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When it comes to EtO abatement, not all scrubbers are created equal
Ethylene oxide (EtO) emissions require precise and reliable control, not just for regulatory compliance, but for worker safety, community safety, environmental responsibility and operational stability. But with several air abatement technologies on the market, each with different pros and cons, how do you choose the right one?
The choice you make can impact everything from installation time to operating costs and maintenance requirements. And depending on your facility’s layout, EtO load and future growth, one approach might serve you far better than the others.
This post outlines three major EtO abatement technologies: acid scrubbers, smart scrubbers and bEtOfilter systems, and where each one fits best.
Regulatory pressure is increasing
In the U.S., the EPA has drastically lowered acceptable EtO exposure levels, pushing many facilities to consider upgrades or complete system replacements. The trend in Europe is similar, with more attention on workplace exposure limits and community emissions near sterilisation or production sites.
These limits are driving a shift: from “passable” scrubbers to “proven” ones. As enforcement becomes more frequent and technology more available, older systems using acid-based methods are being questioned, not just on performance, but on cost, safety and reliability.
The challenge: Balancing performance, safety and operational cost
The technical goal is clear: reduce EtO emissions to well below 1 ppm, reliably and sustainably. But operational teams also face:
Tight spatial constraints
Limited operator resources
Pressure to reduce chemical use
Complex approval processes for new CAPEX
Choosing the wrong technology can lock you into high maintenance and future limitations. Choosing the right one can give you control, flexibility and peace of mind.
A closer look at your options
Let’s break down the three most relevant scrubber types:
1. Acid scrubber (traditional)
Uses sulfuric acid to hydrolyze EtO
Requires chemical handling, refills and hazardous waste removal
Modest operating costs and maintenance
Proven in older installations
Best for: legacy systems where change is limited and handling chemicals is already integrated
2. Smart scrubber (catalyst-based upgrade)
Uses water and a solid catalyst
No acid needed
Stable long-term performance
Ideal for medium-to-high load situations
Best for: facilities wanting to retrofit existing acid systems or reduce OPEX and operator risk
3. bEtOfilter (low-load specialist)
Designed for low concentration, high volume, continuous EtO flows (e.g. aeration rooms)
Modest footprint
No chemicals
Passive system with minimal maintenance
Best for: sterilisation companies with consistent low-load EtO emissions looking for plug-and-play simplicity
For a look at how passive scrubbers are used as an alternative to thermal oxidizers, see our article on rethinking EtO control beyond combustion.
Real-world scenario: A sterilisation company retrofit
One sterilisation facility needed to replace its ageing acid scrubber. Their priority wasn’t just performance, it was operator safety and footprint. They also wanted to avoid any system that required regular chemical handling.
The solution? A smart scrubber retrofit using the existing housing and integrating a catalyst bed.
EtO emissions reduced from 1,500 ppm to <1 ppm
No acid procurement or disposal
Maintenance dropped from weekly to quarterly checks
What experts say
Erik, a senior engineer involved in Trevi’s scrubber development, put it this way:
“The smart scrubber removes the weak points of traditional systems: no acid waste, no headaches, lower cost.”
It’s a sentiment echoed across facilities looking to modernise.
Ready to choose?
There’s no one-size-fits-all answer. But by understanding your EtO concentration, layout, maintenance capacity and compliance timeline, the best option becomes clear.
If you're exploring options, start with these three questions:
What’s your average EtO load?
How much space and operator time can you allocate?
Are you open to retrofitting or is this a greenfield project?
For more tailored configurations, especially in constrained or mixed-load setups, explore how we approach custom engineering for complex EtO emissions.
Looking to assess your setup? Get in touch for a scrubber fit analysis based on your emissions profile and layout.