Is It Ever Safe to Reuse Plastic Bags? Food Safety Experts Weigh In

Plastic food storage bags are incredibly useful to have in your kitchen. Many people use these bags to pack lunches, save leftovers, and prep freezer meals. The single-use bags are disposable, so you can just toss them after using them…but should you? On one hand, you don’t want to be wasteful, and you could save money by getting more uses out of each bag. On the other hand, these bags are not meant to be reused, and doing so could increase the risk of foodborne illness. To get to the bottom of whether or not it’s safe to reuse plastic food storage bags, we spoke to food safety experts who shared when you can get away with it, and when it’s not worth the risk.

Can You Reuse Plastic Bags? 

Plastic food storage bags aren’t designed to be reused—they’re disposable, after all. However, there may be times where it’s safe to reuse them, which can help reduce waste and save money. 

It all depends on what you stored in these bags previously, and whether they were thoroughly washed and dried, notes Sandra Eskin, Chief Executive Officer at Stop Foodborne Illness. “If the bag was used to store dry, non-greasy foods like bread or crackers, it may be reused,” Eskin explains. “But if it was used to store raw meat, fish, poultry, eggs, or dairy, bacteria can linger, even after washing.”

However, reusing plastic bags too many times can be risky, so there are limitations to note. “The bags are typically made from thin polyethylene—a type of plastic that can develop cracks over time that bacteria can settle into,” explains Jessica Gavin, a certified food scientist. You may get away with reusing plastic bags once or twice, but any more than that and the bag may lose its integrity. “Glass food storage containers and reusable bags are a safer and more sustainable option to consider instead”, Gavin adds. 

How to Clean Plastic Bags

Even when they’re used to store dry, non-greasy foods like nuts, pretzels, granola, and grains, you should still wash and dry plastic bags between uses, Eskin notes. But why? According to Eskin, the bags may harbor food particles and bacteria left behind from what they previously held.

So, give them a gentle but thorough wash if you want to reuse them. “You don’t want to be too rough with the bags or turn them inside out, as this can cause holes or tears,” Gavin says. Instead, she recommends adding some soap and warm water to the inside of the bag, sealing it, and shaking the bag to distribute the warm soapy mixture. “Then, open the bag and use the soft side of a sponge to gently scrub it before rinsing,” she adds. The final step is important: Shake out any excess water and prop the bag open so it can air dry until all the water droplets have evaporated. “You should never reuse damp bags (so wait until they dry) because water can harbor bacteria,” Gavin explains. 

Just keep in mind that washing plastic bags doesn’t guarantee they’re safe to reuse. “Microbes can grow inside plastic bags if extra moisture is introduced,” says food scientist Bryan Quoc Le, PhD. “Even if you wash the bags, the microscopic texture of the plastic can harbor microorganisms.”

How to Make Plastic Bags Last Longer

Plastic bags don’t have a long lifespan, but you can probably get a couple of uses out of them with the right care.

For starters, keep them away from heat. “Heat and hot water can further degrade the plastic, potentially releasing chemicals, additives, or microplastics into food,” Gavin explains. When washing plastic bags, use lukewarm water rather than scalding hot water. It’s also a good idea to wait until hot food, such as freshly baked bread, cools down before transferring it to plastic bags.

Keep them away from moisture as well, since moisture can encourage microbial growth, according to Dr. Le. For example, when storing washed fruits or vegetables inside a plastic bag, allow them to dry first.

Another tip is to wash your hands before eating snacks out of plastic bags you plan on reusing. “They are typically used for finger foods, which means that any germs that would be on someone’s hands while eating would also go into the bag and move onto the next cycle of food stored inside,” Dr. Le explains. “Staphylococcus aureus is always on our hands, and it can cause food poisoning, so caution should be used when reusing these bags.”

When to Throw Out Plastic Bags

If you want to be on the safe side, throw out plastic bags after each use. “In most cases, it’s not a good idea to reuse them because you don’t know what microbes they contain,” concludes Dr. Le. 

But if any of the following apply to the bag in question, experts say to throw it away immediately:

• Previously stored animal products
• Has been exposed to heat
• Shows signs of wear, such as tears, holes, stains, or odors
• Has unknown spots or cloudiness that could be mold or mildew