Home Podcasts THMG147 – Hydrofluoric Acid Series, Part I: Introductions

THMG147 – Hydrofluoric Acid Series, Part I: Introductions

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We begin in this episode a series on that dastardly acid called Hydrofluoric. In this episode we explore the chemical a little bit and set up for the rest of the series.

My apologies for the mic on Bob, there was a problem with a little scratchiness.

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  • uses
        • HF like so many other acids are have so many uses that you find them in every corner of your neighborhood. This acid however is a little different. We see very very little use for this acid on the retail level.
          • This means that we will not likely see this in the residential setting. While i am sure there are a ton of uses for it at home, the absolute toxicity of this chemical doesn’t play well on that hole risk benefit thing.
          • I always find it good to run threw a basic list of how things are used. It almost does two things. the first is that it give you and idea of how this chemical reacts. The second is an idea of what situation you might find it.
            • So some random facts about its uses. It has the ability to dissolve sedimentary rocks. Geologist use this stuff to get to small fossils.
            • Which makes it a perfect ingredient for drinking water.
              •  how does it make it a perfect ingredient for drinking water
                • it doesn’t but i didn’t have any other segway. just go with it.
                  •  ok
                  •  Here is a perfect example of a substance that is toxic having a therapeutic dose and benefit. Drinking what amounts to be extremely toxic stuff in small dose can help you.
  • The small amount of fluoride ions we drink in the water goes into your saliva and strengthens the enamel on your teeth.
              • Interestingly or not interesting depending on your point of view, HF is chemical that florinates the water but what is actually added to the water is usually Silicofluoride.
                • The Silicofluoride breaks down to HF. There are 2 other chemicals that are frequently used to do the same things, so don’t just assume that your local water treatment place has HF on site.
          • Hf is used as a precursor for making other things. like to separate uranium isotopes.
            • It is used in pharmaceuticals industry and the creation of most of the fluorinated halocarbons that we loving call refrigerants.
            • The electrical component world utilizes it in the creation of a lot of the electronics that go into circuit boards, wire filaments, semiconductors and metal parts.
            • Cleanears, rust removers, herbicides, glass etching. The list goes on and on and on. This is a really great example of why it is important to know your area, and don’t just assume that an industry doesn’t use it. Go knock on the door and check them out.
          • EPA regulations require that if an industry has more than 1000 gallons that is 50% or greater in concentration, a risk management plan is submitted. across the nation there have been close to 300 facility that have submitted for these plans.
            • However you will be able to gain a better idea of HF in your area by looking at your Tier II reporting system.
  • exposure
      •  From a Physical property standpoint we commonly see HF in two forms. Both in a liquid and a gas, This point often confuses people that are new to the hazmat world.
        • The first form we find it it is a gas. And like many gasses it will be transported and used in a high pressure cylinder. Which is cool because cylinder have a few ways to identify the product inside. One way is the valve number. for Hydrogen fluoride the valve number is going to be 660.
          • The tank sizes can vary from a 10in X 48 inch, 23 in X 66, and even some small ones in the 9 x 19 range. But one things that will remain the same is they will all be a steel tank.
          • IT’s a gas with a molecular weight of 20. and its IDLH is about 30 ppm.
            • So a pretty badass chemical with Regard that is enough to want to rise but it’s also going to chilled coming out of the cylinder and be interacting with moisture in the air. So don’t be so fast to think it won’t be hanging around. Use your meter reading to help dictate your actions.
              • But not your PID because the IP is greater than 15 ev, so even some of you overachievers out there with high power bulbs wont pick it up.
          • now let’s take a look at some other physical properties. The boiling point is 67 F. and the VP is 788 mmHG. We are right on the cusp of this this product being a boiling liquid. Infact in colder temputrate or anything less that 67 degrees it has the ability to be found as a liquid with a very high VP.
        • Let’s shoot over and take a look at the liquid form. And i really shouldn’t use the word Liquid form because from what we just said it is going to make it sound like it’s the gas form but has been chilled. And that couldn’t be further from the truth
          •  When we speak of the liquid form we are referring to the Aqueous form. The aqueous form a substance is that chemical mixed in with water. So HF is dissolved in water in varying degrees and we call this Hydrofluoric Acid.
            • This is very similar to the difference between anhydrous ammonia and the ammonia we use to clean our countertops. the HF is dissolved in the water. This causes the H and the F to break off into separate ions.
              •  Just like ammonia we see HF shipped in both forms and used in both forms.
              • The more hydrogens and Florines disassociate from each other the stronger the acid is. Which is interesting because for all the damage this acid can do to tissue, Rocks, glass etc it is actually considered a weak acid.
                • That amazing considering the list of materials that this stuff does not play nicely with. Here is an expert of an SDS sheet under incompatibilities, “Substance is incompatible with over 35 specific chemicals. Please refer to the NFPA Fire Protection Guide for specifics. Heat. Glass, concrete and other silicon-bearing materials will yield silicon tetrafluoride. Pressure build-up from this process has been known to blow up glass containers. Carbonates, sulphides, and cyanides will yield toxic gases such as carbon dioxide, hydrogen sulphide and hydrogen cyanide. Alkalis, some oxides, fluorine and other water-reactive materials will cause strong exothermic reactions that can be violent. Reacts with most common metals to produce hydrogen. Corrosive to many materials, including leather, rubber and many organics.”
      • this stuff kind of has its own little world of myths and legends associated with it. May of them have to do with the pathophysiology behind how this stuff hurts you
        • It’s not like a normal acid that makes contact with your skin. Most acids will just give you a bad burn. But not HF, HF is the gift that keeps on giving.
          • That’s true but it will still mess up your tissue just like a normal acid. So the degree by which you get “burned can be directly related to the concentration of the acid and the amount of time the acid was in contact with the tissue.
            • Which is kind of unfortunate because HD is one of the few acids that can causing a numbing sensation when exposed for a short period of time. Many of the deaths associated with skin exposure were because people didn’t think they were as contaminated as they were and delayed decon and medical treatment.
          • So we got the burn down. how does this product keep hurting us. First things it does is go deep into your tissue. This accomplished because the F ion is highly lipophilic. (that means it gets along with lipids or fats).
            • As it gets into your tissue it is brought into the cell where it starts to mix and party with the calcium and magnesium in your cells.
              • Wait so it not going after the bones in your body?
                • nope. it’s going after free CA and Mg ions in your cells
              • nasty little fella. because as it reacts with the Ca and Mg it is forming crystals. these crystals fall out of solution and make the Ca and Mg ions that were once floating around and ready to use unavailable for use.
                • This is true unfortunate because we have one or two really vital function that depend on Ca.
                  • give an example.
  • well every signal on every neuron uses Ca to communicate with other neurons. With out that our Central nervous system cannot communicate with the body.
  • The heart beats because of these ca channels and other ion channels that rely on the existence of Ca. no calcium no thump thump.
                  • This drop in Ca and Mg serum is called hypocalcemia and hypomagnesemia. It’s also the driving force behind the extreme pain and cramping that is associated with you last few hour on earth after being exposed to this stuff.
          • So then the next question becomes how much does it take to hurt you and how long?
            • at 3% solution it can take hour even an overnight period before the patient is even aware that they have been exposed. But that just from the burn.
              • to give some ideas, there have been cases of 1% of the body exposed to 50% concentration was enough to produce hypocalcemia
                •  and exposure of 5% of the body with any concentration acid is enough to lower your calcium blood serum.
              • 2.5% body surface contamination can be lethal within 2 to 3 hours. With 2.5% body surface contamination being the min needed for lower concentrations.
            • some real life examples
              • this is a direct quote from a case study. “A 37 year old male laboratory technician was performing acid digestion of oil well core and ditch samples with 70% w/w concentrated hydrofluoric acid in a fume cupboard. He was believed to be seated when he knocked over a small quantity (100- 230 ml) of hydrofluoric acid onto his lap, splashing both thighs.His condition continued to deteriorate despite subcutaneous injections of calcium gluconate and administration of intravenous calcium and magnesium. His right leg was amputated 7 days after the incident. He subsequently died from multi-organ failure 15 days after the hydrofluoric acid spill.”
              • An earlier fatality in 1980 resulted from burns to only 2.5% of the body.A worker who was dealing with a solution containing 5% Hydrofluoric acid had gloves that contained a pinhole. When she consulted her doctor later for pain in her finger a non-specific burn ointment was applied. After several days the damage had developed to the extent that when, still in pain, she finally presented at hospital it was necessary to amputate her finger, due to the serious and irreversible damage that the acid had done to the bone.
          • small take away from this is Calcium gluconate. the idea of this drug is to give calcium to the florida before it drops your levels.
            • While its a great idea to make sure the drug is standing by on scene just in case it is not a fail safe or a magic pill. There are alot of factors that go into living and dying. So don’t do something stupid because you think you have the antidote,
    •  PPE selection
      • So due to the nature of HF. The VP, The low IDLH the acidity and its ability to absorb through the skin a level A is going to be what I think about first
        • With that being said, That is our starting point. We have to take everything into consideration. Remember people working with this stuff on a regular basis are not in a level. So use your meters, use your size up and use the situation to determine what is best
        • This is definitely one of those times that you want to cross check every single piece of PPE to make sure it is compatible. Like the case study showed, even a small imperfection in your PPE can result in death.
      • Personally when it comes to decon i think i would prefer a system that doesn’t use water, that doesn’t spray the crap everywhere. Some kind of a system where you wipe the contaminate off you….. but alas that is topic for another show.
The Hazmat Guys

Author: The Hazmat Guys

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