Confined spaces--a case for ventilation.

Many exposures, some leading to deaths and injuries, in confined spaces could have been prevented by ventilating the space prior to and during the entry. Current standards and guidelines generally do not require ventilation. Nor do they sufficiently emphasize the need for ventilation or provide guidance on how to ventilate confined spaces. Mechanical ventilation is a positive engineering control action that can usually be taken and that will reduce the hazards of adverse atmospheric conditions inside a confined space. Natural ventilation usually is not sufficiently reliable to serve as a primary means of control. Unfortunately, very little specific information is available for designing and implementing ventilation strategies for confined spaces. More published information is needed, such as examples of effective policy and procedures in use by industry and findings from research on confined space ventilation. Basic and applied research can help to demonstrate effective ventilation actions and develop useful design guidelines. Additional published information should increase hazard awareness and reduce the likelihood of accidents.