The three unsafe plastics are #3 PVC, #6 PS, and #7 Other (polycarbonate). They can leach harmful chemicals into food. This guide explains why they matter, how to spot them, and which plastics are safer.
Why Are Some Plastics Harmful For Food Storage?
Not all plastics behave the same when they touch food. Some release chemicals into what you eat or drink. This process is called migration. Heat, fat, and long contact times make migration worse. Understanding this helps you choose containers with confidence.
Which Three Plastics Should You Avoid?
#3 PVC (Polyvinyl Chloride)
PVC often contains phthalates, added to make it soft. Phthalates are linked to hormone disruption. The FDA continues to review phthalate use in food contact materials.
#6 PS (Polystyrene / Styrofoam)
Polystyrene can leach styrene, classified as a possible carcinogen. Research shows higher heat and fatty foods increase styrene migration.
Case example: Hot soup or greasy takeout in foam containers raises contact temperature and fat exposure together. Studies found styrene levels climbed sharply in high-fat simulants at 70°C.
#7 Other (Polycarbonate / BPA)
The #7 code covers mixed plastics, including polycarbonate. Polycarbonate may release BPA, which disrupts the endocrine system.
How Do You Identify Unsafe Plastics By Recycling Code?
Look at the small triangle stamped on the base of a container. Inside sits a number from 1 to 7. This resin code tells you the plastic type. Avoid #3, #6, and #7 for food storage.
| Code | Common Use | Main Concern | Food-Storage Note |
| #3 PVC | Wraps, bottles | Phthalates | Avoid |
| #6 PS | Foam cups, trays | Styrene | Avoid, esp. hot/fatty food |
| #7 PC | Hard bottles | BPA | Avoid |
| #1 PET | Water bottles | Single-use only | Safe once |
| #5 PP | Tubs, lids | Low | Microwave safe |
Which Plastics Are Safer For Food Storage?
#1 PET
Safe for single use and widely recycled. Common in beverage bottles.
#2 HDPE
Sturdy and chemical-resistant. Used in milk jugs and tubs.
#4 LDPE
Flexible with low leaching risk. Found in squeeze bottles and bags.
#5 PP
Microwave-safe and heat-tolerant. It is the strongest all-rounder for reusable food storage.
Procurement example: A buyer sourcing 8 oz Deli Containers with Lids should confirm PP resin. Whether comparing 8 oz plastic containers with lids wholesale or 8 oz Containers with Lids Bulk, resin code drives food safety.
How Can You Use Plastic More Safely In The Kitchen?
Never heat unsafe plastics in a microwave. Replace scratched or cloudy containers, since damage increases leaching. Prefer glass for long storage of hot or acidic food. When buying 8 oz plastic containers with lids, check the base for a #5 stamp before purchase.
What Should You Remember Before Choosing Food Containers?
Know your numbers. Avoid #3, #6, and #7 for food. Choose #1, #2, #4, or #5 instead. This simple habit protects your health at low cost.
For deeper guidance, read our plastic food containers pros, cons, and safe use guide, our disposable plastic takeaway food containers FDA specs, and what type of plastic is a takeaway container.
At SOWINTOP, 30+ years of engineering support OEM and ODM food packaging. We manufacture PP, PET, rPET, CPLA, and CPET formats for foodservice, retail, and co-packing. Products ship FDA, EU 10/2011, GRS, BPI, and BRCGS-aligned. Explore our collection to source safer containers.
Frequently Asked Questions
Which plastic number is safest for food?
Number 5 (PP) is the safest all-rounder. It resists heat and works in the microwave with low leaching risk.
Can I microwave polystyrene containers?
No. Heat increases styrene migration from #6 PS, especially with fatty foods. Transfer food to glass or PP first.
Where can I find safe 8 oz containers?
Search “8 oz plastic containers with lids near me” or check retailers. Compare options on 8 oz plastic containers with lids amazon and 8 oz plastic containers with lids walmart, then confirm the resin code.
Is BPA still a concern in plastics?
Yes. Polycarbonate under code #7 may release BPA, an endocrine disruptor. Choose BPA-free #5 PP for reuse.
