Doc. 44/18Hazards of Oxygen-Deficient Atmospheres

This publication sets out the essential information necessary to prevent asphyxiation incidents involving inert gases.


It is not a detailed procedure for confined space entry but focuses on the considerations that are important when there is an actual or potential hazard from inert gases or oxygen deficiency.

The minimum safe oxygen concentration for entry into a space is 19.5% oxygen. There are applications with oxygen concentrations less than 19,5% where entry is permitted provided that further precautions are taken in accordance with proper risk assessment and national regulations.


As well as the references in the text, this publication is supported by EIGA’s Safety Leaflet SL 01 Dangers of Asphyxiation.


This publication is intended for supervisors, line managers, direct workers and users wherever inert gases are produced, stored, used, or where oxygen depletion could otherwise occur and may be used as the basis for training.


The publication is part of the programme to develop Globally Harmonised publications amongst Regional Gas Associations.