Don’t Miss This
This is only Part 2 of our original investigation into single-use floss picks.
Don’t miss the other parts:
- Part 2 (Climate Change): You Are Here
This is the second part of our in-depth research into the way disposable (single-use) flossers affect the environment.
In this part:
We’re going to estimate the carbon footprint of single-use floss picks.
More importantly, we’ll put that footprint into a real-world perspective that we can all relate to.
And we don’t hide the aim of this investigation either:
It’s to encourage the use of eco-friendlier alternatives, like the Element floss holder.
What are disposable flossers made out of?
Single-use flossers are often made out of one form of plastic or another, including:
- Acrylonitrile butadiene styrene (ABS) 4
Many of the “eco-friendly” single-use floss picks are made with a “bioplastic” like PLA.
But do note:
PLA isn’t as “biodegradable” or “eco-friendly” as manufacturers would like you to believe.
A lot of greenhouse gases (GHGs) are emitted during its manufacture as compared to other plastics.
Moreover, it takes industrial levels of heat (more global warming) to jumpstart PLA’s composting process. Furthermore, the United States Environmental Protection Agency estimates that PLA is hardly recycled in the U.S. 5–8
How we approached our calculations
Click the spreadsheet below to expand and zoom in.
There’s an extremely wide variety of single-use floss picks out on the market.
Given this variety:
It’s almost certain that many disposable floss picks are made out of plastics that are different from the ones mentioned above. Or they’re made out of a mix of different plastics.
Some single-use floss picks might be made out of non-recycled plastic.
Others might be made out of 100% recycled plastic or a mix of new and recycled plastics.
It’s nearly impossible to accurately account for all of these variations, as well as how they might change over time.
Not all plastics, or combinations thereof, have reliable carbon footprint data about them.
Single-use flossers typically come in plastic retail packaging. The packaging may be of a different material than the flossers themselves. Nonetheless, the manufacture of this retail packaging adds to greenhouse gas (GHG) emissions.
All in all…
We can be sure of one thing:
A wide mix of recycled and non-recycled plastics are used to create single-use flossers and their retail packaging.
No surprise there.
Given these complications:
What can we do to estimate the amount of GHGs emitted by the manufacture of single-use flossers?
Well, we found reliable and consistent emissions data on the 9 types of plastics that generate over 87% of consumer plastic waste. 6,7
This data came from the United States Environmental Protection Agency’s (EPA’s) Waste Reduction Model (WARM).
We felt that, by using this data, we’d average out, approximate, or cover many of the possible variations mentioned above.
So we combined the EPA’s data with the calculations from the first part of our investigation.
In the first part of our investigation:
We discovered that about 4,700 metric tons of disposable flosser waste is created in North America.
Using these two sets of data:
We were able to estimate a carbon footprint for disposable floss picks.
As always, we were conservative in our estimates in order to avoid blowing things out of proportion.
We describe the numerous reasons for why our carbon footprint estimates are likely too optimistic.
In other words:
We almost certainly underestimated the real carbon footprint. See the limitation section for more on why that’s the case.
The carbon footprint
For North America, the carbon footprint of single-use floss picks is around 9,784 MTCO2E per year.
What does MTCO2E (metric tons of carbon dioxide equivalent) actually mean?
Well, the manufacture of disposable floss picks emits different greenhouse gases.
These gases include carbon dioxide (CO2).
CO2 is used as the “reference gas” in calculating the global warming potential (GWP) of other gases.
Because it’s the “reference gas”, the GWP of CO2 is set at a value of 1.
Other gases may have a higher or lower GWP than CO2.
For instance, the GWP for methane is at least 28. 9
Molecule for molecule, methane has a far higher (worse) impact on global warming than CO2.
Put another way:
A factory would have to emit 28 metric tons of CO2 to equal the effect that 1 metric ton of methane has on global warming.
In the manner described above, MTCO2E standardizes all the different gas emissions to the impact that CO2 has on climate change. 10–12
The less realistic model
In the very best-case scenario the carbon footprint of disposable floss picks is:
This is solely for North America.
Even so, this number is purely hypothetical and highly unrealistic.
That’s because, for this model, we assumed that all single-use flossers are made from 100% recycled plastic.
How likely is it that this is true?
In the first part of our investigation:
We found 40 different packs of single-use flossers. This included flossers for sale in retail stores and those on Amazon.
None of them were made from 100% recycled plastic.
Even those labeled as “eco-friendly” didn’t use recycled material.
Furthermore, the EPA makes it clear that only 8.7% of all consumer plastic is recycled. 13
However, we’re not so sure single-use flossers are recycled even this much. We believe that a “dirty” and used hygienic product like a flosser is far more likely to be trashed as opposed to recycled.
The more realistic model
Our far more realistic model estimates that 9,784 MTCO2 is emitted every year in order to make disposable flossers.
Solely for North America.
As we just went over:
All of the 40 different packs of floss that we found were made with “virgin” material.
As in: non-recycled material.
Our model assumes that the raw material that’s used to make disposable floss picks is 100% virgin plastic more often than not.
Furthermore, we modeled this assumption across 9 different types of plastic. And we used three different estimates of the number of flossers produced every year.
We also accounted for three different methods of disposal.
The flossers could be:
- Put in the trash (landfill)
We weighted the carbon footprint data by the likelihood of each method of disposal in the real world.
This allowed us to arrive at an average carbon footprint of:
For granular insight, click on our spreadsheet above.
The real-world perspective
What does 9,784 MTCO2E/year mean in the real-world?
Well, every year:
The manufacture of single-use flossers creates the same amount of greenhouse gas emissions as:
- Burning 1,100,891 gallons (4,167,326 liters) of gasoline 14
- Powering your refrigerator for 29,936 years 15
- Producing 815,770 pounds (370,027 kg) of beef 15
…and that’s just for the single-use flossers produced solely for North Americans.
Why we probably underestimated the carbon footprint
- For the calculations in this article, we used several important numbers from part 1 of our investigation (see table 3). In the first part, we described 12 reasons for why those numbers are likely underestimations of the truth. By relying on those numbers for this article, all of the carbon footprint estimates in this article were almost certainly on the very low side.
- Critically, our estimated carbon footprint reflects only the manufacture and disposal of all of the raw plastic that’s necessary to make the single-use floss picks. The carbon footprint doesn’t take into account the conversion of all of that plastic into the disposable floss picks themselves. This means that the actual carbon footprint of single-use flossers is almost certainly higher than our estimate.
- We didn’t take into account the emissions associated with the transport of disposable flossers from faraway places, like China, into North America. Accounting for this would raise the true carbon footprint of disposable floss picks.
- We don’t know what mix of plastics dominates the disposable flosser market. This could’ve moved our carbon footprint estimates up or down.
- We don’t know how many single-use floss picks are made out of 100% non-plastic material or a mix of plastic and non-plastic material. Depending on this non-plastic material, our estimates may rise or fall.
- We didn’t delineate the unknown emissions linked to manufacturing the floss that’s strung on disposable floss picks. It’s unlikely this would’ve significantly changed our estimates. After all, only a small amount of floss is included.
- The EPA’s WARM didn’t have recycling credit data for every type of plastic. This could’ve moved our estimate up or down, depending on the exact credit for each type of plastic.
- The EPA’s plastic recycling rate data is mainly applicable to the U.S. We don’t know if it applies equally well to Canada and Mexico, let alone the rest of the world.
- The EPA’s WARM didn’t have the GHG emissions data for the production of every type of 100% recycled plastic. However, we’re unsure of what real-world implications this may have for our model. That’s because supply and demand for various virgin and recycled plastics changes the price of each on a constant basis. This means manufacturers may switch from one to the other and back again over time. The dynamics of this are highly unpredictable.
- There is more than one way to estimate GHG emissions for plastics. In order to keep things consistent, we relied solely on data from the EPA’s WARM. We realize that their data wasn’t always complete due to the methodologies and choices they made upon sourcing it. However, we believe that the EPA’s information is an excellent starting point for our calculations. It’s unclear how much our estimates would’ve moved up or down had we relied on alternative, but equally reliable and consistent, sources of information. However, we didn’t want to mix and match different sources of data. That’s because the varying methodologies used to determine GHG emissions would’ve made data comparisons tricky or inappropriate.
In his review of this article, Dr. Fusco added some additional thoughts about bioplastics that our article didn’t address directly.
“Bioplastics are intrinsically a ‘nice product’ however they hide an untold truth. It is true that bioplastics are often not as ‘eco-friendly or biodegradable’ as we commonly think, but that’s because of the hidden problems in their production (pollutants and nitrous oxides due to fertilizers and the pesticides used in growing and processing the raw materials) and especially in their recycling/disposal.”
3 Key Takeaways
- 9,784 metric tons of greenhouse gases are emitted due to the manufacture of single-use flossers. And that’s just for North America, every single year.
- This is equivalent to setting 1.1 million gallons of gasoline on fire every year.
- These numbers are most likely underestimations of the true carbon footprint of single-use flossers.