mewrox99
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Conc. Sulfuric Acid. Latex or Nitrile?
I have a question about the use of latex gloves against sulfuric acid.
I have fairly cheap lightly powdered latex gloves, and I have used them against 98% H2SO4. A drop or two spilled on one. I had only noticed it a while
later. It left sulfuric acid's signature brown mark on the glove but didn't seem to absorb because I wasn't injured.
Doing a google search I found compatablity guides rate latex from marginal to poor, while all I have seen have said that nitrile is excellent for
H2SO4.
Should I just buy a box of nitrile gloves for the *really* bad ones like conc. H2SO4, HNO3 etc. and just use latex for the regular chems eg. dilute
NaOH
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Chainhit222
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I dislike latex gloves, they are thin, flimsy, break easily and seem to react with most corrosive materials and break down. I always use nitrile in
the lab and I am not disappointed. However, I have spilled minor amounts of h2so4 and HNO3 on latex gloves, and they seemed to hold out ok so long
they are quickly removed.
I would recommend you get some welding gloves to use though, I have a pair of Lincoln Electric welding gloves in my lab that I use to handle hot shit,
like hot sulfuric acid. I have spilled minor amounts of acids on them, and they hold out pretty well and the acids do not penetrate, just be sure to
give them a rinse afterwords. They only cost like 25$, and you can handle very hot flasks with them. I am fairly sure they can save your hands from a
few hundred ml of boiling hot H2SO4. They are also comfortable, and can be quickly removed in case of bad shit happening. I wear disposable rubber
gloves under them in any case.
This is the brand I use:
http://i.pgcdn.com/pi/75/25/24/752524949_125.jpg
The material (kevlar I think) turns green on exposure to H2SO4. Once they get too beat up you can buy another pair. You could probably slide some
large size disposable gloves over your welding gloves to project them some more and keep them in pristine condition. In conjunction with a face shield
and an apron you have some pretty good protection. Don't go cheap on safety. These gloves are ALOT better then leather gloves btw. The price is worth
it.
And nitric acid burns are not so bad, I had some fairly significant fuming HNO3 (like 94% or so) burns my hands, they only itch a bit and turns the
skin yellow if you rinse it off quickly. Then the epidermis peels off like sunburn after a while, and it is fairly painless. I have not experienced
H2SO4 or NaOH burns, and I would like to keep it that way. At work my mom got a H2SO4 splash on her wrist, and it took a very long time to heal, and
it actually destroyed the flesh unlike HNO3.
HNO3 has a special place in my heart <3
[Edited on 21-6-2010 by Chainhit222]
The practice of storing bottles of milk or beer in laboratory refrigerators is to be strongly condemned encouraged
-Vogels Textbook of Practical Organic Chemistry
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Picric-A
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I have in the past bought polyethene gloves for general lab use. they are extremly cheap (like £3 for 1000) and are comparativly resistant to most
chemicals i use.
I do however have proper nitrile gloves for serious work with cyanides, organometallics ect...
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Lambda-Eyde
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I only use disposable latex gloves when handling moderately toxic chemicals, especially solids. For all work with corrosive liquids I use a pair of
heavy duty (not disposable) nitrile gloves. I recommend that you invest in a good pair of those.
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franklyn
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The medical disposable polyethylene gloves Picric-A recommends simplify
clean up when turned inside out as they are removed , to keep within any
chemical soaked towel or caustic waste you hold in your hand. Tying a
knot to close the opening seals it for disposal.
Perhaps eight years ago at the tool aisle of a discount department store
I bought Mil Spec surplus gloves at 69 cents a pair plus sales tax. Granted
that these are now 23 years old but they are still serviceable in their original
unopened package. There's a small risk older rubber won't hold up during use.
http://www.sciencemadness.org/talk/files.php?pid=103294&...
Items much like these , of recent manufacture are available from dedicated retailers.
https://www.mainemilitary.com/productcart/pc/viewPrd.asp?idc...
https://www.mainemilitary.com/productcart/pc/viewPrd.asp?idc...
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altech6983
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I prefer nitrile, the reason, I was doing an experiment once and I was using latex. At some point some oil got on them (I am pretty sure it happened
in storage shortly before I used them), this caused a small hole. Nitric acid was able to enter, fortunately I noticed and quickly removed them and
washed my hand. After that I have always used Nitrile.
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mr.crow
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Hopefully everyone is aware of the oil + latex issue ;-)
Double, double toil and trouble; Fire burn, and caldron bubble
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unionised
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There are a few things to remember about gloves.
First, no glove gives protection for ever.
Investing in a good pair of nitrile gloves looks like a good idea, but don't forget that once you spill something involatile on them it will start to
soak in and through. You might wipe most of the stuff from the outer surface but the stuff that has soaked in will diffuse through. Probably not a big
deal with most chemicals, but bad news with the toxic stuff. It's possible to be poisoned by a pair of gloves.
Also, gloves can lull people into a false sense of security. You think you are safe so you get careless.
Finally, what makes a good glove for one material makes a poor glove for another. I use latex gloves in the lab if I am using acetonitrile (which is
quite a lot of the time, I'm an HPLC specialist) but I use nitrile gloves if I'm using hydrocarbons.
The ultimate example of this is the PVA coated glove- excellent resistance to many chemicals, but soluble in water.
In the end, there are lots of gloves on the market because they address lots of problems.
No set of gloves will absolve you of having to think about safety.
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ziqquratu
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I generally just wear the cheap latex gloves, purely to keep my hands somewhat clean, and to reduce solvent exposure (mainly to prevent my hands
drying out more than any toxicity concerns). I find they fit better and leave me with better use of my hands than do the disposable nitriles. Any time
I spill something worth talking about (eg. acid, base, toxic, disgusting sticky crap), I just take them off and get a new pair. (Really you should do
this with ALL disposable gloves - they're really only there as a very short term barrier, and all will be penetrated to some degree very quickly by
many chemicals). Sulfuric and nitric acids aren't really a concern, as long as you change gloves as soon as is practical if you spill some on them.
For washing glassware or dealing with hot solutions, I wear normal rubber kitchen gloves. Also wear these when dealing with the real nasties (and I
mean things like tert-BuLi, neat TiCl4, etc - I work in an academic lab, and use these beasts regularly), as they can easily be thrown off (tighter
fitting disposables cannot always be removed so easily). For most spills, just give them a rinse as soon as practical, but do get a new pair every so
often - I find they're kinda self-limiting anyway, since I seem to have a knack for punching holes in them with syringe needles.
Always think carefully about your gloves, though - I've been saved by a heavy pair of non-disposable neoprene gloves when a syringe full of neat TiCl4
failed and spewed reagent all over my hands. But because I could immediately remove the gloves and throw them to the back of my fume hood, the only
damage was the near complete disintegration of the gloves. On the other hand, picking up a syringe containing (as it turned out) HF gas (from
hydrolysis of another reagent) wearing only latex gloves resulted in some unpleasant burns.
I also agree with the comment above - gloves CAN lull you into a false sense of security. They can also reduce dexterity, meaning spills can be more
likely (particularly for those not used to gloves!).
Ultimately, think of your gloves only as a very short term barrier against chemicals - assume that ALL chemicals will penetrate on essentially on
contact and, if what gets on them is not something you'd be happy to soak your hand in, change the gloves.
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blogfast25
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Quote: Originally posted by ziqquratu  | On the other hand, picking up a syringe containing (as it turned out) HF gas (from hydrolysis of another reagent) wearing only latex gloves resulted
in some unpleasant burns.
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Wow! Tell us more?
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ziqquratu
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I'd dispensed quite a bit of a reactant via glass syringe, and left the disassembled syringe at the back of my fume hood for a few hours to allow the
residual material to hydrolyse. For some reason, the gas didn't vent, but, having done this many times in the past (on smaller scales), I thought
nothing of picking it up with the thin latex gloves. A couple of minutes later, my hand started to burn. Quite red underneath, and thorough rinsing
didn't solve the problem.
It was at that point I remembered the hydrolysis product was HF. So I spent the next half hour hunting down some calcium gluconate gel (not as easy as
you'd expect in a reasonable sized chemistry department - apparently nobody uses HF any more!), and had to wear a glove full of the stuff for the next
24 hours. Was rather amusing going through airport security with it on, though (I wasn't flying, just dropping someone off, but there were still a few
questions!).
For anyone else who may have a similar problem in the future, the gel is horrible stuff. Sticky and messy and dehydrates your skin very well. Found
out once I got to the doctor that they recommend you use some moisturiser before applying the gel. You can make the gel yourself using calcium
gluconate and KY jelly, or so I've read, because it can be quite expensive (about $50 per tube, and I needed two). But, better off not to have the
problem in the first place by wearing proper gloves! Since then, I NEVER pick up my dirty glassware without my rubber dishwashing gloves on!
Obviously, see a doctor if you burn yourself (also helps if you can take an MSDS with you - many doctors will have never heard of HF). My burn wasn't
that bad (painful and inconvenient, but not life threatening), but a more serious one requires real treatment - blood tests for Ca and Mg
concentrations, injections of calcium and monitoring by ECG. Always treat HF (and anything that can generate it) with the utmost respect.
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blogfast25
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Thanks for sharing: looks like you've had a close shave...
I'm not equipped to deal with HF and will never work with it in a home/potting shed context.
I do plan some work with soluble fluorides like NaF and NH4F and even as a qualified chemist the thought kind of gives me the creeps. Especially
because I've no real extraction hood. What concerns me most is accidents that could generate HF gas: a miscalculation could cause that. As a
preventive measure I'm planning to keep the pH of all solutions as high as feasible, as that suppresses the hydrolysis of F-. Keeping the fluorides
well away from any acid stocks is another: I've designated a roomy part of the lab for these experiments...
Suitable gloves, good quality goggles and good grade dust mask (when working with the dry powders) will be used. I've no calcium gluconate paste but
will have a bucket of concentrated CaCl2 solution at the ready...
Ideas welcome...
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ziqquratu
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Not sure about the alkali metal fluorides, but NH4F is also highly toxic via skin absorption. In fact, the only Ca gluconate gel in our department
turned out to be in the possession of people working with NH4F (and in very small amounts on very rare occasions at that!).
You really should look into getting the gel - CaCl2 isn't anywhere near as well absorbed, and (if I recall) can disturb other ion levels in the blood
which are already perturbed by the fluoride. As I said, you can make it yourself - Google will tell you how, and calcium gluconate powder itself is
quite cheap, I believe.
Absorption is a big factor - you have to remember that, by the time you feel the burn, the acid has already penetrated quite some depth into the
tissue. It's not a surface burn like with the other mineral acids. That's also why simple washing doesn't do much, and doesn't prevent the systemic
complications of exposure.
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blogfast25
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Yes, NH4F is probably the most dangerous of the ionic water soluble fluorides, second to NH4HF2.
I'll look into calcium gluconate: 'Auravita' offers 250 g for a whopping £20.83 (if I had no scruples I'd consider launching a business in printing
money, oooops, I meant 'alternative medicine' - 'food supplements'!)
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Lyron
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Hi guys,
Excellent recommendations, thanks!
I want to do a super cleaning of some surfaces and involves hot sulfuric acid (~200 Celsius/400 F). The surface to be cleaned is irrelevant at this
point, I just want some recommendations about the container to use and if it needs to be closed or some other trick to prevent the fumes corroding
everything around my hood.
Any help is kindly appreciated!
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hissingnoise
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Your question begets questions - like why sulphuric acid, why so hot and what is it that is so grubby it needs this harsh treatment?
The fumes produced by H2SO4 @ 200*C should be fairly negligible so that wiping exposed surfaces with a soft, dry cloth should be sufficient.
A pyrex jug would seem to be a good container. . .
[Edited on 14-9-2010 by hissingnoise]
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DDTea
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For general use lab gloves, nothing beats nitrile disposable gloves. I use MICROFLEX SUPRENO SE's, and they're great. If there is a split, they
pull apart as soon as you put them on so that you know to get a new pair. They perform admirably against HF, HClO4, and whatever other chemicals I've
thrown at them. Nitrile is also good against organics. It is not good against chromic acid though.
I, personally, prefer disposable gloves for most labwork because it gives me necessary dexterity. Also, disposable gloves are cheap and can be ripped
off and thrown away if they are compromised. The only time I ever care to use non-disposable, elbow length gloves is for cleaning out glassware.
For HF treatment, refer to a document called "First Aid for a Unique Acid: HF" by EB Segal--it's freely available online. Some important things to
keep in mind: if you HAVE Calcium Gluconate 2.5%, limit washing of the affected area to 5 mins--that's enough to remove the acid and anymore washing
just wastes time when you should be applying the gel.
"In the end the proud scientist or philosopher who cannot be bothered to make his thought accessible has no choice but to retire to the heights in
which dwell the Great Misunderstood and the Great Ignored, there to rail in Olympic superiority at the folly of mankind." - Reginald Kapp.
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Panache
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i find all those synthetic gloves impart an 'unreal' feeling and impair your motor control too much. Instead if i am working with something dangerous
i prefer to use real gloves. Finding another person with larger hands than yourself can sometimes be difficult, but not impossible, after sedating
them (people say don't bother but i think its kind), remove in one piece the skin from their elbow down, then slip this sheath over your own hands and
forearms for that just natural feeling only real skin can give, i have heard some primates have similar hands to humans so this may be a further
option if you're unable to source the real thing.
Afterwards you can cheer them up by slipping their skin back on only mixing up the hands (ie right hand on left..), its looks so silly they're sure to
be amused.
Seriously though i buy two sizes of nitrile one quite tight the other larger and always wear two pair with liberal amounts of baby powder, this
alerts you somewhat if liquids ingress. i find this combination better than the thicker washing up gloves.
For ultimate 'i feel nothing' gloves cryo gloves take the cake and eat it too (omg double cliche), it's funny getting people to try and do regular
things with them on, like sending a txt message, HA!
that hf safety protocol is good DDCoffee, um sorry i meant DDTea, ha. I just today purchased some enchant thats 70% fluroborates, don't have any data
yet on that class of chemical but i'm sure its perfectly safe.
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blogfast25
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"First Aid for a Unique Acid: HF" by EB Segal
Interesting document... Its latest version also mentions the use of a new chelating agent for HF, replacing the classic calcium gluconate, called
Hexafluorine (R), 'said' to be much more effective than Ca gluconate. In the UK it's sold, rather pricily, by Kays Medical:
http://www.kaysmedical.com/cgi/ss000002.pl?SS=hexafluorine&a...
Anybody know what it is, chemically speaking? Or have any experience, directly or indirectly, with Hexafluorine?
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juggler
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Nitrile might not be adequate
This page suggests that Nitrile might not be adequate protection for sulfuric acid:
http://www.allsafetyproducts.biz/page/74172
Perhaps neoprene or butyl gloves sound like better protection..
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The WiZard is In
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Calcium Gluconate
You can buy calcium gluconate (albeit 23%) at your
local Tractor Supply store. US $6, 100cc.
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