H₂O₂ / Plasma: Big Lies, Little Chambers

No. EO is not being banned, nor is it currently banned in certain areas. EO continues to be broadly used for processing food products, cosmetics, manufacturing and medical devices. It is a critical sterilant widely used to keep medical devices, implants, endoscopes, (and many more items) safe.

In fact, more than 20 billion devices (approximately 50%) sold in the U.S. annually are sterilized with EO. In many cases EO is the ONLY way these devices can be sterilized because of its highly compatible and gentle nature.

During the deadly 2015 carbapenem-resistant Enterobacteriaceae (CRE) outbreak, the FDA recommended four supplemental reprocessing measures, which included EO sterilization as the most effective in assuring the complete inactivation of highly resistant organisms. (More…)

We are very proud of our working relationships with FDA and many other regulatory agencies. Andersen has 18 FDA clearances (all awarded since 2015) and six regulatory marks and approvals for our innovative line of sterilizers.

• We hold the first and only FDA clearance for terminal sterilization of duodenoscopes – up to 11.6 feet long and down to 1.2 mm diameter (that’s very long and very narrow).
• Andersen recently won two national awards for our proprietary ultra-low emission technology. One of them was the FDA Innovation Challenge.
• Andersen representatives sit on several FDA committees and there is no talk of “getting rid” of EO.

Generally, household H₂O₂ (in that brown bottle) is 3% concentration,1 while sterilization H₂O₂ is at least 50% concentration. Some sterilizers concentrate it to over 90%.2 For comparison: Rocket fuel is 80-90%.3

A recent report chronicling a scholarly search through FDA’s “MAUD” adverse event database for harm caused by H₂O₂ sterilizers revealed many reports describing several types of injuries.

No. That is untrue. Anytime a sales representative tells you their sterilant is not toxic, you should immediately be concerned (how, then, is it killing microbes?). Below is a comparative toxicity table containing industry regulatory toxicity limits for both sterilants. As you can see, the sterilants rate very similarly.

The IDLH and WEL (in red) have more stringent limits for H₂O₂ than for EO – in the case of IDLH, it’s 10x lower for EO. Pressure is mounting from many sides to set the as-yet undetermined Short Term Exposure Limits or STEL (–) for H₂O₂.

“Plasma” the word itself sounds cutting edge and new. But it’s not. It’s just another word for hydrogen peroxide. Definition: Plasma is what happens when H₂O₂ gas under deep vacuum is hit with radio frequency or microwave energy.4

The first H₂O₂ sterilizer hit the market in 1993 – making plasma nearly 30 years old – a “new” version came out in 1998.4

It is far from true that EO technology has stagnated. Andersen received its most recent 510k FDA clearance for a new sterilizer in 2020. As mentioned above we have 18 recent FDA clearances, the FDA Innovation Challenge Award and another recent national award for our proprietary technology.

Ask your H₂O₂ rep where and when their sterilizer “cracks” – or breaks H₂O₂ down. It is often outside the cabinet. If it is inside the cabinet, it restricts chamber space and the chemicals are often not fully broken down by the time you open the door – exposing operators to amounts far above OSHA levels.

There are some serious arguments against H₂O₂ being “green” at all.

Also, if “green” status is awarded simply for a sterilant breaking down into something harmless, EO could also qualify. EPA says, “Ethylene oxide reacts in the air to form formic acid, which is a naturally occurring chemical.” And, as Nature.com asserts, “Formic Acid is one of the simplest and most abundant organic molecules in Earth’s atmosphere…”

Does that feel disingenuous to you? Of course it does! While both sterilants break down into harmless elements, what everyone is worried about is how toxic each chemical is before it breaks down – when operators are potentially exposed to it.

Instead of pretending our sterilant isn’t dangerous, we put many redundancies and safety measures in place. It’s all about smart design and stellar training and service. We’d love to talk to you about this in full detail.

Yes, you absolutely do. All chemicals capable of achieving terminal sterility are inherently dangerous. Under the OSHA General Duty Clause, employers have an obligation to protect workers from serious and recognized workplace hazards even where there is no standard yet set.

One of the hallmarks of H₂O₂ / Plasma is that it corrodes the sterilizer and creates malfunctions leading to leaks. There is ample evidence operator exposure at unsafe levels happens frequently. This list is by no means exhaustive.

• The recent report mentioned above chronicling a scholarly search through FDA’s “MAUD” adverse event database for injuries caused by H₂O₂ sterilizers revealed: skin burns, respiratory complaints, headaches and eye irritation – among other types of harms.
• Anecdotal reports from a ChemDAQ customer showed H₂O₂ levels of 20-40 ppm at the end of each cycle (keeping in mind that one tech may unload 4 every hour).
• Curious about what the two largest H₂O₂ sterilizer manufacturers have to say about one another? STERIS circulated this report on STERRAD and then STERRAD responded with this report on STERIS. Both reports document unsafe levels of off-gassing.
• A 2012 IDI report analyzed H₂O₂ levels around four H₂O₂ sterilizer models on the market and found the levels were “much higher than expected.” One generally reached around 80 ppm when the door was opened at the end of the cycle and occasionally up to 140 ppm.

So, if you do choose H₂O₂, how will you monitor for exposure?

Andersen offers easy-to-use personal monitor badges and recommends they be used on installation, once a year and anytime the sterilizer is moved or reinstalled.

Is it? It is faster for sure. But let’s look at that math. If you use it at top efficiency, your staff will need to fill and empty it about 20 times a day (every 32-48 minutes, depending on the sterilizer). Usable chamber space is often quite small.

Keep in mind this point (emptied 20 times a day) and the point above regarding operator exposure upon opening the door: If one tech is “baby-sitting” the sterilizer, that could mean unsafe exposure levels 20 times in one day!

With an Andersen sterilizer, there’s no need for your techs to run back and forth all day, feeling like they’re trying to empty the ocean with a spoon. We have several options to accommodate your work flow: easy one-and-done, fast or many independent loads in one sterilizer. Also, you don’t need to hope no one is being exposed to unsafe levels of a sterilant with Andersen. You can just test for it.

You will see claims of zero residuals on most H₂O₂ sterilizer websites and literature. Sometimes within a few pages of a statement like, “If white residue is visible on the load, this may be hydrogen peroxide residue. The load will need to be reprocessed to prevent potential injury to the patient.”

That same 2012 report mentioned above chronicles the results when researchers analyzed H₂O₂ residuals on panels made from 11 different types of plastic, on plastic skin staplers and on mock cystonephrofibersopes and bronchofiberscopes.

• 5 of 11 plastic panels showed residuals over 100 ppm immediately after sterilization.
• The mock flexible fiberscopes showed more than 10 ppm for 18 – 40 hours.
• The plastic skin staplers started at 300 ppm, took 24 days to reach 1 ppm and 44 days to reach 0.1 ppm.

Quick reminder: NIOSH set Immediately Dangerous to Life or Health (IDLH) at 75 ppm. And OSHA‘s 8 hour Permissible Exposure Limit (PEL) is 1 ppm.

What we want you to know about
H₂O₂ & EO …

At Andersen we strive to be a resource for you; the sterilization expert on your team. Your salesperson becomes your account representative and operator trainer. You get free training for the life of your sterilizer and emergency support available 24/7/365. In short: We’re here for you in a very literal sense.

We would love to chat about your needs, all your sterilization options and what will ultimately meet your goals.

There are pros and cons for every method and we absolutely encourage honest and open discussion. To help get that conversation started, we’ve created a side-by-side comparison chart for both modalities.

In the table below, the far left column shows which, in our opinion, “wins” on each point – H₂O₂ / plasma in red or EO (Andersen) in teal. As previously discussed, it’s pretty much a draw on toxicity so neither side got it.

One easy-to-see difference, is H₂O₂ / Plasma sterilizers tend to have a large footprint and relatively small chambers. In comparison our sterilizers fit on a counter or a table and the chamber takes up the vast majority of the machine, give you maximum flexibility.

All measurements below are for the chambers (other than the background 5’4″ line).

Below is a detailed comparison table of available H₂O₂ / Plasma sterilization options in the veterinary market against Andersen sterilizers. Each sterilizer name provides a link to its company-owned product information webpage or user manual so you can do further research on your own. Also, when we say “functional capacity” we mean the actual area you can fill with items to be sterilized.

detailed Sterilizer Comparison: H₂O₂ vs. Andersen Sterilizers

Two important notes:

On Sterlink: Keep in mind only the 36 min cycle is FDA-Cleared. They talk about sterilizing single-channel Teflon® / Polyethylene lumen >1.25mm and <600mm but that is NOT included on their FDA clearance.

As for the rest, it all depends on your needs. The functional capacity is very small (3.8x smaller). When calculating cost, keep in mind to calculate 3.8x the cost of all consumables – assuming you’ll be running at full capacity. So for instance their gas costs $5.50 a load x 3.8 =$20.90 in just sterilant (to sterilize the same volume).

On Tuttnauer: All of the PlazMax sterilizers are NOT FDA-Cleared and they don’t claim a sterility assurance level.