The construction industry is notorious for the pollution the production of building materials makes. India’s brick industry alone utilizes over 100,000 kilns and produces 2 billion bricks, creating in the meantime a condition known as ‘brown smog’ spreads for thousands of kilometers. Aside from this, the production of bricks in India makes use of topsoil stripped from arable land. The Eco BLAC brick developed by MIT students hopes to change this with their innovation of a brick that requires no firing and instead makes use of waste boiler ash that would otherwise end up in the landfill.

The Eco BLAC brick is made from 7-% boiler ash, a byproduct of combustion during energy production at small and medium sized factories, mixed together with sodium hydroxide, lime and a bit of clay. Room temperature is the curing point and an ‘alkali-activataion’ technology’ lends the brick its strength.

The development of Eco BLAC brick is part of a larger initiative to develop low-emission and low cost housing in India’s city slums.