What Plastic Symbols Mean

Not all plastic bags keep food "safe".

You’ve probably noticed those symbols at the bottom of plastic bottles, the triangular chasing arrows emblem. We normally don’t think twice about what they mean but, as it turns out, it’s important for everyday folks like us to understand what these numbers signify.

The plastic coding system is a series of symbols that identify the most common plastic material used in the manufacture of a product or packaging.  The symbols are usually embossed on the bottom of plastic containers and bottles. Their purpose is to assist collectors with sorting the collected plastics by material type. They do not necessarily indicate that the product can be recycled or is made from recycled content. (Sustainability Victoria)

That said, let’s identify those seven plastic bottle codes and what things to note in their use.

Polyethylene terephalate or PET bottles are clear and lightweight and come to us as soft drink, juice, water, or salad dressing bottles or some spreads like peanut butter and fruit jam, too. Do not refill them because  they are good for one time use only.

High density polyethylene (HDPE) bottles, because they’re highly resistant material, are used for cleaning chemicals, shampoo, or motor oil. They’re later on used for  grocery bags, cleaning chemicals, picnic tables, flower pots and similar items subject to tough handling.

Plasticised polyvinyl chloride (PPVC) plastics are tough, longer lasting, and are used for everyday items such as detergent, cooking oil, or shampoo bottles. This material releases dangerous dioxins when heated and so must not come in contact with food so avoid entirely.

Low-Density Polyethylene (LDPE) is “healthy plastic” that’s durable and flexible so we see them around a lot for squeezable bottles. It’s also material for sandwich bags, cling wrap, wire and cable coating, adhesives and sealants, and dry cleaning bags.

Polypropylene (PP) is found in syrup, ketchup, and medicine bottles. Being that it can withstand very high temperatures, PP is used to make food warmers and dishwasher-safe items. Other items made out of PP are yogurt and butter containers and bottle caps.

Polystyrene (PS) is another plastic found in the home as aspirin bottles, disposable plates and cutlery, and CD cases. When recycled, it takes the form of plastic molding, insulation, or rulers. They’re more commonly referred to as styrofoam and, well, you know what kind of effect these have on the planet.

Essentially, everything else falls in the Other category, or #7, which means there are substances in there that we are not even sure about. Water cooler containers, baby feeding bottles, and even parts of your electronic gadgets are made of #7. Experts advise against using them as they contain BPA polycarbonate that are not recyclable.

Because plastic has become nearly indispensable in today’s lifestyle, it takes a lot of effort and commitment to steer ourselves into making the right choices. With proper education, we can become more responsible consumers.

For additional information, please watch this insightful video feature from National Geographic on choosing plastic containers and what’s in them and other green ideas for the home.

UPDATED: Nike makes footie uniforms from recycled plastic bottles.