Compostable vs. recyclable: Which is better?

in Sustainable Packaging on April 04, 2012

szakyblog040612.jpgWhen I recently posted in a New York Times blog that biodegradability isn’t what it seems,  and on Packaging Digest that we should be careful with biodegradable plastics and incineration habits, I got a few reminders that some compostable plastics are not made of PLA (polylactic acid), which is the most common polymer used for biodegradable plastics. Some are made of different types of biodegradable plastic that are more easily compostable in the backyard.

This is very true, and I think my question has now become, which is the more sustainable of the two options: recyclable plastics, or biodegradable plastics? We already know that incineration is not the best method for disposal. While it is often referred to as “waste to energy,” it might as well be “waste to air pollution” because it adds to the carbon emissions (already a problem) and introduces other toxins to the atmosphere.

I have always believed that recycling is the best way to go because it makes the most of the energy consumed to make the product. Composting is a great option, and is appropriate at times, don’t get me wrong. But let’s face it–it takes much longer and much more energy to make the majority of our plastics than the time and energy it takes to use that plastic. Think about a plastic cup: manufacturing the cup, and using the energy to make it, takes longer than it does to drink a soda out of that cup. In order to not waste the energy expended in manufacturing, the longer the life of the product, the better. It doesn’t make sense to throw out a pair of shoes that are barely worn, and same goes for a plastic.

Having the option to use recycled plastic replaces the need for virgin plastic made from virgin materials and more energy. Composting doesn’t replace the need for virgin plastic–it simply gets rid of a plastic product after one use. Rather than already having the material from which you can make your next plastic product, you will have organic compost, with which you can fertilize a garden.

Recycling still takes energy, which composting does not, but solely composting limits the end-of-life value of a product too much to give it precedence over recycling–especially when composting of biodegradable plastic still isn’t available on a large scale. Also, making a new product requires energy anyway, so the output of energy to recycle a product would be matched by that of a new product regardless.

One of the drawbacks to recycling is that eventually the plastic material will break down from being reused and recycled so many times and will face another disposal method. This is where composting would be the best option. A product with the longest life and most harmless end would be one that can be recycled, recycled, recycled, recycled, and finally composted when the plastic is too weak. I’ve seen bottles that are both recyclable and compostable (not easily so), but in order for that to be effective, that plastic needs to be everywhere, and still needs to be easily compostable in the end.

Composting and recycling both have their benefits (and their drawbacks) when compared to each other. What we need is for them to work with each other so that we aren’t forced to choose, and our habits can be as positive as possible for the environment.

Which do you view as the future of sustainable packaging?


By submitting this form, you accept the Mollom privacy policy.
500 characters remaining
For most things, cups, bags, etc I agree with you. However, there are some plastics that are not economical to recycle due to their bulk. Expanded plastics like EPS (Styrofoam) packaging in particular. It certainly can be recycled, but since it’s so volumous, it becomes too costly to transport and handle. Therefore, consumer recycling rates of expanded plastics are less than 2%. In this unique case, alternatives like EcoCradle or Greencell foam are smart home compostable alternatives. Do you agree?
I think more investment, development and funds needs to be directed toward pulp fibre-forming as a viable alternative.
Composting generates dirt — as a society do we need more dirt? I don’t think so. Recycling is logical if it can be done efficiently — collection, sorting, and recycling processes consume energy. While you downplay the waste-to-energy option, that might be the best option in some cases because as a society we do need energy. Paper and plastic waste have a good BTU value. Burning paper and plastic packaging does generate air pollution but our society is burning non-renewable fuels to generate energy already! Modern waste-to-energy facilities with pollution control equipment are viable options. So maybe it makes sense to burn the waste materials at their end of life if that is the most efficent utilization of that resource. This really is a complex subject with many alternatives and the best answer varies greatly by the availability of recycling and waste-to-energy facilities.
Very interesting points! Thanks for sharing
Design for recycling or recovery (up-streaming and down streaming)is where we need to get to. LCA is based on cradle to grave. As resources are inherently finite, even LCA is still a one time trick.
Conceptually, good overview but it does need scientific data to prove it. A 1-in-1 comparative analysis should include: type of plastic and package, its weight, GHG/weight, and total energy consumption. It should have a number of recycled times since every plastic degrades different when it is exposed to heat. To the comment regarding to ‘composting generates dirt’, that dirt is biomass. Northern states (I am in IL) have plenty of biomass every year with falling leaves a tree branches. A good composting facility should have this biomass back to nature.
I agree that recycling is a preferred end of life option, but I believe incineration with energy recovery is better than composting. When a plastic is composted, most (>90%) of the carbon is converted to CO2. Incineration releases the same CO2, only you get to extract energy to displace other fossil fuels. Modern incinerators also have sophisticated pollution controls so they emit fewer dioxins and furans than a backyard fire pit.
Good points Tom. I believe that recycling is the way to go. Not to say that biodegradable/compostable plastics don’t have a bright future in store. But we simply aren’t there yet in terms of the technology for it to be a big enough leap ahead of recycling.
The preference is for packaging to be recyclable, composting facilities usually are not able to accept compostable packaging as it does not break down quick enough. There are also concerns that it is difficult to tell the difference between non-compostable and compostable packaging which could cause contamination during collection at the curb. The manufacturers of these products and packaging need to work with the end processors to ensure they are compatible.
Eventually, all products that are intended for one-time-use, will be biodegradable in the not-to-distant future. The fact of the matter is that plastics have a poor track record in terms of recycling. Composting is a great alternative in Cities where space is tight, and in the U.S. most folks don’t have to seperate their trash either. So, throwing away a biodegradable plastic won’t find the value it’s intended to have unless it goes to the composter instead of a landfill. These new bioplastic choices are great alternatives to petroleum and they present a smarter way to make products. Recycling is great in some cases, but as general rule this is a “value point” of a material. If the material is lost, or finds its way into an area sensitive to the environment, then what? It sits there, or get’s digested as food by marine life. It’s an item that has value as long as we need it, and beyond that it get’s forgotten about. Compostable plastic is normally plant based, and will return to nature at some point. Regarding incineration, this is a great option, but i wouldn’t consider it to be the best. While the emissions of these plants have improved greatly, they can still send small particulates into the air that can float around for miles. Anytime you combust, your creating toxins, and for this reason composting is safer. In terms of energy values, burning plastic can be good if you have the correct input’s. Anaerobic digestion, is also becoming another option to capture gas from waste, but is also dependant on the quality of input going in. If you put a bunch of wet crap into an incinerator, you won’t get the same calorific value as you would if the materials were dry. Overall, there are lots of opportunities to improve how we care for our business, and the environment.
Review by A. Stockdale for Rating: We raise guide dog puppies, and have a pet Lab of our own. With two dogs arnoud the house most of the time, effective waste clean-up is a priority. We’ve tried recycling plastic shopping bags (too large, and they often have holes in them), and purchasing special-purpose dog waste bags from the local pet store (varying quality, not biodegradable, and kind of pricey). The best option we had found so far was dog waste bags from Ikea, which were reasonably priced ($1.99 for 50), but not biodegradable. Unfortunately, Ikea has discontinued the product, so we were back to looking for an acceptable solution. After looking at some of the alternatives (flushable bags, in particular), we decided to try these bags from Green Stuff Only.Firstly, the price is hard to beat. If you look arnoud, you’ll see that it’s hard to find bags for much under $.04 a bag. $5.99 for 200 is a very good price, and preferable to ordering thousands of bags to get a comparable price. Secondly, the quality of the bags is good. We’re part way into our first box, and so far I have not had any issues separating a bag from the roll (no holes or tears, etc.), and no problem opening the bags. The plastic has that dry/rough feel that you associate with corn-based biodegradable plastic, and is green in colour, but otherwise seems very similar to the Ikea bags that we were using. Finally, the bag is a good size I can turn it inside out over my large hand, and back again, without any issues. Without being gross, it holds enough.My main concern was getting a reliable bag at a reasonable price, and these certainly fit the bill. The fact that they are biodegradable is an added bonus, although it’s debatable whether they will get much chance to degrade when double bagged (per our local waste disposal recommendations) and buried in a landfill. I would definitely recommend these bags to others.
But they are still throwing up smckesoreens with their myths. While the filmy plastic bags are recyclable, the fact is that only about 4% of them get recycled in the US. You are right, reusable bags cannot be compared in the same way that they present their statistics. Unless, of course you took the time to run life cycle analyses on every type of reusable bag imaginable.The comparison they will never touch with a ten foot pole is the simple fact that every time a person reuses any type of bag, that’s one less plastic bag you are asking them to manufacture. Imagine if everyone in the US rummaged through their closets and attics for all of the free tote bags they ever got, and used those for grocery shopping. You can’t compare the energy cost and waste ramifications of their filmy bags to something that has ALREADY been made.
Don't forget to emphasize that Recycling is the third "R" in in Reduce, Reuse, Recycle. Reducing and Reusing also have potentially large benefits. Composting is a nice addition to our options. I'd like to see more research to find out if we can use the composting process for energy generation with less air pollution than other energy sources.