Ziploc Faces a Class Action Lawsuit for Undisclosed Microplastic Risk. What You Need to Know

CNET

12-05-2025

I've got a box of Ziploc bags in my cabinet, and I'm looking at them completely differently now that S.C. Johnson, the maker of Ziploc, is facing a class action lawsuit. The lawsuit says that the marketing that Ziploc storage bags are "suitable for freezer use" and "microwave safe" is misleading because the bags are made from polyethylene and polypropylene. These types of plastics are known to release microplastics into foods when exposed to extreme temperatures, something that is not mentioned on Ziploc's packaging.
"Repeated exposure to extreme temperatures -- cold or hot -- stresses plastic materials and can lead to the breakdown of their surface layers, releasing tiny plastic particles into food," said Brad Younggren of Circulate Health.
When you microwave food in plastic, the heat accelerates how much microplastics leach into the food. "Similarly, freezing and thawing cycles can cause structural degradation that also encourages microplastic release, not unlike how freezing temperatures crack pavement in winter," Younggren said.
According to the lawsuit, Ziploc bags are "fundamentally unfit" to be used in the way they're advertised.
The average person intakes between 39,000 and 52,000 microplastic particles each year, and that number increases to 120,000 when airborne particles are accounted for. There's no established "safe" or "unsafe" level of microplastic consumption, which is why it's important to know where microplastics come from and how to reduce ingestion.
What's the deal with microplastics?
Microplastics have long been a topic of conversation, mainly because they're important environmental pollutants. But these tiny plastic fragments don't just negatively impact the earth; they have potentially health impacts too. Some days, it feels like we're regularly discovering a surprisingly high amount of microplastics lurking in our bodies. Scientists recently found a spoon's worth of microplastics in the cadaver brains.
While the US Food & Drug administration says scientific evidence doesn't suggest that the amount of microplastics in foods is a risk to our health, not all doctors are convinced. Microplastics located in the blood vessels have been linked to a higher risk of heart attack and stroke. Research has also found tissue inflammation, cell death and lung and liver impacts because of microplastics. That said, there's still plenty we don't know about the effects of microplastics.
What we do know is that microplastics are everywhere. They're in the burned-down plastic spoon you should have thrown away years ago or the plastic-wrapped foods at the grocery store. However, it's not just how we package our foods. Microplastics can enter our food through soil and water contamination where they're grown.
Since microplastics touch so many areas of our lives (did I mention they're also in the synthetic fibers of our clothing?), it can feel challenging to outrun them completely. While there's no established safe or unsafe level of microplastic consumption, most of us want to minimize our contact with them as much as possible.
How can I limit my microplastic use?
The best way to limit your family's consumption of microplastics is to minimize your use of plastic in the kitchen. Remember, microplastics aren't just in plastic bags.
Top places microplastics lurk in your kitchen:
Nonstick cookware
Plastic cooking utensils
Tea bags
Plastic straws
Canned food lining
Plastic cutting boards
So you should probably stop using Ziploc bags to freeze and microwave your food. But where does that leave you? Younggren suggested opting for non-plastic alternatives when you can.
"We recommend microwave-safe glass containers as safer options," Younggren said. Glass containers are more stable under temperature stress, so the risk of microplastic contamination is lower.
There are things you can do beyond changing how you store your food. You can opt for wood cutting boards instead of plastic, or use loose tea leaves or cook in cast iron. You'd probably be surprised by how much plastic is in your kitchen. A good rule of thumb when cooking is to note how often your food comes into contact with plastic. It's difficult to cut it entirely out of your life, though any strides you can make will reduce your microplastic intake.