A Missouri man on death row will not see his execution proceed as planned, now that state governor Jay Nixon has intervened. In a statement issued today, Nixon halted the execution of convicted killer Allen Nicklasson over concerns about the proposed use of propofol for lethal injection.

""As governor, my interest is in making sure justice is served and public health is protected," Nixon said. "That is why, in light of the issues that have been raised surrounding the use of propofol in executions, I have directed the Department of Corrections that the execution of Allen Nicklasson, as set for October 23, will not proceed."

"We do consider this a critical need."

Nicklasson's execution would have been the first in the country to use propofol, a popular anesthetic primarily sourced from Europe. But the European Union has previously stated that propofol exports to the US would be sharply restricted if the drug were used for lethal injections — a scenario that could severely impact myriad medical procedures. "We do consider this a critical need," FDA spokesperson Erica Jefferson told the Associated Press. "Without the drug, we're concerned that surgeries would be delayed and patients would be at risk."

Could result in excessive pain and suffering

Nixon didn't mention the threat of an EU export restriction in his statement. The state's 2012 decision to use propofol for executions also elicited a handful of lawsuits, including one filed on behalf of several dozen death row inmates that claimed the drug was an untested method of execution and could result in excessive pain and suffering.

It remains unclear how Missouri — or any of the 31 other states that still carry out executions — will continue to perform lethal injections. As The Verge reported today, pharmaceutical companies are increasingly refusing to supply government agencies with stockpiles of drugs to be used for executions. "All these companies and people have the same connection to a life-serving profession," Richard C. Dieter, executive director of the Death Penalty Information Center, says. "So they have no interest in participating in executions."