤ 45°F (7°C) within 2 more hours |
| Blend temperature after the first and later milkings | ≤ 50°F (10°C) |
| Drug residues | No positive result on drug residue detection methods referenced in PMO Section 6 (Appendix N) |
Goat milk has a higher SCC limit: 1,500,000 cells/mL.
Sampling and enforcement:
- Official samples (Section 6): at least 4 samples in any 6 consecutive months, taken in at least 4 separate months (or 3 months when one month has two sampling dates at least 20 days apart).
- Enforcement on SCC, bacteria or cooling temperature (Section 6): when 2 of the last 4 consecutive results, taken on separate days, exceed the standard, the agency sends a written notice and takes an extra sample within 21 days (but not before 3 days). When 3 of the last 5 exceed it, the permit is suspended immediately and/or court action is taken.
- Reinstatement (Section 3): for bacteria or cooling violations, a temporary permit is issued after an inspection shows the cause is fixed; for SCC, after a resample of the herd’s milk is within the limit. Accelerated sampling follows (no more than 2 samples a week, on separate days, within 3 weeks), and the full permit returns once the milk meets the standard.
- Drug residue confirmed positive (Appendix N): the permit is suspended (or equally effective measures are taken), and no further pickups or farm use of the milk are allowed until the farm’s milk tests negative on the same or an equivalent method. The penalty is the value of all milk on the contaminated load plus disposal costs. The agency investigates the cause on the farm. After a third violation in 12 months, the agency starts proceedings to revoke the Grade A permit.
- Farm inspections (Section 5): at least once every 6 months. Under the optional performance-based system in Appendix P, farms with a good 12-month record can go to one inspection every 12 months, while poor performers are inspected every 4 or 3 months.
Requirements change; confirm the current version with the program or regulator. This page is not legal advice.
Common mistakes
Section titled “Common mistakes”- Managing to the PMO limit. 750,000 cells/mL is a legal ceiling, not a quality target; most buyers penalize far below it.
- Ignoring the 3-of-5 pattern. One high count looks harmless until it is the third in five samples.
- Cooling failures after equipment changes, power outages or added milk volume, with no temperature record to show what happened.
- Drug storage findings: unlabeled drugs, drugs not for use in lactating cows stored with lactating-cow drugs, or human-use products in the milk house.
- Water supply tests overdue or not on file.
- Treating inspection findings as one-off: repeated debits on the same item lead to stronger action.