Carbon capture utilisation and storage (CCUS) is a carbon reduction technology which captures CO2 from industrial processes and transports it offshore for safe and permanent storage under the seabed.
Under the Continental Shelf Act, all storage of CO2 in Great Britain (GB) will only take place offshore.
Carbon capture
There are 3 different CO2 capture technologies in use.
Post-combustion capture of CO2 occurs after the burning of fossil fuels. CO2 is separated from flue gas when it is passed through a liquid which causes a chemical reaction. This is also called scrubbing.
Pre-combustion capture is where CO2 is separated before the burning of fossil fuels. Fossil fuels are converted into a gas containing CO2 and hydrogen. These gases are separated, with hydrogen then used as a fuel.
Oxyfuel combustion burns fossil fuels with nearly pure oxygen. The flue gas produced only contains water vapour and CO2. These are separated by a cooling process with the water condensing leaving a flue gas of almost pure CO2.
Transporting CO2
The Carbon Capture Utilisation and Storage and Offshore Hydrogen Production (Miscellaneous Amendments) Regulations 2026 (CCUS 2026):
- extends to the transport of CO2 by pipeline
- brings CO2 pipelines under the offshore safety regulations
CO2 is mainly transported by pipeline from the capture site to an offshore installation, where is it stored in a suitable underground reservoir beneath the seabed.
Storing CO2
The final stage of the CCUS process involves injecting CO2 at high pressure from an offshore installation into deep offshore geological formations such as depleted oil or gas reservoirs, or a saline aquifer.
Storage sites will be chosen on the basis of their ability to securely contain CO2 without leakage.
CCUS 2026 clarify responsibilities for accident and incident reporting at wells. This ensures CCUS wells are treated consistently with other major hazard assets regulated offshore.
Offshore hydrogen production
CCUS 2026 and The Health and Safety at Work Act 1974 (Application outside of Great Britain) (Variation) Order 2026 brings offshore hydrogen production under the GB offshore safety framework.
Offshore hydrogen production includes technologies that generate hydrogen at offshore installations with very low or zero CO2 emissions.
Find out more about regulating offshore hydrogen production.
General hazards of carbon dioxide
In GB, CO2 is classed as a 'substance hazardous to health' under the Control of Substances Hazardous to Health Regulations 2002 (COSHH).
Find out more about the hazards of CO2 in our COSHH guidance.