Oklahoma introduced a law allowing it to use nitrogen gas to kill death row prisoners if lethal injections are n't available . Governor Mary Fallin signed into law a bill approving nitrogen as an alternative method of death , giving Oklahoma four different ways to enact its death penalty . The method , which involves pumping a chamber full of nitrogen and leaving a prisoner 's body to die from lack of oxygen , has been touted as 'foolproof ' by supporters , in the wake of the embarrassingly botched lethal injections . Scroll down for video . Gas chamber : The state of Oklahoma has legalized killing death row in-mates with nitrogen . This 1999 file photo shows an Arizona correctional officer explaining his state 's execution method . Executions in the state are currently on hold while the Supreme Court ponders whether the three-drug mix now favored by Oklahoma is constitutional . The pause follows an infamous execution last ear , which saw officials struggle to administer a the poison to an inmate , who writhed on the gurney in pain for some 43 minutes before finally dying . Nitrogen - which has never been used to execute humans before - is now the state 's second choice . The new bill , effective from November 2015 , moves the electric chair back from second preference to third , while firing squad becomes a distant fourth choice if all other methods are unavailable . Proponents tout that nitrogen killings will be 'fast and painless ' for inmates - and also say the method is 'foolproof ' as it requires no medical expertise or complex procedures . In a statement issued as the bill was signed , Fallin , a Republican , said : 'Oklahoma executes murderers whose crimes are especially heinous . ' I support that policy , and I believe capital punishment must be performed effectively and without cruelty . The bill I signed today gives the state of Oklahoma another death penalty option that meets that standard . ' The bill authored by Republican Rep. Mike Christian and Republican Sen. Anthony Sykes had passed the state House on an 85-10 vote and cleared the Senate on a 41-0 vote . Christian , a former Highway Patrol trooper , said : 'The process is fast and painless - it 's foolproof . ' Opponents say there 's no way to know whether the method is painless and effective . 'It just has n't been tried , so we do n't know , ' said Rep. Emily Virgin , a Democrat from Norman who opposes the death penalty . The changes come after a botched execution last year in which Oklahoma was using a new sedative as the first in a three-drug combination . State officials tried to halt the lethal injection after the inmate writhed on the gurney and moaned . He died 43 minutes after the process began . Adam Leathers , spokesman for the Oklahoma Coalition to Abolish the Death Penalty , released a statement blasting the new law . 'This is not only a grotesque waste of resources but indicative of a corrupt value system , ' he said . 'It is sad to know that our State 's collective bloodlust is so unabated that our leadership feels the need to spend resources to put a back up system into place so State sponsored murder can go on uninterrupted . ' The problematic execution was blamed on a poorly placed intravenous line and prompted a lawsuit from Oklahoma death row inmates , who argue that the state 's new drug combination presents a serious risk of pain and suffering . The U.S. Supreme Court is scheduled to hear arguments later this month . The lack of readily-available lethal injection drugs - and problems with stocks the states do have - has vexed several other states . Utah brought back the firing squad earlier this year in response to a drugs shortage , while Tennessee reinstated the electric chair .
Governor Mary Fallin signed bill allowing nitrogen execution into law . Chamber is pumped full of gas , and body dies from lack of oxygen . Method will become Oklahoma 's second choice after lethal injection . the Oklahoma Coalition to Abolish the Death Penalty is due to rule on whether current execution drugs are legal . If gas execution is not available , state will use electric chair or firing squad .