Glass or plastic bottle: What is the better option?

No matter whether with much, moderately, little, or even completely without carbon dioxide – with an average annual mineral water consumption of approximately 148 liters per person in Germany, we can only draw one conclusion: Germans love their water! However, while shopping in the grocery store, one might wonder: Should the water come in a glass or plastic bottle?

We have analyzed and summarized the respective advantages and disadvantages for glass and plastic bottles. Thereby, we consider four categories: Handling, taste, environmental friendliness, and health. Which bottle is the winner? The good old glass bottle or the newfangled plastic bottle?

plastic bottle

Handling

Those of us who still remember from their childhood the water boxes which contained 6 or 12 glass bottles. Those who had to lift those heavy water boxes are probably very grateful for today’s lighter plastic bottles. The plastic water bottles are easier to lift, even if they are bought in bulk, and can thus be carried around without problems. Should they ever slip out of your hand: No problem, because plastic is a very stable material.

This is not the case for the glass bottle: I still remember one or two glass bottles that ceased to exist on our cellar stairs as well as the subsequent laborious picking and sweeping up of the shards which was accompanied by warnings from my parents to not go barefoot near there. Regardless of careful cleaning, usually, you could still find tiny shard pieces of glass even days after the incident.

In terms of handling, the plastic bottle is the clear winner, thanks to its easy and safe handling! 1 – 0

Taste

Maybe you have experienced it: drinking from a plastic bottle tastes a bit different than from a glass bottle. According to experts, the strange aftertaste of beverages in plastic bottles comes from the compound acetaldehyde. This substance is released in small amounts from the plastic into the water – a process that depends on time and temperature. This means that the higher the temperatures the plastic bottle is exposed to and the longer it is laying around in said temperatures, the more acetaldehyde is released into the water.

According to the German Federal Institute for Risk Assessment (BfR), this has no harmful consequences for our health because the quantities released are too small. The release of acetaldehyde can, however, affect the taste. This phenomenon can be observed, for example, if one takes a sip from a plastic water bottle which has been laying in the car for several days during the summer heat and thus has been exposed to enormous temperatures.

As far as taste is concerned, we give one point to the glass bottle as it cannot influence the taste. 1 – 1 

glass bottle

Environmental friendliness

In 1991 reusable bottles were still clearly ahead, with a 91% market share. Remember, reusable bottles can be made of plastic or glass. However, in 2016, this market share declined to just 39%. The reason for this steep decrease is the disposable plastic bottle. Thanks to its practical handling, it has been gaining popularity steadily.

Differentiation

Disposable bottles can only be distinguished from reusable bottles by closer examination, such as a logo or a small inscription. Making a judgement if a bottle is disposable or reusable based on its deposit is invalid since a deposit can now be charged for both. Furthermore, both kinds of bottles can be made of plastic, PET to be precise. PET (polyethylene terephthalate), which incidentally requires petroleum to produce is used for both bottles types. It is used in thicker form for the reusable plastic bottle and in thinner form for the disposable plastic bottle. Hence, it should come as no surprise that almost every second German citizen cannot differentiate between disposable and reusable bottles.  

Recycling

As the name suggests, the disposable bottle can only be used once. Some will understandably frown on what recycling is all about. Aren’t they converted back into new plastic bottles after recycling? Yes and no, is the answer.

Once the disposable bottles have fulfilled their life’s duty, they are sorted by color and chopped up. Their remains are washed, melted down, and then processed as granules. However, this melting process renders approximately half of the plastic molecules unusable for reuse in new plastic bottles. As a result, only a small fraction of the recycled granules – less than 30% – can be added to the new material, which is then used to make new plastic bottles. The remaining recycled granulate is then used for other processes. Exemplary, it can be used forthe production of textile fibers like polyester or as a combustion agent in waste incinerators as well as combined heat and power stations.

While the disposable bottle is thus subject to a complicated recycling process, the reusable bottle is cleaned and refilled accordingly. This process can be repeated around 20 times for PET bottles and around 60 times for glass bottles. With regard to the CO2 balance, the reusable bottle’s transport route, the required water consumption, and cleaning agents must be taken into account. Here, the reusable bottle’s heavier weight can have a negative effect once again since it contributes to higher transport emissions.

Travel distance

However, reusable bottles, whether plastic or glass, often have filling plants in central areas of the respective country which considerably reduces their transport distances compared to disposable bottles. Accordingly, the “Deutsche Umwelthilfe e.V.” estimated that a reusable bottle only travels around 260 kilometers while a disposable bottle travels twice as much. In total, recycling a disposable bottle consumes 55 grams more CO2 than refilling a refillable bottle. Ultimately, anyone who values a positive environmental record should look out for a reusable bottle with a regional filling plant.

Despite refillable bottles, whether made of plastic or glass, being ahead in terms of environmental friendliness, several factors such as the transport route have to be considered as well. Hence, we have decided for a draw between glass and plastic bottles. The clear losers, however, are all disposable bottles as these have a very poor environmental record. 2 – 2

plastic bottles

Health

The plastic bottle has been repeatedly criticized because of the chemicals used in the packaging. These chemicals can get into our bodies through the water. Studies have shown, for example, that PET bottles are significantly more often contaminated with chemical residues. Overall, however, the detected residues in water from plastic bottles are not harmful to our health, the Federal Institute for Risk Assessment assures. Yet, researchers at the University of Frankfurt and Würzburg do not have the same opinion: based on research results, PET bottles are deemed rather critical. PET is a rather porous material that would allow carbon dioxide to escape and, as a result, certain substances may get into the liquid. Ultimately, we ingest these substances when drinking. This might lead to long-term consequences for our health which we currently cannot fully assess yet.  

As a result, since certain health hazards of PET can currently not be excluded, we give our point here to the glass bottle. 2 – 3

Glass or plastic? – The conclusion

Here are our winners for each category at one glance:

Handling: plastic bottle
Taste: glass bottle
Environmental friendliness: a tie between returnable glass and plastic bottles
Health: glass bottle

glass bottles

Due to its better environmental record through refilling, taste, and health compatibility, the reusable glass bottle is our winner!

In the end, it is probably a personal or even logistical decision whether you choose a glass or plastic bottle. Since plastic bottles are easier to transport, it is a more convenient solution for those who do their shopping without a car. But remember: if you do decide to use a plastic bottle, make sure it is reusable!

If you want to reduce your carbon footprint even further and prefer a cheaper alternative to buying a water bottle: the cheapest water which doesn’t even require any transport still comes from our water tap (at least in Germany)!