Just under three years ago, ISO :2021 was updated with new limit values for cleaning processes in dishwasher-disinfectors. In this post, we list the various limit values specified by the standard and provide some insights into each one.
The cleaning efficacy shall be determined by visual inspection and by quantitative detection of protein in accordance with the standard. For invasive medical devices, at least one other validated quantitative analytical test method shall be used to measure one or more additional analytes for type testing.
The acceptance criteria for analytes are specified in terms of both an alert level and an action level. Action levels represent the maximum criteria for an acceptable cleaning process. If analytes are detected between the two levels, they may be considered acceptable according to the cleaning requirements. However, to meet the requirements of the standard, the action level must always be used.
Protein limit
- Warning level ≥ 3 µg/cm²
- Action level ≥ 6.4 µg/cm²
See ISO [42], [51], [72], [76], and [85]
Limit value for Total Organic Carbon (TOC)
- Warning level ≥ 6 µg/cm²
- Action level ≥ 12 µg/cm²
See ISO [85], [67]
Carbohydrate limit
- Warning level ≥ 0.9 µg/cm²
- Action level ≥1.8 µg/cm²
See ISO [34], [40], [53]
Hemoglobin reference range
- Warning level ≥ 1.0 µg/cm²
- Action level ≥ 2.2 µg/cm²
See ISO [73], [34], [35], [42], [51]
ATP threshold
- Warning level ≥ 10 femtomoles ATP ATP/cm²
- Action level ≥ 22 femtomoles ATP
(Note: Conversion between femtomoles and RLU values is required for different ATP)
See ISO [37], [89], [36], [37], [43]
Endotoxin limit
- Warning level ≥ 2.2 EU/instrument
- Action level ≥ 20 EU/device
(Note: EU = Endotoxin Units)
See ISO [9], [12], [32], [33], [37], [41], and [50]
References
- ISO :2021.Washer-disinfectors —Part 5: Performance requirements and test method criteria for demonstrating cleaning efficacy
- References ISO :2021