Before You Recycle, Learn What the Numbers Mean
Not all plastics are made from the same materials, and different types of plastics are typically used for specific products in daily life. The Society of the Plastics Industry (SPI) created the resin identification coding system in the late 80s to help identify the six most common plastics used on a regular basis. Keep in mind, the SPI resin identification code is not meant to tell you whether or not you can recycle a plastic. The code is simply meant to identify what type of plastic resin was used when making the product.
The good news is that GLR partners with a variety of companies to recycle many various types of plastic. We can also help our clients increase their knowledge on what the different SPI codes mean to their businesses. The following is a list of grades of plastic:
HDPE: High-Density Polyethylene
SPI code: 2
Attributes: HDPE is a plastic made from petroleum and types of HDPE plastics include bottles with pigment and without. Those with pigment have a higher resistance to cracking and chemicals, so this type of bottle is ideal for packaging household items such as certain cleaning products. Other HDPE plastics are made into injection-molded containers that serve as various food packaging because they are resistant to warping.
Tidbit: One report says the United States along with Western Europe made up 44% of the global market
for HDPE in 2007. Another statistic states HDPE in partnership with code “1” (PET or PETE plastics) makes up 96% of all plastic bottles and containers in the United States.
HDPE plastic is used in:
LDPE (4): Low-Density Polyethylene
SPI code: 4
Attributes: LDPE is a thermoplastic made from petroleum. Thermoplastics are characterized by the fact that they can be frozen and reheated repeatedly for reshaping. LDPE is a resistant and flexible plastic, so it’s used to make packaging and film-like materials.
Tidbit: LDPE plastic sales in the United States totaled roughly 7 billion pounds in 2008, according to one report.
LDPE (4): Low-Density Polyethylene SPI code: 4 Attributes: LDPE is a thermoplastic made from petroleum. Thermoplastics are characterized by the fact that they can be frozen and reheated repeatedly for reshaping. LDPE is a resistant and flexible plastic, so it’s used to make packaging and film-like materials. Tidbit: LDPE plastic sales in the United States totaled roughly 7 billion pounds in 2008, according to one report.
PETE or PET: Polyethylene Terephthalate
SPI code: 1
Attributes: PETE (PET) is a polymer resin. It’s an excellent barrier to water, oxygen and carbon dioxide. It’s also shatter resistant and has a superb resistance to most solvents.
Tidbit: One of the most common grades of resin used in plastics, polyethylene is the runner up to HDPE in volume sold. In 2005, the average household generated 42 pounds of PET, according to one report.
PET polyethylene plastic is used in:
SPI code: 5
Attributes: PP is a thermoplastic polymer. It has good chemical resistance and a high melting point so it’s oftentimes used for hot-fill liquids. It also has excellent visual clarity and low moisture transmission. Tidbit: One report says sales and use of polypropylene plastic in the United States, Canada and Mexico was 17.2 billion pounds in 2008.
PP plastic is used in:
SPI code: 6
Attributes: A versatile plastic, polystyrene is characterized as either a rigid or a foamed product with a low melting point that’s great for insulation in foam form. PS is sometimes combined with rubber to make a high-impact polystyrene. Tidbit: One form of polystyrene is commonly known as “Styrofoam,” which is actually a trade name of a product made by Dow Chemical.
Polystyrene is used in:
PVC: Polyvinyl Chloride (Vinyl)
SPI code: 3
Attributes: PVC plastic has stable electric properties. It’s chemical resistant and has high-impact strength. A diverse resin, PVC can be found in flexible and rigid materials. With PVC plastic, rigid materials retain shape when empty and unsupported. Tidbit: PVC plastic is one of the less recycled materials. One report states that generally less than 1% of PVC plastic is recycled each year.