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Ethylene Oxide (EtO) Analyzer

Fast, accurate, real-time measurements of Ethylene Oxide at the Fenceline.

What is
Ethylene Oxide?

Ethylene oxide (EtO) is a key carcinogen that is widely used in medical sterilization centers and produced in industrial chemical plants. It's primarily used as a sterilant for commercial medical sterilizers and the food industry. It is also an intermediate product for glycols, ethoxylates, and ethanolamines in chemical manufacturing.

Why monitor EtO at the fenceline?

Recently, the U.S. Environmental Protection Agency (EPA) has determined that the “confidence in the hazard characterization of EtO as ‘carcinogenic to humans’ is high” and is seeking to lower the human exposure limits to EtO from ppm (parts per million) to safer ppb (parts per billion) values.

Facilities emitting EtO into the ambient air are located near businesses, schools, and residential communities where people unknowingly breathe in the trace amounts of released gas. As a carcinogenic, breathing in EtO can increase your risk for certain types of cancer. To ensure the safety of the surrounding communities, the EtO levels at the perimeter of the emitting facilities need to be closely monitored for compliance with the regulatory limits of this harmful gas in ambient air.


How is Ethylene Oxide currently measured?


The current EPA Methods are TO-15 and TO-15A:

  1. A discrete air sample is captured in a Summa canister and shipped to a laboratory for analysis.

  2. The canister contents are directed through a solid adsorbent which pre-concentrates the volatile organic compounds (e.g., EtO) as well as some common air constituents (e.g., CO2).

  3. Cryogenic cooling is then used to remove most of the CO2 prior to compound separation via a gas chromatography column.

  4. The EtO concentration is measured via selective ion or scanning mass spectrometry.


This multi-step method has several limitations that makes it difficult to address the emerging EPA need to measure low ppt-levels of EtO. It has cross-interference with other gases, has issues with natural production of EtO in storage, and takes multiple days—if not weeks—due to air samples transport to the lab for prep & analysis.

Blue Skies

EtO Real-time Detection Made Simple.

Nikira Labs' Ethylene Oxide Analyzer (EOA) is a next-generation instrument for real-time, high-precision measurements of ethylene oxide. The EOA is based on Cavity-Enhanced Absorption Spectroscopy technology to measure the EtO concentration in ambient air. This proactive in-situ realtime capability simplifies the time-delayed "grab sample" process to make the EtO data insight accessible and actionable in realtime.


Nikira Labs
EtO Analyzer

  • Built for Flexible Fenceline Monitoring

    • 22” x 9” x 5.5” (56cm x 23cm x 14cm)

    • Weighs a feather-light 4 Kg / 8.8 lbs

    • Built-in WiFi accessibility

    • RS-232, USB-A, HDMI Ports

    • Low sub-30 Watt Power Usage

  • Extremely Precise, Real-time EtO Measurements

    • Measurement Range1 ppb - 1 ppm

    • Precision of < 2 ppb (1sigma, 1sec)

    • Data Rate of 1 Hz

Real World Applications


The EtO analyzer was placed in a car and driven near an EtO sterilization facility. The EtO increase over a median smoothed baseline was determined, and EtO spikes greater than 1.2 pbb were deemed to be observations (blue dots).


EtO spikes were consistent with expected downwind monitoring of facility (green dot) as determined by HYPLIT trajectories.


In stationary deployment, the analyzer and sonic anemometer were placed proximate to the EtO source (1 ppm EtO/air flowing at 2 SLPM). The leftmost figure displays periodic EtO spikes as wind direction changes. The rightmost figure plots EtO versus wind direction, which provides a clear indication of where the source location is.

Questions? Need More Information?
Let us know about your needs and we will assist you. 

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