By 2050 we will have more plastic in our oceans than life in our oceans. How many of us think do I really need that plastic packaging? Is this plastic recyclable? This plastic that I have bought, where will it end up? It's about time we start thinking about how we buy, use and eventually dispose of plastic.

In today's wastemanagement Wednesday we will go through the different types of plastics, and some safety tips in the end. Let's start, Shall we?

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1. PET or PETE

Polyethylene terephthalate (PET) is the most commonly used and widely known form of plastic (thermoplastic). It's produced from the synthesis of ethylene glycol and terephthalate acid. It is naturally colorless, semi-crystalline material. Has a resin identification number of 1.

Characteristics of PET

1. PET doesn't react with water or food which is why it's commonly used for consumable packaging.
2. It's very strong for its light weight, which means less material is required for use such as plastic film for packaging.
3. It's shatterproof making it a great alternative for glass as a container.
4. Has a very high melting point (>200 deg), and it being a thermoplastic it can melt and still retain its chemical properties.

**Typical uses of PET **: Packaging for soft drinks, water, sports drinks, ketchup, salad dressing and in the textile industry it's commonly known as polyester.

**Environmental Impact **: Moderate Hazard as it's non-biodegradable but easy to recycle back to its constituent raw materials to be repurposed for other uses. Plastic breaks down after multiple uses allowing antimony to seep into liquids.

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2. HDPE

High-density polyethylene is a type of plastic made from petroleum. Its sometimes called alcathene or polythene when used for pipes. Has a resin identification number of 2.

Characteristics of HDPE

1. It has a high strength to density ratio.
2. Can tolerate high temperatures, not as high as PET and strong chemicals.
3. It is harder and opaque as compared to PET.

Typical uses of HDPE : Milk bottles, bleach, cleaners and most shampoo bottles.
Environmental Impact : Low impact, highly recyclable.

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3. PVC

Polyvinyl chloride was accidentally synthesized by German Chemist Eugene Baumann. Its produced by polymerization of the vinyl chloride monomer (VCM). Let's get into the chemistry of this...shall we? JUST KIDDING!!, I don't want to bore you with bonds and chemical reactions. PVC has a resin identification number of 3.

Characteristics of PVC

1. Has high hardness and mechanical properties.
2. As raw PVC, its heat stability is very poor. Heat additives are added to improve its ability.
3. Has very good insulation properties hence its use as an electrical insulator.
4. Its chemically resistant to acids, salts, bases, fats, and alcohol, makes it suitable for sewage pipes.

Typical uses of PVC: Electrical Insulation material, plumbing fittings, toys, tablecloths, shower curtains, deli meat wraps, cleaner bottles.
Environmental Impact: Hazard. When heated it releases toxic fumes and chemicals that can leach into food. NEVER NEVER heat in the microwave food wrapped in PVC plastic.

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4. LDPE

Low-density polyethylene (LDPE) is a thermoplastic made from the monomer ethylene. It was the first grade of polyethylene, produced in 1933 by Imperial Chemical Industries (ICI) using a high-pressure process via free radical polymerization. Has a resin identification number of 4.

Characteristics of LDPE

1. It can withstand temperatures of 80 degC to 95 degC without degrading.
2. Its resistant to impact (doesn't break easily.
3. It's waterproof and resistant to chemicals.
4. It's quite flexible and tough.

Typical uses of LDPE: Electrical Insulation material, dry cleaning bags, bread bags, garbage liners, produce bags.
Environmental Impact: Low impact, highly recyclable.

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5. PP

Polypropylene (PP) is a thermoplastic “addition polymer” made from the combination of propylene monomers. It is a white, mechanically rugged material, and is resistant to many chemical solvents, bases, and acids. Has a resin identification number of 5.

Characteristics of PP

1. Its resistant to acids and bases making it suitable for cleaning agent products, first-aid products.
2. Its shape after a lot of torsion, bending, and/or flexing. Ever seen plastic hinges? That's PP plastic.
3. It has a high resistance to electricity hence useful in making electronic components.
4. Has a varied range melting point 130 - 170 degC depending on the polypropylene. At 0 deg it becomes brittle.

Typical uses of PP : Pill bottles, Bottle caps, straws, yoghurt tub, margerine tub
Environmental Impact : Low Hazard, highly recyclable

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6. PS

Polystyrene is a synthetic aromatic polymer made from the monomer styrene. It's also is made into a foam material, called expanded polystyrene (EPS) or extruded polystyrene (XPS), which is valued for its insulating and cushioning properties. Polystyrene can be solid or foamed. Has a resin identification number of 6.

Characteristics of PS

1. It has a low melting point. Ever tried burning that packaging that comes with TVs, Music Systems?
2. In its raw state it's translucent, colorants are added to give different variations of polystyrene.
3. It's slow to break down.
4. It can be solid or foamed.

Typical uses of PS: Typically referred to as styrafoam and is used in cups, plates, take-out containers, coolers, packaging peanuts.
Environmental Impact :Hazard, styrene can leach from polystyrene. This can lead to nervous system damage and cancer. Highly non-biodegradable.

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7. Other

This is a catch-all category for plastics that don’t fit into the #1-6 categories. It includes polycarbonate, bio-based plastics, co-polyester, acrylic, polyamide and plastic mixtures like styrene-acrylonitrile resin (SAN). Has a resin identification number of 7.

Typical Uses of Other: Baby bottles and “sippy” cups, baby food jars, 5-gallon water bottles, “sport” water bottles, plastic dinnerware and clear plastic cutlery.

Conclusion

Now that you know your plastics you can better protect yourself and the environment. In conclusion below are some safety tips.

1. Know the code: Look at the bottom of the plastic to see the number, codes 1,2,4 and 5 are consider safest while 3 and 6 should be avoided as they leach harmful chemicals.
2. Reconsider heating plastics in the microwave. Get ceramic bowls or containers labelled as microwave safe for this purpose.
3. Use the plastic for it's intended purpose. Code 1 plastics are single-use plastics meaning they are designed to be used only once.
4. Don't freeze: Unless plastic is labelled as freeze safe, don't. Once frozen most plastics become brittle and easily break leaking into food.

STAY WOKE PEOPLE!!!

References

1. PET or PETE
   Ecostar Plastics:PET, Creative Mechanicims: PET or PETE
2. HDPE
   Wikipedia:HDPE, BPF:HDPE, eplactics:HDPE
3. PVC
   PVC.org, Wikipedia:PVC
4. LDPE
   Plastics Make It Possible:LDPE, Wikipedia:LDPE
5. PP
   PP:Wikipedia, British Plastic Federation;Polypropylene, Creative Mechanicims: PP Plastics
6. PS
   Chemical Safety Post:Polystyrene, Reference.com:Polystyrene
7. Other
   The Amaizing Medicine

Image Sources
Know Your PlasticsPET logo, HDPE logo, PVC logo, LDPE logo, Polypropylene logo, Polystyrene logo, Other

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