What is Prometheus Materials ProZERO?

Prometheus Materials' ProZERO is a building material produced by using microalgae to biomineralize a limestone-like binder, growing the cementing mineral biologically instead of manufacturing it by heating limestone in a kiln. Because it skips the high-temperature kiln process responsible for much of conventional cement's carbon dioxide emissions, ProZERO is formulated as a lower-carbon substitute for portland cement in masonry and construction products.