Monitoring of Ethylene oxide

Ethylene oxide

Ethylene oxide (EtO) is an organic compound, defined by the formula C2H4O. Ethylene oxide is a colorless and flammable gas with a faintly sweet odor. Ethylene oxide is produced by oxidation of ethylene in the presence of a catalyst.

EtO is a toxic gas that leaves no residue on items it contacts. Hence EtO is a surface disinfectant that is widely used in hospitals and in the medical equipment industry to replace steam in the sterilization of heat-sensitive tools and equipment, such as disposable plastic syringes.


Monitoring of Ethylene oxide

The odor of EtO cannot be detected below 700 ppm.  As such, ethylene oxide monitoring — via instrumentation — has long been practiced.

The cheapest monitoring equipment uses a metal oxide semiconductor device, also called a MOS. These sensors should be considered as a first response monitoring tool. They allow to take quick action in case of leaks of EtO. They allow to monitor EtO and keep it safe under a set concentration. These sensors are suited when accuracy is less important than alert triggers or historical trends.

Another method for detecting EtO is a gas chromatographic on which we will not further elaborate because very expensive and not practical in the field when continuous monitoring is necessary. Another ethylene oxide monitoring technique is infrared. This technique is also expensive and is known to have problems with steam, moisture, and ammonia. Sensitivity can also be an issue.

EtO badges are often employed in public services. Badges are not instruments, and do not give real time data. Most badges must be mailed to a laboratory to determine personal exposure results. Not only is this after-the-fact information, but it can also be misleading. The badges only yield a single-number integrated average. Short term high exposures are simply averaged into the single number. Thus, a true time history cannot be provided. As such, in some cases, the results could actually be worse than the badge is able to indicate.


Ethylene oxide monitoring in the cloud

By combining a MOS sensor with a cloud device, InsightAir brings the data into the cloud. This allows for trending long term historical data and fast-response alerts in case of exceeding a set limit. The user of the system gets a login and password to InsightAir’s cloud dashboard, allowing instant access to the data of the ethylene oxide monitoring device.  The system can be used as an early warning system – the rising EtO concentrations are detected rapidly and warning signal is sent to the users.