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Five thousand dirty nappies! That’s the staggering number of changes parents face before the average Aussie ankle-biter leaves nappies behind at two-and-a-half years old, and why the environmental costs of nappies are worth worrying about.
With 95 percent of Australian babies wearing disposables, visions of landfill nappy mountains have sent environmentally conscious parents to cloth. But landfill isn’t the only consideration, and with new eco-products on the market, we take a fresh look at which nappy is best – disposable or reusable.
Where do your nappies grow?
Disposables often consist of a plastic outer layer, fastenings and an absorbent core with a protective top layer. Plastic components come from non-renewable sources, while the core is cellulose fibre pulp - commonly from pine plantations in Australia. The core also includes a water-absorbent polymer, sodium polyacrylate, which is not biodegradable.
Most cloth for reusables comes from home-grown cotton, with nappies then manufactured in Asia. However researchers at the University of Queensland (UQ) in 2009 found shipping cotton overseas incurs a small energy cost compared to other stages in the life cycle.
Most reusables also require waterproof covers or pilchers, usually plastic PVC. Greener options include polyurethane laminated fabric (PUL), which lasts longer than plastic and can be used for multiple children. Eco-friendly nappy liners include bamboo flushable, reusable and compostable options.
While cotton crops require irrigation, pine plantations are associated with reduced run-off and thus both options incur a water resource cost at this stage. The UQ study finds water depletion associated with cotton irrigation for reusable nappies is 16-48 m3 (1 m3 = 1,000 L) during a child’s first two-and-a-half years, while reduced runoff in forestry plantations racks up 31-62 m3.
Disposable nappies use 3.1-6.3 GJ (gigajoules) of energy during their life-cycle, and pulp production accounts for 75 per cent of the total for non-renewable energy. Home laundered resuables are less energy hungry at 0.83-1.3 GJ, and use less non-renewable and total energy over their life cycle than any other system.
Wee, waste and water
Approximately 800 million disposable nappies end up in landfill in Australia each year, and most of their mass is not biodegradable. The UQ researchers found disposable nappies produced more than 20 times the solid waste of home- or commercially-washed cloth.
While a child produces around 91 kg of faeces during their nappy wearing years, urine accounts for more than half of the solid waste generated by disposables. Flushing faeces down the toilet (which is recommended) reduces solid waste by 86 kg, but increases water consumption by 3.9 m3 over the life cycle.
But disposables are becoming lighter; 2008 research by The Environment Agency in Britain found an average reduction of 13.5 per cent in weight in less than a decade.
Some partially biodegradable disposables are available, but none are fully biodegradable. Some brands can be
commercially (but not home) composted.
Dr Kate O’Brien, lead author of the UQ study, also notes, “The main impact of disposables occurs during production, so I wouldn’t assume that compostables result in a substantial reduction in environmental burden.”
The major eco-cost of reusables comes from laundering. While commercial washing reduces water usage, transportation between users and the laundry increases energy costs considerably. Eco-friendly home laundry practices can significantly reduce costs – using a front loader rather than a top loader for home-washing reduces water usage by more than half, from 68 to 23 metres cubed.
Some disposables can contain a cocktail of chemicals you may wish to avoid, including chlorine, dioxins, dyes and tributyl tin, all of which have been linked to health concerns, along with sodium polyacrylate, associated with skin irritations and allergic reactions.
A 2000 German study also linked disposables to undesirable temperature increases in testicles, though not in cloth nappies. However, this research is controversial and not yet substantiated.
The decision is tricky. The disposable racks up a shocking solid waste cost, but washing, drying and cotton production mean reusables aren’t blame free.
The greatest benefit of reusables, and why they pip disposables to the eco-post, is they put consumers in control. By choosing organic cotton and eco-friendly pilchers and liners, cold washing in a front-loader, line drying and using products on multiple children, your environmental footprint shrinks.
But if never-ending washing fills you with dread, line drying isn’t possible, or water resources are a concern, then all is not lost. Modern eco-friendly disposables are lighter, partially biodegradable under the right circumstances, and are free of the chemical nasties in more commercial brands. A number have the FSC sustainable forestry certification. Whatever your decision, it has to consider your precious bundle, you, your finances, and the environment; the most important outcome is raising a happy, healthy future environmentalist.