PET is also known as a wrinkle-free fiber. It’s different from the plastic bag that we commonly see at the supermarket. PET is mostly used for food and drink packaging purposes due to its strong ability to prevent oxygen from getting in and spoiling the product inside. It also helps to keep the carbon dioxide in carbonated drinks from getting out.

Quite special compared to the other types, HDPE has long virtually unbranched polymer chains which makes them really dense and thus, stronger and thicker from PET. HDPE is commonly used as the grocery bag, opaque milk, juice container, shampoo bottles, and medicine bottle.

PVC is typically used in toys, blister wrap, cling wrap, detergent bottles, loose-leaf binders, blood bags and medical tubing. PVC or vinyl used to be the second most widely used plastic resin in the world (after polyethylene), before the manufacture and disposal process of PVC has been declared as the cause of serious health risks and environmental pollution issues.

Polyethylenes are the most used family of plastics in the world. This type of plastic has the simplest plastic polymer chemical structure, making it very easy and very cheap to process. LDPE polymers have significant chain branching including long side chains making it less dense and less crystalline (structurally ordered) and thus a generally thinner more flexible form of polyethylene.

Stiffer and more resistant to heat, PP is widely used for hot food containers. Its strength quality is somewhere between LDPE and HDPE. Besides in thermal vests, and car parts, PP is also included in the disposable diaper and sanitary pad liners.

Same as LDPE, PP is considered a safer plastic option for food and drink use. And although it bears all those amazing qualities, PP isn’t quite recyclable and could also cause asthma and hormone disruption in human.

Polystyrene is the Styrofoam we all commonly used for food containers, egg cartons, disposable cups and bowls, packaging, and also bike helmet. When exposed with hot and oily food, PS could leach styrene that is considered as brain and nervous system toxicant, it could also affect genes, lungs, liver, and immune system. On top of all of those risks, PS has a low recycling rate.

Number 7 is for all plastics other than those identified by number 1-6 and also plastics that may be layered or mixed with other types of plastics, such as bioplastics. Polycarbonate (PC) is the most common plastic in this category, isn’t used as much in recent years due to it being associated with bisphenol A (BPA). PC is also known by various name: Lexan, Makrolon, and Makroclear. Ironically, PC is typically used for baby bottles, sippy cups, water bottles, water gallon, metal food can liner, ketchup container, and dental sealants. Due to its toxicity, several countries have banned the use of PC for baby bottles and infant formula packaging.