One of the most enduring misconceptions about PET, the recyclable and food-grade plastic most often used for beverage bottles, is that it pollutes our environment.

As a result, many are pushing consumers to switch to reusable/re-fillable bottles but few are asking the important question: Do reusable bottles trump beverages originally packed and sold in PET when it comes to their ‘green’ credentials?1

According to Charlotte Metcalf, CEO of the South African National Bottled Water Association (SANBWA) every single material used to manufacture reusable/re-fillable beverage bottles has an impact on the environment. This impact differs between each material be it plastic, aluminium, glass or stainless steel, or any other less well-known packaging materials which may be used for this function.

“Current wisdom is that it should not be assumed that reusable bottles have a lower environmental impact than single-use bottles,” Metcalf said. “It may be true if only the carbon footprint is considered but the water footprint of the bottle during its life cycle is equally important.

“Because of the very many variables that need to be considered when studying or calculating this impact, there are very few accurate life cycle studies. More critical research is required before the question can be answered reliably.

“For example, the amount of water used over the reusable bottle’s lifetime to maintain its hygiene status can be considerable and the carbon savings negligible. For example, although glass is inert and can easily be reused, it takes a lot of energy to produce, transport and recycle. Further, glass breakage in the environment is dangerous and extremely difficult to remove.

“Also clouding the issue is that reusable bottles do not last forever and their recycling rate contributes greatly to their environmental impact. While the recycling rate of aluminium cans is about 72%, the recycling rate of reusable bottles is unknown, and many probably get sent to landfill instead of being recycled. Here, too, it is vital to consider what the material degrades or decomposes into,” she said.

Metcalf added that there are several other issues about the use of reusable bottles that consumers should be aware of. For her, ‘design, design, design’ is the biggest issue, not the material.

“When it comes to ‘design’, I do need us to look past the alluring bright, sparkly, pretty bottles and rather make sure that the designs do not feature any parts, voids, ridges, liners and spaces in which bacteria can accumulate and that cannot be properly cleaned.

“Reusable bottles should have wide necks so that you can access the interior with a bottle brush. There should be no loose liners in the cap or bottleneck, and no straws. With these design features, a reusable bottle can easily become like your pet’s water bowl, lined with slime-forming bacteria or even air-borne disease-causing organisms,” she warned.

Metcalf’s daily routine for cleaning reusable bottles would include (she has yet to find a reusable bottle design she trusts with her family’s safety) scrubbing clean all surfaces inside the bottle using soap, hot water and a brush. Rinsing alone is not enough, neither is only soaking bottles in a sanitiser and not all bottles are dishwasher safe.

Reuseable/refillable must also be regularly examined for pitting and wear-&-tear regardless of the material they are made from, and discarded as soon as they become worn and difficult to clean. Also, they must be dedicated to water because, once used for other beverages containing sugar, fats and flavouring but not properly washed, these ‘added nutrients will fuel the growth of unwanted organisms.

Asked what is a good material to opt for, for health and sustainability, Metcalf says there is not one – PET in combination with a rigid recycling programme is a good option but there is no ‘best’; each material has its pros and cons, she said.

“New studies suggest aluminium can negatively affect human health and release toxins into the environment. Low-quality stainless-steel bottles can present toxic lead levels from the sealing dot on the base (only buy 18/8 food-grade stainless steel) and glass can easily break so it is not a good idea for a child’s lunchbox.”

SUGGESTED SIDEBAR or BOX: PET’s recyclability

The argument that a beverage bottle – an inanimate object which cannot make a decision or take an action – is responsible for ensuring it is discarded in a recycling bin rather than alongside the road, in a river or on a beach is an irresponsible one. It perpetuates behaviour which contributes to much of the abuse of our planet instead of working to encourage responsible choices that can make meaningful change.

• PET is 100% recyclable and South Africa has an efficient recycling stream.
• Recycling a PET bottle reduces its carbon footprint by some 25%.
• PETCO, the producer responsibility organisation which administers extended producer responsibility (EPR) schemes on behalf of its members, reported in its latest annual report that 83 967 tonnes of all identified products registered with PETCO were collected for recycling, representing a 69% collection rate.
• that 79 571 tonnes of all identified products registered with PETCO were recycled, representing a 66% recycling rate.
• More than 111 795 tonnes of carbon emissions were alleviated.
• In excess of 462 086 cubic metres of landfill space was saved.
• Over 25 000 tonnes of rPET availability was enabled by PETCO.

Notes to editors:

1. Reusable bottles can be made from virtually any material, including plastic. The comparison therefore is not plastic reusable bottles vs metal vs glass reusable bottles, per se but reusable bottles vs beverages originally packed and sold in PET (that is, according to Food Safety legislation).

2. A study published recently (a report into the climate impact of plastics by McKinsey & Company and based on 2020 information from the United States excluding ocean pollution) concluded that plastics are frequently maligned when it comes to leakage to the environment, toxicity, use of resources, and production emissions, but argued that (as Metcalf does), while these important considerations need to be addressed, an opportunity exists for a more balanced, science-based perspective on plastics versus alternative materials.

The report did, however, highlight two important overall findings. The first was that plastics have a lower greenhouse gas impact in 13 of the 14 non-plastic alternative applications analysed, including both direct and indirect value-chain emissions. The second was that, for the majority of food packaging applications, there are few viable alternatives to plastics.