Nonhazardous confined space

Before a person can enter a nonhazardous confined space, the following conditions must be met ... 

The product is considered nonhazardous for international transport purposes. However, it is an oxidizing agent sensitive to decomposition by water, direct sources of heat, catalysts, etc. Decomposition is accompanied by the Hberation of oxygen and heat which can support combustion and cause pressure bursts in confined spaces. Decomposition in the presence of organic material is rapid and highly exothermic. 

The column 8 elements are all nonhazardous gases however, they can displace the oxygen in the air inside of buildings or in confined spaces and cause asphyxiation. Inert gases are commonly shipped and stored as compressed gases or cryogenic liquids. These materials are quite cold and can cause thermal bums. They also have large expansion ratios. DOT does not place them in a hazard class unless they are under pressure. 

Confined-space entry can be divided into two broad areas nonhazardous spaces which have been ventilated and hazardous spaces that are known to contain hazardous materials. 

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