Brimstone cement certified as ASTM C150

Brimstone, the US-based industrial decarbonisation start-up, has received third-party certification that its cement meets or exceeds ASTM C150 standards for ordinary Portland cement (OPC), becoming the first ultra-low carbon, carbon-neutral or carbon-negative cement to meet this critical and universally-accepted industry requirement.

"At Brimstone, we believe decarbonising cement relies on three essential principles: producing the exact same trusted material, at much lower carbon, and at equal or lower cost to other options,” said Cody Finke, co-founder and CEO of Brimstone. “Not only will our process slash carbon emissions and compete on price, we've now proven that it delivers the exact same material relied on by engineers and builders worldwide, and without forcing millions of construction workers to get retrained to use a new material."

The achievement validates that Brimstone's carbon-negative process produces cement that is identical in all respects (performance, safety, and composition) to OPC produced through the conventional, carbon-intensive process. Brimstone's technology uses carbon-free calcium silicate rock, eliminating CO₂ from the source rock. The process also generates magnesium compounds that permanently absorb CO₂ from the air, making the process carbon-negative.

As OPC comprises 95 per cent of all cement produced in the US, this breakthrough is essential to the construction industry, claims Brimstone. At industrial scale, Brimstone expects to sell its OPC and SCM at the same price as conventionally made or sourced materials.

In April 2022, Brimstone secured US$55m in a Series A funding round led by Bill Gates-backed Breakthrough Energy Ventures and DCVC. The company is using these funds to build a pilot plant to test its technology with a view to full scale commercialisation.