Microbial barrier testing by ASTM F1608

The ASTM F1608 method is used to determine the passage of airborne bacteria through porous materials used in the packaging of sterile medical devices. With the test, different materials can be compared to determine which one offers the best protection against contamination.

A mist of bacteria spores (Bacillus atrophies) is sprayed on the porous testing material in an exposure chamber. Spores that get through the material are trapped on a special filter and counted. The number of spores sprayed originally is compared to the number of spores that got through to conclude how well the material blocks the bacteria. 

The results are expressed as a “Log Reduction Value” (LRV), representing the effectiveness of the material in preventing bacteria from passing.