Everything you need to know about Alabama’s new nitrogen gas executions

Alabama will be performing a new method of execution using nitrogen gas on Thursday after an inmate survived the traditional lethal injection in November 2022. If successful, the method will be the latest execution technique to be used since 1982.  

Kenneth Eugene Smith was convicted of stabbing Elizabeth Sennett to death in 1988. Smith, along with two accomplices, was hired and paid $1,000 by her husband to kill his wife so he could collect insurance. 

The controversial method has raised legal and ethical questions as states grapple with upholding death penalty laws and what are the most humane methods for executing people. Here’s what to know about the latest plan.

What is nitrogen hypoxia?

While nitrogen is colorless, odorless, and tasteless, it is one of the most common gasses in our atmosphere, making up 78% of the air humans breathe. However, when administered to humans without the proper ratio of oxygen, it can prove fatal by suffocating the person.  

How is it supposed to work?

According to the state’s execution protocol, the inmate will be escorted to the execution chamber on the day of their execution and placed on a gurney with a pulse oximeter. Team members will properly secure a mask on the inmate’s head. Gas will be administered through a tube feeding into the mask for 15 minutes, depending on the flatline of the inmate’s electrocardiogram.  

What are the legal implications? 

Smith has attempted to block the execution, arguing to the U.S. Court of Appeals for the 11th Circuit on Friday that the execution method is cruel and unusual punishment and that the state is in violation of his due process rights by going forward with his execution despite pending appeals. 

Last week, Reuters reported that the United Nations asked Alabama to stop Smith’s execution by nitrogen hypoxia, saying the United States would be violating international law. 

“We have serious concerns that Smith’s execution in these circumstances could breach the prohibition on torture or other cruel, inhuman or degrading treatment or punishment, as well as his right to effective remedies,” Ravina Shamdasani, spokeswoman for the U.N. Human Rights Office, said at a press briefing.

However, the pending approval of the new execution method will be decided by the Supreme Court.

Why are states using it?

The drugs typically used for lethal injections have become increasingly difficult to obtain due to European pharmaceutical companies being against lethal injection executions. 

Oklahoma, Mississippi, and Alabama are the only states to have adopted nitrogen hypoxia execution procedures, but they have yet to perform them. 

Former Death Penalty Information Center Executive Director Robert Dunham told Scientific American that lethal injections weren’t always reliable and often resulted in more inhumane circumstances. 

“The lethal injection process, in many respects, created a myth that what you had was a simple medical procedure in which the prisoner was put to sleep,” Dunham said. “That created a false distance between the reality of capital punishment and the public perception of capital punishment.”

“It’s readily available. It’s 78% of the air we breathe, and it will be a lot more humane to carry out a death sentence,” former Alabama state Sen. Trip Pittman said.

Who came up with the idea?

Michael Copeland, an assistant professor of criminal justice at East Central University in Ada, Oklahoma, wrote a report about the use of nitrogen gas as an alternative form of execution. Former Oklahoma Rep. Mike Christian proposed the idea in 2014 after recent attempts at lethal injection had faced challenges. 


Copeland’s report suggested that the use of nitrogen hypoxia was a “humane” alternative to lethal injection and would be easily accessible compared to obtaining drugs for lethal injection from foreign pharmaceutical companies, StateImpact Oklahoma reported

Is it painless?

Other forms of execution have been tried in the past, such as electrocution and the firing squad. Because nitrogen hypoxia has yet to be used as a form of execution, there is little information on how inhumane it is compared to other uses of deadly gasses. Though in some studies testing the effects of breathing pure nitrogen on humans for short periods, physical discomfort was not reported. However, breathing pure nitrogen would cause someone to be unconscious.