Plant-based hydrogel may slash the lifespan of diapers and tampons from centuries to months

Disposable sanitary products can take 500 years to decompose, but a research team at the University of Waterloo is on a mission to cut that down to just a few months.

Tiz Mekonnen, an associate professor in the department of chemical engineering at the University of Waterloo, is one of the researchers creating a plant-based super-absorbent hydrogel which degrades in three months.

The hydrogel is designed to replace petroleum-based plastics in common hygiene products like diapers and tampons. 

Mekonnen explains why replacing petroleum-based plastics is necessary.

“[Plastic] stays in the environment and the process, it leaches to the environment very slowly generating microplastics. So the microplastics will leach into the water we drink, the air we breathe in, as well, with huge impact on our health and the environment," he told CBC News.

WATCH | Waterloo researchers develop plastic alternative:

Waterloo researchers develop plastic alternative for diapers, tampons

January 20|

Duration 1:02

Disposable hygiene products like diapers and tampons are a daily necessity, but the plastics they contain can take decades to break down. Researchers at the University of Waterloo have developed a plant-based superabsorbent hydrogel to replace petroleum-based plastics in these products. Dr. Tizazu Mekonnen, a chemical engineering professor at the university, led the team behind the hydrogel. CBC K-W’s Diego Pizarro spoke with Mekonnen about how it was created and the environmental benefits it could offer.

How it compares to current hygiene products

Common hygiene products are currently made from a synthetic material, specifically, a chemical component called sodium polyacrylate, which Mekonnen explains is bonded together and can’t degrade in the environment.

The material his team created is made from cellulose, a structural component of plants which degrades much quicker. More specifically, Mekonnen describes the material as a plant derivative called carboxymethylcellulose and hydroxyethyl cellulose. 

Within seven weeks, the material lost 72 per cent of its weight and after three months completely disappeared, he said.

LISTEN | Plant-based hydrogel could be the future for diapers and sanitary pads :

The Morning Edition - K-W7:06Plant-based hydrogel could be the future for diapers and sanitary pads

Researchers at the University of Waterloo have developed a plant-based superabsorbent hydrogel that will reduce the environmental impact of hygiene products like diapers, pads and tampons. Associate professor in the department of chemical engineering at the University of Waterloo, Tiz Mekonnen, explains what the hydrogel is made of and why it's better for the environment.

Although the study isn’t at the human testing stage yet, Mekonnen says their final material is comparable or even better than the synthetic material.

The researchers have tested the product with imitation urine, proving that it absorbs moisture without oozing out. Not only is the material better, according to the researchers, but it isn't any bulkier than a regular diaper.

“Let's say that it's a baby diaper, if the baby sits on it, we want to make sure that it doesn't ooze out the absorbed water. We demonstrate that it doesn't,” said Mekonnen. 

The final product resembles a powder, turning into a jelly-like material once it comes into contact with moisture, such as urine, water or feminine fluids. 

Another consideration of the study is whether it's safe for diaper and tampon users. Mekonnen says they've collaborated with a professor in biomedical engineering and used fibroblast cells to test the safety.

"We grow them on the material and we demonstrate that cells can grow safely on it and it's quite safe," he said.

Next steps in the study

Before the product can be tested on humans, it needs to be tested on animals, says Mekonnen. The researchers are applying for federal and provincial funding to continue scale up the study, while also receiving funding from CTK Bio Inc Data based in Vancouver.

At this stage, it remains a lab study. The researchers have enough data to publish journal articles and they've filed a patent application.

Mekonnen says multiple factors such as cost, exact materials and industrial equipment are part of their continued study.

Until they receive further funding, the timeline for the product to hit Canadian markets remains unclear.

Once more funding is secured, they will consult Health Canada for approval and look  into collaborating with diaper and tampon manufacturers, “who showed a lot of interest already,” said Mekonnen.

Better for the earth, but still disposable

If approved, the environmental impacts of the plant-based products will be less problematic for the earth. 

Patrick Gilbride,  executive Director of Reep Green Solutions, says while the research and innovation is really encouraging, there are other solutions for people to consider before the new technology hits the market.

“So we certainly look at encouraging people to refuse and reduce the amount of ways that they have or possible reuse products or find reusable products,” said Gilbride.

“When we think about waste, we think about it in a hierarchy." 

He says reusing and recycling are at the bottom of the hierarchy, with disposable products “whether they’re plastic-based or not, is another sort of tier below that.”

Gilbride says solutions to using disposable hygiene products would include reusable diapers or menstrual cups.