Sodium azide/nitrite suicides in the Netherlands between 2015 and 2022

In 2017, a 'right-to-die' organization publicly announced the legally available and existing chemical "agent X″ as a method of suicide. Both sodium azide as sodium nitrite were mentioned as "agent X". Based on the external examination reports registered in Formatus by the forensic physicians working at the Public Health Services and data from Statistics Netherlands, an observational study was conducted into the number of sodium azide and sodium nitrite deaths in the period from 2015 to 2022 in the Netherlands as well as the characteristics of these deceased. The number of sodium azide and sodium nitrite suicides in that period was compared with to the total number of suicides and suicides by self-poisoning in that same period. Between 2015 and 2022, 172 sodium azide and sodium nitrite suicides were identified on the basis of external examination reports drawn up by forensic physicians whereby 12 % (n = 20) of the cases were confirmed by toxicologic screening. The first case was reported in 2017. The total group contained approximately an equal number of men (53 %) and women. 38 % of all suicides was 70 years or older at the time of death with an average age of 59 years. Compared to all suicides in the Netherlands, people who opted for sodium azide and sodium nitrite were more often female (p < 0.001) and on average older (p < 0.001). 70 % (n = 120) had a history of psychiatric illness. The use of sodium azide and sodium nitrite for suicide increased between 2017 and 2022, with a provisional peak (n = 50) in 2021. The rate sodium azide and sodium nitrite suicides in relation to the total number of suicides and intoxications per year increased gradually in the period 2017-2021. This study is the first to our knowledge that investigates the numbers of sodium azide and sodium nitrite suicides and the associated characteristics of the individuals. Since 2017 a rise of these suicides was observed. More research to investigate characteristics on the individuals should be done in order to create accurate suicide prevention methods in the future and pay attention to the trends regarding the use of these suicide powders.