Cheap Seats 2020
One Trick Pony - 05/06
By Rich Trzupek
They say that when the only thing in a carpenter’s toolbox is a hammer, ever project looks like a nail. Similarly, if you’re a reporter obsessed with a particular chemical, every pandemic looks like it’s about ethylene oxide.
Last week in the paper that used to be The Chicago Tribune, ace environmental reporter Michael Hawthorne warned readers about the dangers of using N95 masks sterilized using ethylene oxide. Instead, he believes an alternative process should be used for sterilization, although it uses a compound that is even more dangerous.
OK, Hawthorne will self-righteously protest that he doesn’t advocate any such thing! He’s only quoting the experts! That’s journalism! And it would be, if he were interested in vetting experts, getting alternate points of view and having the wit to sort them out. Clearly that is not to Mikey’s taste. Like many modern “journalists” he’s built a career on fishing for “experts” who agree with whatever narrative he’s currently pushing.
In a shocking display of willful ignorance, Hawthorne penned a story that ran in the April 29 edition of the Trib warning about the dangers of off-gassing of ethylene oxide in N95 masks sterilized using that compound. How “off-gassing” would occur he didn’t bother to explain.
Off-gassing is a phenomenon that occurs when you have liquid residue in a product. Liquids have vapor pressures, meaning they will evaporate into gas phase over time. Some types of treated lumber will off-gas formaldehyde over time, for example. The key here is that you need the storage that the liquid phase offers before off-gassing can occur.
One of the reasons that ethylene oxide is used for sterilization so widely is that it has a boiling point of 50 F. At room temperature, as used in sterilization, all ethylene oxide is a gas. When the sterilization chamber is vented at the end of a cycle, all of the residual ethylene oxide gas is swept from the room. There’s no liquid, so there can be no “off-gassing.” Everything that’s been treated is ethylene oxide free.
This is not true of the alternative that Hawthorne’s “experts” are pushing: hydrogen peroxide. It has a boiling point of 302 F, meaning that there is a very real possibility of condensed hydrogen peroxide residue remaining in an N95 mask, or other medical equipment, treated using it.
No worries according to Hawthorne. Hydrogen peroxide is a common household disinfectant after all. Nothing to see here.
As the old saying goes: Beware of setting chemical exposure policies based on the advice of journalists with agendas. Using good old 3 percent hydrogen peroxide to swab out your kid’s scraped knee is a fine use of the chemical. It will do nothing but good. Putting on a respirator that may contain hydrogen peroxide residue is idiotic.
First of all hydrogen peroxide is a known animal carcinogen and possible human carcinogen. Like ethylene oxide, OSHA’s Permissible Exposure Limit (PEL) for hydrogen peroxide is 1 part per million by volume (ppmv). This is the maximum exposure OSHA believes is safe in the case of a healthy adult working an eight hour day.
But let’s compare the Immediately Dangerous to Life and Health (IDLH) concentrations of each. The IDLH is a concentration that the Centers for Disease Control establishes for inhalation of different chemicals. It’s the “taking a breath of this stuff is likely to kill you” dose.
The IDLH for ethylene oxide is 800 ppmv.
The IDLH for hydrogen peroxide is 75 ppmv.
So, to recap, according to ace reporter Michael Hawthorne, we should NOT treat respirators with a compound that is sure to remain is gas phase throughout the sterilization process and thus not contaminate the mask, but we SHOULD treat them with a compound that could condense out in the mask and thus off-gas over time and – the frosting on the cake – is more than 10 times likely to kill you when inhaled.