The most commonly recommended plastic numbers for food and drink are 1, 2, 4, and 5 because they’re less likely to leach chemicals into your items during normal use. While other types exist, these four codes are widely considered the standard for safety in household storage and everyday containers.
Which Plastic Numbers Are Safest?
Plastic resins are identified by a number inside a triangle, known as a resin identification code. These numbers help you identify the type of material and its typical chemical stability. For food contact, you’ll want to prioritize materials that have a lower risk of breaking down when they touch your food or liquids.
| Plastic Number | Name | Common Uses | Safety Profile |
|---|---|---|---|
| 1 | PET | Water bottles | Generally safe for single use |
| 2 | HDPE | Milk jugs | Very stable, low leaching |
| 4 | LDPE | Food bags | Flexible, very stable |
| 5 | PP | Yogurt tubs | Heat resistant, very stable |
Number 5, or polypropylene, is often regarded as the best choice for containers that need to hold warm food or go through a dishwasher. It’s durable and doesn’t soften easily when exposed to heat. Number 2 and 4 are also excellent, though they’re usually found in thin films or squeezable bottles rather than rigid storage containers.
What You Should Know About Leaching
Chemical leaching happens when the substances used to make plastic migrate into the food it contains. This process isn’t instant; it usually speeds up when the plastic is exposed to high heat, strong acids, or long periods of wear. Older, scratched, or cloudy containers are more likely to release particles, so it’s a good practice to replace them if they look worn.
Tip: Avoid putting any plastic containers, even those marked as microwave-safe, into the microwave if they show deep scratches or signs of melting.
While you might see claims about “BPA-free” plastics, it’s worth noting that manufacturers sometimes replace one chemical with another, like BPS, which may have similar properties. You should prioritize glass or stainless steel for high-heat cooking to eliminate these concerns entirely.
Mistakes That Increase Your Risk
Many people mistakenly assume that “recyclable” means “safe for all uses.” A plastic container might be recyclable through your local program, but that doesn’t mean it’s designed to handle boiling water or a hot dishwasher cycle. Using a container in a way it wasn’t intended for is the fastest way to cause chemical migration.
Can I put my plastic containers in the dishwasher?
Only if the manufacturer specifically labels them as dishwasher-safe. Even then, the high heat of a drying cycle can degrade the plastic over time, so placing them on the top rack is a safer choice to reduce direct heat exposure.
Are all number 7 plastics dangerous?
Not necessarily, but number 7 is a catch-all category for “other” plastics, which means it doesn’t have a standardized chemical composition. Some number 7 plastics are safe, while others might contain polycarbonate that releases chemicals; if a container doesn’t specify its materials, it’s safer to avoid using it for food.
Is it safe to reuse water bottles marked with number 1?
They’re intended for single use because the plastic is thin and can harbor bacteria if cleaned repeatedly. Over time, these thin plastics develop tiny cracks where germs hide, and they aren’t built to withstand the scrubbing required to keep them clean.
Frequently Asked Questions
Does the recycling number mean the plastic is safe?
No, the number only indicates the type of resin used to make the item. It tells you how to recycle it, but it doesn’t guarantee that the specific product is free from additives or safe for your particular food storage needs.
Should I avoid all plastics for my children?
Many parents prefer glass or silicone for children because these materials are inert and don’t leach chemicals. If you choose plastic, stick to numbers 2, 4, or 5 and inspect them frequently for cracks or signs of degradation.
Do I need to worry about the expiration date on plastic?
Plastic doesn’t have a traditional expiration date, but it does have a useful life. If a container becomes cloudy, develops a strange smell, or feels sticky, the surface is likely breaking down and it’s time to recycle it.
Check the bottom of your containers to see which numbers you currently use for daily meals. If you find mostly number 7 or older, worn-out items, consider switching to glass or stainless steel for your primary food storage needs. This simple change reduces your exposure to unknown additives over the long term.