Which class of biosafety cabinets protects the user against direct contact with the contents of the cabinet?

• A. Class I
• B. Class II
• C. Class III
• D. All of the above

Answer: (C)

The protective idea is that some cabinets fully isolate the user from what’s inside. A Class III cabinet is a completely enclosed, gas-tight unit with attached gloves. You manipulate everything inside through those gloves, so the operator’s hands never contact the contents directly. This design gives the highest level of containment for the user (and for the environment and product as well). In contrast, the other classes involve front openings where hands reach into the cabinet, so direct contact with contents isn’t inherently prevented, even though there are airflow protections and filters in place. That makes Class III the cabinet type that prevents direct contact with the cabinet’s contents.