Plastic Codes

All recyclable plastics are stamped with a code. These codes were developed by the Society of the Plastics Industry, Inc. to assist in the recycling of post-consumer plastics and to help identify the materials used in the making of plastic items.

Most plastic is made with one of six resins: polyethylene terephthalate (PETE); high density polyethylene (HDPE); polyvinyl chloride (PVC or vinyl); low density polyethylene (LDPE); polypropylene (PP); or polystyrene (PS). The SPI resin identification code has assigned each of these resins a number from 1 to 6. The last SPI resin identification code, 7, refers to “other” and simply means that a resin other than the first 6 was used. By learning the SPI codes, you can make sure you know what types of resin you are allowing near your family.

You can use the following information and following the Wikipedia links to learn more!

PETE Type: Polyethylene Terephthalate (PET, PETE)

Properties: Clarity, strength, toughness, barrier to gas and moisture.

Uses: Soft drink, water and salad dressing bottles; peanut butter and jam jars

Safe or not?: Take care with #1, these items are meant to be used only one time. They are not easily cleaned resulting in the growth of bacteria. Use it once and then recycle it.


HDPE Type: High Density Polyethylene (HDPE)

Properties: Stiffness, strength, toughness, resistance to moisture, permeability to gas.

Uses: Milk, juice and water bottles; yogurt and margarine tubs; trash and retail bags.

Safe or not?: Currently appears safe.


Vinyl Type: Polyvinyl Chloride (V)

Properties: Versatility, clarity, ease of blending, strength, toughness.

Uses: Juice bottles; cling films; PVC piping

Safe or not?: PVC is one of the most dangerous plastics. It is harmful to both humans and the environment.


LDPE Type: Low Density Polyethylene (LDPE)

Properties: Ease of processing, strength, toughness, flexibility, ease of sealing, barrier to moisture.

Uses: Frozen food bags; squeezable bottles, e.g. honey, mustard; cling films; flexible container lids.

Safe or not?: Currently appears safe.


PP Type: Polypropylene (PP)

Properties: Strength, toughness, resistance to heat, chemicals, grease and oil, versatile, barrier to moisture.

Uses: Reusable microwaveable ware; kitchenware; yogurt containers; margarine tubs; microwaveable disposable take-away containers; disposable cups and plates.

Safe or not?: Currently appears safe.


PS Type: Polystyrene (PS)

Properties: Versatility, clarity, easily formed

Uses: Egg cartons; packing peanuts; “Styrofoam”; disposable cups, plates, trays and cutlery; disposable take-away containers; yogurt and margarine containers

Safe or not?: Polysturene is composed of Benzene, a known human carcinogen. It is a threat in manufacturing, use and after use. Expanded polystyrene foam takes 900 years to decompose. It is a component of Napalm and most hydrogen bombs. Avoid styrofoam as much as possible.


Other Type: Other

Properties: Dependent on polymers or combination or polymers.

Uses: Beverage bottles; baby milk bottles, most “unbreakable” plastic.

Safe or not?: This one is tricky. We’ve all heard about BPA, found in #7 plastic. However, not all #7 contains BPA. It can also refer to “recycled” plastics. If possible, contact the manufacturer and inquire about the composition of your item in question. It’s best to err on the side of caution though and avoid as much as possible.

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