Your milk's date depends on which state you're in

We've written about California's AB 660, which standardized date label wording across the state as of July 1. That law is easier to understand once you see what it's a response to, which is a national vacuum.

There is no federal date labeling system. The Congressional Research Service puts it plainly: except for infant formula, federal law does not require the federal food safety agencies to implement a national food dating system. Dating emerged instead from consumer demand and industry practice, and the states filled the gap one at a time, in whatever order and shape they wanted.

The result is not a compromise. It's fifty separate answers.

The scale of the patchwork

Research by Harvard Law School's Food Law and Policy Clinic with the Natural Resources Defense Council found that 41 states plus the District of Columbia require date labels on at least some food items, while nine states require them on nothing at all.

The geography is arbitrary in a way that's almost funny. By that report's count New York requires date labels on no foods at all, while all six of its neighboring states, New Jersey, Pennsylvania, Connecticut, Massachusetts, Vermont, and Rhode Island, have requirements. One qualifier, since the report is explicit that its nine-state figure reflects the categories it assessed: New York does require date labeling on molluskan shellfish under the FDA model Food Code, which nearly every state has adopted and which that count treats separately.

Harvard's Date Labeling Policy Finder sorts state approaches into two buckets. A "negative" policy requires date labels for certain foods and also prohibits or limits selling or donating that food after the date. A "moderate" policy requires labels but leaves sale and donation alone. Under that classification, 23 states have negative policies and 27 plus DC have moderate ones. California's AB 660, for all the attention it got, lands in the moderate category, because it governs wording without restricting what happens after the date passes.

That distinction between the two buckets is the whole ballgame, because a label rule is a labeling question and a sale-and-donation restriction is a food waste question.

Montana, where the rule has teeth

The clearest example of a negative policy is a single dairy rule that has survived four decades of challenges.

Grade A milk sold in Montana must carry a sell-by date no more than 12 days after pasteurization. Retailers have to pull it from shelves at that point. After the date, the milk cannot be sold, and it cannot be donated. The rule was adopted by the state's Board of Livestock in 1980.

There is a narrow carve-out: schools and hospitals may distribute milk in half-pint packages after the sell-by date if it was purchased before the date. Otherwise, past-date milk is out of commerce entirely.

The Harvard clinic, which made a short documentary about the rule, reports that stores holding past-date milk must throw it out, and that they are not permitted to pour it down the drain and recycle the cartons but are instead supposed to put the full cartons into dumpsters.

What the litigation found

An out-of-state distributor, Core-Mark, challenged the rule, and the hearing produced the most useful numbers in this story.

After more than a thousand pages of testimony, the hearing examiner found that improvements in production and processing since 1980 had made a 21-day shelf life the going standard for the American and Canadian milk processing industry, and that the 12-day rule therefore blocks the sale of milk for 43 percent of the window, nine days out of twenty-one, during which the milk is fresh and of good quality.

The examiner issued a proposed decision recommending the Board consider repealing the rule. The Board voted unanimously to retain it without modification. The Montana Supreme Court then affirmed the district court's denial of Core-Mark's petition, holding the 12-day rule a valid exercise of the Board's authority. A later legislative attempt at repeal, House Bill 399, died in committee.

The case for keeping it deserves fair statement, because it isn't nothing. The Board of Livestock's executive officer has said the rule puts more power and knowledge in the hands of consumers. A dairy farmer who sits on the Board has argued that stores left holding past-date milk have a supply management problem rather than a labeling one. Montana dairy farmers testified that repeal would hurt their business, and a Teamsters representative warned it would close three processing plants in the state. Running the other way, the 12-day window plainly makes it harder for out-of-state processors to compete in Montana, which benefits in-state dairy, and that was the distributor's central complaint. A state representative who has pushed for repeal, and who has been in the grocery business since 1989, says Montana is now the only state left with a mandatory sell-by date on fluid milk.

So the rule is simultaneously a consumer-information measure, a jobs argument, a trade barrier, and a food waste generator, depending on which stakeholder you ask. All four descriptions are accurate.

Why the industry's own fix didn't take

Faced with the patchwork, the grocery industry tried voluntary standardization. The Product Code Dating Initiative, established by what were then the Grocery Manufacturers Association and the Food Marketing Institute, encouraged manufacturers to converge on standardized label language.

A 2019 analysis by Harvard's Center for Health Law and Policy Innovation found that the initiative conflicts with state law in more than half of all U.S. states. Among states with date label rules, 27 had at least one law that conflicts with the voluntary standard for at least one food product. The conflicts clustered in shellfish, in nine states, eggs, in nine states, and milk and dairy, in eight.

Which is the structural problem in one finding. A manufacturer can't voluntarily standardize into compliance when the underlying state rules disagree with each other.

What standardizing is estimated to be worth

Two organizations have put numbers on federal standardization, and characteristically they don't match. ReFED estimates that standardizing date labels nationally could divert 582,000 tons of food waste per year and generate $2.41 billion in annual economic value, addressing roughly 15 percent of preventable food waste. Harvard's CHLPI estimates 398,000 tons per year and a total economic value of $1.8 billion.

As we've written before about food waste figures, the gap between two credible estimates is usually a difference in what's being counted rather than a sign that one of them is wrong. Both point the same direction.

What this means for the carton in your hand

The date printed on your milk is partly a property of the milk and partly an artifact of your state's rulemaking history. In Montana it's a legal deadline enforced against retailers. In Texas it may not exist. In New York, nothing on the carton was required to be there at all.

That's the practical reason Savery calculates from the day you bought something and the category it belongs to, rather than reading whatever is printed on the package. The printed date is answering a question that varies by jurisdiction. Your refrigerator does not.