Winter and the Silent Killer

Winter, as they say, is coming,  and with it comes the silent killer.  And no, I’m not talking about cold temperatures, I’m talking about carbon monoxide.

When it’s cold we want to huddle inside our heated houses or cars and make sure there are no drafts to disturb our carefully controlled warm environments. But too little air exchange between where we’re staying toasty and the outside world can be dangerous sometimes—especially when we have a crack in the furnace heat exchanger or a damaged kerosene heater.  Carbon monoxide, the silent killer, can start to build up around us and our loved ones.

People take carbon monoxide for granted.  Let’s face it, it is an easy gas to forget until it’s too late. We seal up our house to save on fuel bills, never thinking about whether a little indoor/outdoor exchange of air just might keep us from dying.

Never take carbon monoxide buildup for granted. The CDC does everyone a favor by explaining the dangers.

Butane Boneheads

Fire fighters battle smoke

Here’s a good one for you taken from an article by Dan Ferguson with the Langley Times:

Langley fire blamed on cannabis oil extraction process

“The fire that sent a Langley Township resident to hospital last week was caused by a butane gas explosion while cannabis oil was being extracted from marijuana, investigators believe.

A 56-year-old man was transported to hospital by air ambulance after he suffered extensive burns in a noon-hour fire on Thursday, Aug. 11 in a house near 204 Street and 76 Avenue.

The victim was conscious and able to walk to the stretcher before he was loaded onto the ambulance.

He is expected to recover.

The fire was small and damage was limited to a portion of the house interior and an exterior deck.

Multiple, police, fire and ambulance units attended.”

Do they never learn?

It just goes to show that one good reason to legalize pot is to get these candy-ass pot extraction gurus out of the supply equation.  Butane is a dangerous gas for amateurs to handle.

Next time you’re thinking of doing butane extractions in your home, buddy, get a gas detector before you blow up your entire neighborhood.  There are enough safety issues in the gas world without amateurs adding to them.

 

Ethylene Prophecies

Temple of Apollo

Delphi Temple of Apollo

Fifteen years ago there was a radical geological discovery that would change our evaluation of an important facet of Ancient Greek culture.  It was first published in the Geological Society Of America’s Journal.  Here’s how they introduced the article’s premise:

“Scientists are revisiting the problem with results that would definitely please the ancients. In the August issue of GEOLOGY, J.Z. de Boer reports on a four-year interdisciplinary study that has successfully identified young faults at the Oracle site and has also pinpointed the emissions responsible for the Pythia’s (prophetess of Apollo) trance state—light hydrocarbon gases from bituminous limestone. De Boer and colleagues found ethane, methane, and ethylene in spring water near the Oracle.”

But although the public loved the idea, as time went by other scientists questioned the conclusion.  Ethylene gas, at various concentrations, can indeed act as a narcotic and induce the trance-like states reported at Delphi, but there are other considerations.

As Erowid points out, “At the turn of the 20th century, writers covering the first major archeological excavation at Delphi dismissed the “pneuma” stories as fable. Findings from later geological and chemical analyses appeared to support the view that the Oracle may have inhaled naturally occurring ethylene (ethene) gas as part of the ceremony. The research1 compiled is compelling, and received favorable coverage in the scientific and popular press.2,3,4,5

Given that measuring actual ethylene levels present at the temple site over 2000 years ago is impossible, the explanation is likely to remain speculative.

Recent critics6,7 of the ethylene theory have pointed out further issues. Foster and Lehoux, 2007, “argue that both the empirical evidence and the argument mustered by the de Boer team for the ethylene-intoxication hypothesis are inadequate for two reasons. The first reason is scientific: the concentrations of ethylene identified by de Boer, Hale, et al. would have been insufficient to cause a trance-like state. The second reason is historical and philosophical: the evidence and argument presented to link the mantic behavior of the Priestess to ethylene intoxication is dubious. In the conclusion, we suggest that this tenuous argument was widely propagated because it appealed to essentially positivist inclinations and sentiments in the science-reading public. Its conclusions appealed to these inclinations so effectively that readers did not notice the weak evidence and problematic argument mustered to support the conclusion.” (Foster J, Lehoux D. 2007)”

Unfortunately, Erowid is unintentionally in error.  The gas analytic methodologies utilized by de Boer’s team were not up to par and should be completely re-evaluated.  The first inadequacy was their time weighted average results were statistically irrelevant.  This was not, in my opinion, in any way a reflection of their professionalism.  Detailed analysis over a prolonged period was not their objective.

Also, there is the issue of whether their results—abbreviated as they were—could in any way be indicative of the levels of ethylene emissions back during the time the Temple of Delphi was active.  That would be impossible to say.

The issue of historical evidence is also therefore not relevant.

Therefore the entire issue is still open to further investigation.

 

 

Hydrogen Sulfide Absorption- Part 2 of 2

calibration gas kit

It’s hard to get an accurate H2S reading from your gas detector if the H2S part of the calibration gas keeps disappearing into the tubing.  People use a wide variety of tubing to connect their calibration gas to their gas detectors, including everything from Tygon to Teflon® to PVC, we’ve had the best result with Viton® fluoroelastomer tubing.

“Known for its resistance to oils and chemicals, this remarkable material retains its good mechanical and chemical resistance properties at extremely high temperatures better than any other known elastomer. Viton® is also a standout material in its resistance to weather-related aging and ozone. In fact, samples weathered in direct Florida sunlight showed little or no change in properties or appearance after 13 years of exposure. Viton’s® fluid resistance far exceeds that of most other synthetic rubbers. It is resistant to hydrocarbons such as benzene, carbon tetrachloride, toluene, and xylene — fluids that normally act as solvents on rubber, disintegrating the material; leading to tubing failure. Engineers looking for exceptional resistance to petroleum-based fuels, oils, lubricants, and mineral acids at elevated temperatures will often turn to Viton®, because most other thermoplastics cannot meet the necessary resistance levels.”

For once, I agree with the sales material.

In all my years of testing gas detectors H2S mixes, I can honestly say Viton® has never let me down.  Teflon® is too stiff.  Viton® tubing wins the prize.

 

Hydrogen Sulfide Absorption- Part 1 of 2

Sewer worker in sewer.

Are you wondering whether or not it matters which type of tubing you use to connect your gas detector to your calibration gas cylinder?  Well if you are, your main concern should be whether or not it will react or be absorbed with hydrogen sulfide.  For many tubing polymers, your biggest issue will be absorption, so you that’s what you should look for.  In part 1, we’ll look at a study that points the way to our mutual concerns.  It was in Water Research Volume 42, Issue 15, September 2008, Pages 4206–4214 and authored by Asbjørn Haaning Nielsen, , Jes Vollertsen, Henriette Stokbro Jensen, Tove Wium-Andersen, Thorkild Hvitved-Jacobsen.  Here’s the abstraction:

“Hydrogen sulfide oxidation on sewer pipe surfaces was investigated in a pilot scale experimental setup. The experiments were aimed at replicating conditions in a gravity sewer located immediately downstream of a force main where sulfide related concrete corrosion and odor is often observed. During the experiments, hydrogen sulfide gas was injected intermittently into the headspace of partially filled concrete and plastic (PVC and HDPE) sewer pipes in concentrations of approximately 1000 ppmv. Between each injection, the hydrogen sulfide concentration was monitored while it decreased because of adsorption and subsequent oxidation on the pipe surfaces. The experiments showed that the rate of hydrogen sulfide oxidation was approximately two orders of magnitude faster on the concrete pipe surfaces than on the plastic pipe surfaces. Removal of the layer of reaction (corrosion) products from the concrete pipes was found to reduce the rate of hydrogen sulfide oxidation significantly. However, the rate of sulfide oxidation was restored to its background level within 10–20 days. A similar treatment had no observable effect on hydrogen sulfide removal in the plastic pipe reactors. The experimental results were used to model hydrogen sulfide oxidation under field conditions. This showed that the gas-phase hydrogen sulfide concentration in concrete sewers would typically amount to a few percent of the equilibrium concentration calculated from Henry’s law. In the plastic pipe sewers, significantly higher concentrations were predicted because of the slower adsorption and oxidation kinetics on such surfaces.”

It’s a wonderful study on the issue of hydrogen sulfide interface with specific materials and well done.  It demonstrates the value of academic evaluation of issues vital to our gas detection community.  In particular, the elements of this study will surprise you for the discoveries relating to reaction and absorption in real world environment.

I was surprised that the element of humidity was dealt with rather off-handedly as I consider it a critical element in interface environment.  But that does not detract from its evaluation of oxidation kinetics et al.

The default tubing selected for reactive gases is Teflon, but it is not always the best selection.  Over the last ten years, alternatives have emerged that are worth considering.  We’ll detail them in the next post.

 

Carbon Monoxide and Eugenics

carbon monoxide

I’ve worked with carbon monoxide for so long that it reminds me of an old tiger.  Safer than the young Turk tigers so aggressively pacing the cage to stake out their territory.  Older tigers are safe if handled right, but still deadly.

Really, I’ve worked with carbon monoxide for so many years as an industrial and safety applied gas that sometimes I make the mistake of thinking that it’s like an old, tamed tiger, that, although deadly, just needs to be controlled.

Because of that familiarity, t’s hard to remember that carbon monoxide has a sordid past, just like many older tigers.  The horrible things they did that we don’t know about.  That’s how it is with carbon monoxide, which some think of as “the gentle poison.”

It was, sadly, a favorite of the United States Eugenics movement.  In a ruthlessly accurate article published in SFGate back in 2003, investigative reporter Edwin Black pointed out that:

“Eighteen solutions were explored in a Carnegie-supported 1911 “Preliminary Report of the Committee of the Eugenic Section of the American Breeder’s Association to Study and to Report on the Best Practical Means for Cutting Off the Defective Germ-Plasm in the Human Population.” Point No. 8 was euthanasia.

“The most commonly suggested method of eugenicide in the United States was a lethal chamber or public, locally operated gas chambers. In 1918, Popenoe, the Army venereal disease specialist during World War I, co-wrote the widely used textbook, “Applied Eugenics,” which argued, ‘From an historical point of view, the first method which presents itself is execution . . . Its value in keeping up the standard of the race should not be underestimated.'”

The gas to be used?  Carbon monoxide.

Carbon monoxide was used to euthanize and by some is still used to euthanize pets on an ongoing basis, but other hideous options have emerged.

So if you’re ever tempted to ignore OSHA warnings about carbon monoxide, you might re-read the OSHA Carbon Monoxide Fact Sheet.  If you don’t feel like it, maybe you’ll remember why the creepy Eugenicists wanted to use it.  Carbon monoxide may not seem like something to worry about compared to other work hazards, but remember the old tiger in the cage.

Carbon monoxide is never tamed, just handled safely.

 

H2S Calibration Gas Quality Blamed on Customers- Part 1 of 3

unhappy customers

 

H2S Calibration is still a problem for many calibration gas manufacturers.  They’re not happy about their H2S stability, ammonia stability or even nitrogen dioxide stability—unless they’re talking to customers because they want more business.    Then they say everything is fine with their hydrogen sulfide calibration gas.

Oddly, many of these same calibration gas manufacturer’s blame the problem on their customers.  Of course, this is done behind the customer’s back, but that’s what they do.

“Gas goes out of here just fine,” they say, “but after they’ve got their hands on it for a few weeks or a few months, the gas concentration goes to hell.”

You wouldn’t believe what big manufacturer told me that.

It doesn’t matter what the reactive gas mixture is, either.  I’ve heard customers blamed for everything from a MSA 10045035 (a 4 gas mixture with 20 ppm hydrogen sulfide/ 60 ppm carbon monoxide/ 1.45% methane/ 15% oxygen balance nitrogen in a 58 liter cylinder) cylinder where the hydrogen sulfide concentration fades to half its original value or an ammonia mixture that does the same thing.  Behind your back, calibration gas manufacturers are blaming you, the customer, for their quality problems.

That’s not good.  It’s kind of like blaming your little brother because you’re room is a mess.

But is there any truth that the customer is responsible for non-stable calibration gases?

Well, yes and no.

We’ll go into that in Part 2.

Gas Stability with a Bang

HF cylinder exploded

 

The following excerpt from a Purdue University posting regards the issue of time sensitivity for various compressed gases. In particular, they are concerned with Hydrogen Fluoride, Hydrogen Bromide. The picture shows how real the problems can be.
“The compressed gases listed above have a shelf-life provided by the manufacturer that must be strictly followed. There have been numerous incidents involving these compounds related to storage past the expiration date. For example, Hydrogen fluoride (HF) and Hydrogen bromide (HBr) cylinders have a shelf-life of one to two years, depending on the vendor. Over time, moisture can slowly enter the cylinder, which initiates corrosion. As the corrosion continues, HF and/or HBr slowly react with the internal metal walls of the cylinder to produce Hydrogen. The walls of the cylinder weaken due to the corrosion, while at the same time the internal pressure increases due to the Hydrogen generation. Ultimately, these cylinders fail and create extremely dangerous projectiles and a toxic gas release.”

Lest you think these type of problems are limited to pure HF or HBR, consider that they also site Hydrogen sulfide and Hydrogen chloride as problems too, and there are others.

The moral is that just because gas is in a cylinder, doesn’t mean it’s safe.

 

How to Ruin Your Calibration Gas

calibration gas regulator

 

Regulators are the saboteurs of the calibration gas industry.

Why?

Well, it’s common knowledge in the gas detector and calibration gas industry, but everyone hates it except the companies hawking calibration gas, including the OEM gas detector manufacturers, the distributors and the customers.

Every fixed flow regulator, like for example the MSA 467895,  should be screwed into a disposable calibration gas cylinder with the control knob in the “open” position.  Why?  To flush out the interior of the regulator.  Otherwise, with the regulator in the closed position, the room air inside the regulator can become part of the cylinder.  Room air is high in humidity.  You don’t want the gas from the cylinder slamming up to the regulator and adding that humidity (water) to the calibration gas you just paid so much money for.

Calibration gas manufacturers like this approach because the gas gets used up more quickly and you’ll have to buy calibration gas sooner.  Same for the gas detector companies like ISC, etc.

You use more gas, they make more money.

You’d think there would be a better way, wouldn’t you?  A way to screw in the regulator without ruing your calibration gas mixture.  Well, there is, but if nobody tells you, the gas detector companies, distributors and calgas companies can keep making more of your money.

 

Magic MSA 10045035 Calibration Gas?

10045035 msa

 

I like brand name products, like MSA 10045035 calibration gas.  I think we all do.  We feel safer when it’s a brand name—even if the “brand name” product is made by someone else then sold to the OEM brand name company.  Like, they’re magic.

But are they?

No, they’re not.

Scientists have proven conclusively time and again that labels aren’t the same thing as calibration gas.  But we knew that already, didn’t we?  It’s just that brand name labels always make us feel better.

I love MSA gas detectors.  Always have.  They’re great and the company that makes them are great.  However, they don’t make calibration gas.  None of the gas detector companies do.  They don’t even do a great job of quality assurance for their third party calibration gas manufacturers.  They’re primary concern is price.  I’ve watched them go back and forth between vendors for years.

All OEM gas detector manufacturers resell calibration gas.  They charge super high prices for the these gases and they like the profit.  But, honestly, if I want calibration gas for an MSA detector I’d buy it directly from a calibration gas manufacturers.  Why should I pay for a pass-through profit?

Seriously.

When put under the interrogation light, the gas detector manufacturers will whip out their “demanding specs.”  I’ve seen a lot of specs in my life, but less quality.  Specs don’t keep vendors under control.  Never have, never will.  Specs are what you show people who complain to shut them up.  Quality is a different matter altogether.

So I’d buy a high end MSA replacement actually made by a calibration gas company.  Don’t buy calibration gas from OEM’s  like MSA, ISC and Honeywell just to stuff money in their pockets.  Keep the money in your own wallet.

Calibration Gas Generators and Why They Suck

Unhappy Calibration Gas Generator Custoer

Unhappy Calibration Gas Generator Customer

 

Someone has to make a decent calibration gas generator.  The ones manufactured by ACD and Vici just plain suck.  I’ve heard so many complaints about them over the years I feel sorry for them.

We tried to interview the guy in the customer, but couldn’t get him to say the words “calibration gas generator” without him bursting into tears.  Go figure.

I’ve always liked the idea, but wish there was something better out there.  There are always ACD calibration gas generators for sale on eBay, but it’s hard to hold that against them.  eBay sellers will sell anything for a buck.  Come to think of it, that should be eBay’s new name.  AnythingForaABuck.com.

We’re going to do some research in this area to see what can be done.  And we’ll talk to customers using the gadgets and see why they think calibration gas generators suck.

 

Heat Distribution During Cylinder Fill

cylinder thermal distribution

This picture shows the thermal distribution of a 103 liter steel cylinder filled to 500 PSIG within 3 minutes.  It’s fascinating to see the limited heat transfer at the bottom of the cylinder.  Also the central heat mass in the center of the cylinder is worth noting.  (White and the lighter yellows represent the hotter portion.  Red, oddly, is cooler. 🙂  This interesting information when applied to the issues relating to manufacturing fuel oxidant blends.