The US should not permit any new carbon dioxide pipelines until updated federal safety regulations are finished, a dozen Democratic members of Congress said in a letter sent to President Joe Biden on Tuesday.

Carbon capture and storage (CCS) is a key element of Biden's climate agenda, but landowners along the routes of major CCS pipeline projects proposed in the Midwest are refusing to sign over land to build the pipelines in part due to safety concerns.

The Pipeline and Hazardous Materials Safety Administration (PHMSA) is working on new safety regulations for carbon pipelines that it has said will be proposed in 2024.

Biden should issue an executive order halting any federal permitting for new carbon pipelines until then, the members said, led by Ilhan Omar of Minnesota and Jesús "Chuy" García of Illinois.

"A moratorium is necessary to protect communities from the construction of pipelines that we know will soon be operated under outdated safety standards," the letter said.

PHMSA moved to strengthen its carbon dioxide pipeline oversight after a 2020 carbon pipeline rupture in Mississippi hospitalized 45 people. Carbon dioxide is odourless and can cause dizziness, confusion, unconsciousness, and even suffocation depending on exposure levels.

"New pipeline infrastructure will invariably put more communities in danger given the complexity of transporting CO2 thousands of miles with what could create dozens of points of entry and exit for CO2," the letter said.

Summit Carbon Solutions, Wolf Carbon Solutions and Navigator CO2 Ventures together hope to run 3,580 miles (5,760 km) of carbon dioxide pipeline across the Midwest, capturing carbon emissions from ethanol and other industrial plants and transporting it to underground storage sites.

The letter was endorsed by environmental organizations that are opposed to the pipeline projects, including Food & Water Watch and the Sierra Club and other progressive groups.