TST INDICATOR STRIP, Type 5
Valid Article
TST INDICATOR STRIP, Type 5
Definition
Sterilization indicator to be placed inside individual load items and to assess attainment of the critical process variables at the point of placement. This indicator reacts to all critical process variables.
Requirements according to Type 5 of chemical indicators for steam sterilization.
Synonym
Sterilisation chemical indicator type 5, Type 5 integrating indicator
Specifications
Type 5 integrating indicators are chemical indicators (CI) designed to reach their endpoint response when exposed to critical variables: time, temperature and the presence of steam.
Stated value (SV): value or values of a critical process variable at which the indicator is designed to reach its endpoint as defined by the manufacturer.
Quality standards
Technical specifications
- Indicator clearly marked with type of process for which it is intended to be used:
- number indicating the type of indicator: 5
- combination of a letter plus a number to indicate a category: i5
- Abbreviated descriptions of the process shall be in accordance with the following symbol: "STEAM" all steam sterilization processes
- Stated values for temperature (three) at
- 121°C
- 135°C
- one temperature in between – that mimic the death curve, or biological response, of the microorganisms inside a BI (biological indicator) when exposed to ideal, saturated steam conditions.
- Stated values for time (ensures that Type 5 CI is labelled for use in 132°C/270°F do not change too quickly or inappropriately at lower temperatures)
- at 121°C: >16.5 min
- at 135 °C: > 1.2 min
- After exposure of the indicator the end point shall be clearly observable.
- In use, the indicator agent shall not offset or bleed, penetrate the substrate to which it is applied, or materials with which it is in contact.
Presentation of the indicator strip:
- Reinforced white paper strip
- +/- 5 x 2cm containing a paper wick and a chemical pellet which melts and migrates as a dark colour along the paper wick
- This migration is visible through a window market ACCEPT or REJECT.
Packaging & Labelling
Pack of 100 or 500
Instructions for use
- Place 2 TST strips, wrapped in 2 layers of sterilization paper in the middle of each load (or 1 strip in each basket) to be sterilized in order to validate the sterilization cycle. Stick the strip in the sterilization register after completion of the cycle.
- Place 1 TST strip inside the box or the wired basket containing each surgical set, for the OT staff to check upon opening the set.
The TST indicator is not sensible to its position in the space.
- If the color bar reaches or crosses into the ACCEPT window, it is a pass and the necessary conditions of time, temperature and steam have been met for sterilization
- If the color bar is in the REJECT region or on the line, it is considered a fail. The pack should be reprocessed and the cause of sterilization failure should be investigated.
(Cf Introduction: Disinfection and sterilization in the field)
Storage
- Store unopened and resealed packages at 40 – 60% relative humidity conditions
- Room temperature: 15-30°C, Protect from sunlight
- Do not store near strong alkaline or acidic products such as cleaning / disinfecting agents.
- After use, the indicator will not change visually within 6 months when stored in the above conditions.
MSF requirements
This type of TST strip was selected:
- Better performance compared to the type 6 chemical indicator
- Result is clear: pass or fail