O.C.O Technology, producer of carbon negative Manufactured Limestone (M-LS), has attained a performance rating of ‘excellent’ with a four-star score after passing its BES 6001 assessment with flying colours.

The sought-after BES 6001: Issue 3.1 Framework Standard for Responsible Sourcing, demonstrates the product’s sustainability credentials at a time when, given the Government’s increasing focus on sustainable development, is increasingly important.

Experts from accredited certification body Construction Products Certification (CPC) who undertook the detailed audit process, awarded O.C.O bonus points for their responsible use of resources, waste prevention and management, water abstraction, transport impact and business ethics.

Colin Head, CPC Chief Executive, said: “O.C.O Technology has an innovative product which can make a considerable contribution to sustainable construction. The award of BES 6001 certification with a performance rating of ‘excellent is a significant achievement for the company.”

His comments were echoed by Kelvin Nutman, CPC Senior Assessor, who added: “O.C.O Technology had prepared remarkably well for their BES 6001 assessment, which resulted in a positive recommendation for certification and I look forward to working with them again in the future.

The artificial limestone is created by treating Air Pollution Control residues (APCr) from the Energy from Waste (EfW) sector with waste carbon dioxide gas. Because more CO2 is permanently captured than is used in the manufacturing process M-LS has been recognised as the world’s first carbon negative aggregate.

Paul Barber, O.C.O’s General Manager – Operations, said: “This was a rigorous and very thorough process and we are delighted that the CPC team could see the huge potential that O.C.O technology and M-LS has in making future building projects much more sustainable.

“An increasing number of developers and construction companies are responding to the demand for more environmentally-friendly products and processes and we believe that achieving BES 6001 accreditation with an “excellent” level of attainment will be another important stepping stone in underlining the benefits that a carbon negative aggregate delivers.”

Until recently, M-LS has predominantly been used as a block mix, so far going into more than 21 million blocks produced in the UK – the equivalent to 8,000 three-bedroom houses – but increasing awareness within the construction sector means it is now in demand for other uses, including as a component of low carbon asphalt mixes.

In addition to improving the sustainability of building projects, its use also helps to protect valuable virgin aggregates.

O.C.O’s carbon negative M-LS aggregate