The Case for Lightweight Water Bottles:
The waste management company that serves my neighborhood has been asking us to remove glass bottles from recycling bins and to dispose of them with garbage, as they can’t find markets for post-consumer glass in the region. So, I’ve been experiencing first-hand not only how perfectly recyclable materials become trash when no one wants them, but also how important lightweight packaging design is, as my trash can has become rather heavy!
Packaging accounts for a small percentage of the total carbon footprint of a given beverage, the major contributor usually being the product itself, which is particularly important when dairy or plant-based ingredients are used. Other more intense use of energy happens in manufacturing, distribution, plus product cooling and heating at home. Some life cycle assessments show that packaging contributes with single digits percentage of the total carbon footprint. A well designed package can support reduced emission goals in many ways, most importantly via food waste minimization, which represents from 20 to 40% of the total food produced, depending on how developed a country is, with enormous amounts of greenhouse gases generated by that waste.
Bottled water is the beverage segment with the fastest growth, already surpassing the consumption of carbonated soft drinks. The product itself is usually subject to minimum processing, so the relative footprint brought by water bottles tends to be higher than for more complex beverage formulations. However, from a sustainable packaging point-of-view, it’s worth-noting that:
- The highest volumes of bottled water are delivered in returnable jugs,
- Recycled PET content already reaches 100% for some brands,
- Bio-based materials have been increasingly used by global brand owners, who claim that at 30% content, the use of bio-based PET can reduce from 11 to 18% the overall carbon footprint of a PET bottle, depending on the technology adopted. Bio-based is now moving to 100% renewable sources.
So, the lighter the bottle, the better it is for the environment, right? Yes, but…
What happens post-consumption or at the end of a packaging life is something taken more or less seriously by different societies, regulators, and brand owners. A well designed lightweight bottle can definitely reduce the amount of waste going to landfills and incinerators, and should be an obvious goal for CPGs. But it’s the designer’s responsibility to avoid problems for retailers, consumers, and recyclers downstream. It is a general principle of the Extended Producer Responsibility, Sustainable Materials Management, and Circular Economy to observe the hierarchy of attributes such as durability, reusability and recyclability when designing a new product or packaging.
An interesting exercise was recently conducted to evaluate which top selling bottled waters around the world used the best design thinking process to create the highest performing bottle for a set of key indicators. This study analyzed the benefits and penalties of design choices, from efficient material usage to recycling friendliness. A summary is available at this link, but here are a few key highlights:
- Lightweight bottles drive cost savings – there is a clear trend towards extremely light bottles, sold at low price (safety, convenience drivers) as opposed to premium, heavier weight bottles (“like glass premiumization”). Efficient Material Usage varied from 42.0 to 15.0 grams per liter of product, however no strong correlation could be found with shelf prices which ranged from $.020-$.056/L).
- Lightweighting increases packaging performance risk – the data shows that the lightest bottles present higher packaging quality variability (weight, material distribution) and performance (top load, internal pressure) than heavier bottles. Some extremely light bottles require pressurization (Liquid Nitrogen dosing) to sustain the specified top load and may lose the internal pressure overtime due to gas permeation or leaks.
- Additional attention to design for recyclability is needed – extreme lightweighting is one of recent negative trends tracked by PET recyclers, as it impacts:
- The quality of post-consumer bottle bales (more bottles contained in one bale means higher contamination potential by colored or non-PET bottles)
- The separation efficiency in the recycling process (the extremely thin PET walls get separated with labels during elutriation and eventually are lost to waste).
Label materials, inks, and glues may be a problem – the competitive analysis showed that some bottles were designed more carefully than others regarding the impact of label materials on the PET recycling stream. It is well established that some silicone-based glues and paper labels, just to name top finds, and contribute to defects such as haze and black specs when using PCR.
I would add my personal concerns regarding Green Marketing – in addition to saving costs, brand owners realize the benefits of the positive image brought by lightweight bottles (e.g. Coke’s Eco-Flex®, Danone’s Ecoligera®, Nestlé Water’s Eco-Shape®, Niagara’s Eco-Air, and Pepsi’s Eco-Fina®). Such marketing efforts might backfire as collectors, intermediate processors, and reclaimers have to handle a larger number of bottles to achieve the same throughput (e.g. 1 tone of post-consumer PET bottles contains 13,228 more bottles today than in 2006, representing a significant drop in recycling process yields). Green designers and brand owners are being increasingly ranked for the recyclability of their material choices, which may jeopardize goals to close the loop in their own packaging. They must also go the extra mile to ensure that their post-consumer packaging is wanted in the recycling bin, not elsewhere.
ABOUT THE AUTHOR:
Marcio has dedicated most of his career to environmental management and governance for the beverage industry. Marcio worked for Coca-Cola in Brazil and later at Coke Headquarters Atlanta. His career has numerous contributions to sustainability platforms (packaging, recycling, efficient use of water, and drinking-water safety). Mr. Amazonas currently is part of Plastic Technologies, Inc. (PTI) business development team, focusing on Latin America and coordinating sustainability projects.