Plastics marked with resin codes 1, 2, 4, and 5 are generally BPA-free. These codes are stamped on the bottom of most plastic containers inside a small triangle. The plastics most likely to contain BPA are code 7 (a catch-all “other” category that includes polycarbonate) and sometimes code 3. Knowing these numbers helps, but the full picture is a bit more nuanced than just flipping a container over.
What the Recycling Numbers Mean for BPA
Every plastic container sold in the U.S. carries a resin identification code, a number from 1 to 7 inside a triangle of arrows. Here’s how each one relates to BPA:
- Code 1 (PET or PETE): Used for water bottles, soda bottles, and many food containers. BPA-free.
- Code 2 (HDPE): Used for milk jugs, detergent bottles, and some food containers. BPA-free.
- Code 3 (PVC): Used for cling wraps, some squeeze bottles, and plumbing pipes. Some code 3 products may contain BPA, though it’s not the primary concern with this plastic.
- Code 4 (LDPE): Used for grocery bags, bread bags, and squeezable bottles. BPA-free and chemically stable.
- Code 5 (PP): Used for yogurt cups, medicine bottles, and food storage containers like deli tubs. BPA-free, and widely considered one of the safest plastics for food contact.
- Code 6 (PS/Polystyrene): Used for foam cups, takeout containers, and disposable cutlery. BPA-free, but can release other toxic compounds when heated.
- Code 7 (Other): This is the problem category. It’s a catch-all that includes polycarbonate, the plastic actually made from BPA. It also includes newer bio-based plastics that are perfectly safe. You can’t tell which is which from the number alone.
The simplest rule: codes 1, 2, 4, and 5 consistently meet FDA safety requirements for BPA-free materials. Code 7 requires extra scrutiny.
Where BPA Actually Shows Up
BPA is a building block of polycarbonate plastic, a hard, clear material used in shatterproof windows, eyewear lenses, reusable water bottles (especially older ones), and some food storage containers. If you have a rigid, clear plastic container that feels more like glass than typical Tupperware, and it’s marked with a 7, there’s a reasonable chance it’s polycarbonate.
The other major source isn’t plastic at all. Epoxy resins made with BPA line the inside of many metal food cans, bottle caps, and even some water supply pipes. These coatings prevent the metal from corroding into your food, but BPA from the lining can migrate into the contents, especially in hot-fill or heat-processed canned goods. This means your exposure to BPA may come more from canned soup than from a plastic container.
The FDA has removed authorization for BPA-based materials in baby bottles, sippy cups, and infant formula packaging. These changes happened in 2012 and 2013, so any baby bottle currently on the market should be BPA-free. The agency made this change because manufacturers had already abandoned BPA in these products, not because of a formal safety ruling.
What Makes BPA Leach Into Food
Even in containers that do contain BPA, the chemical doesn’t just pour into your food at a constant rate. Certain conditions speed up leaching significantly. Heat is the biggest factor. Microwaving polycarbonate containers, pouring boiling water into them, or leaving them in a hot car all increase BPA migration. Acidic and alkaline foods pull more BPA from container walls than neutral ones. Even boiling tap water in a polycarbonate container increases leaching because degassing the carbon dioxide raises the water’s pH.
Ultraviolet light and exposure to air accelerate the aging of polycarbonate plastic, which in turn releases more BPA. Repeated use and washing with harsh alkaline detergents also break down the material over time. Old, cloudy, or scratched polycarbonate containers release more BPA than new ones. If you’re unsure about a container’s material, avoiding the microwave and the dishwasher’s heated dry cycle reduces your exposure regardless.
Why “BPA-Free” Labels Can Be Misleading
When manufacturers removed BPA from their products, many replaced it with closely related chemicals, primarily bisphenol S (BPS) and bisphenol F (BPF). These substitutes now appear in can linings, thermal receipt paper, and plastics marketed as BPA-free. The Canadian Food Inspection Agency has confirmed that both BPS and BPF are used as alternative can linings.
The problem is that these replacements behave a lot like BPA in the body. A systematic review comparing the hormonal activity of BPS and BPF to BPA found their potency to be in the same order of magnitude. BPF’s ability to mimic estrogen averaged about the same as BPA’s, and BPS came in at roughly a third of BPA’s estrogenic strength. Both chemicals also showed androgenic, anti-androgenic, and anti-estrogenic activity similar to BPA. In practical terms, a “BPA-free” label on a product doesn’t guarantee it’s free from chemicals that act the same way in your body.
How Safety Standards Have Shifted
Regulators have taken very different positions on BPA over the past decade. The European Food Safety Authority’s stance illustrates how dramatically the science has evolved. In 2015, EFSA set a temporary safe daily intake for BPA at 4 micrograms per kilogram of body weight per day. In 2023, after a comprehensive re-evaluation, EFSA slashed that limit by a factor of 20,000, down to 0.2 nanograms per kilogram of body weight per day. That’s an extraordinarily large reduction, reflecting new evidence about BPA’s effects on the immune system at very low doses.
The FDA has not matched this level of restriction. It still considers BPA safe at current exposure levels in food contact materials, aside from the specific bans on baby bottles, sippy cups, and infant formula packaging. This gap between U.S. and European positions means that American consumers who want to follow the more cautious standard need to take their own steps to reduce exposure.
Practical Ways to Reduce Exposure
Stick with containers marked 1, 2, 4, or 5 for food storage. Code 5 (polypropylene) is especially practical because it handles heat better than most plastics and is widely available in food containers, from deli cups to reusable meal prep sets.
For canned foods, look for brands that specifically state they use BPA-free linings, but understand that the replacement chemicals may carry similar risks. Rinsing canned vegetables or choosing frozen or fresh versions when possible reduces exposure from can linings. Glass and stainless steel containers sidestep the issue entirely for food storage and water bottles.
If you do use any plastic containers for food, avoid microwaving them, don’t put them through harsh dishwasher cycles, and replace them when they start to look scratched or cloudy. These simple steps reduce leaching from whatever chemicals are present in the material, whether it’s BPA or one of its substitutes.