GB 18281.5-2015Sterilization of health care products -- Biological indicator -- Part 5: Biological indicators for low-temperature steam and formaldehyde sterilization processes (English PDF)

3.1 Low temperature steam formaldehyde sterilization

By the power exhaust, so that pre-packaged goods in the vacuum state is exposed to steam at temperatures below 100 °C, the injection of formaldehyde gas,

Such sterilizing agents in the maintenance time remains steady process.

5.1

Test bacteria should be Bacillus stearothermophilus or other has been found to comply with the requirements of this strain of microorganism equivalent performance.

Note 1.Bacillus stearothermophilus have been reclassified to Bacillus stearothermophilus.

Note 2.The currently considered applicable to Bacillus stearothermophilus, as NCIB8224, DSM6790, ATCC10149 and ATCC12980.

5.2

If the use of a test bacteria Bacillus stearothermophilus ground outside, then this strain of bacteria resistance test suitability should be determined.

7.1

low temperature steam formaldehyde sterilization agent biological indicator carriers and inner packing material should conform to ISO 11138-1.2006 5.2

And ISO 11138-1.2006 requirements in Appendix B of.

Note. Due to the cellulose surface chemical formaldehyde adsorption filter paper type is not suitable as a carrier.

7.2

should comply with the determined exposure conditions.

a) Minimum temperature exposure. not less than 5 °C (above the manufacturer claims the highest temperature);

b) maximum exposure temperature. According to the manufacturer's maximum claims; If the manufacturer is not declared, should not be less than the maximum exposure temperature

100 °C;

c) Exposure time. not less than 60min.

Note. These conditions have become a caution, with practical limits on bacteria in the range of application of low temperature steam formaldehyde sterilization process. Selection criteria to be able to significantly

It shows the actual low temperature steam formaldehyde sterilization process to the actual requirements of the carrier.

9.1

Manufacturers should be based on ISO 11138-1.2006 6.4 Characteristics of predetermined resistance requirements.

9.2

Proliferation amount viable count should be less than 0.1 × 10n/per unit (eg. bacteria per ml suspension, each to be inoculated with bacteria, each student

Adhesive tape cells).

With cell proliferation and the amount of biological cells with 9.3 to be vaccinated should be not less than 1.0 × 105.

9.4

resistance should be expressed as D value at 60 °C, and in minutes (min). Each batch/lot of contamination or biological indicator carriers D

D values apply at 60 °C that is kept to one decimal place.

9.5

when tested in accordance with Appendix A, the medium carrier contamination or biological indicator comprises D60 value to stearothermophilus Bacillus

Should >=6min. Other micro-organisms should also be applied to the D value.

Resistance 9.6 biological indicator can also be used FBIO value indicates (see ISO 11138-1.2006 3.7). This section GB 18281 and its

The specific part of his resistance shall be tested in accordance with specific conditions standards.

9.7

shall be according to ISO 11138-1.2006 Determination of D value of Appendices C and D of the given method.

9.8

D value determination and survival - kill response characteristics based on the process parameters in Appendix A.

9.9

Survival - killing range available ISO 11138-1.2006 Appendix E formula to calculate.

NOTE. To compare different batches of the same manufacturer's product information for the user is useful.

Example. Apply ISO 11138-1.2006 Appendix E of the formula and the population and minimum D values given in this section, survival - kill reaction characteristic values are.

--- 60 °C when. survival time >=18min, kill time <=54min.

Appendix A (Normative)

Determination of low temperature steam formaldehyde sterilization process resistance method

A.1 General

This method is based on a carrier immersed in formalin contamination qualitative testing. The results of this test method than the use of gas cavity

The results of the method have better reproducibility.

A.3 provides the special requirements of the test method.

A.2 Ranjun carrier exposure conditions

A.2.1 test system comprising an aqueous solution of formaldehyde containing 10mL test tube, and the tube placed in a water bath of automatic temperature control. Measurement

Test systems should be able to (accurate to ± 10s) period of time to maintain a specific exposure conditions in 1min ~ 150min.

Chemical analysis methods to determine the concentration of the aqueous formaldehyde solution A.2.2.

A.2.3 the method should be validated.

A.3 Method

A.3.1 The carrier contamination completely immersed in the test tube has been preheated to 60 °C ± 0.5 °C of 1mol/L ± 0.01mol/L of aqueous formaldehyde

Solution.

A.3.2 confirm Ranjun carrier is completely immersed in formalin instead of floating on the surface.

A.3.3 The protection technology to prevent accidental contamination during testing.

A.3.4 at the end of the set exposure time, remove the formaldehyde solution in the carrier contamination.

A.3.5 remove excess liquid carrier, which will be equipped with immersion filtered 2% Na2SO3 solution tubes 10min at room temperature,

The reaction on the carrier out of the residual formaldehyde. Cover tube. Try not to pay attention to stir formaldehyde solution and neutralizer in order to prevent "washed away" micro test biological.

NOTE. histidine and cysteine are effective neutralizers.

A.3.6 specific growth media should guarantee coverage test microorganisms.

NOTE. This test applies soybean casein digestive enzymes.

A.3.7 The carrier was transferred to a growth medium containing 10mL (A.3.6) tube. Cover tube.

A.3.8 The tubes were kept 90 °C 60min to stimulate spore activity.

A.3.9 Finally, the culture carrier (see ISO 11138-1.2006 in Chapter 7).

A.4 Determination of resistance

Resistance characteristic values are applied ISO 11138-1.2006 Annex C, D and Appendix E for a given method for determining the Appendix.

Appendix B (Informative)

Low temperature steam formaldehyde Biological indicators for liquid test method principle

B.1 General

To indicate Test method reproducibility, use of specific test equipment (resistance tester) and test methods. In the low-temperature steam

Formaldehyde sterilization process, the resistance tester formaldehyde gas concentration is extremely difficult to achieve a stable, because when a certain amount of formaldehyde injected into the container, will

A small amount of water droplets (condensate) dissolved formaldehyde appears. It was dissolved in water in accordance with the concentration of different temperatures, higher than in the gaseous

State concentration of 1000-fold to 10,000-fold.

Therefore, this part of the formaldehyde concentration can clear liquid test methods in order to achieve reproducible test methods.

B.2 low temperature steam formaldehyde sterilization processes

Even under continuous steam conditions and a stable concentration of formaldehyde gas sterilization process is still heavily dependent on the design of the sterilization chamber and the negative

Load characteristics thereof. Formaldehyde sterilization process can be simply divided into two steps.

a) in the steam sterilization process, the load surface will produce droplets condensate film, the condensation process is very fast;

b) because the formaldehyde concentration changes in the gas-liquid equilibrium state of great (1.1000 ~ 1.10 000), the time to reach the required balance

Relatively long, in practice, the time required for 10min ~ 2h.

The sterilization process depends on the concentration of formaldehyde in the liquid state, for example, the surface of the condensate. Confirm this equilibrium conditions constant term non-time

Often difficult.

references

[1] ISO 14161.2000 Sterilizationofhenlthcareproducts-Biologicalindicators-Guidancefor theselection, useandinterpretationofresults

[2] ISO 14937.2000 Sterilizationofhenlthcareproducts-Generalrequirementsforcharacter- izationofasterilizingagentandthedevelopmentvalidatinecontrolofsterilizationprocessfor medicaldevices

[3] EN14180.2003 Sterilizersformedicalpurposes-Lowtemperaturesteamandformalde- hydesterilizers-Requirementsandtesting

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