Resin Identification Numbers 1 to 7
What Does 1 to 7 Inside the Triangle Mean?
The number inside the chasing arrows triangle tells you exactly what resin polymer your plastic container is made of, whether it is microwave-safe, and if your curbside bin accepts it.
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Curbside RecyclableNumber 1: PET or PETE
Polyethylene Terephthalate
Found in: Single-use plastic water bottles, soda bottles, peanut butter jars, salad dressing bottles, cooking oil containers.
Microwave Safe?
No (Chemical Leaching)
BPA & Toxicity
BPA-Free
Recycling Rule: Widely accepted in virtually all municipal blue bins. Avoid refilling single-use water bottles multiple times or leaving them in hot cars.
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Curbside RecyclableNumber 2: HDPE
High-Density Polyethylene
Found in: Milk jugs, laundry detergent bottles, shampoo and body wash containers, bleach bottles, motor oil jugs.
Microwave Safe?
No (Chemical Leaching)
BPA & Toxicity
BPA-Free
Recycling Rule: Very easily recycled into new plastic lumber, park benches, and drainage pipes. Rinse thoroughly before tossing in the bin.
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Rarely / Never RecyclableNumber 3: PVC or V
Polyvinyl Chloride
Found in: Plumbing pipes, vinyl siding, blister packaging for electronics, shower curtains, medical IV tubing.
Microwave Safe?
No (Chemical Leaching)
BPA & Toxicity
High chemical hazard
Recycling Rule: Do NOT microwave and do NOT put in curbside bins. PVC ruins recycling batches if melted alongside PET or HDPE.
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Special Drop-off OnlyNumber 4: LDPE
Low-Density Polyethylene
Found in: Grocery bags, bread bags, bubble wrap, shrink film, flexible squeeze condiment bottles, dry cleaning bags.
Microwave Safe?
No (Chemical Leaching)
BPA & Toxicity
BPA-Free
Recycling Rule: Do NOT put flimsy grocery bags in regular home recycling bins as they jam sorting machines. Return them to retail supermarket collection boxes.
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Curbside RecyclableNumber 5: PP
Polypropylene
Found in: Yogurt containers, sour cream tubs, takeout food containers, reusable water bottles, bottle caps, prescription pill bottles.
Microwave Safe?
Yes (Reheat Only)
BPA & Toxicity
BPA-Free
Recycling Rule: Look for the "5 PP" stamp on leftover containers if you plan to reheat food in the microwave. Accepted in most curbside programs today.
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Rarely / Never RecyclableNumber 6: PS or Styrofoam
Polystyrene
Found in: Disposable foam coffee cups, styrofoam takeout clamshells, egg cartons, disposable plastic cutlery, clear CD jewel cases.
Microwave Safe?
No (Chemical Leaching)
BPA & Toxicity
Can leach styrene
Recycling Rule: Never microwave food in Styrofoam containers! Almost no curbside plant accepts foam. Many cities have completely banned single-use PS.
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Rarely / Never RecyclableNumber 7: OTHER or BPA / PLA
Other / Mixed Plastics
Found in: Baby bottles, 5-gallon water cooler jugs, sunglasses, acrylic display cases, compostable PLA plant-based corn plastic.
Microwave Safe?
No (Chemical Leaching)
BPA & Toxicity
Variable
Recycling Rule: Check for a "BPA-Free" label on older number 7 containers. Compostable PLA plastics must go to commercial composting, not standard recycling.
The Golden Rule of Kitchen Plastic: "Numbers 2, 4, and 5 Are Safest"
Toxicologists and environmental health researchers generally consider plastics with numbers 2 (HDPE), 4 (LDPE), and 5 (PP) to be the safest for human food contact because they do not rely on BPA, phthalates, or heavy metal catalysts.
Conversely, be extremely cautious with Number 3 (PVC), Number 6 (Styrofoam), and generic Number 7 (Polycarbonate), especially when heated with acidic, oily, or boiling food.