There's a common belief that onions can absorb toxins, and some people worry that storing onions in plastic containers or bags might cause them to absorb harmful chemicals. But what does science say? Can onions absorb toxins from plastic?
Understanding the Concern
This concern usually stems from two ideas:
Onions are known to absorb odors and moisture from their surroundings.
Some plastics, especially non-food-grade or low-quality plastics, can leach chemicals such as BPA (Bisphenol A) or phthalates, especially under heat or pressure.
So it's natural to wonder-if toxic substances are released from plastic, will onions (or other foods) absorb them?
What the Science Says
Onions do have porous cell structures, which allow them to absorb moisture and certain airborne compounds.
However, there is no strong scientific evidence that onions specifically attract or absorb toxins from plastic more than other foods.
The real issue lies in the type of plastic used. If food is stored in non-food-grade containers-especially under heat-it increases the risk of chemical migration into the food.
Safe Storage Matters More
Rather than focusing on whether onions absorb toxins, it's more important to:
- Use food-safe plastic packaging, such as PET or HDPE certified for food contact.
- Avoid heating food in plastic containers not labeled microwave-safe.
- Store onions in breathable, dry environments-not sealed plastic-since they require ventilation to stay fresh.
At Mingda, all of our packaging containers-including PET jars and HDPE bottles-are made with food-grade, BPA-free materials that meet international safety standards like FDA and ISO 22000. This ensures that no harmful substances leach into the food, whether it's onions, spices, or health supplements.