Three popular bills that would ban synthetic designed drugs have hit a roadblock on Capitol Hill.

Sen. Rand Paul from Kentucky has put an indefinite hold on the drug legislation.

A bipartisan group of lawmakers supporting a ban on drugs marketed as “bath salts” and “spice” are vowing to fight the block.

“It’s frustrating, but we have to keep working to convince one senator to remove that hold and move it forward,” Pennsylvania Sen. Bob Casey said. “I’m confident there can be a resolution here.”

Back in October, a local boy died after using designer drugs. Investigators said Brandon Rice smoked synthetic marijuana, also known as bath salts and spice.

The drug was banned in Pennsylvania last year.

Critics said the federal bills go too far in restricting chemicals that could potentially be used in scientific research.

A temporary ban on bath salt chemicals by the Drug Enforcement Administration expires in eight months, so the pressure is on Congress to pass a permanent federal ban.