RMIT researchers have found a way to turn recycled cigarette butts into bricks with a step-by-step implementation plan for saving energy and solving a global littering problem.

Over six trillion cigarettes are produced each year globally, resulting in 1.2 million tonnes of toxic waste dumped into the environment. Researchers have previously shown fired-clay bricks with 1% recycled cigarette butts are just as strong as normal bricks with less energy used to produce.

The analysis showed that if just 2.5% of global annual brick production incorporated 1% cigarette butts, it would offset total cigarette production each year.

The team has now developed a detailed plan for bringing the brick making and waste management industries together, implementing cigarette butt recycling into bricks at a mass scale.

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

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

“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.”

The plan, published in a special issue of the journal materials, shows how cigarette butts can be collected and recycled on an industrial scale.

Different incorporation methods are outlined – using whole butts, pre-shredded butts, or a pre-mix where the butts have already been incorporated into other brick making materials.

Requirements for maintaining health and safety are also methodically detailed, with analysis showing how risks can be mitigated for both industrial brick making and handmade bricks.

The new study also details for the first time the types of harmful bacteria found on cigarette butts, analyses how heavy metals can leach from them into the environment and examines the energy value of butts in the brick making process.

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).