top of page

The 7 Types of Plastics

Have you ever paused to ponder the enigmatic triangles at the bottom of your bubble tea cup or plastic takeout containers, wondering about the hidden significance of the numbers nestled within? They may seem like random symbols, but they hold important information about the materials we use and their impact on the environment.

The Resin Identification Code (RIC) system was introduced in 1988 by the Society of the Plastics Industry as a way to categorize plastic resins into seven different groups. These groups are represented by numbers from 1 to 7, which are often nested inside the familiar triangular symbol found on the bottom of many plastic containers.

The RIC system was created to establish a consistent and standardized method for recycling post-consumer plastics. However, the use of the system is voluntary for packaging producers and can be misleading as the codes in packaging are often interpreted as “I’m Recyclable!”. By identifying the resin type, consumers and recycling facilities can make informed decisions about how to handle and recycle these plastics effectively.

Now, let's delve into the different categories represented by the numbers in the RIC system and discuss the benefits and drawbacks associated with each type of conventional plastic.

Conventional Plastics, from 1 to 7:

1. Polyethylene Terephthalate (PET or PETE):

Also known as polyester, PET is the most widely used plastic resin worldwide. It's commonly found in the convenience industry and is considered safe for single-use food and beverage contact by the FDA. However, PET is not ideal for multiple uses, long-term food storage, or high-temperature contents due to its susceptibility to oxidation.

2. High-Density Polyethylene (HDPE):

HDPE has a decent strength-to-density ratio, making it durable and suitable for freezing and heating. It can be recycled efficiently up to 10 times and is used in various applications such as industrial and food service industries, children's toys, floor tiles, and artificial lawns. On the downside, HDPE is susceptible to oxidation and stress cracking.

3. Polyvinyl Chloride (PVC):

PVC is one of the least favorable plastic resins in terms of food contact applications and recycling. The number 3 indicates its strength and elasticity, which comes from softening chemicals like phthalates. These additives can be toxic, disrupting the human hormonal system and causing potential harm. PVC is commonly found in industrial applications, cleaner bottles, shower curtains, and household items.

4. Low-Density Polyethylene (LDPE):

LDPE is commonly used in bread wrapping, shopping bags, and packaging foam. Unfortunately, most LDPE products don't end up being recycled due to the lack of infrastructure in municipal recycling facilities. As a result, LDPE contributes significantly to terrestrial and marine plastic waste.

5. Polypropylene (PP):

This is the resin used for most of ShareWares' products! PP or "Polypro" is the second most widely produced plastic after PET. It's easily recycled, light weight, heat & impact resistant, flexible, highly durable, and can withstand high temperature dishwashing to ensure packaging is fully sanitized. PP is commonly used in food contact materials such as cups, containers, and utensils. It is considered the safest choice among conventional plastics as it doesn't react with hot, fatty, or acidic foods, and inherently doesn't contain BPA, BPS, or BPF.

Our coffee cups are made by a B-Corp and have the following attributes:

6. Polystyrene (PS):

PS, commonly known as styrofoam, is a less preferred plastic due to challenges in recycling. It’s cheap to produce, lightweight, and easily formed; the lightweight nature of PS acts as a double-edged sword, rendering it uneconomical to recycle. It's often found in disposable cups, containers, and building insulation. PS is fragile and breaks up easily, contributing to microplastic pollution in beaches and marine life. Numerous studies also suggest that the styrene used in the production of polystyrene plastics and resins is a possible human carcinogen.

7. Miscellaneous Plastic Category:

This category includes all other plastics (polylactic acid, acrylic, nylon) that don't fall into the previous six categories. These plastics can contain various resins, plasticizers, additives, and phthalates. They are generally not accepted at conventional recycling centers. Polycarbonate is also represented by the #7 code, and generally contains the compound Bisphenol A (BPA). Baby bottles, car parts, medical and dental equipment have all commonly been made from #7 plastic over the last few decades. These products are difficult to recycle conventionally.

That covers conventional plastics. Now, let's explore other packaging materials and their pros and cons.

Glass - This material is quickly becoming one of the most popular for reusables around the world! There aren’t any risks of chemical leaching or migration into foods, it’s microwave and oven safe, and not to mention easy to clean. Disadvantages of glass as a reusable choice to work in a system like ours is the sheer weight and brittleness of the material, leading to higher transportation and damage costs. Glass reusables are on the pricier side of those on the market, in comparison to plastic or silicone options.

Stainless Steel - Like glass, stainless steel has quickly risen as a top choice for reusables. It's corrosion resistant, doesn't leach chemicals, and is highly durable. Stainless steel can be manufactured a) from iron ore-based primary raw materials, and b) from recycled materials. It is 100% recyclable and estimated that 85% of stainless steels are recycled at the end of life. Stainless steel tends to be pricier compared to other options.

Silicone - Silicone is a synthetic rubber consisting of silicon, oxygen, and other elements - usually carbon and hydrogen. It’s heat-resistant and has antimicrobial properties. The silicon in this popular cookware and kitchen utensils material is derived from non-renewable silica and passed through petroleum hydrocarbons for production.

When heated, silicone reusables run the risk of leaching unwanted, harmful siloxane compounds into food or beverages. Silicone products are also challenging to recycle.

Most municipal recycling facilities that receive silicone products divert them to the landfill where they remain for hundreds of years. When recycled, silicone is always downcycled into a lesser-value product such as playground mulch or industrial lubricant.

Bioplastics -

Plastic made of plants? The ‘sustainability’ of bioplastics is marketed on every platform imaginable, and there is much innovation going on in the space. Some of the most commonly known examples of bioplastics include polylactic acid (PLA) found in products like water bottles or as lining in paper packaging. However, the greenwashing around the ‘compostable’ nature of bioplastics is tremendous.

Almost all bioplastics won’t ‘compost’ unless disposed of in an industrial composter to biodegrade properly (more on that coming soon!). Bioplastics which find their ways to landfills break down in an oxygen-deprived (anaerobic) environment, releasing methane, a greenhouse gas 25x more potent than carbon dioxide at trapping heat in the atmosphere. Bioplastic waste also contributes to the marine waste stream just as significantly as any other material, given that the materials cannot biodegrade in water.


bottom of page