Standardization of color change interpretation for sterilization chemical indicators: A multicenter analysis aligned with international safety color standards.

Abstract

Background: To establish a standardized framework for interpreting color changes in chemical indicators (CIs) in sterilization, and improve accuracy and clinical feasibility.

Methods: A questionnaire was administered to 902 health care professionals to evaluate their interpretation difficulties, confusion rates, and support for a unified color standard. In addition, pre- and post-sterilization CI color data were collected across 4 sterilization modalities: steam (n = 74), hydrogen peroxide plasma (n = 63), ethylene oxide (n = 38), and formaldehyde (n = 28). Data were compared with ISO 11140-1:2014 and GB/T 18282.1-2025.

Results: Among clinical staff, 32.71% reported interpretation difficulties, with the main reasons being ambiguous color changes (58.3%) and non-uniform standards (41.7%), and 25.17% had confused indicators for different sterilization modalities. Notably, 87.36% supported a unified color standard. Post-sterilization color changes varied markedly across and within modalities: steam predominantly turned black, plasma predominantly turned yellow, ethylene oxide predominantly turned green/blue, and formaldehyde predominantly turned green.

Conclusions: The current lack of cross‑manufacturer harmonization in CI color‑change schemes leads to confusion and misinterpretation risks among clinical staff. A unified, intuitive color‑change standard, preferably based on an international safety color system, is urgently needed to improve the accuracy and practicality of sterile package assessment, thereby ensuring patient safety and reducing clinical risks.