Glass vs PET
Analysis of Environmental Effects
We've done a lot of research into our packaging materials in order to assure ourselves (and our customers) that we have the best solution for shipping our honey, based on safety and environmental suitability.
Dan's is a bit of science nerd at heart and with Linda being a Doctor, we wanted to make sure we were making the overall best decisions for our honey.
Initially we were glass fans, we bought into the fact that plastic was a dirty word, was less recycled and glass gave a better, more premium experience overall.
But once we dug below the surface, the glass argument started to be come less clear cut and logical.
We have put some of the facts we have discovered to explain why below...
Manufacturing Feasibility
Domestic Production:
- The NZ glass industry only produces long run bottles i.e. beer and wine. This limited glass production capacity means that you would have to import glass jars from China or the Middle East, increasing carbon emissions considerably
- PET can be produced domestically, reducing the need for long-distance shipping.
Carbon Footprint
Energy Consumption:
- PET production requires less energy compared to glass manufacturing
A glass jar requires 17 - 24 times more energy to produce compared to a PET jar.
Carbon Footprint - Manufacturing:
Here is an analysis of a 500g honey jar in both PET and Glass formats. This demonstrates a significant advantage to using PET for the environment as the CO2 produced during production is only a 1/6 of the CO2 produced when making glass
Carbon Footprint - Shipping:
- PET is significantly lighter than glass, reducing transportation emissions. Our 500g PET jar weighs approximately 28g - a 500g glass jar weighs about 200g (7 times heavier)
- From our calculations below shipping glass honey jars emits 1.8 - 1.9 x more CO2 per unit weight than PET jars.
- This is due to extra weight of the jar but also weight limits per pallet, smaller amounts of jars per shipper and pallet stacking limits all due to the weight of jars.
Life Cycle Assessment (LCA)
Zooming out and taking a whole life cycle perspective - here is a comparison based on a 1L glass bottle vs a 1L PET bottle.
Key Takeaways
CO₂ Efficiency
PET bottles are significantly more CO₂-efficient across all stages unless glass bottles are reused multiple times.
Reuse Advantage
Glass bottles outperform PET in closed-loop systems where they are reused several times (e.g., deposit-return schemes). Unfortunately these are not widely available in our markets (with the exception of Germany)
Transportation
PET is far superior due to its lightweight nature.
End-of-Life
PET recycling is more common, but improperly disposed PET is more harmful than inert glass.
Summary
• PET jars are better for long-distance, lightweight, single-use needs.
• Glass jars are better if a robust reuse system is in place.
Our Jars are
References for the above summary
PET Bottle Emissions:
• Franklin Associates. Life Cycle Inventory of 100% Postconsumer HDPE and PET Recycled Resin. American Chemistry Council, 2018.
• PlasticsEurope. Eco-profile of Polyethylene Terephthalate (PET) Resin. Updated regularly, available on the PlasticsEurope website.
Glass Bottle Emissions:
• Wernet, G., et al. (2016). The ecoinvent database v3: Background and methodology. This dataset is widely used for estimating emissions for various materials, including glass.
• European Container Glass Federation (FEVE). Environmental Product Declaration for Glass Bottles, 2018.
Transportation and End-of-Life:
• U.S. Environmental Protection Agency (EPA). WARM (Waste Reduction Model), which provides emission factors for recycling and waste disposal of PET and glass.
• World Economic Forum, Ellen MacArthur Foundation. The New Plastics Economy: Rethinking the Future of Plastics, 2016.
Some more interesting articles are below
https://carbonbright.co/glass-vs-plastic-packaging-which-is-better
https://www.bbc.com/future/article/20230427-glass-or-plastic-which-is-better-for-the-environment
https://napcor.com/pet-life-cycle-assessment-report-2023/
https://oceanblueproject.org/glass-vs-plastic-bottles-from-waste-to-worth/
https://www.researchgate.net/publication/348005008_Life_Cycle_Assessment_of_Beverage_Packaging