How Expiration Dates Were Invented: A Brief History

Everyone · Explainer · Updated October 1, 2026 · LearnLife Editorial

What Are Expiration Dates and Why Were They Invented?

Expiration dates are labels printed on packaged foods and perishable items that indicate the last date the product is guaranteed to be safe to consume or of optimal quality. The invention of expiration dates stemmed from the need to protect consumers in a growing industrial food system where products traveled far from their production sites. Before mass production and refrigeration, people bought fresh food daily from local sources and consumed it quickly. However, as food began to be produced on a larger scale and shipped across regions, the risk of spoilage and contamination increased.

To address these risks, manufacturers and regulators developed expiration dates as a tool to communicate safety information directly to consumers. Expiration dates help ensure that food is consumed within a time window when it is least likely to cause illness and still tastes good. They also provide a standardized system to minimize disputes over product freshness and liability for foodborne illnesses. These dates support public health efforts by promoting safer food handling and consumption practices.

When Did Expiration Dates Start to Be Used?

The concept of expiration or “use by” dates began appearing in the early 1900s, but widespread adoption took several decades. Initially, food products were often sold without any date labels, relying on consumers’ senses to judge freshness. With the rise of canned foods in the late 19th century, some manufacturers started printing “packed on” or “best before” dates. However, these were mostly voluntary and inconsistent.

After World War II, industrial food production and preservation technologies improved rapidly. Refrigerators became more common in American households, and products began to move longer distances from producers to consumers. This created an urgent need for clearer labeling to prevent illness and reduce returns or complaints about spoiled goods. By the 1970s, governments and industry groups in the U.S. and other countries began establishing more formal standards requiring dates on many perishable items.

For example, infant formula was among the first products to have federally mandated expiration dates due to its critical health implications. Over time, labeling expanded to dairy products, meats, baked goods, and other foods. Today’s expiration dates are part of a regulatory framework designed to balance safety, quality, and consumer information.

How Are Expiration Dates Determined?

Food manufacturers determine expiration dates through scientific testing known as shelf-life studies. These tests simulate real-life storage and handling conditions to estimate how long a product remains safe and of good quality. To do this, manufacturers store sample batches of a product under controlled temperature and humidity, then analyze them at regular intervals.

For example, a yogurt manufacturer may keep samples refrigerated and test them every few days for signs of spoilage such as microbial growth, changes in texture, or off-flavors. Alongside sensory tests, chemical analyses identify breakdown products that affect safety or taste. The point at which quality declines unacceptably or safety risks emerge sets the baseline for the expiration date.

Manufacturers also build in safety margins to account for variations in home storage, transportation delays, and consumer use. These margins ensure that even if a product is stored improperly for a short time, it is unlikely to cause harm before the printed date. Regulatory agencies may provide guidelines or require testing protocols to standardize how expiration dates are set for different food categories.

How Do Expiration Dates Work in Practice?

To understand how expiration dates work in everyday life, consider a hypothetical example involving a loaf of sliced bread. The bakery produces the bread and packages it on January 1. Through shelf-life testing, they find that under typical room temperature storage, the bread stays fresh and safe to eat for five days before mold growth becomes likely.

The bakery sets the expiration date for January 6, meaning consumers should ideally finish the bread by that date. If you buy the bread on January 3, you have about three days left before it reaches its expiration. If the bread looks and smells fine after January 6, it might still be safe to eat a day or two later, but the risk of mold increases. Eating it much later could cause illness.

This example shows how expiration dates guide consumers on timing but also require judgment. Proper storage, like keeping bread in a sealed container or refrigerating it, can extend freshness slightly. Similarly, expiration dates for refrigerated items like milk or deli meat are based on testing under ideal refrigeration, so storing these items at higher temperatures reduces their actual shelf life.

Why Do Expiration Dates Matter for You?

Expiration dates play an important role in protecting your health and your budget. They act as safety checkpoints to prevent consumption of spoiled or contaminated foods that could cause food poisoning or allergic reactions. For example, eating dairy or meat after their expiration date increases the risk of bacterial infections such as salmonella or listeria, which require medical attention in severe cases.

In addition to safety, expiration dates help you manage food quality. Many products lose flavor, texture, or nutritional value over time. Following expiration dates ensures you enjoy food at its best. This also reduces food waste by preventing premature disposal of products that are still good.

Managing expiration dates can save money. For example, if you buy yogurt with a “use by” date a week away, planning to eat it within that week avoids throwing it out. However, knowing when some products remain safe beyond their expiration dates can prevent unnecessary waste. For instance, canned goods often remain edible long after printed dates, though quality may decline.

By understanding expiration dates, you can make informed decisions about food safety, quality, and waste prevention.

What Are Common Terms Confused with Expiration Dates?

Expiration dates are part of a broader system of food date labels that often confuse consumers. Knowing the differences helps you interpret them correctly:

• “Use by” date: This is typically the last date recommended for safe consumption. It appears on highly perishable foods like dairy, meat, or prepared meals and should be strictly followed.

• “Best by” or “Best before” date: Indicates when the product is expected to be at peak quality or freshness. It is not a safety deadline. Foods may still be safe to eat after this date but could have diminished flavor or texture.

• “Sell by” date: Intended for retailers to manage stock rotation. It tells the store when to remove a product from shelves but is not a direct safety indicator for consumers.

• “Packed on” or “Manufacture date”: Shows when the product was made or packaged but does not provide expiration information.

Confusing these terms can lead to discarding food too soon or consuming unsafe products. For example, a “sell by” date on milk is not the same as “use by.” Milk may stay safe for several days after the “sell by” date if refrigerated properly.

What Should You Do Next Regarding Expiration Dates?

To use expiration dates effectively and keep food safe, follow these practical steps:

1. Always check the date on packaging when buying: Choose products with the latest dates to maximize freshness at home.

1. Store foods according to recommended conditions: For example, keep dairy and meat refrigerated below 40°F (4°C) and seal dry goods tightly.

1. Use a first-in, first-out system: Organize your refrigerator and pantry so older items get used before newer ones, reducing waste.

1. Inspect foods visually and by smell before consuming: If a product is past its date but looks and smells normal, it might still be safe. However, avoid tasting spoiled food.

1. Understand the label terminology: Prioritize “use by” dates for safety and treat “best by” as quality guidance.

1. Plan meals and purchases around expiration dates: Buy quantities you can consume before products expire.

1. When unsure, discard high-risk foods: It’s better to be cautious with perishable items like meats or dairy.

These steps help balance food safety with reducing unnecessary waste and saving money. For more detailed explanations of expiration date terminology and safety tips, check articles like What Expiration Dates Really Mean and Why We Have Expiration Dates and How They Affect Food Safety.

Frequently asked questions

Are expiration dates the same across all states in the U.S.?

No. Expiration date regulations vary by state and product type. Some states require dates on certain foods, while others do not. The federal government mandates expiration dates on items like infant formula but leaves many labeling requirements to states or manufacturers.

How can I safely determine if food is still edible after the expiration date?

Use your senses—look for mold, unusual colors, or textures; smell for off odors. If any signs of spoilage exist, discard the food. When in doubt, especially with perishable items, err on the side of caution to avoid illness.

Why do some products have multiple dates on their packaging?

Different dates serve different purposes—“sell by” guides retailers, “best by” indicates quality peak, and “use by” focuses on safety. Multiple dates help everyone in the supply chain manage product freshness and safety effectively.

Can freezing extend the expiration date of food?

Yes. Freezing slows down spoilage by stopping bacterial growth and chemical changes. For example, freezing milk before its expiration date can keep it safe for weeks or months longer. However, freezing may affect texture or taste.

What should I do if I find expired food in my pantry or fridge?

Check if it’s a perishable or non-perishable item. For non-perishables like canned goods, inspect for damage or bulging cans and use your senses. For perishables, it’s safest to discard expired items. Regularly rotate food to prevent buildup of expired goods.