What is an expiration date?
An expiration date is the last calendar day a manufacturer guarantees a consumable product (food or medicine) will be at its labeled level of quality, safety, or effectiveness. How that date is defined and regulated depends on the product type:
– For most packaged foods (except infant formula), date labels are voluntary and indicate quality—taste, texture, or appearance—not necessarily safety.
– For prescription and many over‑the‑counter (OTC) medicines, federal law requires an expiration date that reflects the period during which the manufacturer guarantees the product’s potency, safety and stability.
Key takeaways
– Food dates (best by, use by, sell by) are usually quality indicators; they’re not federally required (except for infant formula). Use your senses (look, smell, texture) to check food for spoilage.
– Drug expiration dates are federally mandated and indicate the period the manufacturer assures safety and effectiveness. Use caution: expired drugs may be less effective and, in a few cases, could be unsafe.
– Proper storage and handling extend the useful life of foods and medicines. When in doubt about a medication, consult a pharmacist or prescriber.
Sources: Investopedia; USDA/FSIS; FDA (listed at end).
How expiration dates work (definitions and labeling)
Open dating vs. closed dating
– Open dating: A calendar date on food (month/day; often also year for shelf‑stable or frozen goods). It’s readable and intended to indicate “best if used by” type dates.
– Closed dating: Manufacturer codes (letters/numbers) used internally to record production date/time—unreadable to most consumers.
Common food date-label phrases and meanings
– “Sell by”: A direction for retailers—when to remove the product from shelves. Not a safety date for consumers.
– “Use by”: Manufacturer’s recommended last date for optimal quality (taste/texture). Often used for perishable foods.
– “Best by” / “Best if used by”: Suggests peak quality before this date. Not a safety cutoff.
– “Do not use after” / “Do not use past”: A stricter instruction; indicates the product should be discarded after this date because it may be unsafe or ineffective.
Regulation differences: food vs. medicine
– Food: Aside from infant formula, federal law does not require date labeling. The USDA’s Food Safety and Inspection Service (FSIS) requires truthful, non‑misleading labels if dates are used and lays out basic open‑dating display rules.
– Medicine: The FDA requires expiration dates on prescription drugs and many OTC medicines. The date indicates the period the manufacturer guarantees potency and safety based on stability testing. The FDA can sometimes approve extensions in declared shortages based on reviewed stability data.
How manufacturers decide quality dates
Manufacturers calculate “quality dates” by considering:
– The food’s composition (fat content, moisture, acidity, preservative use).
– Packaging type (vacuum, modified atmosphere, barrier films).
– Storage conditions in transit, at retail, and expected household storage (temperature, humidity).
– Microbial growth potential for perishable items.
These calculations produce conservative dates intended to ensure consistent quality for most consumers.
Food safety vs. food quality: practical distinctions
– Quality date: Indicates expected peak taste/texture. A product may be edible after this date if there are no signs of spoilage.
– Safety indicators: For many perishable foods (meats, dairy, seafood), smell, appearance (slime, discoloration), texture, and temperature abuse (left out too long) are better signs of spoilage than the printed date.
Food safety tips — practical steps
1. Read the label: Note the type of date and whether the product is perishable.
2. Follow storage instructions: Refrigerate promptly, keep fridge ≤ 40°F (4°C), freezer ≤ 0°F (−18°C).
3. Use the sensory check: look, smell, and check texture—if anything seems off, discard.
4. Heed physical spoilage signs: bulging cans, leaks, mold (except certain cheeses where surface mold can be cut away—follow product guidance), sliminess on meat.
5. When in doubt, throw it out: for highly perishable items (raw poultry, ground meat, infant formula), err on the side of safety.
6. Freeze when you can’t use by the date: freezing preserves safety and quality for much longer, though texture may change.
7. Consult authoritative charts: use the USDA/FSIS food storage chart to check recommended refrigerator/freezer storage times.
Fast fact
The USDA has noted that a large share of food loss and waste in the U.S. stems from confusion over labeling and premature discarding—smell and other sensory checks are often more accurate for safety than quality dates.
Medication expiration dates — practical steps and cautions
What the date means
– For drugs, the expiration date is the last day the manufacturer guarantees full potency and safety, based on stability testing.
– Labels often list “EXP” followed by month/year or a specific date.
Practical steps for medication use and storage
1. Store medicines as labeled: cool, dry places away from sunlight; avoid heat and humidity (bathroom cabinets often too humid).
2. Keep medicines in original containers with labels intact (helps with dates, lot numbers, and instructions).
3. For critical medicines (insulin, nitroglycerin, certain injectables, epinephrine auto‑injectors), follow manufacturer instructions closely and consult a pharmacist before using past expiry.
4. If a required drug is in shortage, FDA may authorize extended dates based on reviewed stability data—consult authoritative guidance.
Is it okay to use some medicines after their expiration dates?
– General rule: Don’t rely on expired medications for critical uses. Some medicines lose potency over time and may be ineffective (dangerous if treating life‑threatening conditions).
– Some pharmaceuticals remain chemically stable past their labeled date, but you cannot be certain without manufacturer or regulatory reassessment. If you’re considering using an expired drug (e.g., in an emergency), discuss with a pharmacist or a medical professional.
– Exception: In controlled government programs (e.g., certain stockpile programs), stability testing has allowed extended dating under strict oversight; this is not a recommendation to use expired drugs at home.
Discarding expired medications — safe steps
1. Check for take‑back options: local pharmacies, community take‑back events, or the DEA National Prescription Drug Take Back Day. These are the safest disposal routes.
2. If no take‑back option is available, follow FDA guidance:
– Mix medicines (do not crush tablets) with an undesirable substance (kitty litter, used coffee grounds), place mixture in a sealed container, and put in household trash.
– Remove or obscure personal information on prescription labels to protect privacy.
– Some drugs have specific disposal instructions—follow them (e.g., some may be flushed only when recommended).
3. For controlled substances, prefer take‑back programs—don’t just throw them away or give them to others.
How long can you eat food past its expiration date? Can unopened food be eaten?
– There’s no single answer—depends on:
– The date type (quality vs. safety)
– Food type (canned, dry, refrigerated, frozen)
– Storage conditions (temperature control)
– Unopened, shelf‑stable goods (canned goods, dry pasta) often remain safe well past the “best by” date if packaging is intact and storage has been appropriate. Canned goods with bulging, rust, leaks, or severe dents should be discarded.
– Perishables (dairy, fresh meats) can be unsafe quickly if not refrigerated properly. Use “use by” dates as stronger guidance for perishables, and trust sensory checks.
Common-sense practical checklist for food and medicines
For food:
– Check date type and storage instructions.
– Store promptly at recommended temps; refrigerate leftovers within 2 hours.
– Look, smell, touch before consuming.
– Freeze if you won’t use a perishable before its date.
– Dispose if signs of spoilage are present.
For medicines:
– Note expiration dates and discard expired medications safely.
– Store medications per label instructions; keep critical meds in appropriate temperature conditions.
– Ask a pharmacist about the stability of a specific drug if you’re unsure.
– Use take‑back programs when available.
Quick answers (common questions)
– Can you use medicines after expiration? Not recommended for critical medications. Consult a pharmacist for specifics.
– How long past a food date can you eat it? It depends—shelf‑stable unopened items may be fine weeks to months after “best by” if stored properly; perishables are riskier. Use sensory checks.
– Does “best by” mean unsafe after that date? No—usually quality, not safety. But for perishable items follow “use by” more closely.
Bottom line
Expiration dates are helpful signals, but their meaning differs by product type. For most foods, dates are quality indicators—use common sense and sensory checks to decide whether food is safe to eat. For medicines, expiration dates are regulatory assurances of potency and safety; err on the side of caution and consult health professionals or pharmacists before using expired drugs. Proper storage, timely use, and safe disposal reduce risk and waste.
Sources and further reading
– Investopedia — “Expiration Date” (source provided by you): https://www.investopedia.com/terms/e/expiration-date.asp
– USDA FSIS — Food Product Dating: https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/food-product-dating
– USDA FSIS — Food Storage Chart: https://www.fsis.usda.gov/food-safety/safe-food-handling-and-preparation/food-safety-basics/food-storage-chart
– U.S. Food & Drug Administration (FDA) — Expiration Dating for Drugs: https://www.fda.gov/drugs/pharmaceutical-quality-resources/expiration-dating-drugs
– FDA — How to Dispose of Unused Medicines: https://www.fda.gov/consumers/consumer-updates/where-and-how-get-rid-unused-medicines
If you’d like, I can:
– Produce a printable quick‑reference checklist for your fridge/medicine cabinet.
– Look up specific guidance for a particular medication or food item (e.g., “how long is milk safe after the date?” or “is it safe to use expired epinephrine?”).