The Washington PostDemocracy Dies in Darkness

The ‘sell-by’ dates on your groceries are useless. Here’s why.

Pick up a gallon of milk or a carton of eggs and it will probably have a "sell-by" or "best-by" label. But what does that date actually mean? It's unclear! The date can signify different things in different states. And many items stay fresh long after the expiration date passes.

In fact, the whole labeling system is a total mess, argues a new report (pdf) from the Harvard Food Law and Policy Clinic. Date labels are often so inscrutable and differ so widely from state to state that they're essentially worthless as information. (The U.S. Department of Agriculture has a whole page straining to make sense of the whole muddle and does a good job explaining how long various foods will last.)

And, the report argues, those labels may be leading Americans to throw out tons of perfectly good food each year — one reason why the United States rubbishes about 40 percent of the food it produces, or $165 billion in wasted food each year.

Why food labels are so confusing

So how did we reach this point? The report (pdf), written by Emily Broad Leib and others with support from the Natural Resources Defense Council, traces the history of food labeling. Back in the 1970s, urban shoppers, understandably, wanted to know whether their food was fresh. So, in response, dozens state governments began passing a patchwork of different labeling laws.

At this point, Leib writes, Congress could have stepped in to pass a uniform national standard. But that never happened — and hasn't to this day. The result was the "uneven and piecemeal creation of an American date labeling regime" that now looks like this:

That's all led to plenty of confusion. As Leib writes, these dates often don't tell us much about the safety of food. They indicate vague things about freshness and quality. Eggs can typically last 3 to 5 weeks after purchase if refrigerated. Chicken can last a couple of days. Processed hot dogs can last two weeks after the "sell-by" date passes. Canned foods can last 1 to 5 years if stored properly.

Yet surveys have found that most consumers can't really say what the labels mean: In a 2007 study, 25 percent of respondents thought you were supposed to throw away food once it reaches the "sell-by" date — and that's not even the intent of the label.

(On the flip side, food that hasn't reached its sell-by date isn't necessarily safe either. The temperature at which food is stored is far more important to food safety than the date, but surveys have found that consumers tend to pay most attention to the date labeling.)

It's possible that perplexing date labels are one reason why Americans throw out so much perfectly good food. Although this hasn't been measured directly, studies in Europe and Britain suggest that befuddlement over date labeling accounts for 20 percent of avoidable food waste. Seeing as how the United States wastes some $165 billion worth of food each year — to say nothing of the water and energy used to grow it — that's significant.

Can the labeling system be fixed?

The report ends with a chapter on recommendations to tidy up the labeling mess. Leib argues that "sell-by" dates — which are mainly intended for use by manufacturers and retailers — should be invisible to the consumer. And, the report notes, it ought to be replaced with a simpler standard to communicate quality and safety more clearly.

Leib has a few suggestions along these lines, although they're hardly definitive. Perhaps something like “Peak quality (or freshness) guaranteed before [Date]” might be clearer. There's also some evidence that relying on "freeze by" dates for certain foods could lead to less waste. But, Leib says, it's worth trying to figure out what the most effective system actually is here.

Further reading: 

-- Here's how the world manages to waste half the food it produces. Note that confusing date-labeling systems are only one small factor here.

-- Andrew Breiner of Climate Progress, who wrote about the labeling study first, also notes a recent U.N. report finding that we emit about 3.3 billion metric tons of greenhouse gases each year in the course of producing wasted food. That's about twice the annual emissions of India. So there's a climate-change angle here, too.