Which ventilation method involves creating a negative pressure to remove hazardous atmospheres from a confined space?

Negative pressure ventilation is the method that effectively creates a vacuum effect within a confined space, allowing for the expulsion of hazardous gases, vapors, or smoke. This approach is particularly valuable in situations where there are hazardous atmospheres that need to be mitigated before entry. By creating a negative pressure, air from the outside is drawn into the confined space, facilitating the removal of these dangerous elements while simultaneously preventing contaminants from escaping into the surrounding area.

In addition to eliminating harmful atmospheres, this method also helps ensure that the air inside remains less contaminated or is replaced with fresh air, enhancing the safety of rescue personnel. This makes negative pressure ventilation a crucial technique for maintaining a safer environment in confined spaces, especially in emergency rescue situations.