Food waste unveiled as key ingredient in sustainable diapers

By Isobel Williams via SWNS

Food waste could be the key to environmentally friendly diapers - and even sanitary pads, suggests a new study.

Scientists have accidentally discovered an eco-friendly material which can sop up liquid like a sponge in a class demonstration gone wrong.

Components made from protein biomass that are often discarded by the food and agricultural industries has been found to be ideal for replacing plastics in sanitary products.

These components are sustainable and biodegradable and could potentially allow future diapers and sanitary pads to be flushed down a toilet or used as fertilizer.

In a demonstration designed to teach students what can go wrong in the lab, Dr. Antonio Capezza from KTH Royal Institute of Technology in Sweden added wet cotton to his experiment to mimic unwanted humidity.

Once the product dried, he realized, the material had become super porous, meaning it could sop up liquid like a sponge.

Some cotton-based alternatives to plastic sanitary products are already on the market, but they rely on virgin cotton and may need bleaching or other chemical treatment for their production.

Looking for a more sustainable material source, the team identified proteins and other natural molecules left over from food and agricultural production that might otherwise be landfilled or incinerated.

The researchers mixed the proteins together in different proportions and added water and bicarbonates, such as baking soda, as foaming agents; the sweetener glycerol as a plasticizer; and natural extracts as preservatives.

They then managed to create protein-based absorbent prototypes that resembled disposable sanitary products.

Once exposed to water or soil, the materials completely biodegraded in a few weeks.

The team hope that, with further development, this research could lead to single-use sanitary products that can be flushed or used as fertilizer for crops, such as corn and wheat, which would in turn provide the starting materials to make new sanitary products.

For this reason, Dr. Capezza describes his invention as a “fully circular design.”

He added: “So it was sort of an accident, but a good one, because that led us to an entirely new line of research.

“And our tests have shown that because it's protein based, there's no risk whatsoever that these products will pollute the soil with microplastics or other unwanted chemicals when they break down.”

They estimate that these protein-based sanitary products would be about 10 to 20 percent more expensive than traditional plastic diapers and pads.

The team is now preparing for pilot studies to test the feasibility of scaling up production.

Dr. Capezza argues that his product is a more marketable alternative to washable diapers, as although they avoid the plastics issue altogether, few caregivers want to use them.

He said: “The acceptance rate will be much higher than if you come to a customer and say, ‘Okay, now you have to wash your diapers.’”

The full results are due to be presented at the spring meeting of the American Chemical Society in New Orleans.