GB/T 38499-2020 in English

Definition of stability: The ability of a disinfectant to remain effective for use after being stored under specified conditions, which is quantitatively evaluated by the rate of change of the active ingredient content (≤10-15%) or the maintenance of the microbial killing ability.

1. Sample requirements

Must use shaped packaging disinfectant, 3 independent production batches, and large barrel packaging must use simulated small packaging with the same material.

2. Instrument accuracy

• Constant temperature and humidity chamber: temperature ±2℃, humidity ±5%
• Lighting test chamber: illumination control 4500lx±500lx

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3. Evaluation criteria

Enterprise execution path

1. New raw materials must be tested: New active ingredients must be tested for strong light exposure
2. Double verification: Accelerated test results must be confirmed by long-term testing
3. Packaging labeling: 25°C storage conditions must be marked with the "Avoid high temperature" warning

Recommended testing frequency

Test phase	Test time point
Long-term testing	0, 3, 6, 9, 12 months (extended to 24 months)
Accelerated testing	Immediate testing after the test

This standard systematically integrates the three major method systems for disinfectant stability evaluation for the first time. Compared with the 2002 version of the Technical Specification for Disinfection:

• Newly added strong light irradiation test as a mandatory test for photostability
• Refine the correspondence between accelerated test and shelf life
• Clarify the priority principle between chemical method and microbiological method