Biological Safety Level (BSL) is a biocontainment designation system with requirements intended to protect personnel from potentially harmful pathogenic exposure in a research or manufacturing environment.
The Centers for Disease Control (CDC) specifies four broad Biological Safety Levels, each of which corresponds to a level of exposure danger and a set of design features and operational protocol. Each increasing level builds on the previous level(s):
All BSL facilities require that personnel follow “standard microbial practices”: no food or drink; no cosmetics; hands and gloves are frequently washed and surfaces routinely decontaminated. Sterilization and entry/exit protocol vary by BSL level.
There is no necessary correlation between a BSL and an ISO cleanliness level since they correspond to two different sets of concerns: protection of personnel and the environment from biological exposure vs. protection of a sensitive sample from contaminant exposure.
Any BSL environment can require any ISO cleanliness standard, depending on the sensitivity of the process to airborne particulates (including aerosols and germs). BSL applications that involve storage or handling of packaged pathogens may tolerate a relatively “dirty” environment, such as ISO 8, whereas processing unpackaged pathogens susceptible to contamination by airborne particles might require an ISO 5 environment.
As a practical concern, the most challenging applications involve hazardous microbes (BSL-2 or higher) that are also highly sensitive to particulate contamination (requiring ISO 5 or cleaner). These situations require a high volume of micro-filtered air passing through the enclosure to guarantee cleanliness, and therefore also a high volume of exhausted air to ensure negative-pressure containment. Such systems typically incorporate high-capacity exhaust fans and ductwork, often with system redundancy, and sophisticated airflow monitoring systems.
Yes, but it depends on your specific application. Modular cleanrooms are rarely appropriate for BSL-3 and BSL-4 applications, which typically require sophisticated facility integration involving air handling systems and environmental monitoring equipment.
Terra provides BSL-2 modular cleanrooms, but how a given BSL specification affects cleanroom design and construction is not always clear. Some operations that fall under BSL-2 may require single-pass air that is filtered before being exhausted to the outside; others may allow recirculation of air and release of unfiltered exhaust air.
For this reason, Terra requests that any BSL application receive careful review by the appropriate process validation expert, who can translate the process and BSL requirement into specific environmental design specifications involving ISO cleanliness level, pressure levels, air change rates, air circulation, and exhaust air treatment, among other factors.
Once these issues are clear, Terra can propose the most economical way to address your BSL application.