We did do extensive research, and glass came out significantly ahead in the long term, even when accounting for transport and manufacture, this is because glass is multi-use where bottles are re-used hundreds of times before needing to be replaced.
Plastic: <8% reusability via energy-intensive melting and re-shaping.
Glass: >95% reusability via washing, and of the remaining 50% > 99% can be reused via melting and re-shaping.
Over the average lifespan of a glass flask (n≈18 million), it released about 40% less CO2 equivalents compared to the amount of plastic needed to fulfil the same role.
Plastic: <8% reusability via energy-intensive melting and re-shaping.
Glass: >95% reusability via washing, and of the remaining 50% > 99% can be reused via melting and re-shaping.
Over the average lifespan of a glass flask (n≈18 million), it released about 40% less CO2 equivalents compared to the amount of plastic needed to fulfil the same role.