March 29, 2024, 11:24:22 AM
Forum Rules: Read This Before Posting


Topic: Help, Mishap in Lab with H2SO4 and HNO3  (Read 7028 times)

0 Members and 1 Guest are viewing this topic.

Offline OCIIStudent

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Help, Mishap in Lab with H2SO4 and HNO3
« on: March 07, 2008, 02:02:58 PM »
Hi all,

On 3/6 I was in lab and we were doing nitration of acetanilide with conc. H2SO4 (.6mL) and conc. HNO3 (.5mL).  When I was pouring the test tube with the cold conc. H2SO4 and HNO3 solution (about 1.1 mL total), some of it got on my right pointer finger near the top and a little under my nail, and left a yellow stain.  I think some of it may have ended up on other parts of my hand(s) but the feeling is barely noticeable, if at all.  I was my hand for about a minute with cold water and soap afterwards.  I also forgot to mention that I almost didn't even notice that some of it had spilled on me until I felt something wet on my finger and realized what it was, but it didn't pain much.

If anyone could please tell me what the yellow spot could be and if this is really that serious or not it would be greatly appreciated.

Thank you

Offline Arkcon

  • Retired Staff
  • Sr. Member
  • *
  • Posts: 7367
  • Mole Snacks: +533/-147
Re: Help, Mishap in Lab with H2SO4 and HNO3
« Reply #1 on: March 07, 2008, 02:40:47 PM »
Ah, yes, your first kiss from sweet lady chemistry.  She can be a real ***** at times.  Nitric acid yellows skin on contact, it's just the way it interacts with skin proteins.

It seems like you've had a mild exposure, I had one of those once: I was using nitrile gloves one size too small, and was working with con. nitric.  I felt the moisture on my middle fingertip, and I knew the cause -- if gloves are too tight, they become more permeable, even if they don't rip.  The group didn't want to take any chances, and made me rinse in cold tap, and soak in bicarbonate solution.  It was a tiny exposure really, but I got the skin yellowing you got.  In time, the yellow spot will dry, and peel off. 

Concentrated HCl just makes the skin red, a typical chemical burn.  I've never had a conc H2SO4 burn, I do know it chars paper rapidly, but I don't know what it'll do to skin.

Aqua Regia, as they told me, will simply rapidly strip your skin clean off.  Hence, my "belt and suspenders" mode in the photo here:

http://www.chemicalforums.com/index.php?topic=23722.msg90280#msg90280
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 27635
  • Mole Snacks: +1799/-410
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Help, Mishap in Lab with H2SO4 and HNO3
« Reply #2 on: March 07, 2008, 03:30:48 PM »
As far as I remember from my early chemistry times - in the case of nitric acid, if it is just yellow and not hurting now, it won't hurt later and the color will disappear in a few days/weeks. Nothing to worry about. As Arckon wrote - yellow stain is just effect of the way nitric acid reacts with proteins.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info

Offline OCIIStudent

  • Very New Member
  • *
  • Posts: 2
  • Mole Snacks: +0/-0
Re: Help, Mishap in Lab with H2SO4 and HNO3
« Reply #3 on: March 07, 2008, 05:36:33 PM »
Thank you for the information Arkcon and Borek, you two really help put my mind at ease over this.  This was the first time we had dealt with either conc. H2S04 or conc. HNO3.  When I realized that some of the product from mixture of the two acids had gotten on me I was kinda worried what would happen because they are both strong.  I wish my university would let us wear gloves during our labs.. shoes are required to protect our feet but gloves are not worn to protect our hands, makes no sense to me at all :S.

Thank you both again!

Offline hmx9123

  • Retired Staff
  • Full Member
  • *
  • Posts: 897
  • Mole Snacks: +59/-18
Re: Help, Mishap in Lab with H2SO4 and HNO3
« Reply #4 on: March 14, 2008, 10:42:26 PM »
Hydrochloric, sulfuric, nitric and phosphoric will only leave topical burns.  Glacial acetic burns from the 'inside out' (not really, but it feels like it) and leaves your skin all puffy, but other than that doesn't do much.  The bad one is HF (hydrofluoric), as it's poisonous and feels like someone's cutting your joints apart with a dull rusty spoon.  Other than that there are exotic acids, which you simply have to learn about as you go.

Sponsored Links