Nitrogen hypoxia – a new method of execution.

In 2018, the US state of Alabama became the third state, along with Oklahoma and Mississippi, to authorize the use of nitrogen gas as a method of execution.

Nitrogen is a colorless, odorless and tasteless gas that makes up 78% of the atmosphere, with 21% oxygen and 1% of other trace gasses. Nitrogen does not support respiration and displaces oxygen in the lungs. However, it does allow for the exhalation of carbon dioxide. The theory behind nitrogen hypoxia is that changing the composition of the air to 100% nitrogen will cause an individual to lose consciousness and then die from lack of oxygen.

Much of what is known about death from nitrogen exposure comes from the study of industrial accidents. Nitrogen hypoxia is a form of inert gas asphyxiation, in which a person is exposed to pure nitrogen gas until they die from oxygen deprivation.

On the evening of the 25th of January 2024, the state of Alabama carried out the first execution by Nitrogen hypoxia, that of Kenneth Eugene Smith at Holman Prison in Atmore.
Below is a chronological report of Smith’s execution:

A team held bi-weekly practice sessions to ensure the process ran smoothly and the mask Smith wore provided the proper seal, according to the state.

After Smith was strapped to the gurney in the execution chamber, the state said in a court filing that it would place a “NIOSH-approved Type-C full facemask supplied air respirator over Smith’s face.

The warden then read the death warrant and asked Smith if he has any last words before activating “the nitrogen hypoxia system” from another room.

The state's experts claimed that the level of nitrogen would lead to cardiac arrest within five minutes.

They argued Smith should not suffer since the introduction of nitrogen will knock him out in moments.

The execution took about 22 minutes, and Smith appeared to remain conscious for several minutes. For at least two minutes, he appeared to shake and writhe on the gurney, sometimes pulling against the restraints. That was followed by several minutes of heavy breathing, until breathing was no longer perceptible.

Alabama offers death-row inmates a choice between nitrogen hypoxia and lethal injection. Smith chose nitrogen after he survived an hours long attempt to execute him by lethal injection in 2022, during which he was repeatedly stabbed with needles and placed in what he called an “inverted crucifixion position.” But he continued to wage a legal battle against the use of the method and the state’s protocol for administering it.

7:53 p.m.

Drapes were open in the media witness room. Smith had four witnesses in the room. Smith was wearing a full face mask with a plastic tube running out of a rectangular hole in the concrete block wall of the death chamber connected to the mask. He was strapped to the gurney cruciform, with his arms secured by straps. His body was secured by straps. He raised his head to look into the witness room and appeared to recognize the witnesses who were there for him. He smiled through the mask and made the sign language sign for "I love you" and the OK sign with his left hand. He worked the fingers of his left hand as if counting.

7:55 p.m.

He was given the opportunity to make a statement. His words were difficult to hear, muffled by the mask. "Tonight, Alabama caused humanity to take a step backward," he said. He continued to speak but the words were inaudible. He thanked those who supported him through this process and his previous execution attempt. "I love all of you," he said as he ended his statement. "Thank you for supporting me. I love all of you."

7:56 p.m.

The Rev. Jeff Hood, holding a Bible, approached Smith and they appeared to pray.

7:57 p.m.

A prisons staff member inside the death chamber approached Smith and checked the seal of the mask. The nitrogen apparently began flowing at this time.

7:57 to 8:01 p.m.

Smith writhed and convulsed on the gurney. He appeared to be fully conscious when the gas began to flow. He took deep breaths, his body shaking violently with his eyes rolling in the back of his head. Hood, standing about 15 feet away, made the sign of the cross several times. Smith clenched his fists, his legs shook under the tightly tucked-in white sheet that covered him from his neck down. He seemed to be gasping for air. The gurney shook several times during this time. Hood removed his eyeglasses and wiped away tears.

8:02 p.m.

Smith appeared to lose consciousness. His chest remained still for about 20 seconds then he took several large gasps for air. There appeared to be saliva or tears on the inside of the facemask.

8:06 p.m.

Smith's gasping appeared to slow down.

8:07 p.m.

Smith appeared to take his last breath.

8:15 p.m.

The curtains to the witness room were closed.

In a news conference following the execution, Department of Corrections Commissioner John Q. Hamm said Smith's reactions were "nothing out of the ordinary."

"It appeared Smith held his breath for as long as he could, and struggled against his restraints," Hamm said. "This was expected."

Hamm said the nitrogen flowed to Smith's mask for about 15 minutes.

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