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Dan Vizine
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Hazardous combinations of simple chemicals
I was just reading another topic on the forum concerning H2S. My thoughts were focused on the simplest combination to make this toxic gas and it
turned out to be very easy from readily available chemicals.
That got me thinking about other combinations of simple chemicals that pose significant, and sometimes hidden, hazards. There seem to be a lot of
aspiring chemists here and they might benefit from this topic.
A very accessible combination of chemicals is HCl and formaldehyde. Hopefully this combination isn't used on purpose in reactions anymore, although at
one time it was used for chloromethylation. Anyone following an old OS prep. might run across it.
The specific danger is the production of ClCH2OCH2Cl, known as bis(chloromethyl)ether or BCME for short. This is a very potent carcinogen for
these reasons:
1) It's a good alkylating agent. Both ends (see 2).
2) The "bite" size is just right to bridge two strands of your DNA.
3) It is "tuned to succeed". The lability of the chloromethyl is just right, it survives the aqueous media but readily reacts with nitrogenous bases.
4) You can't detect it at the allowable threshold without sophisticated tools. It was a tool in our "carcinogenesis" program for NCI way back when.
So here is my caution: Never knowingly heat together HCL and formaldehyde, even aqueous solutions. Since these are simple compounds you need to always
consider the possibility of their generation in situ. This is a significant cancer hazard.
[Edited on 2-5-2014 by Dan Vizine]
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gdflp
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Another dangerous combination of simple chemicals is formic acid and sulfuric acid, the sulfuric acid acts as a catalyst causing the formic acid to
decompose HCOOH --> H2O + CO, producing large quantities of carbon monoxide.
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Dan Vizine
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The addition of nitric acid to ethanol forms the metal etching solution "Nital". How much acid is added is important.
5% - safe, but don't store
10% - transitions over to hazardous
15% and above - liable to spontaneous decomposition
while mixtures of ethylene glycol and nitric acid can detonate after initiation from heat, friction or impact.
**********************************************************
Potassium is a problem when mixed with many things. Some are just more treacherous than others.
Many people know that K plus a halocarbon is an explosion waiting to happen, but a lot fewer know that with dry ice it forms a shock sensitive
explosive.
Interaction with iron halides can cause violent explosions.
Interaction with Hg is extremely exothermic.
**********************************************************
Potassium permanganate can be dissolved in conc. H2SO4 to give the exceptionally potent and somewhat unstable oxidant manganese heptoxide. This can
react violently and inflame upon contact with organic matter.
**********************************************************
Gallium can quickly destroy aluminum alloys.
**********************************************************
The use of magnesium to dry methanol needs to be carefully monitored to prevent runaway exotherms during the dissolution.
[Edited on 3-5-2014 by Dan Vizine]
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Brain&Force
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You missed the simple one...bleach and ammonia.
Hydrogen and oxygen can also be a hazard near an open flame. Hydrogen and chlorine can be a hazard near blue or UV light.
At the end of the day, simulating atoms doesn't beat working with the real things...
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phlogiston
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A colleague once left a mixture containing acetone and H<sub>2</sub>O<sub>2</sub> overnight on his bench to find a white
precipitate in the morning.
I greatly enjoyed his surprise when I demonstrated to him how this material reacts to a mild blow of a hammer.
-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer
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Zyklon-A
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Also bleach + hydrochloric acid. Although chlorine isn't quite as bad as chloralamine, both would be bad if made on accident.
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Steam
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Calcium Carbide and moisture goes to Acetylene gas. However most people who have Calcium Carbide know this!
Also do not dump Acetone in bleach. Haloform reaction starts which go very easily become a runaway reaction sending chloroform vapors into the air!
DISCLAIMER: The information in this post is provided for general informational purposes only and may not reflect the current law in your jurisdiction.
No information contained in this post should be construed as legal advice from the individual author, nor is it intended to be a substitute for legal
counsel on any subject matter. No reader of this post should act or refrain from acting on the basis of any information included in, or accessible
through, this post without seeking the appropriate legal or other professional advice on the particular facts and circumstances at issue from a lawyer
licensed in the recipient’s state, country or other appropriate licensing jurisdiction.
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numos
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According to Wikipedia, a reaction occurs between ethylene and disulfur dichloride or sulfur dichloride to form mustard gas. I have no wish to try
this, so can anyone confirm? Both these chemicals don't seem too exotic, although I don't know how anyone could accidently combine (bubble?) these
together.
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sasan
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Reaction of KCN and CuSO4 solution driving off dicyanogen gas,very dangerous
Combination of sulfuric acid with some organic materials such as sugar
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bismuthate
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Bismuth and perchloric acid is a rather obscure danger and silver nitrate, and sodium chromite with a bit of 35% H2O2 I've found can be very dangerous
(It can act like a carcinogenic and red version of a baking soda volcano.
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Zyklon-A
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Quote: Originally posted by numos | According to Wikipedia, a reaction occurs between ethylene and disulfur dichloride or sulfur dichloride to form mustard gas. I have no wish to try
this, so can anyone confirm? Both these chemicals don't seem too exotic, although I don't know how anyone could accidently combine (bubble?) these
together. |
Yes, that reaction does occur. Sulfur chlorides are somewhat exotic, although made from direct combination of sulfur and chlorine gas, it
needs to be distilled, and the entire procedure is a mess. I have done it before, it's not fun.
Sulfur chlorides are not something you're going to just find lying around.
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zig
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It was a clear autumn morning in the mid 90s, kid cousin and myself preparing to walk to school. Pressed for time, my reasoning behind using superglue
to fix her torn backpack seemed brilliant. It became clear (as i watched her backpack begin to smoke and eventually catch fire) cotton+superglue is
not so brilliant. A surprising amount of people (read: the majority of non-stem types) are unaware of this fact, considering its potential to toast
the ignorant!
I'm aware cotton is not an isolated chemical.
"The chemists are a strange class of mortals, impelled by an almost insane impulse to seek their pleasures amid smoke and vapor, soot and flame,
poisons and poverty; yet among all these evils I seem to live so sweetly that I may die if I were to change places with the Persian king."
-Johann Joachim Becher
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DraconicAcid
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I think that "pretty much anything and perchloric acid" is a generally well-known danger.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Zyklon-A
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What do you mean by that? Cotton is probably >98% cellulose.
The reaction of Cyanoacrylate and cellulose is quite well known, but I can't seem to find any actual equations.
Does anyone know what exactly is happening?
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DraconicAcid
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Quote: Originally posted by Zyklonb |
What do you mean by that? Cotton is probably >98% cellulose.
The reaction of Cyanoacrylate and cellulose is quite well known, but I can't seem to find any actual equations.
Does anyone know what exactly is happening? |
I seem to recall that the hardening of the glue is a reaction that's initiated by water. With cotton, the hydroxyl groups of the cellulose work just
as well, and the exothermic nature of the reaction makes it run away.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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bismuthate
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Draconic acid, the reaction with bismuth is VERY violent (it explodes) and unexpected (bismuth isn't very reactive).
Also H2SO4 and fluorides are very dangerous together. Both are found in many households.
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woelen
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A really dangerous one is mixing of calcium hypochlorite and sodium dichlorocyanurate.
A few years ago, someone in the Netherlands nearly died. He had a jar of calcium hypochlorite and used that for chlorinating his swimming pool. It was
sold as so-called shock-treatment. A while later he purchased another jar of shock-treatment, of the same brand. This bottle happened to be sodium
dichloroisocyanurate.
He still had some calcium hypochlorite and put this in a bucket. Then he added the sodium dichloroisocyanurate, just to make up the right amount for
his swimming pool (both are shock treatment, both are pool chlorinators and are in similarly looking bottles). Then he added some water. Soon after
that, the material in the bucket started reacting in a very exothermic reaction. The mix became so hot that it charred and a huge cloud of very toxic
fumes and gas came from the mix (probably chlorine, chloramine and other nitrogen-chlorine compounds). He had to run away and stumbled and inhaled
quite a lot of the fumes and was sick of it for a few days afterwards.
I have done a smnall scale experiment and mixed 2 grams of granular calcium hypochlorite and 2 grams of granular sodium dichloroisocyanurate. When the
dry powders are mixed, nothing happens. Then I added a small amount of water, When this is done, a very scary reaction occurs. A lot of gas is
produced, a yellow oil is produced and a lot of crackling noise is produced. Finally, there was one loud crack and all material was swirled out of the
test tube
The yellow material most likely was NCl3 and a small pocket of NCl3 must have exploded and swirled everything out of the test tube. Fortunately the
test tube was not shattered.
Both the sodium dichloroisocyanurate and the calcium hypochlorate are sold as "choc" treatment in jars of 2.5 kg or 5 kg:
<img>http://www.interline-products.com/savefile/21746/000%20Interline%202012/Producten/Waterbehandelingsproducten/52781524%20Pool%20Power%20Chlo
orgranulaat%20Choc,%205%20kg.jpg</img>
The most insidious of this reaction is that it is with commonly available chemicals, which both are used in exactly the same application, are sold in
identical jars. One hardware store has the dichloroisocyanurate, the other has calcium hypochlorite and sometimes they switch over time, probably
depending on the margin they can realize with the product.
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Zyklon-A
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Another thing is potassium with an oxide coating + mineral oil. Although this isn't exactly a "simple chemical", it isn't something many people would
expect to be very dangerous. As potassium is oxidized by air, it forms several different oxides including peroxide (O-) and superoxide
O2-. These very powerful oxidizing agents (especially superoxide) can detonate if they are subjected to shock in the presence of
fuels (eg. mineral oil.)
DraconicAcid, ok thanks. I also read (while looking for the equation) that a reaction can be initiated by water. I didn't realize
that the hydroxyl groups in cellulose can do the same thing.
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DraconicAcid
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Quote: Originally posted by Zyklonb | Another thing is potassium with an oxide coating + mineral oil. Although this isn't exactly a "simple chemical", it isn't something many people would
expect to be very dangerous. As potassium is oxidized by air, it forms several different oxides including peroxide (O-) and superoxide
O2-. These very powerful oxidizing agents (especially superoxide) can detonate if they are subjected to shock in the presence of
fuels (eg. mineral oil.) |
Yep. I was once destroying an old jar of dispersed potassium- I had added isopropanol to react with the potassium, and once the reaction had pretty
much stopped, I used a spatula to scrape some of the stuff off of the sides of the jar into the reaction mixture.
BAM!!
Suddenly the jar was on fire, and I had no idea where the spatula had gone.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Dan Vizine
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I had exactly the same experience not 3 weeks ago. I had melted oil coated K under xylenes as the first step in getting oil free K. The collected skin
was pressed free of gross amounts of K then put into a steel pan for disposal. As I scooped small spoonfuls up and sprinkled it into water, all of a
sudden the residue exploded. It was maybe 15 - 20 grams of material that didn't have the color I had associated with hazardous K, yellow to brown, it
was a more normal purple-gray.
It was a low grade explosion, but quite loud. All of the residue had essentially vanished into smoke. My neighbors have long since stopped being
concerned or even surprised by these events.
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zig
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Quote: Originally posted by Zyklonb | What do you mean by that? Cotton is probably >98% cellulose.
The reaction of Cyanoacrylate and cellulose is quite well known, but I can't seem to find any actual equations.
Does anyone know what exactly is happening? |
There exists a certain breed of chemist that take great pleasure in 'correcting' this kinda thing.
"Well technically, 'backpack' is not a simple chemical. Consider the potential presence of dyes / plastics / act."
I am glad you're not one of them!
"The chemists are a strange class of mortals, impelled by an almost insane impulse to seek their pleasures amid smoke and vapor, soot and flame,
poisons and poverty; yet among all these evils I seem to live so sweetly that I may die if I were to change places with the Persian king."
-Johann Joachim Becher
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IrC
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Quote: Originally posted by Dan Vizine | Many people know that K plus a halocarbon is an explosion waiting to happen, but a lot fewer know that with dry ice it forms a shock sensitive
explosive. |
After searching for a few hours and many links I still find no information about this. Also I notice some of the posts here are more on the lines of
hearsay rather than in a format belonging in a chemistry forum. Failing to state reaction equations or the resultant chemical of concern, as with the
quote above. What does it form? Without knowing the actual chemical how can one look it up, learn the danger? Many things are shock sensitive. How
shock sensitive is whatever chemical you are describing? We have K, CO2, yet I find it unlikely C2K2 is the resultant product, nor do I see mention of
Potassium Carbide being either shock sensitive or explosive. So clearly something else is being formed. A peroxide, a super-oxide? When you said "a
lot fewer know that with dry ice it forms a shock sensitive explosive", I believe you. After hours searching still nothing mentioned anywhere on the
subject.
Not to put this one request on you personally or exclusively (I picked your post because I was intrigued by your information), but can people please
be more precise chemically when you make additions to this page? How else can we be better informed as to what it is that needs to be studied in
greater depth for the sake of safety?
"Science is the belief in the ignorance of the experts" Richard Feynman
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froot
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Nickel Carbonyl
This can quite possibly happen apon an unsuspecting suburban resident.
According to the article it can be synthesized quite easily. All you need is a warm nickel alloy in contact with CO.
The exposure limits are frightening!
Quote: | The hazards of Ni(CO)4 are far greater than that implied by its CO content, reflecting the effects of the nickel if released in the body. Nickel
carbonyl may be fatal if absorbed through the skin or more likely, inhaled due to its high volatility. Its LC50 for a 30-minute exposure has been
estimated at 3 ppm, and the concentration that is immediately fatal to humans would be 30 ppm. Some subjects exposed to puffs up to 5 ppm described
the odour as musty or sooty, but because the compound is so exceedingly toxic, its smell provides no reliable warning against a potentially fatal
exposure. |
We salute the improvement of the human genome by honoring those who remove themselves from it.
Of necessity, this honor is generally bestowed posthumously. - www.darwinawards.com
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woelen
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I only give examples with chemicals which can be obtained outside of typical chemistry outlets (e.g. hardware stores, online health shops and so on).
I myself had an explosion with MMS-powder and hydrochloric acid. MMS stands for "Miracle Mineral Solution". The entire idea behind this is total crap,
but in fact, MMS is NaClO2 (80%) with the remainder being NaCl. It is sold in many places (e.g. look at eBay, below are two examples):
http://www.ebay.nl/itm/Sodium-Chlorite-80-Pure-Water-Purific...
http://www.ebay.nl/itm/Sodium-Chlorite-28-Solution-Kit-Safet...
If you add MMS-powder (from the first seller, linked above) to 30% HCl, then it starts bubbling violently, somewhat like adding NaHCO3 to 30% HCl.
Instead of CO2 bubbles you get pure bright yellow ClO2-bubbles. One time I made the mistake to do this outside in daylight and the gas above the
liquid did KABOOM a few seconds after it appeared.
MMS-powder is sold in many places (we also have sellers in the Netherlands for this stuff) and only few people know that this material can lead to
hefty explosions. Mixing it with fuels like sugar, powdered sulphur, fine dry wood can also lead to dangerous things. I know of one person on
sciencemadness (mewrox99) who had spontaneous ignition of such a mix.
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Dan Vizine
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Quote: Originally posted by IrC | Quote: Originally posted by Dan Vizine | Many people know that K plus a halocarbon is an explosion waiting to happen, but a lot fewer know that with dry ice it forms a shock sensitive
explosive. |
After searching for a few hours and many links I still find no information about this. ....... Many things are shock sensitive. How shock sensitive is
whatever chemical you are describing? We have K, CO2, yet I find it unlikely C2K2 is the resultant product, nor do I see mention of Potassium Carbide
being either shock sensitive or explosive. So clearly something else is being formed. A peroxide, a super-oxide? When you said "a lot fewer know that
with dry ice it forms a shock sensitive explosive", I believe you. After hours searching still nothing mentioned anywhere on the subject.
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Hi IrC,
From Bretherick's Handbook of Reactive Chemical Hazards 6th Ed:
Non-metal oxides
1. Gilbert, H. N., Chem. Eng. News, 1948, 26, 2604
2. Mellor, 1941, Vol. 2, 241
3. Mellor, 1940, Vol. 8, 436, 544, 554, 945
4. Pascal, 1963, Vol. 2.2, 31
MRH Dinitrogen oxide 3.72/54, nitrogen oxide 4.60/61
Mixtures of potassium and solid carbon dioxide are shock-sensitive and explode violently on impact, and carbon monoxide readily reacts to form
explosive‘carbonylpotassium’ (potassium benzenehexoxide) [1].........
and for the alloy with sodium:
Carbon dioxide Staudinger, H., Z. Elektrochem., 1925, 31, 549
Mixtures of the alloy and solid carbon dioxide are powerful explosives, some 40 times more sensitive to shock than mercury fulminate.
[Edited on 13-5-2014 by Dan Vizine]
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