Plastics are everywhere in our daily lives, from bottles and bags to toys and furniture. But not all plastics are the same. Different types of plastics have different properties, uses, and environmental impacts. Knowing how to tell them apart can help you make better choices as a consumer and a citizen.
One way to tell different types of plastics apart is by looking at the recycling symbols on them. These symbols are usually found on the bottom or the side of plastic products, and they indicate the resin identification code (RIC) of the plastic. The RIC is a number from 1 to 7 that corresponds to a specific type of plastic resin. Here is what each number means:
1: Polyethylene terephthalate (PET or PETE). This is a clear, strong, and lightweight plastic that is widely used for beverage bottles, food containers, clothing fibers, and carpets. It can be recycled into new bottles, containers, fibers, or other products.
2: High-density polyethylene (HDPE). This is a stiff, durable, and opaque plastic that is used for milk jugs, detergent bottles, shampoo bottles, toys, pipes, and buckets. It can be recycled into new bottles, containers, pipes, or other products.
3: Polyvinyl chloride (PVC). This is a versatile and flexible plastic that is used for pipes, hoses, window frames, siding, flooring, shower curtains, and vinyl records. It can also be mixed with other additives to create different colors and textures. It can be recycled into new pipes, flooring, or other products.
4: Low-density polyethylene (LDPE). This is a soft and flexible plastic that is used for plastic bags, wraps, films, squeeze bottles, and coatings. It can be recycled into new bags, films, or other products.
5: Polypropylene (PP). This is a tough and heat-resistant plastic that is used for yogurt cups, margarine tubs, microwaveable containers, bottle caps, straws, and automotive parts. It can be recycled into new containers, caps, or other products.
6: Polystyrene (PS). This is a hard and brittle plastic that is used for disposable cups, plates, cutlery, egg cartons, meat trays, and packing peanuts. It can also be expanded into foam (EPS) for insulation, cushioning, and packaging. It can be recycled into new cups, plates, or other products.
7: Other. This is a catch-all category for any plastic that does not fit into the previous six categories. It includes plastics made from more than one resin (such as laminates), or plastics made from newer or less common resins (such as polylactic acid or PLA). These plastics may have different properties and uses depending on their composition. They are usually not recyclable.
Another way to tell different types of plastics apart is by doing some simple tests on them. Here are some examples of tests you can try at home:
Density test: Cut a small piece of plastic and drop it into a glass of water. If it sinks, it is likely HDPE or PVC. If it floats, it is likely PET or LDPE.
Burn test: Use a lighter or a match to burn a small piece of plastic and observe the flame color and smell. If it burns with a yellow flame and smells like burning candles or wood, it is likely PS. If it burns with a blue flame and smells like burning oil or gasoline, it is likely PP. If it burns with an orange flame and smells like burning sugar or vinegar, it is likely PET.
Scratch test: Use your fingernail or a knife to scratch the surface of the plastic. If it leaves a mark easily, it is likely LDPE or PP. If it does not leave a mark easily, it is likely PET or HDPE.
These tests are not foolproof and may not work for all types of plastics. They may also release harmful fumes or chemicals when burning the plastic. Therefore, you should always do these tests in a well-ventilated area and wear gloves and eye protection.
Knowing how to tell different types of plastics apart can help you make informed decisions about how to use them and dispose of them properly. Some plastics are more recyclable than others, and some plastics are more harmful to the environment than others. By learning more about plastics and their impacts, you can reduce your plastic waste and contribute to a more sustainable future.
