Plastic identification systems are increasingly being adopted by the community of recycling programs, as a powerful tool to assist in sorting plastics.  Recovery and recycling facilities can easily categorize items by product material simply by looking at the numbers embossed on the product.  Because plastic needs to be recycled separately for each type, in order to preserve the value of the recycled material. 

Plastics are classified and labeled as follows: PETE “1”, HDPE “2”, PVC “3”, LDPE “4”, PP: “5”, PS “6” and PC “7”.

The above symbols are usually written on the bottom of plastic boxes, plastic bottles, plastic caps... 

1. PETE or PET (Signature No. 1)

PET (Polyethylene terephthalate) is one of the most commonly used plastics.

PET plastic is often used to store liquid foods such as soft drinks bottles, mineral water bottles, soft drinks, beer, sauce bottles, juice bottles, etc.

PET plastic should only be used once, should not be reused many times, you should not reuse it many times because it is likely that the plastic will penetrate into your food and drink, affecting your health. 

2. HDP or HDPE (Symbol No. 2)

HDP (High Density Polyethylene) is the best of all plastics.  This is the type of plastic that experts often recommend choosing when storing food.

HDPE plastic is considered the safest of all for the following reasons:

High strength, good impact resistance, less deformation, scratches.  High thermal stability.

Chemically inert (not affected by the environment, does not release toxicity)

Therefore, HDPE is used to manufacture items such as: hdpe plastic bottles, milk bottles, hard plastic bottles, detergent bottles (not affected in acidic environment), cooking oil, toys and so on.  some plastic bags. 

3. PVC (Signature No. 3)

PVC plastic is a very dangerous plastic because it contains many toxic substances such as phthalates and BPA, which can dissolve in food under the effect of heat.

PVC is used to produce: Packaging films, food wraps, transparent glass plastic films.  Bottles such as cooking oil bottles, water containers, liquid food solutions.  Toys and many other products. Do not reuse plastic #3 for food, especially hot food. 

4. LDPE  (Signature No. 4)

Plastic No. 4 LDPE-Low-Density-Polyethylene is chemically inert and has high strength.

Similar to plastic #2, LDPE - Low Density Polyethylene is a chemically inert plastic, but less physically strong than HDPE.  Due to its chemical inertness, LDPE plastic is often used to make chemical bottles, nylon gloves, nylon bags, shopping bags and cake covers.  LDPE plastic is not used in microwave oven, avoid high temperature.

In addition, LDPE plastic is easy to break, break, scratch, and have less physical impact resistance than plastic No. 2. 

5. PP plastic (Sign No. 5)

PP (polypropylene) plastic is the most heat-resistant plastic, so it is widely used in the manufacture of food containers, especially food boxes that can be used in the microwave.  PP plastic is usually slightly transparent.

PP is the plastic recommended by experts, because of its chemical inertness, high mechanical strength and heat resistance, and very safe for health. 

6. PS (Sign No. 6)

PS (Polystyrene) plastic, also known as recycled plastic, is a cheap, poor quality plastic

PS (Polystyrene) plastic is a cheap and light plastic.  Can be found on the shells of some snack containers, drinking glasses, egg cartons and picnic knives and forks.

Although they are remarkably resistant to heat and cold, at high temperatures they can release toxic substances.  In addition, it is not allowed to store items with strong acids and strong alkalis.  Therefore, this type of plastic is not allowed to hold food and drink for a long time.

Plastic No. 6 is often used for styrofoam containers or disposable spoons.

7. PC plastic or no symbol (other)

Plastic No. 7 includes PC (toxic) and other plastics.  Plastic No. 7 is often used to produce: water bottles, plastic containers for chemicals.. Or food containers such as yogurt, noodle boxes, plastic boxes for butter...

Most notably in this group, some contain Bisphenol A (BPA) which is a toxic substance used in the production of plastics.  Plastic number 7 represents the symbol of unsafe and toxic plastics.  Especially when storing hot food, it is very dangerous to contaminate food.