To toss or not? Knowing when ‘expired’ really means expired

ASU Biodesign researchers tell us ways to avoid wasting food

February 24, 2020

According to the Natural Resources Defense Council, Americans toss out approximately 25% of the food we buy. Carelessness, confusion over label dates and food spoilage are the three main reasons food is wasted. The problem has become so significant that the U.S. Department of Agriculture has announced the ambitious goal of reducing food waste by 50% by the year 2030. 

Devin Bowes, a nutritional epidemiologist at Arizona State University’s Biodesign Institute, is dedicated to helping the public understand ways they can improve their health through food choices. Bowes studies what we put in our bodies and how dietary behaviors can lead to chronic disease. She is passionate about food policy and sustainability. fruit in a plastic bag Photo courtesy of Download Full Image

Recently, Bowes and Rolf Halden, director of the Biodesign Center for Environmental Health Engineering, were featured in Discover magazine’s Feb. 7 article, "Is ‘Expired’ Milk Safe to Drink? Here’s How to Know When to Throw Away Food."

In the article, Bowes explains that food poisoning is not as prevalent as many people may think.

“More often people become sick from not storing their food properly or unsanitary food preparation,” she said.  

According to Halden, “Humans have an innate ability to sense issues with food, ranging from appearance to smell to tactile clues.”

He explains that we can often rely on our sense of sight, touch and in particular, smell. "While this is not perfect, it enables us to quickly reject food that potentially is compromised," he said.

One important issue is that there are no established standards around how food producers label expiration dates. The table below provides a guide*:


How long you can keep after printed sell date

Pasteurized eggs

up to five weeks

Pasteurized milk

up to seven days or until it sours


up to six weeks after sell date, cut off moldy sections with a 1 inch margin


up to seven days past its sell date (avoid eating if moldy and toss it)

Poultry & ground meat

use within one to two days of sell date or freeze by that date

Cut meats

use within 3-5 days of sell date or freeze

*Based on information provided in Discover, Feb. 7, 2020

Researchers also advise to avoid over-shopping, buying only the items that you will use immediately. If you purchase more than you need, be sure to freeze the unused items to be used at a later date. This practice saves money and also saves our landfills from being overburdened by unnecessary waste.

portraits of man and woman

Devin Bowes and Rolf Halden

Bowes is part of a team of researchers who are working to protect human health and critical ecosystems by detecting, minimizing and ultimately eliminating harmful chemical and biological agents through early detection and engineering interventions. The center was established in 2012 and has since gained international recognition for their expertise in studying healthy access to food, water and sustainability while avoiding exposure to toxins and environmental pollutants.

The Discover article advises calling the USDA Meat and Poultry Hotline at 1-888-674-6854 if you have a question. According to Discover, the hotline receives 50,000 food safety questions a year. 

Article adapted from Discover magazine

Christine Lewis

PhD candidate and science writer, Biodesign Institute Center for Applied Structural Discovery and the School of Molecular Sciences