# Realistic chemical spill accident in high school chemistry class

In a story I'm writing, a teenager spills chemicals on herself in a high school chemistry class, causing her to be put under the safety shower. The spill destroys her clothes and causes minor burns. I would like this to be realistic and since I know nothing about chemistry, I have two questions:

• Is there a chemical used in high school chemistry that when spilled could cause this situation to occur?

• If so, do you know of an experiment that would use that chemical?

• Seems realistic to me, assuming high schools still do chemistry practicals. A large spillage of even dilute hydrochloric acid would have me putting the victim under the emergency shower just to be on the safe side. Others should be able to comment on the sort of chemicals high schools use as I'm not American and long out of education I don't know. – Waylander Mar 29 '17 at 12:52
• As Waylander said, for stains KMnO4 (routinely used in redox titrations) is by far the best option. For acids it will probably vary from place to place. Personally I used H2SO4, HCl, and HNO3 in high school; of the three the most dangerous is HNO3. However, I doubt that we had anything > 1 M. Advanced students might possibly be allowed to use more concentrated acids under very strict supervision although that will obviously depend on the system (I used 6 M HCl couple of times). – orthocresol Mar 29 '17 at 13:32
• Unless the clothes being destroyed are an important part to the story, it might not matter too much since after a chemical spill/burn like that you typically strip down then go into the safety shower, if my memory is correct, it's to prevent further contamination of chemicals back onto your skin from your clothes. – Iqbal Khan Mar 29 '17 at 16:05
• @hBy2Py Depends on your high school chemistry lab. My teacher had a (sealed) ~250 mL flask of liquid bromine she brought out on occasion (as a demonstration piece for element properties). It always filled me with an abundance of trepidation, and she never let students handle it, but I could certainly imagine a more cavalier student with a more lax teacher accidentally breaking such a thing and spilling it on themselves. – R.M. Mar 29 '17 at 16:13
• > Maybe I should rephrase my question as, what chemical used in high school chemistry would cause a teacher to put a student under a safety shower? |||| NONE. this is the point of high school chemistry - it is as safe as possible. The worst case scenario is eye burn from spills and in the case the eye would be rigorously rinsed with water (preferably, isotonic salt solution). – permeakra Mar 30 '17 at 10:10

## 9 Answers

Collecting together the responses from the comments and Ben Norris's answer and adding one of my own, individual solutions in water of the following chemicals are realistic options for a liquid spill in a high school chemistry lab, leading to destroyed clothes and time under a safety shower:

As for an experiment leading to a spill, one possible example would be in the course of filling a buret in preparation for a titration. Burets are usually quite tall and narrow (click image for larger version):

(Marketing image from Microtech Scientific)

A slip while filling one could easily result in spilling a few hundred milliliters or more of liquid on oneself.

• From looking at the list, is it safe to assume this is a "pick one" list, not a "mix 'em all together" list? – Cort Ammon - Reinstate Monica Mar 29 '17 at 18:40
• @CortAmmon Yes, I intended this as a "pick one" list. See my edit to clarify. – hBy2Py Mar 29 '17 at 18:46
• Yes, but it should not be let near the students. Actually, I have an idea, and maybe I should submit it as an answer to cash in on that sweet HNQ rep... but I am too lazy. A high school lab would probably still need a preparation room, in order to make stock solutions, etc. There will likely be concentrated acids inside there. Now, a naughty student wandering about the lab can easily find him/herself in trouble. – orthocresol Mar 29 '17 at 22:46
• @orthocresol Is high-school the same as UK secondary school / sixth-form? More advanced classes use conc H2SO4. I recall practical lessons in preparation of esters and dehydration of glucose. – Stop Harming Monica Mar 30 '17 at 9:34
• Likewise, @orthocresol - I recall doing experiments with concentrated sulfuric too. It's not brought out until the upper years, but it was certainly there. – ArtOfCode Mar 30 '17 at 10:49

The real high school accidents that I know of involved flammable liquids (ethanol or methanol) igniting.

If you want to be realistic, base on the above.

• To be fair, the fact that these made national news probably indicates these are worst case scenarios. (Not that this means they are fake or anything.) The news has a selection bias toward the unusual. – jpmc26 Mar 29 '17 at 21:01
• Here's a couple more from schools near me: dnainfo.com/new-york/20161117/inwood/… and abc7ny.com/education/… – mba12 Mar 30 '17 at 19:54

My answer is a carbon-copy of hBy2Py's answer except to outline the specific damage that would occur in each case. And to add another candidate, potassium hydroxide$\ce{KOH}$.

## Potassium permanganate ($\ce{KMnO4}$)

This is probably the most innocuous. It has antiseptic properties and I wouldn't consider it especially dangerous. That being said in high concentrations caustic burns have been reported. These sort of concentration is not likely to be encountered in a high school laboratory though.

Visually this spill would be the most spectacular. It is very strongly colored even in dilute solutions. It will stain clothes a bright purple color. The permangenate ion then reduces to a kind of gross brown colour over time.

## Sulfuric acid ($\ce{H2SO4}$)

This, and the other two acids below, is substantially more dangerous than the $\ce{KMnO4}$ above. A 1 mol.L$^{-1}$ (or perhaps 2 mol.L$^{-1}$, again, I'm not sure the max allowable concentration in a high school lab) solution of this acid given enough time will slowly degrade most fabrics. It turns paper a brown color as it slowly oxidizes the cellulose in it over time. A similar reaction would occur with cotton I assume.

I'm not sure how bad any burns to the skin would be from solutions of the above concentrations. That being said, I would definitely want to wash myself if I spilled any quantity on me though.

## Hydrochloric acid ($\ce{HCl}$) and Nitric acid ($\ce{HNO3}$)

Much of what was said for sulfuric acid above can be said for these two; though, these two in high enough concentration though can also produce noxious fumes. Hydrogen chloride ($\ce{HCl}$) gas in the case of hydrochloric acid, and Nitrogen dioxide ($\ce{NO2}$) for nitric acid. The fumes of these two gasses are highly toxic. To achieve these gases though you'd need to have a highly concentrated solution, again above a concentration I'd expect to have a modern high school lab.

## Sodium hydroxide ($\ce{NaOH}$)

I'm not sure of the clothes destroying nature of sodium hydroxide (sometimes called lye), but it would definitely give you issues at a concentration found in a high school lab. Any hydroxides are going to be especially dangerous as they can convert the naturally occurring fats and oils in your skin in to soap. This process is called saponification. If you get some on yourself and it's left unwashed you will feel your fingers and hands become slimy from the soaps on your fingers. It feels like when you have soapy water on your fingers.

## Potassium hydroxide ($\ce{KOH}$)

This is an extra compound I've added. It's a hydroxide like the sodium hydroxide above, and so everything I've said there applies to it too. Potassium hydroxide is a stronger base than sodium hydroxide and so its effects will be felt at a lower concentration. A 2 mol.L$^{-1}$ solution will definitely cause saponification. And so, if potassium hydroxide were to be found in a high school lab it might be found at a concentration that would cause chemical burns.

• "Potassium hydroxide is a stronger base than sodium hydroxide." Can you provide a citation for this? I've never heard or read this before, as best I can recall. – hBy2Py Mar 30 '17 at 11:12
• @hBy2Py "Dissociation, Chemical Exchange, and the Proton Magnetic Resonance in Some Aqueous Electrolytes" The Journal of Chemical Physics 21, 1688 (1953) aip.scitation.org/doi/abs/10.1063/1.1698644 – DavePhD Mar 30 '17 at 12:55
• Interesting -- so the $\ce{Na+}$--$\ce{OH-}$ ion pairs are more strongly associated, essentially? – hBy2Py Mar 30 '17 at 13:05
• It looks like at low concentrations you wouldn't notice the difference, but at at higher concentrations the odd Na+ and OH- will form ion pairs more than KOH would. From figure 4 in the above reference it looks like you'd notice the difference from a concentration of 5% protons or higher, which would be about 5 mol/L based on my late night calculations. That's actually a bit higher than I thought it would be. Definitely higher than high school lab concentrations. Nice ref @DavePhD. I learnt something today. – tmgriffiths Mar 30 '17 at 14:05
• Also, technically permanganate reduces to the ugly brown color, going from $\ce{Mn(VII)}$ to $\ce{Mn(IV)}$. – hBy2Py Mar 31 '17 at 15:03

A real example from personal experience which, with slightly altered circumstances, could have had the effects you describe.

A student chemistry teacher taught us the chemistry of manufacturing oleum (by passing SO3 through sulfuric acid) then set up an apparatus to demonstrate the reaction. All went well.

After the demonstration, we all began to write up the experiment and the teacher began to clear up. When he reached the flask of oleum he had manufactured he tipped it into the sink. I remember the horror on my (and other pupil's) faces but he was too quick for us to stop him.

There was a loud explosion. Fortunately, he hadn't made very much oleum and the reaction between it, the water and rubber tubing in the sink was not overly violent. He was not hurt. We were too far away to be injured, though a lot of the equipment was damaged.

A little more oleum, a little more water in the sink and a student sitting closer and things could have been worse.

Sulfuric acid will do this. Concentrated sulfuric acid might not be common in high schools due to safety considerations. However, perhaps you could include the teacher getting in trouble for using something so dangerous.

I can imagine some "teacher's pet" being allowed to help prepare (after school) reagents for class. Realistically, the only thing which would "destroy" clothing is concentrated sulfuric acid, which should not be part of the chemicals available to high school children. The problem with your question is that it assumes the teacher/school administration has allowed the classes to involve materials which are inherently unsafe, not just "unsafe" but actively dangerous. It's certainly possible, but not very likely, imho. IOW, not very realistic. Frankly, I've seen more really bad practice in high school biology labs. For instance, one class I was in had an OPEN 5 Gallon Bucket of formaldehyde solution (it may have had an animal corpse in it, I don't recall)!! They had it "by" the open windows (which was apparently the teacher's idea of "proper ventilation"!!). And while that was like 20 years ago or so, it was in an affluent suburban school. If someone were to be carrying that at chest level and collide with another student, a safety shower (if they even had that in biology labs, but why not?) would be appropriate. But while concentrated sulfuric acid will burn holes in clothing, it won't "destroy" it, nor will any of the other chemicals (at least not on time scales of minutes).

• At first I had trouble with the "destroys her clothes" part, too. But a common use of the phrase implies more "renders undesirable/unfit to be worn again", rather than physical obliteration. The former is a much lower bar to reach, and I think most parents would just throw away any chemical-contaminated clothing out of an overabundance of caution. – hBy2Py Mar 29 '17 at 14:25

Nitric acid would be a good example. It will dissolve certain synthetic fibers, color any organic material (including skin) exposed to it yellow/orange and cause a chemical burn wound to form, which would certainly require the use of a safety shower.

Major caveat is that the fumes are extremely toxic and thus the chemical would normally only be handled in a fume hood. However I could easily imagine the chemical being spilled during transport.

• Yup, in multiple years of chemistry lab the only harm I ever suffered was from nitric acid--a drop of it got on the outside of a bottle and I picked up the bottle. (College chem lab, not high school!) It was handled under a fume hood but that doesn't mean somebody couldn't be careless, or the victim of other factors. Suppose somebody else has an oops and jumps back, bumping the person handling a bottle of it. – Loren Pechtel Mar 29 '17 at 19:09

Nitrating mixture (concentrated H2SO4 and HNO3).

Christian Friedrich Schönbein spilt this on his apron (no lab coats in them days I guess) and dried it over the stove, resulting in spectacular deflagration and leading to the invention of nitrocellulose.

We were allowed dropper bottles of those acids when I was in 6th form, for instance in one fun afternoon, trying to find an acid that dissolves aluminimum.

• The funny thing about nitric acid is that it becomes less active against metals when it is at very high concentration (99% or higher). Pretty sure you were "only " allowed to handle 63% nitric acid. 99% is really hard to obtain unless you distill it yourself. – Jeppe Nielsen Mar 30 '17 at 14:17

Tina, don't listen to the naysayers :)

You absolutely can write a realistic scenario that accomplishes everything you are asking in the context of a high school chemistry class. The only thing is that we need a bit more information about your context and your aims. For example:

In what historical era and location is your scene going to play out? The reagents available in a 2017 public high school chemistry class will be very different from what was available in a public high school in 1965.

How risky / dangerous do you want this to be? Do you want this to be a normally safe and common activity that goes wrong because of clumsiness or tomfoolery, or do you want this to be something slightly dangerous or perhaps even very dangerous, so that both teacher and students are warned and ready to respond when something goes wrong?

This guide for high school teachers comes from the American Chemical Society and it gives a lot of specific information that may be helpful to you.

Do you want the student to put herself under the safety shower? Current published guidelines for high school chemistry classes say students should be taught to walk quickly but calmly to the shower and pull the handle immediately under certain circumstances. For example, the ACS guide says this:

Students should be taught the “stop, drop, and roll” technique to be used if their clothes catch on fire elsewhere, and in the laboratory taught to walk calmly to and use the safety shower to extinguish clothes that are on fire. A drill to practice these exercises is recommended.

If you do not want the student to be forced to undress completely, perhaps a spill resulting in a small clothing fire (with or without burned hair) might accomplish all of your goals. If that would do, I suggest that you could have the students be performing metal salts flame tests using the petri dish technique, in which metal salts are burned in a small amount of methanol (methyl alcohol) and the material is identified by the rainbow of colors that are observed in the flame. This would be a great visual when your book is made into a movie :)

Here is a link to a middle school guide for one version of the flame test. Having a small spill of burning alcohol cause clothing to catch fire is quite realistic. Most such events are easily handled, but the risk is real and the safety shower, while not the best approach for significant amounts of burning liquids, would absolutely work to put out a clothing fire ignited by a small amount of flaming alcohol.

I should point out that over the years there have even been a few published classroom incidents in which poor ventilation caused a large amount of methanol fumes to accumulate and a massive fireball resulted. There are some people who feel the flame test should not be part of a modern curriculum, but is is widely performed, colorful, fun for students, teaches something quite fundamentally important both in chemistry and in physics, and falls well within a safety zone appropriate to this age group. You can purchase a kit here and elsewhere.

Because links may evaporate, I will embed a description of a flame test involving methanol in a petri dish:

Flame Tests

Description: Methanol solutions of salts are burned to observe that different wavelengths of light are emitted by different materials

Materials:

• Methanol
• Petri dish
• Cover (to extinguish flame)
• NaCl (yellow)
• SrCl2 (red)
• LiCl (red)
• KCl (violet)
• CuCl2 (green)
• CaCl2 (red-orange)
• H3BO3 (green)

Procedure:

Several variations exist including the “Petri dish” method (described here), the squirt bottle method (ref 1), the H2 balloon method (ref. 2), the guncotton method (ref 3) and the Magic Eraser method (ref 4).

1. Sprinkle a spatula full of each salt into separate Petri dishes.

2. Cover salt with methanol (10 mL). Turn off the lights for a better visual effect. Use the lighter to start up the flame for each sample.

3. To extinguish the flame, put the cover over the Petri dish and let cool before removing.

Discussion: When an element is burned, the electrons are excited. As the electrons from an excited state relax back to a ground state, they will emit photons of light. These photons will have different colors depending on the element and its discrete energy levels. That is, different wavelengths of light (colors) will be emitted when the electrons of different elements go down the step(s) between their energy level(s). Each element will have its own set of steps therefore each will have its own color.

Safety: Wear safety glasses and goggles while preparing and during the demonstration. Be sure to allow time for the cover to cool before removing.

And here's what it looks like:

If you prefer a chemical spill that causes the teacher to put your student under the shower, that is also easily accomplished in a high school chemistry class. Somebody has already suggested that if a chemical spill occurred the student would be undressed before entering the shower. This is not correct: the ACS high school chemistry teachers guide I referenced above says about corrosives:

If splashed on clothing, the clothing must be removed while under a safety shower. Do not remove the clothing and then get under the shower. While under the shower, remove all clothing, including shoes, socks, wristwatch and strap, and other jewelry if they are splashed with corrosives (this is no time for modesty). Stay under the shower for at least 15 minutes while someone else calls a doctor.

Most safety showers are fully exposed, but there are times when they may be located in an alcove with a door that can be closed or a privacy curtain that can be pulled across. There are also safety showers with built-in plastic curtains that can be pulled around for privacy.

If you want the safety shower to be required for a chemical spill resulting from an experiment generally recognized as safe, then any of the mild corrosives will do but you will need to have the student be drenched with the material -- a small spill of most "safe" high school chemicals would not result in a full shower, and of course if ANY splash involves the face then the eyewash station would be the first thought. I've seen people fully drenched from the eyewash station, though, so perhaps that would fit your needs?

If you want to create real fear of injury from a minor chemical spill or splash, this can still be accomplished within a realistic high school setting. I'll pick just one example: it's not unknown for chemistry classes to have students etch mirrors using hydrofluoric acid, which in liquid form is one of the most noxious substances you can come into contact with anywhere below graduate-level chemistry. Even with immediate irrigation the stuff has a tendency to percolate into the body, and you will probably die despite treatment if a small glassful spills in your lap. For this reason it's not used at all as a reagent in high school. However, HF acid is one of the few things that will etch glass, and it is used in various forms for glass etching. The demonstration of an acid that can dissolve glass appears in chemistry courses even at the high school level. This stuff is so nasty that the slightest splash will cause immediate alarm. The correct response is immediate and prolonged irrigation and the immediate application of calcium gluconate gel as a neutralizing agent.

Here's a link to a college-level class guide in which liquid bath glass etching is performed, and if this were an AP class perhaps something like this might appear. Somebody is bound to comment that hydrofluoric acid would not be provided to regular high school students, and thankfully in a strict sense that's true. However, the stuff does still show up in high school classes in various forms. It's routinely found in high school electronics classes in the "liquid tin" solutions used for tin-plating the copper traces on printed-circuit boards, and that same reaction could easily be part of chemistry segment on metals. And here's a link to a fund-raising prospectus in which a high school chemistry teacher recently raised money so that inner-city high school students could "etch glass mirrors with hydrofluoric acid". The link includes photos of the students displaying their etched mirrors, one of which I will embed here.

Of course the material given to these students used was not a liquid form of HF even though it's billed that way -- it's actually a cream that contains fluoride salts. If washed off quickly enough it will cause only superficial injury (and ruin your clothes) -- but if there were any sort of splash you can bet the teacher would be rushing a student under the shower ASAP.

So if you want to create a real fear, the mere mention of hydrofluoric acid would do it. As a physician (board-certified in Emergency Medicine) I have treated several patients for exposure to hydrofluoric acid, including one unfortunate janitor who died a week later (despite rapid and aggressive treatment) after what initially appeared to be a minor splash from an unknown roof-cleaning chemical. It wasn't until we called the poison center to find out what was in that branded stripper/cleaner that we knew it was going to be bad, and even then it was hard to believe how bad. Believe it or not, all the area hospitals actually ran out of calcium gluconate supplies before he died, so yes, scary.

Lots of options for you, but in the end I think you'd be best served by the colorful flame test: put a Bunsen burner together with a spilled petri dish of alcohol and you get a lot of excitement, a quick trip to the shower, and the kind of damaged clothing and minor burns that people can easily understand. And no need for your student to disrobe.