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Puzzle Of Nitrogen Execution Could Present Issues For State

A tank filled with liquid nitrogen is seen outside of an Oklahoma City business that sells nitrogen for various commercial uses.
Whitney Bryen
Oklahoma Watch
A tank filled with liquid nitrogen is seen outside of an Oklahoma City business that sells nitrogen for various commercial uses.

The condemned man enters the room where he will draw his last breath.

He will be restrained in some way, perhaps strapped to the T-shaped platform where other offenders have been executed by injection.

He may have taken a sedative or will be given one in the room. But he likely won’t be too groggy.

The prisoner may then have a mask or a plastic hood or bag strapped to his face. Colorless, odorless nitrogen gas will stream into the mask from a tank similar to those used to inflate helium balloons. The gas could come from any one of thousands of distributors or manufacturers nationwide.

If all goes according to plan, the man will be dead within minutes, oblivious to the fact that his blood-oxygen level is plummeting and he will soon pass out.

The above steps are an approximation, based on research, of how the state of Oklahoma could use nitrogen inhalation to carry out future executions, becoming the first state to do so.

Yet uncertainty surrounds how the state will obtain the gas, how it will force inmates to inhale it, what will happen should they hold their breath or resist, and how to ensure guards and visitors are safe from its toxic fumes, all of which could open up legal, practical and public-perception challenges.

State officials insist that executions using nitrogen hypoxia will be humane, although details have been scarce about how the first nitrogen execution would look. At a March press conference in which they announced the change of method, Oklahoma Department of Corrections Director Joe Allbaugh and Attorney General Mike Hunter contended it would be free of the problems that have plagued the state’s use of lethal injection.

Allbaugh declined an interview about his agency’s ongoing work on an execution protocol, which will spell out in detail the policies and procedures for carrying out a nitrogen execution. Allbaugh said in March he hoped to have a preliminary protocol in 90 to 120 days, but recently told StateImpact Oklahoma that the effort will take longer than expected.

“We are continuing to develop the protocol in collaboration with the Attorney General’s office,” Corrections Department spokesman Matt Elliott said in a statement to Oklahoma Watch. “We feel confident that we will develop a protocol that provides an effective and humane execution method for the state of Oklahoma.”

Only two other states, Mississippi and Alabama, have passed laws allowing nitrogen executions, but neither is developing a protocol yet. 

Meanwhile, attorneys for death row inmates are poised to scrutinize the protocol and challenge any uncertainty or hint of cruelty in its procedures or science. That could delay the state’s next execution by months as attorneys take the matter to court, reminding judges that Oklahoma botched one execution in 2014 and used the wrong drug in another one in 2015.

If there are complications in using nitrogen, they will likely arise at crucial steps in the protocol, which will be written to avoid violating the Eighth Amendment’s ban against cruel and unusual punishment or creating a spectacle that the public and elected leaders would not accept. The entire nation – much of the world, in fact – will be watching.

At the March news conference, Hunter said the state will forge ahead because Oklahomans favor capital punishment and families of murder victims deserve justice.

“This is the safest, the best and the most effective method available, and we’re moving forward,” he said.


Nitrogen comes in different grades. These tanks, kept at an Oklahoma City business, are filled with food-grade nitrogen used in restaurants often for cooling or freezing purposes.
Credit Whitney Bryen / Oklahoma Watch
Oklahoma Watch
Nitrogen comes in different grades. These tanks, kept at an Oklahoma City business, are filled with food-grade nitrogen used in restaurants often for cooling or freezing purposes.

Acquiring Nitrogen

Nitrogen is everywhere in more ways than one.

The chemical element makes up 78 percent of the earth’s atmosphere. Discovered in the late 18th century, nitrogen is non-reactive, meaning, unlike oxygen, it usually won’t lead to combustion.

Nitrogen has many uses and comes in dry, liquid and gaseous forms. It is in fertilizer, ammonia, nitric acid, nylon and dyes, and is used to preserve food, cool semiconductors, make ice cream and fill tires.

At compressed-gas supply stores, it’s common to find dozens of canisters of nitrogen on the grounds, waiting to be delivered to restaurants, spas and other businesses.

Obtaining nitrogen for executions would appear to be easy for the state, which, like others, has run into problems finding companies willing to provide the drugs for lethal injection.

But public and legal pressure could complicate acquiring nitrogen gas. While many states, including Oklahoma, have laws protecting the confidentiality of providers of prescription drugs and medical supplies used in executions, lawyers and death-penalty opponents have pressed to get and publicize suppliers’ names. More companies now refuse to sell drugs for use in executions.

Preparing the Inmate

The Corrections Department’s former protocolfor lethal injection, from 2014, outlines a process involving more than 10 teams made up of at least 50 people in all. Those include the command team, the restraint team, the special operations team, the intravenous team and the traffic control, witness escort and victim services teams.

Most of those could easily fit into a nitrogen protocol, as procedures before and after the execution would likely remain the same. Among those are receipt of an execution date order; invitations to witnesses; the offender’s 35-day notification packet; the last meal; the final statement, and the post-death monitoring of staff’s psychological responses.

But some procedures could change in subtle or even dramatic ways.


The execution table in the death-penalty chamber at the Oklahoma State Penitentiary in McAlester.
Credit Oklahoma Department of Corrections
Oklahoma Department of Corrections
The execution table in the death-penalty chamber at the Oklahoma State Penitentiary in McAlester.

One area is restraint.

In the previous protocol, restraint team members secured the person to the execution table with straps. To deliver the drugs, primary and backup catheters were to be inserted. In the bungled execution of Clayton Lockett in 2014, three drugs were injected: midazolam, a sedative; vecuronium bromide, a paralyzing drug, and potassium chloride, which stops the heart. Lockett writhed and moaned, and investigators later determined an IV had been improperly placed, causing drugs to enter surrounding tissue rather than the bloodstream.

In theory, use of nitrogen would not involve medical professionals or IV insertions.

That’s what Hunter said in March and what a report on nitrogen execution –prepared by Michael Copeland, a professor at East Central University in Ada, and his colleagues –found in 2014.

“The administration of a death sentence via nitrogen hypoxia does not require the use of a complex medical procedure or pharmaceutical products,” said the report, prepared for a legislative hearing. Only a hood and a tank of the inert gas would be needed, the study said.

But a key question is whether offenders would need a sedative to reduce the chances that they thrash about and disrupt the process. The 2014 protocol stipulated that offenders be offered a mild sedative no less than four hours before the execution, ensuring they arrive in the execution chamber fully conscious. After being strapped down, the person was allowed to make a final statement for witnesses to hear.

Could a mask or hood for nitrogen delivery be installed firmly over the face or head without sedation? Would the person’s head instead need to be secured first? Or would medical personnel have to insert an IV to inject a sedative, which could create similar risks as before?

The Execution

Conducting an execution is neither simple nor easy, particularly with a new method that has no track record, say capital punishment attorneys and others who track death penalty issues.

Death from nitrogen comes not from what’s in the gas, but what isn’t. Nitrogen is air without oxygen, yet a person dying from it doesn’t feel as if they are suffocating. They still breathe in and expel carbon dioxide but may begin to feel lightheaded, fatigued and have impaired judgment.

Several breaths can render a person unconscious, with death following in four to five minutes, according to Copeland’s report. That’s based on experiences of people who have used nitrogen for suicides.

Janis Landis, president of the nonprofit Final Exit Network, which promotes assisted suicide rights, said the physiology of nitrogen is “very well understood.”

“It’s so dangerous precisely because it is quick and painless,” she said. “The evidence is there.”

Death may not occur quickly when nitrogen gas is diluted, however. Copeland’s report noted that masks not tightly sealed over a person’s face could delay the onset of unconsciousness and death because of oxygen getting in. Corrections officials also might need to procure nitrogen with special scrutiny, as it is  sold in different grades.

Arizona attorney Dale Baich, a federal public defender who represents Richard Glossip, an Oklahoma death row inmate whose execution was postponed after the botched Lockett execution, said he had little comment yet on nitrogen executions because of the many unresolved details.

“We don’t know who is going to be doing this,” Baich said. “Are the folks competent to perform this procedure? There are too many unknowns to really comment other than to say it’s not as simple as the state would lead the public to believe.”

Don Knight, another attorney representing Glossip, cited scenarios that could complicate using nitrogen and could open up the method to constitutional challenge.

“What if the person struggles and fights?” he said. “What if you can’t get the mask on?

“Are you going to force the person’s head into the helmet? How is that going to look?”

Robert Dunham, executive director of the nonprofit Death Penalty Information Center, said even with the eventual guidelines in place, there will be imponderables.

“How do you ensure that the nitrogen won’t leak out or that oxygen won’t leak in?” he said. “Those are all the types of things that they will have to address. It’s not like a medical procedure with a patient who’s cooperating.”

Protection Concerns

Although nitrogen dissipates quickly in the air, proximity to it can kill. Additionally, nothing alerts people to its presence because the gas is odorless and tasteless.

Because of the risks, a specially trained corrections officer or health care worker would have to place a tight mask over the inmate’s face.

It’s unclear whether the person would do that before or after the inmate enters the death chamber and is strapped to the special table. The flow of nitrogen also would have to be controlled so that it can’t escape and endanger prison personnel and observers should the inmate refuse to breathe. The tank would have to be placed in or near the execution chamber or elsewhere in the prison and connected via a gas line.

Pure nitrogen is extremely potent and has been fatal in industrial settings.

In May 2017, for instance, a worker in a Houston auto body shop, preparing to paint a car, died after accidentally hooking his respirator to a nitrogen hose instead of the compressed air hose, Federal Occupational Safety and Health records show

Public Perception

Over decades, execution methods preferred by states have evolved, moving in many cases from hanging, electrocution, the gas chamber (hydrogen cyanide) or firing squad to lethal injection, although some states still allow or use the other methods.

Eighteen states have abolished the death penalty. The number of executions has plummeted over the past two decades, from 98 in 1999 to 23 in 2017, according to the Death Penalty Information Center.

Jennifer Moreno, a staff attorney with the Death Penalty Clinic at Berkeley Law in California, said that when lethal injection emerged for executions, the government pitched it as a reliable method that could be trusted.

Oklahoma Watch is a nonprofit organization that produces in-depth and investigative journalism on important public-policy issues facing the state. More Oklahoma Watch content can be found at www.oklahomawatch.org.
Oklahoma Watch
Oklahoma Watch is a nonprofit organization that produces in-depth and investigative journalism on important public-policy issues facing the state. More Oklahoma Watch content can be found at www.oklahomawatch.org.

“As we‘ve seen over the years, that hasn’t turned out to be true,” she said.

Public perception could play a factor in acceptance of executions conducted using nitrogen. If a condemned inmate enters the chamber wearing a mask or plastic hood or the guards must wear gas masks, will the process be perceived negatively? After Oklahoma announced it would switch to  nitrogen, critics across the country compared the proposal to Nazi gas chambers.

In Oklahoma, 47 inmates are on death row in the Oklahoma State Penitentiary in McAlester. The state has not carried out the death penalty in 3½ years, since Charles Warner was executed by lethal injection after being convicted in 1997 for the sexual assault and murder of an 11-year-old girl.

A 2016 pollby SoonerPoll found that a majority of Oklahomans support the death penalty, although it also found that most would support abolishing it if a life sentence without parole, property forfeiture and restitution to victim’s families were required instead. Also that year, 66 percent of Oklahoma voters approved State Question 776, which amended the state constitution to affirm the death penalty and the right to change execution methods.

With nitrogen inhalation, however, deep uncertainties remain, Moreno said. “Just like lethal injection, the devil is going to be in the details.”

Oklahoma Watch is a non-profit organization that produces in-depth and investigative journalism on important public-policy issues facing the state. Oklahoma Watch is non-partisan and strives to be balanced, fair, accurate and comprehensive. The reporting project collaborates on occasion with other news outlets. Topics of particular interest include poverty, education, health care, the young and the old, and the disadvantaged.
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