The quest to quench

by Chris DeArmitt

Thirst – it can drive you to drink!. In fact, when it comes to survival, we need hydration more than we need food. When at home, we can take satisfy our thirst with tap water, but when we’re on the go, we need other options, but which one is right for you?

As an independent materials scientist, I have spent thousands of hours unpaid to read the science around plastic materials and the environment to share the facts for free via my book, podcasts, radio, TV and articles like this one. So, what are the facts around PET? How does it compare to other materials? Is it the perfect choice for drink containers or are there better alternatives? My job as a scientist is to find the ideal material for each application, so let’s take a look.

PET is a thermoplastic, meaning that it is easily formed into complex shapes by melting it. It is classified as an “engineering plastic”, meaning that the mechanical properties are extremely good, being stiff, strong, impermeable and so on. Although most people associate PET with the iconic drink container application, many people do not realise that there are other applications including automotive parts, aerospace, toys, medical devices and so on.

How is it that such a high performance material came to be used for drink containers? Normally, such materials would be too expensive, but manufacturing efficiencies lowered the price of PET dramatically. Another factor is that the mechanical and barrier properties are so good that the amount of PET needed to make a bottle is extremely low compared to aluminium, steel, glass or other plastics like PE or PP. Over time, the amount of PET used to make a bottle has decreased by over 50% and further reductions are on the way. That lowers price and environmental impact.

While we’re on the topic of environmental impact, how does PET stack up? There are multiple life cycle studies comparing different materials used to make drink containers and PET consistently has the lowest impact, especially for carbonated drinks. Any marketing campaign telling you otherwise is soundly refuted by peer-reviewed science.

Changing to so-called alternative materials means more materials use, more waste, more GHG, fossil fuel use and more litter. Does that sound like a great plan? At the end of life, PET is one of the most collected and recycled material, which further bolters its environmental credentials. Recycling reduces the impact a further 70-80% compared to new PET.

Designers like PET because it is possible to make containers with captivating shapes and colours. Crucially, the transparency of PET allows the customer to see the product they are about to buy and instantly know the amount left as well. – something not possible with opaque materials. The use of a cap means that it can be resealed to prevent waste. One average, packaging has 3% of the impact compared to the food it protects which accounts for the other 97% of impact, so PETs ability to ensure that the drink is preserved and then fully consumed is a big deal.

What about safety. As you can imagine, food contact materials are highly regulated and PET has been found to be safe through decades of testing. Having reviewed that data, it is probably fair to say that PET is the saftest of all the options. Claims to the contrary are desperate attempts to get us to spend our money on more expensive products with higher environmental impact like metal or glass.


As a scientist whose job it is to recommend the perfect material for each application, I would have had to invent PET if it didn’t already exist – it’s that good of a fit! It is the safest, most environmentally responsible and affordable choice.

I’ll drink to that.