Background
The increasing use of embodied carbon data & Life Cycle Assessment (LCA) for business & purchasing decisions has highlighted the vital importance of having accurate and representative data for composite materials so that these products can be considered equally and fairly against other materials such as steel, aluminium and concrete. In this respect, composite materials have historically been disadvantaged since these other major materials have benefited from a longer period of embodied carbon data-gathering and data-sharing (within their industry), in some cases for 20-30 years or more.
This issue has been brought into sharper focus by recent dialogue with Circular Ecology who manage the Inventory of Carbon and Energy (ICE) database, which is used quite widely by companies in the construction & infrastructure sectors as a reference point for material carbon data. This ICE database has, until the release of v4.0 of the database in late 2024, included old data for glass-reinforced polymer (GRP) composite parts (a value of 8.1 kg CO2/kg GRP part dating from the late 1990s), which has then be used by some parties to portray GRP composite parts in a negative light compared with other materials. Circular Ecology has acknowledged the inaccuracy in this old data by removing it from its most recent database releases.
This “old” embodied carbon data point does not represent current manufacturing processes or raw material data and is significantly higher than the data for embodied carbon now being generated by multiple suppliers for GRP parts today which are typically in the range 2.5-4.0 kg CO2/kg GRP part.
The need for assembling and publicising/publishing accurate data for composite parts (both made from GRP and also from carbon fibre reinforced polymer (CFRP)) has never been greater and the future growth & success of the composites industry (in the construction & infrastructure and other sectors, both in the UK & globally) will definitely require the wide availability and use of accurate and relevant embodied carbon data. This need will be further heightened by anticipated future market disruptors, such as CBAM (Carbon Border Adjustment Mechanism) implementation in the EU & UK in the coming years, which will require accurate embodied carbon data to minimise additional border tariffs.
Recommended data sources for interested parties to use
Composites UK does not hold any embodied carbon data itself and therefore can only act as a signpost to data sources for interested parties (both composites part suppliers and potential users) to use.
Our primary recommendation remains the EuCIA “Ecocalculator” which uses industry average data provided by trade associations and sector groups and we believe this free-of-charge tool gives a good basis for calculating embodied carbon data for specific products, processes and locations.
As a second source of data, an increasing number of UK composites industry players have calculated and published (usually in the form of Environmental Product Declarations (EPDs)) embodied carbon data for their specific products which can then be used by others as a general indication of typical embodied carbon numbers for GRP or CFRP products manufactured by specific processes in the UK.
In addition, industry players can pay to access data bases such as GaBi, which have an increasing range of relevant composites material carbon data.
Finally, some raw material suppliers have begun to display Global Warming Potential (GWP) numbers on their datasheets, and this practice is likely to become more widespread in the future. We therefore recommend that all manufacturers of composites parts push their material suppliers to provide embodied carbon data for their products wherever possible, to increase transparency with this important topic going forward.
In conclusion and as a general guide, we would expect to see values for embodied carbon (or GWP) to be in the range of 2.5-4.0 kg CO2/kg GRP part, based on typical manufacturing processes and formulations for GRP composite parts manufactured in the UK.
Potential next steps
Looking to the future, it could clearly be advantageous for the composites industry to develop a databank of embodied carbon data for different product types and processes, along the lines of the World Steel databank which the global steel industry has assembled over the past 20 years or more. Composites UK, as a neutral non-competitive presence in the UK composites industry, could play a role in helping to set up and/or manage such a databank but for such a databank to have value, it needs a wide range of UK composites industry players to be willing to contribute (and keep updated) data which can then be used as anonymised, indicative embodied carbon numbers for different product and process options, and also to be willing to pay for the administration costs involved in managing such a database. Composites UK will look to test the level of willingness of UK composites industry players to provide data and to cover the costs of managing such a database in the coming months. In addition, there are a range of initiatives linked with further developing the use of LCAs, and networks of LCA users, in some cases funded by UK-government-funding bodies (such as the LCA-RSIN project network seeking to bring a harmonised cross-sector and cross-material approach to LCA development in the UK). The UK composites industry needs to ensure that it makes best use of such initiatives, to strengthen the availability of accurate embodied carbon data, developed in a harmonised manner with other materials, and so to enable valid side-by-side comparison of the embodied carbon in different materials to be done with confidence and accuracy.
Correct as of 31st March 2026