Wednesday, 27 June 2007

Cloth vs Disposable Nappies - Environmental Footprint

I have heard many people say that there is no difference in the environmental impact of disposable vs cloth nappies - I found this fairly hard to believe so I did some research (read "googling") and found this very scientific study, click here.

In the opening "Summary" this study says: "there was no significant difference between any of the environmental impacts" of the different types of nappies. I wonder if this is where people are getting their information from? It seems to me that there are some serious misunderstandings happening here with regards this study, and there are also some problems with the study itself.

Keep reading if you're interested...

Firstly, there being "no significant difference" is not the same as being "no difference". The first is a technical statistical term, the second is a laymans term. What you need to find a "significant difference" is big enough numbers of people using both cloth and disposable nappies. This study had heaps of people using dispoable, but very small numbers of people using cloth - this lowered its chances of getting a significant result at the start.

Looking at the results graphs at the end, I bet that if they had studied large numbers of people using cloth then the results would have been, on almost every measure, that cloth nappies are better than disposable.

I read the whole report and throughout I found that they weren't trying to find out how environmentally friendly you could be when using cloth, but how they thought people in the UK actually did clean their cloth nappies.

They had a whole lot of assumptions, many of which did not match with how I clean my son's cloth nappies.

They assumed that:
  • Cloth nappies were produced in the US, and disposables were produced within Europe (so the environmental costs of transport were larger for cloth, per nappy).
  • 80 of people using cloth will soak and 100% of them will use a nappy soaking solution. The chemical composition has been assumed the be the highest level indicated on the label.
    some people will use a detergent when they wash (after using a sanitiser)
  • 49% of people will use fabric softener in their wash (and that the softener contains the maximum level of chemicals indicated on the packet).
  • 19% of nappy wash loads are tumble dried, then they adjusted the data to assume it was 60% (based on how many people own tumble driers even though only 19% of people said they used them). A tumble drier uses about 15 times as much energy as a cold water wash - so this is a significant amount of energy.
  • 10% of people iron their nappies (who could be bothered!)
  • 86% of people used one nappy liner per change (though no evidence for this - I reuse my nappy liners)
  • they argue that the number of cloth nappies bought over the 2.5 year period is 47 per child, though they have only evidence that people buy 43, and they do not take into consideration reusing some nappies on subsequent children - something that can't be done with disposables.
Even with these assumptions cloth nappies perform better than disposables on most of the measures that they calculated.

I don't recall any mention of where the energy that you use in the house is coming from: if you have a green energy provider, wash in cold water and dry your nappies in the sun (like I do) - your total environmental footprint for your nappies must be many times lower than for disposables. Considering that each disposable you use needs to be grown, harvested, produced, transported, and disposed of, each with their costs to the environment.

People can make the choice to use disposables, if they like, for whatever reason. But it shouldn't be because they think there is "no difference" in the environmental footprint between cloth and disposable nappies.

By the way, I think that cloth nappies should be called "reusable" and disposable should be called "land-fillable" nappies. Do you think that would go down well? :-)

4 comments:

Unknown said...

Another consideration of the land-fillable nappies is the "significant" proportion of components derived from non-renewable resources (plastics). It is forseeable that use of plastics in applications such as this may become too expensive or prohibited (due to massive reductions in the supply of crude oil) and everyone will have to swap to cloth nappies anyway! Just have to wait and wait and wait and see...

Anonymous said...

Hi Donna (returning the visit),

Good post. I'll have to point my wife this way. We're in Tanzania and we use cloth for our kids, except for travelling, etc.

I'm always wary of studies like this. Like you said, it only shows what some people do, not what you could do to make it better. And I would think that for the most part people who use cloth nappies are generally more conscious of environmental impact. We certainly don't dump in tons of soap, we don't use fabric softener, we line dry (nothing bleaches organic matter better than the sun), we re-use on the second child, we don't use liners (although someone gave us some recently, and we use them selectively), we definitely don't iron, and we don't soak. It also means that we don't have to put 50 or so disposable nappies in an incinerator each week and pump that smoke into our yard and neighbourhood. So yeah, I'd say, for us, cloth nappies are much better on the environment, and are far more cost effective.

Derek said...

I wonder who was paying for that study?

It's ridiculous, really...

Or maybe disposable crockery and cutlery is better for the environment than washing up plates and metal cutlery, too. How wonderful!!!

Donna said...

Wonderful!
Maybe we shouldn't wash our clothes, we can just buy more?