What are the 7 types of plastic? [ Detailed Answer ]

The 7 types of plastic we commonly use today are: (1) Polyethylene Terephthalate (PET or PETE or Polyester), (2) High-Density Polyethylene (HDPE), (3) Polyvinyl Chloride (PVC), (4) Low-Density Polyethylene (LDPE), (5) Polypropylene (PP), (6) Polystyrene (PS), and (7) Others–which include fiberglass, acrylic, nylon, and styrene, among others.

Plastic is one of the most common items in our lives, and it’s everywhere. Plastic is used in packaging food, water bottles, clothing, furniture, toys – you name it. But plastic can also be a problem for our environment because when thrown away without being recycled or reused it doesn’t break down as quickly as other materials. This means that due to the slow breakdown process of plastics they will just keep building up over time until they finally create a huge pile of trash.

These 7 types of plastic have differences in properties, which means they are also utilized differently. Some are more versatile, while others cannot be reused and recycled.

Polyethylene Terephthalate (PET)

PET is used for packaging a lot of food and drinks because of its ability to prevent oxygen from coming in which causes products to spoil. This plastic is also what makes up a huge chunk of our trash since water bottles remain to be a topper in terms of garbage classification.

Despite its recyclability, the use of PET plastic remains to be discouraged because it contains a carcinogen called antimony trioxide. This chemical becomes more harmful the longer the liquid stays in the PET bottle.

High-Density Polyethylene (HDPE)

With its unbranched polymer chains, HDPE plastic is indeed, very dense. Its high density allows it to be versatile in usage, too. Like PET, this type of plastic is also widely used in the food industry, specifically made into milk jugs, medicine bottles, and juice bottles.

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When it comes to packing food and drinks, HDPE is naturally a better choice than PET since it is sturdier and heavier. Its density also equates to durability, making it perfect for bulkier packages.

Highly flexible and more stable, its density contributes to being a safe choice not only for packing food and beverages, but also in containing shampoo, soap, and other cleaning agents. Apart from being recyclable, this plastic is also repurposed into plastic lumber and pipes.

Polyvinyl Chloride (PVC)

Used in various industrial and mechanical projects, PVCs are also used in a wide variety of everyday essentials such as toys and cling films. More commonly referred to as vinyl, this type of plastic is also widely used in the medical industry.

Turned into blood bags and medical tubes, PVC used to be among the most widely used types of plastic resin after polyethylene. Production decreased after research showed that it is also the most toxic type of plastic.

It is not only the manufacturing process of PVC that is considered to be highly dangerous to the environment, but also the disposal phase. Its hazards could be blamed on its many toxic chemicals, including bisphenol A (BPA), lead, dioxins, cadmium, mercury, and phthalates.

Low-Density Polyethylene (LDPE)

As mentioned, polyethylene remains to be the most used type of plastic all around the world. LDPE is turned into sandwich bags, squeezable bottles for honey and mustard, container lids, and food containers.

Both reusable and recyclable, this low-density plastic is most often used as bags for bread and frozen food, as well as coating for milk cartons. Although LDPEs are recyclable, it is best for you to leave the process to your recyclers and not to do it on your own.

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Despite studies showing how this plastic can affect human hormones, it is still a safer choice for food and drinks compared to other plastic types.

Polypropylene (PP)

PP plastic is used in hot food containers, thanks to its high resistance to heat. With its natural stiffness, the strength of this plastic is quite in between LDPE and HDPE. It is dense, but has more rigid limitations when it comes to heat resistance.

Apart from food containers, PP is also used in producing disposable diapers, sanitary napkins, car parts, bottle caps, and thermal vests. Despite being possibly reusable, this type of plastic cannot be recycled. It is made up of harmful chemicals causing asthma and other respiratory problems when ingested.

Polystyrene (PS)

More commonly referred to as styrofoam, PS used to be widely used by fast food restaurants because it is lightweight, cheap and versatile. It is also used in making bike helmets, egg trays, and insulation materials.

Despite its many uses, disposable utensils made of styrofoam have been widely discouraged. Fast food restaurants started switching to paper cups and plates after several studies have proven how hazardous it is when its particles mix with the food it contains, which happens when the food is hot or oily.

Styrene, PS’s main component, is proven toxic to the brain. This type of plastic cannot be recycled and ends up in landfills instead, adding to the burden of landfill shortage all around the world.

Other plastics

For plastics that do not share the same properties mentioned for the other types, they are classified under ‘Other’. This includes polycarbonate (PC), which is the most common under this plastic type.

Why are we not using polyethylene instead of plastic?

PC is regarded as plastic that should be avoided at all costs due to the presence of BPA. BPA is a harmful chemical linked to increased risks of breast cancer, prostate cancer, and brain and other neurological impairments, among others.

Common questions about the types of plastic

Is plastic bottle number 1 safe?

Although generally safer than the other plastic bottles, PET bottles should still be used with caution. Its harmful chemicals tend to be more active after the bottle has been confined in a warm temperature for a long time. Being conscious of where you put your bottle should be a habit.

What is the safest plastic?

Thanks to its high density, HDPE is the safest plastic among the ones mentioned above. Highly resistant to extreme weather conditions, it is also easily recyclable without emitting too much harsh chemicals.

Which number plastic bottle is safe?

PET bottles should never be reused. The safest plastic bottles you can reuse are plastic bottles 2 (HDPE), 4 (LDPE), and 5 (PP).
Each plastic type is designed for its own uses. It is still best to choose reusable materials over plastic. However, if it cannot be helped, choose plastic that is safe, recyclable, and non-toxic.