Should I stop using plastic packaging?

My audit suggests it would be very difficult, and would harm the climate.

We all hate plastic, right? And when it comes to choking sea creatures, befouled beaches and the spread of micro-plastics throughout the environment then with good reason. And yet … is “ending plastic,” as some urge, either feasible or desirable? And what should individual citizens do about it in a country like the UK?

These are topical questions, since world nations agreed at the beginning of March to create an international treaty to tackle what the BBC called the “plastic crisis”. A group of scientists has called for the treaty to require a “substantial reduction” in virgin plastic production as well as waste by 2030. Some want virgin plastic production to be ended by 2040.

Single-use plastics will be in regulators’ cross-hairs. The United Nations Environment Programme has called for them to be entirely phased out as part of a wholesale shift towards multi-use products and circular economies.

Meanwhile, at ground level there is strong pressure on consumers to anticipate these global trends and go plastic-free in their personal lives. Greenpeace publicises “nine ways to reduce your plastic use”. WWF promotes its own list of “ten ways to reduce your plastic footprint”. Surfers against Sewage has created a network of 718 Plastic Free Communities dedicated to “kicking our addiction to avoidable single-use plastic, and changing the system that produces it.”

My experiment

That sets the scene for an experiment I carried out. What would it take, I wondered, for me as a fairly average UK consumer, to eliminate single-use plastics from my life? And if I succeeded then would I have helped the environment?

I have tried to answer these questions by counting, weighing and classifying by material type all the grocery packaging items I collected for recycling over six weeks in my two-person household. First of all this tells me which packaging materials are most common. If plastics are marginal then perhaps I wouldn’t have to make big changes to eliminate them. If they are ubiquitouus then the task would be much larger.

Then, weighing the total amount of each packaging material type gives an answer to my second question about what a personal reduction in plastic would mean for the environment. By factoring the weight of each material collected against DEFRA’s “UK carbon scores” for each material type I can calculate the relative contribution to climate change of the different packaging materials I use.

DEFRA’s carbon scores don’t provide the whole environmental picture, of course. They ignore non-climate impacts like the ecological effects of plastic litter in the oceans, air pollution from poorly controlled burning of plastics or the environmental spread of micro-plastics. However, I think they provide an important benchmark for my situation, for two reasons.

The first is that waste treatment in Britain, including in Buckinghamshire where I live, is reasonably well managed. The council assures me that none, or only a minuscule proportion, of plastic or other waste it collects for recycling is exported. Plus, all non-recyclable waste collected in Buckinghamshire is incinerated with good air pollution control. The second reason is that climate change accepted by most people as the single most important environmental challenge we face. If I’m going to over-simplify then I don’t feel uncomfortable looking just through the prism of climate change.

I counted all the packaging I had collected for recycling, using packaged goods item rather than item of packaging as the basis of calculation. This is because I want to know what proportion of the goods I buy are packaged primarily with different materials, and I don’t really care about the number of individual bits of packaging - the number of lids and films, for example.

Most packages that I counted were in fact made up of a single material - masses of polyethylene bags, e.g. for fresh herbs and vegetables, for example. But quite a number include more than one material type. For example, multi-packs of tomatoes in metal tins come in card sleeves - in this case I counted each tin as the primary package and set aside the card sleeve for weighing only. Similarly, I counted each glass jar as a single glass-packaged item, adding its metal or plastic lid to the respective material pile for weighing that material type. I did the same for the plastic film on rigid plastic containers.

When it came to weighing I grouped all items of packaging into six material groups: rigid plastic, flexible plastic, paper/card, glass, metal, and laminated card. In some of my analysis I then grouped together the rigid and flexible plastics into a single category.

And finally, I applied DEFRA’s UK carbon scores to the total weight of each packaging material to derive life-cycle climate impact of each material, including resource extraction, manufacturing, transport and disposal, measured as kg of carbon dioxide.

My findings

My first finding is that plastic is by far the most common packaging material of groceries that I buy: it was the primary material in 71% of grocery items. All other material types were marginal in comparison, with glass in second place as the primary packaging material for just 14% of goods items (see chart below).

The picture changes radically when I look at the mass of different packaging materials. Glass shoots up to 68% of the entire weight of packaging, while plastics shrink to 16%, especially due to the extreme light weight of flexible plastics such as films and bags.

Finally, factoring in life-cycle carbon emissions of different packaging materials, I see that plastics still contribute a low share of CO2 emissions relative to the proportion of grocery items packaged (39% versus 71%) whereas for glass the share of CO2 emissions is much higher than the proportion of goods packaged (42% versus 14%).

What do I take from this? Well the first thing is simply that - for better or worse - plastic packaging is now intrinsic to the delivery of groceries for an average UK family who, like me, shops in any of the mainstream supermarkets. Quite simply, going “plastic free” looks like a mirage for all but a tiny minority of the really committed who are prepared to turn their lives upside down in pursuit of this one goal.

My second conclusion is that - in the very important context of living in a country with a generally well functioning waste management system with significant recycling and little or no dispersion of collected waste to the environment - the preponderance of plastics relative to other packaging materials is in fact for the better, not the worse, in terms of climate impact. And if there is any kind of packaging material we as consumers should be trying to avoid it is - ironically - glass!

Of course there’s another argument, which is that we are suffering an epidemic of over-packaging and that our goals should be to reduce packaging, and to buy more unpackaged goods. And as an eco-conscious (if still quite average) consumer I’m there already, where it doesn’t radically reduce my convenience or mean having to buy sub-standard produce - we’ve all shied away from open trays of wilted vegetables!

But if we fixate on packaging we can miss the bigger picture, which is that packaging generally contributes relatively little to the overall impacts of grocery supply chains, plus that by efficiently protecting and extending the useable life of groceries packaging greatly reduces overall environmental impacts.

Both points are well illustrated by a study published by the State of Oregon in the USA looking at the contributions to lifecycle carbon emissions of different stages in food production and delivery. Focusing on foods, it shows that packaging is a small contributor to overall climate impact, and utterly trivial in the case of meat and dairy.

Moreover, as noted above, good packaging reduces overall environmental impacts by reducing overall waste and emissions, even if the impacts of the packaging itself increases. Or as a scientific paper quoted in the study puts it:

“The whole value chain has a responsibility to explain that sustainability is not synonymous with recycling, recyclability, recycled content, biodegradability and other popular buzz words, but that it is the overall resource efficiency of the supply chain that should be the main priority.” (Russell, 2014)

My conclusions

I conclude several things from this analysis in terms of how UK consumers wanting to live in an environmentally responsible way should think about plastic packaging and behave in relation to it and to the goods packaged in it.

1. Going plastic free is virtually impossible and anyway counterproductive in terms of climate change, the major environmental challenge we face. It is in fact a distraction from real beneficial change and should not be pursued.

2. Having said the above, do avoid consuming plastic packaging unnecessarily. For example, switch to long-lasting polypropylene shopping bags and you may never need to buy another disposable carrier bag again. If the quality is still good, then buy loose onions, broccoli and the like rather than bagged.

3. Likewise, don’t drop litter. So much of the plastic packaging that ends up in the environment is there through thoughtlessness. It’s not difficult to bin it.

4. Of the plastic packaging you consume, do collect what you can for recycling, while making a point of learning how to do it better (people putting non-recyclable or dirty materials in the recycling bin can be as big a problem as people not collecting for recycling at all).

5. Finally, and above all else, avoid wasting groceries as far as you possibly can (well, and everything else too!), since this is a far larger source of climate impacts than the packaging. Do buy and use the reduced price foods that your local supermarket will otherwise throw away. Do put leftovers in the fridge and eat them the following day. Do freeze or otherwise preserve foods that you can’t eat immediately.

Some caveats

My groceries packaging audit was pretty rough and ready. I think it approximates to reality sufficiently for the conclusions I’ve drawn, but there are some obvious sources of uncertainty or bias, which are worth just running through, if only to prevent myself or anyone else putting too much weight on the results.

First of all, a proper university-grade study would have measured all packaging not per packaged item but per kg of packaged goods. But that would have required me to start noting the weight of all groceries as it came into my house, which would have been a much larger job. So there may be biases in my figures if some kinds of packaging material are used disproportionately for heavier groceries.

Secondly, I have included only packaging materials that I collected for recycling, so excluding non-recyclable or soiled items that I put into the residual waste bin. This includes a number of supermarket sandwich boxes, and cheese packaging that it is difficult to clean without washing in hot water with detergent - which is not an ideal thing to do in terms of the climate. Not a large number of items overall, but worth noting. N.b. I also did not count my in-house use of cling film, even though I have switched to recyclable polyethylene and do collect it for recycling.

By restricting my survey to groceries this means I also excluded the mainly cardboard packaging used by general internet retailers like Amazon. We accumulated quite a bit over the six weeks of the study, made of paper/card, in particular, and this packaging fraction would have been more prominent in overall usage if I had included this.

Finally, I had to adapt some of the UK carbon scores as published by DEFRA to my material classification. DEFRA cited different scores for different plastic polymers, for example, and differentiated between steel and aluminium. I chose numbers in the middle of DEFRA’s ranges, or weighted towards what I knew were the more common materials in my personal basket: for example I collected almost no alu drinks cans and mostly steel food cans. For completeness, the scores I used were as follows:

Rigid plastic = 2900; flexible plastic = 2600; laminated card = 2350; paper/card = 1550; metal = 1500, glass = 725, all expressed as grams of carbon emissions per kg of packaging material over its life-cycle and in a UK context.