Decoding the Plastic Recycling Numbers

Plastics pose a significant threat to both the environment and our health. Sadly, many everyday products come wrapped in plastic. The good news is that a large portion of plastics are recyclable, which is crucial as plastics can take up to 1,000 years to break down in landfills.

Most plastic items display a recycling symbol formed by arrows, typically located at the bottom, to indicate if the item is recyclable. The number inside the triangle, ranging from one to seven, signifies the type of plastic used.

Let’s dive deeper into these code numbers, also referred to as plastic numbers, and uncover their meanings.

Types of Plastic

Next, let’s examine the seven types of plastic and their specific traits [source: Seaman]:

Plastic No. 1

PETE is commonly used for items such as plastic bottles for soda, large containers, water cooler bottles, and cooking oil bottles. It's the most prevalent type of plastic and is designed for single use, not for reuse.

Plastics of Type 2

HDPE is typically found in containers that hold liquids like milk, cleaning agents, laundry detergent, and shampoo.

Plastics of Type 3

PVC is the material behind vinyl products, ranging from siding to seat covers. Previously, it was widely used for trays that held fruits, sweets, and food wrap like cling film and aluminum foil. However, due to concerns about plasticizers such as phthalates possibly seeping into food, many producers have switched to alternative materials for food wraps, especially those meant for microwave use.

No. 4 Plastics: This category refers to low-density polyethylene (LDPE), commonly used in products like plastic bags and food wraps.

Plastic shopping bags and cling films are manufactured from low-density polyethylene (LDPE), a lightweight and flexible material.

No. 5 Plastics: Known as polypropylene (PP), these plastics are found in products such as furniture, luggage, pill bottles, toys, and packaging for cereal and yogurt.

Polypropylene (PP) is a plastic used in the production of furniture, suitcases, pill bottles, toys, and packaging for items like diapers, cereal, and yogurt cups.

No. 6 Plastics: These are made from polystyrene (PS), a rigid plastic often found in disposable items like cups, plates, and various packaging materials.

Polystyrene (PS) is commonly found in toys, as well as in Styrofoam cups, takeout boxes, and rigid packing materials.

No. 7 Plastics: This category encompasses various other plastics, including acrylic, nylon, baby bottles, and fiberglass.

This final category serves as a catch-all for other plastics like acrylic, nylon, fiberglass, and items like baby bottles.

The Plastic Coding System

The numbers on plastic items, typically displayed inside a recycling triangle, refer to the resin identification code (RIC). This system was created in 1988 by the Society of the Plastics Industry (now the Plastics Industry Association) in the United States.

Resin identification codes are essential for recognizing the specific type of plastic resin used in a product, a critical step for recycling. Different plastics require unique recycling methods and have varying compatibility with recycling systems.

Are Certain Types of Plastic Safer Than Others?

Certain plastics are considered safer than others, depending on factors such as potential for chemical leaching and environmental effects. Aspects like temperature, UV light exposure, and the type of substances they store (e.g., acidic or fatty foods) can affect the safety of specific plastics.

The safety of plastic products depends on their specific application and handling. For instance, a container designed for cold storage may not be suitable for microwave use. Always check the manufacturer's guidelines for safe usage recommendations.

Recycling Plastic

When it comes to recycling plastic, it's important to understand a few key points. For instance, plastics marked as No. 7 — the catch-all category — often consist of a mix of recyclable and non-recyclable materials. Without specialized knowledge, it can be hard to distinguish between the two, so it's usually best to avoid recycling these items [source: Anderson].

Secondly, only clean plastic can be recycled, so ensure that items are thoroughly washed before placing them in the recycling bin.

Third, even if a plastic item is clean and recyclable, there's no guarantee it will be recycled. Local regulations often dictate what can be collected, so it’s a good idea to check your city’s recycling guidelines. Some plastics that are not accepted for curbside pickup may still be recycled at designated drop-off locations.

Finally, if a product lacks a recycling symbol, it should be disposed of in the trash. It’s better to keep potential contaminants out of the recycling process rather than risk improper recycling.

Recycling Compostable Plastics

The recycling process for compostable plastics presents unique challenges and widespread misunderstandings. While these plastics are often confused with traditional plastics, they are actually intended to degrade in specific composting environments, not to be recycled. If they end up mixed with regular recyclables, they can contaminate the recycling system, diminishing the quality of the recycled materials.

Despite what the term "compostable" implies, these plastics don’t decompose easily in home composts or the natural environment. Their designed purpose is for industrial composting facilities, where controlled conditions enable them to break down in a few months.

Unfortunately, such industrial composting facilities are not universally available. The public's confusion over terms like biodegradable, compostable, and recyclable underscores the need for more accurate labeling and public education on these types of plastics.

Ultimately, the environmental impact of compostable plastics hinges on proper disposal methods and the availability of appropriate composting facilities to ensure they decompose effectively.