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/refillable 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?
According to Charlotte Metcalf, CEO of the South African National Bottled Water Association, every single material used to manufacture reusable/refillable 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 that 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 says. “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 notes.
Metcalf adds 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 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 warns.
Metcalf’s daily routine for cleaning reusable bottles (she has yet to find a reusable bottle design she trusts with her family’s safety) would include 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.
Reusable/refillable bottles must also be regularly examined for pitting and wear-and-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.
“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.”
Image credit: Freepik