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Lesson

Understanding expiration and food safety labels

Published:
October 12, 2026
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  • State-specific rules on expiration dating, since not all states follow identical requirements for all food categories.

We left these specific numbers out until they're checked against current official sources.

AThe super simple explanation

Phrases like "best by," "sell by," and "use by" are mostly manufacturer estimates of peak quality, not strict safety cutoffs, except for infant formula.

Food can often still be safe to eat after a "best by" date if it's been stored properly and shows no signs of spoilage.

"Sell by" dates are mainly for the store's inventory management, not a deadline for consumers.

Infant formula is the one product where the date on the package is a legally required safety-related deadline.

BWhy does this even matter?

  • Misunderstanding date labels leads to a lot of unnecessary food waste when people throw away food that's still safe to eat.
  • On the other hand, ignoring real spoilage signs just because a date "hasn't passed yet" can still make you sick.
  • Knowing the one true exception — infant formula — protects a genuinely higher-risk situation.

COkay, how does it work?

"Best by" or "use by" signals peak quality; "sell by" is for store stocking.

DShow me an example

A yogurt past its date

A container of yogurt is five days past its "best by" date but has been refrigerated the whole time, smells normal, and shows no mold.

It's likely still safe, though the quality (taste/texture) may have declined slightly from its peak.

Illustrative example with made-up people and numbers — not current rates or rules.

EWords you should know

Best by/best if used by
A manufacturer's estimate of when a product is at peak quality, not a safety deadline for most foods.
Sell by
A date meant to guide store inventory and shelf stocking, not a deadline for consumer use.
Use by
The manufacturer's suggested last date for best quality; for infant formula, it's a required safety deadline.
More in “Words everyone pretends to know” →

FCommon mistakes

  • Throwing away still-good food purely because a "best by" date has passed.
  • Assuming all date labels mean the same legal thing.
  • Using infant formula past its "use by" date.
  • Ignoring obvious spoilage signs (smell, mold, texture) just because the date hasn't passed.

GThings to know

  • Infant formula is the one category where federal law requires the date to represent a real safety cutoff.
  • Proper storage (consistent refrigeration, sealing leftovers) extends how long food stays genuinely safe, regardless of the printed date.
  • When in doubt about a food's safety, USDA's guidance is: when in doubt, throw it out.

HQuick recap

  • Most date labels indicate quality, not a strict safety deadline.
  • Infant formula is the one legally required safety-related date.
  • Use your senses and knowledge of how food was stored, not just the date.
  • When truly unsure about spoilage, it's safest to discard the item.

IQuestions people are too embarrassed to ask

JQuiz me

Totally optional. Nobody's grading you.

Question 1

Q1. What is the one food category where the date label is a required legal safety deadline?

Question 2

Q2. What does a 'sell by' date mainly tell you?

Question 3

Q3. What should you also check besides the printed date?

KWhat next?

  1. 1.Check your fridge for items past their 'best by' date and assess them using your senses before discarding.
  2. 2.Note which foods in your kitchen fall into the higher-risk perishable category (dairy, meat, eggs).

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