Is it safe to buy flour in a plastic-lined paper bag?
Low concern. Dry flour is a lower-migration food, but transfer it for freshness and cleaner storage.
What's actually in it
Flour is dry. That makes it a lower-concern food for plastic migration than warm, oily, or acidic foods.
A thin plastic liner in a paper bag is mostly a freshness and spill-control choice. The better home habit is to transfer flour to a sealed glass jar or canister after opening.
What the research says
A 2021 FDA review in Food Addit Contam Part A looked at migration into dry foods. It found that dry-food migration is not always zero and depends on the migrant, packaging, food particle size, temperature, humidity, and whether there is a barrier layer.
A 2025 study in J Hazard Mater found plasticizers in 85% of analyzed foods, but it also showed exposure varies by food and packaging context.
Buy the flour that works for your budget. Once open, move it to glass or a sturdy canister and keep it cool and dry.
The research at a glance
| Study | Journal | Year |
|---|---|---|
| Migration of food contact substances into dry foods: A review. | Food Addit Contam Part A Chem Anal Control Expo Risk Assess | 2021 |
| Plastic additives in the diet: Occurrence and dietary exposure in different population groups. | J Hazard Mater | 2025 |