Diapers: to change or not to change

Whether they are used on the very young or the very old, disposable diapers must be regarded as one of the most convenient products of modern society. Question is: what type of impact do these products have on the environment?

Conventional reusable diapers are most often made from cotton, which has large impacts in terms of the water use, pesticides, and carbon dioxide emissions. See: ( https://blogs.nicholas.duke.edu/citizenscientist/the-fabric-for-our-lives/ ). Of course, the diaper is only made once, but washed many times in hot water and dried in a forced-air clothes dryer. Washing these diapers adds a significant increment to sewage treatment.

Disposable diapers often incorporate polypropylene or polyethylene, both petroleum-based plastics, which release fossil CO2 when they are burned and offer no net sequestration of carbon if they are land-filled. Some newer diapers are fabricated with “glueless” methods, which reduces the use of artificial chemicals. Some disposable diapers are produced with biopolymers of plant origin, which may offer long-term net carbon sequestration from the atmosphere if they are land-filled. A raw material, itaconic acid derived from the fermentation of plant materials, is polymerized to produce fabric.

The magnitude of the material consumption in diapers is impressive. Assuming that the typical infant uses more than 4 diapers each day, each weighing 33 grams (when dry), then this infant is responsible for about 125 kilograms (about 275 lbs) of disposable diapers in its first 2.5 years. In the European Union, each conventional disposable diaper is estimated to release 89 grams of CO2 from the production of raw materials; glueless models can reduce that impact by about 10 percent. Manufacturing, packaging, and shipment are relative small sources of energy use, but significant emissions are also associated with the disposal of diapers after use.

Multiplied by the number of infant children involved, the CO2 emissions add up quickly—estimated at 2.7 million tons of CO2 annually for the European Union and presumably roughly similar for the U.S. For comparison, total CO2 emissions in the U.S. are about 6700 million tons/yr. Thus reducing the use of disposal diapers would have a rather small effect on our national inventory of greenhouse gas emissions. Alternatively, polymers derived from plants could reduce these emissions to near zero, and provide some net carbon sequestration from the atmosphere.

As with all solutions to environmental impact, change begins at home.

References
Mendoza, J.M.F., S.A. Popa, F. D’Aponte, D. Gualtieri and A. Azapagic. 2019. Improving resource efficiency and environmental impacts through novel design and manufacturing of disposable baby diapers. Journal of Cleaner Production 201: 916-928.

Mendoza, J.M.F., F. D’Aponte, D. Gualtieri and A. Azapagic. 2019. Disposable baby diapers: life cycle costs, eco-efficiency and circular economy. Journal of Cleaner Production 211: 455-467.

Mirabella, N., V. Castellani, and S. Sala. 2013. Life cycle assessment of bio-based products: a disposable diaper case study. International Journal of Life Cycle Assessment 18: 1036-1047