Aims and Objectives To report on sodium azide-related enquiries received by the UK-NPIS with the intention of evaluating their nature, frequency and severity . There has been concern about the use of this chemical in deliberate self harm. This study seeked to explore if sodium azide was a significant public health problem in the UK.

Method and Design A retrospective observational study of telephone enquiries to the NPIS received between 1-January, 2008 and 31-May, 2024 was performed. Enquiries involving sodium azide were extracted and examined for data regarding intention of exposure, nature of exposure, symptoms and outcomes.

Results and Conclusion The UK-NPIS received 757,737 enquiries during the study. One-hundred-and-twenty-five enquiries related to potential exposure to sodium azide are summarised in table 1.

In DSH enquiries, reported dose (n=6) was stated as 30 mL of 30%, 5-10 g, 10g, 1 spoon, 1 teaspoon or 2 ‘packets’. Laboratory was reported as the chemical source in 5 cases, internet in 1 (year=2020), and unknown in 4 cases.

Symptoms were unknown in 4 cases, with 1 asymptomatic. Reported symptoms included GI upset (4), drowsiness (3), hypotension (3), lactic acidosis (3) tachycardia (2) and abnormal liver function (2).

Outcomes were known in 4 DSH cases; 2 complete recoveries and 2 fatalities (2011 and 2024). Among the 31 PPE/mortuary protocol enquiries, 5 additional deaths were identified (2013, 2017, 2018 2019, 2020).

Conclusion: Sodium azide enquiries account for a small proportion of total UK-NPIS enquiries, and current data does not indicate that it is an emerging trend as a method of suicide. However, seven deaths are described in this data. Death often occurs before medical intervention is available. Future work will look at ONS data to identify any areas of concern and whether wider public health action is required.