Ki Discus Testing

Independent Air Flow Services is accredited to carry out the KI Discus Testing, which has been designed to enable operator protection factors (and where appropriate, product protection and cross contamination factors) to be measured for:

1. Class I and Class II open-fronted microbiological safety cabinet
2. Special hybrid facilities such as carcinogen and radio-pharmaceutical cabinets
3. Cytotoxic Cabinets

Unlike test methods using a micro-biological aerosol challenge the KI Discus technique enables cabinets to be tested:

1. With no bacterial contamination risk of the containment facility
2. With no bacterial contamination risk of the laboratory

A further advantage of the KI discus test Is that result are available within a few minutes.

KI-DISCUS Principles of Operation

A fine mist of potassium iodide droplets, produced by a spinning disk, is used as a challenge aerosol to measure the containment of a cabinet or fume cupboard. Centripetal collectors sample the air outside or inside the cabinet – depending on the nature of the test. The collectors deposit any potassium iodide particles that are in the sampled air on to filter membranes.

At the end of the sampling period the filter membranes are placed into a solution of palladium chloride whereupon the potassium iodide “develops” to form clearly visible and easily identified grey/brown dots.

A knowledge of the number of droplets in the challenge produced by the mist generator and the number collected in the air samplers enables the protection factor for the cabinet to be calculated. All open-fronted microbiological safety cabinets are assessed on this protection factor.

Biological Safety Cabinet Class II & Cytotoxic Drug Safety Cabinet

• AS 1807 (Clause 4.12) Determination of Air Barrier Containment – Potassium Iodide
  Test KI Discus (Clause 5.2.2)