October 06, 2016

Sell By and Use By Dates Explained

Articles by Dr. Erdman are for informational purposes, and are not to be taken as specific medical advice.

How many times have the ‘use by’ or ‘sell by’ date on a packaged food caused you to rethink eating or purchasing a product? Does either of those dates say anything about whether the product is safe to eat? Are these dates regulated by the government or backed by any research showing good reason for them?

The average family in America wastes over $1500 worth of food each year. Moldy bread and spoiled produce should be discarded for obvious reasons. Yet many perfectly fine foods are tossed based on the ‘use by/best by’ and ‘sell by’ dates. A recent report from Harvard found that 90% of Americans throw out food prematurely based on a misunderstanding of what these dates really mean.

There is only one processed food in the U.S. that has mandated dating by the federal government, and that is baby formula. These ‘use by’ dates are actually based on scientific evidence. Baby formula must contain the full nutrition listed on the product label. The use by date is the date determined to be the latest date full nutrition is available, before it starts to breakdown or separate. These dates should be followed.

Well what about other products? There are about half the states that require dating of some products, but such labeling varies widely among those states. There simply is no uniform system for labeling, nor is there a federal requirement to do so. Those labels are pretty much at the whim of the manufacturer.

There are two types of food dating labels; open and closed. Closed labeling is written in code for use by the manufacturers. Closed labeling is found on shelf stable products in cans or boxes. Open labeling is when you see an actual date on the package. Open labeling is mostly used on perishable foods like meat, eggs and dairy.

When you see a ‘sell by’ or ‘use by’ date, do they mean the same thing? No. This is where the consumer misunderstanding comes into play. Do they have anything to do with food safety? No.

A ‘sell by’ date is not even meant for consumers. It is meant to help retailers rotate their shelf stock. There is actually a push to make sell by dates invisible to consumers. It has no bearing on the foods safety of use at all. Of course the government still recommends you by the food before the ‘sell by’ date expires. Why? Who knows – it’s the government!

When the term ‘best if used by (or before)’ is printed, it is usually the manufacturer’s determination of that products best flavor or quality period. It is not, however, a measure of the food safety or spoilage. Manufacturers will obviously be very conservative on these dates knowing people will toss old stock and buy new product based on these dates.

To be fair, some manufacturers do use lab tests or researched values for their dates. Some use consumer taste testing to determine dates. But in all cases we, the consumer, have no way of knowing how that date is set or calculated.

A ‘use by’ date is the last date of use for peak quality. Again, this date is determined by the manufacturer and varies widely. Of course the USDA recommends following that date. However, the USDA also states this, “‘Use by’ dates usually refer to best quality and are not safety dates. Even if the date expires during home storage, a product should be safe, wholesome and of good quality if handled properly.” In other words, ‘use by’ dates are not really use by dates…only the government!

The other food with mandatory dates are eggs. They have a 3 digit code (January 1 is 001, December 31 is 365). This date is 45 days from when they were packed, and is a ‘sell by’ date. Eggs do stay fresh a long time. If in doubt, put an egg in a bowl of water. If it floats, don’t eat it. It should sink to be fresh.

Date labeling has come from demand by consumers who have been removed from the process of buying fresh food. If you buy food from a neighbor or farmers market, chances are it’s pretty fresh. But if you are like the majority of people who buy all their food from a giant retailer, you generally have no way to determine freshness, other than these labels. At the very least you should know what they mean, and act accordingly. The best case scenario is that you buy perishable food from places where you can know its history.