Disposable nappies are one of the biggest contributors to plastic waste – but how green are the alternatives?

Every minute more than 300,000 disposable nappies (or diapers) around the world are incinerated, sent to landfill or pollute the environment. They are one of the biggest contributors to plastic waste globally. When they were first conceived in the 1940s, no one could have predicted the curse they have become on the planet.

The plastics, pulps and viscose and cottons that go into each single-use nappy come with their own carbon footprint and environmental impact – for example, the industry gets through 248 million barrels of crude oil annually, according to the Ellen MacArthur Foundation. And because of the combination of materials, they are very hard to recycle – particularly once used.

With each baby getting through 4,000-6,000 nappies in their pre-potty-trained life, even the newest of newborns very quickly racks up a sizable carbon footprint.

But that doesn’t mean that the arguments for the alternatives are necessarily clear-cut, with many ‘eco’ offerings also coming with an environmental cost.

Disposable nappies are ubiquitous, with around 95% of families in developed countries opting to use them, reports the Ellen MacArthur Foundation. Convenience is a huge part of the argument in their favour.

The market is worth over $60 billion annually. And even as birth rates in some countries decline, a growing ageing population means that the adult nappy market is increasing, predicted to reach $19 billion by 2031.

Similar challenges exist around sanitary waste products, which are made from many of the same materials as nappies.

The effects of single-use nappies are often worse in the developing world, where a lack of waste infrastructure and policymaking can make their disposal even more problematic. More than a fifth of waste found in Indonesia’s waterways is nappies, a 2018 World Bank report on marine debris in the country found. Plastic fibres, likely from nappies, have been found in the stomachs of fish in Javan riverways. Meanwhile, fishermen in West Africa complain of hundreds of nappies along the coastline.

Research also suggests that some nappies may contain toxic chemicals which could harm children and the environment.

Some of the best ways to improve the environmental footprint of this option have come from lighter products, which use fewer materials. And using cellulose-based products for the absorbent part of the product rather than plastic-based can also have a positive impact.

In one innovative way to deal with the mounting problem of disposable nappy waste, researchers at the University of Kitakyushu in Japan have been experimenting with creating concrete with them. They have found that replacing 40% of the sand with shredded nappies has no impact on the strength of the concrete.

Reusable nappies have come a long way since the days of towelling or cloth alternatives with pins. Many options now come with shaped material outers and washable inners.

The biggest hindrance for many people is the initial upfront cost. Although this is undoubtedly higher than single-use alternatives, over the long run they may work out to be more cost-effective, particularly if used for multiple children. Additionally, once the true costs of disposable nappies are taken into consideration, disposable nappies are artificially cheap, the Ellen MacArthur Foundation argues.

Another downside to reusable nappies is the washing and drying of them, which comes with its own environmental impact. In some areas, centralized washing services are available which will collect dirty nappies from households and drop off clean ones.

Washing below 60 degrees, with a full load, in an energy- and water-efficient washing machine can reduce the environmental impact of this option, a report for the United Nations Environment Programme (UNEP) highlights. Line drying is also encouraged.

Another alternative is bio-based or compostable nappies, which avoid the use of plastic. These are also single-use, but have a better environmental profile than a standard single-use nappy. This includes helping to avoid freshwater and marine pollution, for example.

But these bio-based alternatives do come in tandem with higher agricultural land use and water depletion, the UNEP report notes. They also often contain plastic elements, such as the tabs to close them.

One innovator in this space is gDiapers, which won a challenge from the Global Plastic Innovation Network, convened by World Economic Forum’s UpLink and the Global Plastic Action Partnership.

The company uses only materials which are compostable, along with a ‘collects and exchanges’ function. This ensures no nappies go to waste. Once collected they are converted to a nutrient-rich compost.

Meanwhile Ubuni, another Uplink organization, is also innovating by creating bio-textile nappies from agricultural waste. After use, the nappies are also composted, helping create a circular economy.

The UNEP highlights the importance of taking a ‘lifecycle perspective’ when looking at the relative pros and cons of nappy options. The highest impacts of reusable nappies come in the use phase, whereas for single-use nappies it is in the production and disposal.

Consumer behaviour plays an important part in the relative impact of the options, the report also notes.