GB/T 18280.2-2025 Sterilization of health care products - Radiation - Part 2: Establishing the sterilization dose
1 Scope
This document specifies methods for determining the minimum dose needed to achieve a specified requirement for sterility and methods to substantiate the use of 15kGy, 17.5kGy, 20kGy, 22.5kGy, 25kGy, 27.5kGy, 30kGy, 32.5kGy or 35kGy as the sterilization dose to achieve a sterility assurance level (SAL) of 10-6, as well as methods of sterilization dose audit used to demonstrate the continued effectiveness of the sterilization dose.
This document defines product families for sterilization dose establishment and sterilization dose audit.
This document is applicable to the establishment and maintenance of radiation sterilization dose for medical devices.
Note: This document is applicable to medical devices, but the establishment and maintenance of radiation sterilization dose may be applicable to other products.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB 18280.1 Sterilization of health care products - Radiation - Part 1: Requirements for development, validation and routine control of a sterilization process for medical devices (GB 18280.1-2025, ISO 11137-1: 2025, MOD)
GB/T 19973.1 Sterilization of health care products - Microbiological methods - Part 1: Determination of a population of microorganisms on products (GB/T 19973.1-2023, ISO 11737-1: 2018, IDT)
GB/T 19973.2 Sterilization of health care products - Microbiological methods - Part 2: Tests of sterility performed in the definition, validation and maintenance of a sterilization process (GB/T 19973.2-2025, ISO 11737-2: 2019, IDT)
ISO 13004 Sterilization of health care products - Radiation - Substantiation of selected sterilization dose: Method VDmaxSD
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in GB 18280.1 and the following apply.
3.1.1
batch
defined quantity of a product intended or purported to be uniform in character and quality, which has been produced during a defined cycle of manufacture
[Source: GB/T 19973.1-2023, 3.1]
3.1.2
bioburden
population of viable microorganisms on or in product and/or sterile barrier system
[Source: GB/T 19633.1-2024, 3.2]
3.1.3
false positive
test result interpreted as growth arising from the product, or portions thereof, tested when either growth resulted from extraneous microbial contamination or turbidity occurred from interaction between the product, or portions thereof, and the test medium
3.1.4
fraction positive
quotient in which the number of positive tests of sterility is given by the numerator and the number of tests performed is given by the denominator
[Source: ISO 11139: 2018, 3.122]
3.1.5
incremental dose
dose within a series of doses applied to a number of products, or portions thereof, and used in a dose setting method to obtain or confirm the sterilization dose
[Source: ISO 11139: 2018, 3.138]
3.1.6
negative test of sterility
test result for which there is no detectable microbial growth from product, or portions thereof, subjected to a test of sterility
3.1.7
packaging system
combination of the sterile barrier system and protective packaging
[Source: GB/T 19633.2-2024, 3.11]
3.1.8
positive test of sterility
test result for which there is detectable microbial growth from product, or portions thereof, subjected to a test of sterility
3.1.9
sample item portion; SIP
defined portion of a health care product that is tested
[Source: GB/T 19973.2-2025, 3.10]
3.1.10
standard distribution of resistances; SDR
reference set of resistances of microorganisms and corresponding probabilities of occurrence
[Source: ISO 11139: 2018, 3.263]
3.1.11
sterile barrier system
minimum package that minimizes the risk of ingress of microorganisms and allows aseptic presentation of the product at the point of use
[Source: GB/T 19633.2-2024, 3.25]
3.1.12
sterility assurance level; SAL
probability of a single viable microorganism occurring on a product after sterilization
Note 1: It is expressed as the negative exponent to the base 10.
Note 2: The term SAL takes a quantitative value, generally 10-6 or 10-3. When applying this quantitative value to assurance of sterility, an SAL of 10-6 has a lower value but provides a greater assurance of sterility than an SAL of 10-3.
[Source: ISO 11139: 2018, 3.275, modified, Note 2 added]
3.1.13
sterilization dose audit
exercise undertaken to confirm the appropriateness of an established sterilization dose
[Source: ISO 11139: 2018, 3.281]
3.1.14
test of sterility
technical operation performed as part of development, validation, or requalification to determine the presence or absence of viable microorganisms on product or portions thereof
Foreword i
Introduction iv
1 Scope
2 Normative references
3 Terms, definitions and abbreviated terms
4 Definition and maintenance of product families for dose setting, dose substantiation, and sterilization dose audit
5 Selection and test of product for establishing the sterilization dose
6 Methods of dose establishment
7 Method 1: dose setting using bioburden information
8 Method 2: Dose setting using fraction positive information from incremental dose experiment to determine an extrapolation factor
9 Method VDmax——Substantiation of the selected sterilization dose
10 Sterilization dose audit
11 Worked examples
Bibliography
