Public and industry attention on cross-contamination of aerosols was high during the COVID-19 pandemic. Containment controls (specifically negativepressure) were frequently deployed. As such, the need for validation protocols relating to containment of single-door measures is on the rise. This paper aimsto demonstrate how a field-testing team can establish a protocol for validating containment.After reviewing the definitions of contamination ratio (CR) and barrier effectiveness (BE), this paper illustrates a testing protocol for their determinationin any room. The paper details the data collection needs. The paper illustrates the calculation method for processing field data into reportable results. Thepaper includes three sample tests, with measurements and results, to illustrate the testing protocol.