Itâ€™s 3am and your newborn baby is crying, again. Your half-asleep partner gives you a quick nudge as a reminder that itâ€™s your turn, so you sombrely make it to your feet and mosey to the baby room. While checking on the little one, you can see by the look on her face that this is not just a request for a quick â€˜rock-a-byeâ€™ session, but instead that sheâ€™s got a nice little present with your name on it.
Without hesitation, you begin to go through the motions that have become like clockwork; a wipe here, a little powder there, and just your luck, thereâ€™s one disposable nappy left. Suddenly something hits you, maybe it was the VOC free paint you used in the babyâ€™s room clearing your head, the clarity that can only come with prolonged sleep deprivation, or upon admiring the â€˜Future Environmental Warriorâ€™ onesie, and you begin to wonder if going with disposable nappies was the best option for the environment. Well I can assure you that you are not the only one facing this question and that, once again, our good friend Mr. Life Cycle Assessment is here to save the day.
Every year 800 million disposable nappies are dumped in Australian landfills, making up approximately 5% of landfill content (1). With that being said, cotton (the most common material for reusable nappies) requires 12 mega litres of water per hectare to cultivate (2), and a significant amount of energy and more water nearly every day to wash and clean reusable nappies. So which option is the best? To get the answer to this challenging question were going to have to put on our life-cycle thinking caps once again.
The Technical Stuff...
After further research and review of some already existing life cycle studies on nappies (3, 4), the nappy options and life cycle stages can be understood in the following way.
Option 1: Disposable Nappy
Life Cycle Summary: Softwood Growth and Production; Softwood Pulping Mill; Nappy Manufacturing using Pulp and Additional Plastics; Nappy Use; and Nappy Disposal (Transport throughout).
Option 2: Reusable Nappy
Life Cycle Summary: Cotton Growth, Production and Processing; Nappy Manufacturing; Nappy Use; Nappy Soaking, Washing, Drying and Wastewater Treatment/Disposal; and Nappy Disposal (Transport throughout).
Three main options are being considered in the study: Disposable Nappies, Reusable Nappies with an efficient washing machine, and Reusable Nappies with a less-efficient washing machine. Note that other nappy options exist (e.g. compostable and alternative material nappies) but due to limitations in the scope of the study these three most common options were selected. The reusable nappies are assumed to be dried on a clothesline. The functional unit being applied is 2.5 years of nappy use, which is the average time period of nappy use for one child. The average weight of a single disposable nappy is 50g and 125g for a cotton reusable. An estimated 5,020 disposable and 36 reusable nappies will be used over this time period. The study is limited to these three choices in order to focus on the most common material options; pulp and plastics for disposable and cotton for reusable.
The same method as used in The Hand Drying Dilemma Article, is used to deliver the results of the study in a way that can be understood in eco-points, which provides a single environmental performance score for each option being assessed based on the environmental impact it contributes to over its entire life. For reference, 100 eco-points is equivalent to the annual environmental impact of one Australian citizen in terms of emissions, waste and resource consumption.
Hurry up! Time for a Change!?!
So without further ado, here are the results of the nappy study. Coming in third place with the highest score of 1.52 eco-points over the 2.5 year life span is the disposable nappy. In second place, with a solid 0.74 eco-points is the reusable nappy with a less efficient washing machine, thus leaving the reusable nappy with the efficient washing machine as our most environmentally preferable option at 0.55 eco-points.
The main areas responsible for impact in the life of the disposable nappies were the high material inputs, which used a significant amount of energy, water, produced a lot of waste emissions, and made a large impact on global warming. The main issue for the reusable nappy is water consumption. As previously mentioned, cotton is a water intensive crop and, in addition to the water used for washing, this led to the impact on water scarcity impact coming out much greater than the disposable nappies.
As you can see from these results certain variables can easily alter the scores (e.g. the efficiency of your washing machine, the way electricity is generated in your State/Territory, and to what extent you can consistently drip dry your reusable nappies). In order to keep the study open to the overall Australian context, the Australian average electricity mix was applied to these results. If you wish to acquire the results for your specific region of Australia as well as more detailed figures to the overall results then please continue onto the following link.
Keep on Reusing!
So with respect to the overall results- assuming an average Australian family in a sunny State with a cloth line in the back yard- for these two options, those of you that are rocking out your cotton-bottom babies- Good Choice!!, and for the rest, maybe the next time you run out of those disposable doo-dads consider giving the landfill-saving, future-environmental-warrior-friendly reusable nappies on a go.
Please note that the purpose of this study is not to give you the end-all answer to your environmental decision making but instead to get you thinking how we can do better by considering the impact our products contribute to over their entire life. Or as Oâ€™Brien et al. (3) found: The major difference between the nappy systems, according to, is that the user has much more control over the environmental impact of home-washed reusables. There are still plenty other great nappy options that are available, such as compostable nappies and hemp or bamboo fabric. The key is to continue asking these questions to your providers and reminding yourself that every dollar is a vote.
Written by Ben Kneppers, LCA Practitioner, Edge Environment
Source from: The Green Pages.
1: Roxburgh, C 2008, Nappies and the Earth, The Green Nappy Company, viewed 1 March 2010, http://www.greennappy.com.au/
2: Tennakoon, S.B. and Milroy, S.P., Crop Water Use and Water Use Efficiency on Irrigated Cotton Farms in Australia, Agricultural Water Management, vol. 61, pp. 179-194, 2003
3: Oâ€™Brien, K et al. Life
Cycle Assessment: Reusable and Disposable Nappies in Australia,
Environmental Engineering, School of Engineering, The University of
Queensland, Brisbane, viewed 1 March 2010, http://www.crdc.com.au/
Amonier, S et al. 2008, An Updated lifecycle assessment study for
disposable and reusable nappies, Environment Agency, Bristol, UK,
viewed 1 March 2010, http://randd.defra.gov.uk/