Volatile chemicals, while typically used in a fume hood, sometimes need to be used in conjunction with biological experiments, requiring the use of volatile chemicals within a biosafety cabinet (BSC). While a 100% exhausted Class II Type B2 cabinet is most often mentioned as a safe option, this is not always possible or necessary. International safety standards have recommended “minute” amounts of volatiles can safely be used in a Class II Type A2, but what constitutes “minute” can be left up for interpretation. While no universal volume of any volatile chemical should be deemed safe to work with in a Type A2 BSC, here we present a way to make a proper assessment.
In this paper, we explore:
- How BSCs work and why volatile chemicals are such a problem.
- A series of equations developed to calculate the internal concentration, maximum amount allowed safely, and the time required for the evacuation of any volatile chemical, as shown by calculation and confirmed experimentally.
- The introduction of a tool to find the safe working volume of each specific chemical and your specific BSC that can be used to aid in the most accurate risk assessment