Cumulative atmospheric hazards or disasters

CUMULATIVE ATMOSPHERIC HAZARDS OR DISASTERS

The word 'cumulative' refers to increment by successive additions. Atmospheric hazards or disasters refers to oxygen deficiency, dust, chemical vapours, welding fumes, fog or mists that can interfere with the body's ability to transport and utilize Oxygen. Such hazards have negative toxicological effects on the human body. 

Confined spaces can be found in industrial settings,public utilities and the construction industry. The safety hazards associated with confined spaces can cause serious injury and death. These hazards can be called as atmospheric hazards or physical hazards.

Atmospheric hazards include:

• Oxygen deficiency
• Oxygen displacement
• Flammable atmospheres and
• Toxic gases

Oxygen deficiency: Low levels of oxygen can be caused by consumption of Oxygen during open flame operations such as welding, cutting or brazing. In addition, low levels of Oxygen can be present in manholes that are located near garbage dumps, landfills and swampy areas where fermentation has caused the consumption of oxygen.

Oxygen displacement: Some type of gases will displace oxygen from a confined space. Sometimes Nitrogen is used to purge gases from tanks. If a person enters the tank before Nitrogen was properly removed and vented from the tank, the person could die within a matter of minutes

Flammable atmospheres: Some confined spaces could contain flammables like solvents, fuel oil, gasoline, kerosene, etc that provide fuel for combustion. For the atmosphere to become flammable, it must have the proper mixture of oxygen and fuel. A fire hazard is possible in confined spaces if the right mixture of oxygen, fuel and a spark are present.

Toxic gases: Toxic gases can be present in a confined space because of type of manufacturing processes or toxic substances during production or biological and chemical breakdown of the product being stored in the tank. Common types of toxic gases encountered in confined spaces are:

1. Hydrogen sulphide: Colourless gas with odour of rotten eggs It inhibits exchange of oxygen at the cellular level and causes asphyxiation. It causes a loss of sense of smell
2. Carbon monoxide: It is a colourless and odourless gas and inhibits the body's ability to transport Oxygen to all parts of the body
3. Solvents: Solvents such as kerosene, gasoline, paint strippers, degreasers are flammable and when inhaled at high concentrations causes Central Nervous System (CNS) effects such as dizziness, drowsiness, lack of concentration, confusion, headaches, coma and ultimately death

Two or more of the above listed hazards or disasters occurring together adds-up the effects and this is called 'Cumulative atmospheric hazards or disasters'