Self-administered and assisted suicides by asphyxiation using a plastic bag with helium were first recorded in the 1990s. Since the 2000s, guides have spread on the internet, in print and on video and the frequency of suicides by this method has increased. The suicide bag with inert gas method was originally developed by
John Hofsess and the NuTech group, which consisted of Hofsess,
Derek Humphry, engineers and physicians. In the book
Final Exit by
Derek Humphry, a suicide bag was described as a large plastic bag with an adjustable velcro strip around the neck. Its use with inert gases was mentioned in the
Supplement to Final Exit in 2000. The
euthanasia-rights advocacy group
Exit Australia distributed a manufactured version of the bag in Australia in 2002, alarming government officials and
anti-abortion groups. In 2007,
The Vancouver Sun cited Russel Ogden, Canadian criminologist and right-to-die advocate, who said that the combination of a suicide bag and helium was "a method of choice" within the right-to-die movement for people who are
terminally ill and that its promotion does not appear to cause an increase in the number of suicides. However, he said that he has no way of knowing if the method was being used by people with terminal illnesses or by people who are mentally ill. In 2008,
Ludwig Minelli, founder of
Dignitas, filmed four people committing suicide by helium inhalation. Nitschke's organisation sells suicide kits that contain nitrogen tanks and regulators. He promotes the use of nitrogen and suicide bags with lectures and films, such as
Doing it with Betty – in which an elderly woman describes how to make a plastic 'exit' bag, and with published materials such as workshop handbooks. Nitschke calls the suicide bag death a "
hypoxic death", and likens it to
pneumonia, the "old person's friend", where hypoxia occurs because pneumonic inflammation stops the lungs extracting sufficient oxygen from the air, and "a peaceful death often results". In 2015 author and right-to-die advocate Derek Humphry reported that
Worthington Industries, the world's largest manufacturer of disposable helium cylinders, had announced that their helium cylinders will guarantee only 80% helium, with up to 20% air, making them inappropriate for use with a suicide bag in Humphry's opinion. In many countries it has also become increasingly difficult for private individuals to obtain cylinders of nitrogen for possible use with a suicide bag as suppliers have been alerted to this method and there are few other reasons for a private individual to seek to purchase a cylinder of nitrogen. Dutch psychiatrist Boudewijn Chabot, in his 2015 book
Dignified Dying, calls the suicide bag with inert gas method "rapid, painless and safe". ==Legal issues==