Residual Ethylene Oxide

Ethylene oxide is one of the most commonly used sterilization methods in the medical industry, thanks to its compatibility with most material used in the manufacture of medical device. However, ethylene oxide has the mutagenic potential and has been classified as a human carcinogen by the International Agency for Research on Cancer (IARC). Therefore, it is vital to ensure that the amount of residual ethylene oxide remaining on or in a device has been controlled in safe level before using a device sterilized in this way.

Types of Ethylene Oxide Residues

• Ethylene Oxide (EO) – the residue that may remain after processing has been completed
• Ethylene Chlorohydrin (ECH) – the residue that may form when EO comes into contact with free chloride ions
• Ethylene Glycol (EG) – the residue that may form when EO comes into contact with water

Residuals Ethylene Oxide testing is designed for identification and quantification of ethylene oxide, ethylene chlorohydrin, and ethylene glycol.

Standard for Residual Ethylene Oxide Analysis

• ISO 10993-7

STEMart offers residual ethylene oxide testing service utilized gas chromatography techniques described in the ISO 10993 standard for medical devices. This test helps manufacturers show the safety of products sterilized by EO by determining compliance with accepted residual limits.

Residual Ethylene Oxide Testing Methods

• Simulated use extraction

Determine the amount of residue the patient or user will be exposed to during routine use of the device with water extraction.

• Exhaustive extraction

The medical device is extracted until the amount of residue detected in an extraction is less than 10% of the amount detected in the first extraction, or until the cumulative residue levels detected do not increase significantly.

Extraction Methods

• Submersion

Submerse the device in the water.

• Fluid path

Fill the part of device in contact with patient or patient's body fluid with water.

Residual Ethylene Oxide Testing Technologies

• Gas Chromatography with Solid-Phase Micro Extraction
• Gas Chromatography using headspace sampling for ethylene oxide (ETO)
• Gas Chromatography water extracts for ethylene oxide (ETO)
• Gas Chromatography water extracts for ethylene chlorohydrin (ECH) and ethylene glycol (EG)

STEMart provides accurate residual ethylene oxide testing to help manufacturer to ensure the residues in their product meet the limits set in the ISO 10993-7 standard. If you have additional questions about Residual Ethylene Oxide testing or would like to find out more about our services, please feel free to contact us.

Reference

• International Organization for Standardization. Biological evaluation of medical devices — Part 7: Ethylene oxide sterilization residuals. Geneva (Switzerland): ISO 10993-7; (2008).