Do paper takeout bowls release chemicals into hot soup?
Use caution with hot soup in coated takeout bowls. Heat and long contact time can increase chemical migration from food-contact coatings.
What's in the bowl
Paper takeout bowls are not just dry paper. To hold hot soup, many need a water-resistant coating, such as polyethylene, PLA, or another food-contact polymer. Some grease-resistant packaging has also used PFAS.
Hot liquid and long contact time can raise migration from food-contact materials. The safest habit is simple: do not store hot soup in the takeout bowl longer than needed.
What the research says
A 2026 study in Analytical and Bioanalytical Chemistry tested 17 bio-based and biodegradable food-contact materials. The researchers found oligomers, additives, and degradation products in the materials.
The same study used in vitro tests for cytotoxicity, oxidative stress, inflammation, and endocrine activity. Extracts from PLA, bio-polyester, and bio-polyester-PVOH showed the highest cytotoxicity, while bio-polypropylene and bio-polyethylene showed endocrine-disrupting activity.
This study does not prove every paper soup bowl releases the same chemicals. It does show that bio-based or biodegradable food packaging still needs chemical safety testing. Plant-based packaging is not automatically lower risk.
What to do at home
Transfer hot soup to a porcelain, glass, or stainless steel bowl when you can. Do not reheat food in coated takeout bowls. Move leftovers to glass or stainless steel before storing them.
The research at a glance
| Study | Journal | Year |
|---|---|---|
| Evaluating the chemical safety of bio-based and biodegradable food packaging materials through non-targeted LC-HRMS analysis and in vitro bioassays. | Anal Bioanal Chem | 2026 |