From 2001 to 2007, the Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) conducted studies to develop alternative methodologies to full-scale explosion testing for determining the ultimate strength of mine seals. As a result, the PRL developed and proposes an alternative seal-strength evaluation method based on a hydrostatic pressure-loading concept. The researchers suggest pressure loading a seal using water to twice the expected dynamic design load. The hydrostatic chamber test offers a means of validating seal designs, establishing appropriate resistance functions and determining the ultimate strength of seals through testing to failure. This article contrasts the full-scale explosion and hydrostatic testing of mine seals using a simple dynamicsystem model and principles.