BOWIE-DISK TEST SHEET (TYPE 2)
A Bowie‑Dick Test Sheet is a Type 2 chemical indicator used in pre-vacuum steam sterilizers to assess the effective air removal and steam penetration before executing steam sterilization cycles. It typically consists of a heat-sensitive paper sheet that visually indicates residual air by its color change
Description
INDICATIONS:
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Daily monitoring: Run once daily before the first load in pre-vacuum (dynamic air removal) steam sterilizers .
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Qualification testing: After installation, relocation, or major repair (3 consecutive passes required)
- Detects sterilizer faults: Reveals air leaks, incomplete air removal, steam quality issues, and presence of non-condensable gases
INSTRUCTIONS FOR USE.
- Warm‑up cycle: Run an empty warm-up cycle to normalize chamber temperature—critical for accurate test
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Test pack prep:
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If DIY: create a pack using 4–8 layers of clean, non‑ironed surgical towels (approx. 230×300 mm, 250–280 mm thick)
- Or use pre‑assembled/packet test packs.
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- Placement: Lay the sheet in the center of the towel pack. Then place the pack horizontally on the bottom shelf, directly over the drain line in an otherwise empty sterilizer
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Run cycle: Use the designated Bowie‑Dick cycle:
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134 °C for ~3.5 min, or 132 °C for ~4 min; drying phase omitted or minimal
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- Interpret results:
- Pass: Uniform color change across the sheet (e.g., yellow → dark brown/black or blue → black)
- Fail: Non‑uniform, streaked, or patchy color → air still present
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Response:
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If pass, proceed with usual sterilization loads.
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If fail, stop and investigate vacuum system (door seal, leaks, steam trap), then repeat until passing result achieved
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Documentation:
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For routine checks: record date, operator, sterilizer ID, and result.
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For qualification: three consecutive passing cycles required
- Retain the used sheet or test card for traceability and audit compliance.
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