Cigarette butts are made from a cellulose acetate material which is causing a major littering and waste disposal problem worldwide.

Over 6 trillion cigarettes are produced each year globally, resulting in 1.2 million tonnes of toxic waste dumped into the environment.

They can take years to degrade becoming microplastics but also with remnants of nicotine, heavy metals, and many other chemicals they’ve absorbed into the surrounding environment.

E-cigarettes also pose a plastic problem and as yet no manufacturer has come up with a commercially successful paper filter replacement for cigarettes that consumers like.

Researchers at RMIT University, Australia, have been working on developing bricks that use recycled cigarette butts in their composition.

Lead researcher Associate Professor Abbas Mohajerani said cigarette butts are saturated with toxic chemicals, including over 60 known to cause cancer.

Professor Mohajerani explained:

“Firing butts into bricks is a reliable and practical way to deal with this terrible environmental problem, while at the same time cutting brickmaking production costs.

“We need to do far more to stop cigarette butts from polluting our streets, rivers and oceans, and prevent them leaching harmful toxins into our environment.

“Our ultimate goal is a world free of cigarette butt pollution: our industry implementation plan outlines the practical steps needed to bring this vision to reality.”

By analysing the butts’ energy value, the team in the School of Engineering at RMIT showed the incorporation of 1% cigarette butt content would reduce the energy required to fire bricks by 10%.

“It takes up to 30 hours to heat and fire bricks, so this is a significant financial saving,” Professor Mohajerani said.

During firing the metals and pollutants in the butts are trapped and immobilised in the bricks.

Bricks made with cigarette butts are also lighter and provide better insulation – meaning reduced household heating and cooling costs.

Professor Mohajerani, who has spent over 15 years researching sustainable methods for cigarette butt recycling, has also developed technology for incorporating butts into asphalt concrete.

He said the technical solutions would need to be backed up by more stringent laws and harsher littering penalties.

There would also need to be better collection of cigarette butts to prevent littering and enable them to be reused in this way.

Professor Mohajerani said:

“My dream is a dedicated brickmaking recycling facility in every country, that can recycle butts and solve this pollution problem for good.”

Reference: ‘Implementation of Recycling Cigarette Butts in Lightweight Bricks and a Proposal for Ending the Littering of Cigarette Butts in our Cities’, with lead author and PhD researcher Md Tareq Rahman, is published in Materials, in a special issue focused on Novel Sustainable Technologies for Recycling Waste Materials (DOI: 10.3390/ma13184023).