ABSTRACT
The presence of the atmospheric hazard, combined with one or more serious procedural deficiencies, inadequate or improper ventilation, created the conditions antecedent to accidents in conventional workspaces. In almost all of the fatal accidents documented by national institute for occupational safety and health and occupational safety and health administration, entrants failed to ensure ventilation of the space prior to entry or during work. One of the outcomes from the hazard assessment performed as part of the planning process for entry and work is to determine the need for ventilation. Ventilation is part of the assurance that the space will be safe for entry and will remain safe for work. The role of ventilation as a critical element in hazard control is recognized in technical standards and legislation on confined spaces. A confined space containing a hazardous environment would require initial entry to ascertain conditions and to apply any necessary measures to prepare it for further work.
