Does vinegar neutralize lye??

[sarathan]

I'm confused! In the Everything Soapmaking book, it says that vinegar neutralizes lye and it's a good idea to pour vinegar on your equipment before washing it. But then I've heard that it's a complete myth and vinegar is no better than plain water. Has anyone tried using vinegar?

 

[Lil Outlaws]

I've heard it does, though it's much weaker than lye so it takes a bit.. ???

I do know that my home cleaning products are vinegar based and I always have a spray bottle for cleaning the counters. I got a chunk of raw soap on my arm the other day and it was burning to high heaven even when I washed it, so I sprayed my counter spray on it and it went away.

 

[surf girl]

If you so some searches for "titration" or "neutralization" with the keywords "sodium hydroxide" and "acetic acid", you'll be able to find how much vinegar (acetic acid in 4 or 5% solution) it would take to neutralize sodium hydroxide (lye, a base) or vis versa. Anyhoo, I didn't scan around too many sites, but here's one http://www.roguesci.org/megalomania/syn ... esis5.html and it notes: "It will take about 126 g of sodium hydroxide to neutralize 4 L of 5% vinegar." That's 4L of vinegar to neutralize about 4.5 oz of lye.

Someone can double check my math, but what I figure is, say you're soaping a couple pounds of oil with a 30% solution, and you've got roughly 300mL water and 4.5 oz, or just around 1 1/4 cups of lye solution. Say you spill a teaspoon (5 mL) on yourself. That's 0.0167 of your solution, so it would take 4000 mL x 0.0167 = approx 67 mL or, roughly, 1/4 cup of vinegar to neutralize that teaspoon.

So the answer is, yes, vinegar neutralizes lye, but it takes a lot of it. So I suspect that's why the guidelines say to wash the lye off well using running water. I suppose if you have a vat of vinegar handy to bathe in if you have a large spill, it might be of some use... And if there's a little left on your skin after washing, spraying or rinsing with vinegar wouldn't hurt...

 

[yafa]

If you so some searches for "titration" or "neutralization" with the keywords "sodium hydroxide" and "acetic acid", you'll be able to find how much vinegar (acetic acid in 4 or 5% solution) it would take to neutralize sodium hydroxide (lye, a base) or vis versa. Anyhoo, I didn't scan around too many sites, but here's one http://www.roguesci.org/megalomania/syn ... esis5.html and it notes: "It will take about 126 g of sodium hydroxide to neutralize 4 L of 5% vinegar." That's 4L of vinegar to neutralize about 4.5 oz of lye.

Someone can double check my math, but what I figure is, say you're soaping a couple pounds of oil with a 30% solution, and you've got roughly 300mL water and 4.5 oz, or just around 1 1/4 cups of lye solution. Say you spill a teaspoon (5 mL) on yourself. That's 0.0167 of your solution, so it would take 4000 mL x 0.0167 = approx 67 mL or, roughly, 1/4 cup of vinegar to neutralize that teaspoon.

So the answer is, yes, vinegar neutralizes lye, but it takes a lot of it. So I suspect that's why the guidelines say to wash the lye off well using running water. I suppose if you have a vat of vinegar handy to bathe in if you have a large spill, it might be of some use... And if there's a little left on your skin after washing, spraying or rinsing with vinegar wouldn't hurt...

surf girl i like your math!
Yes indeed Acid neutralizes base! I did the calculations, i double checked that Website numbers, i got a similar number, i got 132 gr of lye needed to neutralize 4 L of vinegar. just to add that, the thing is you need less vinegar than what you think, the moment you add the vinegar (which is basically water and acetic acid) to the lye your are diluting the lye! so it is not anymore 30%, it is less.

 

[angbaby4974]

Interesting, I was reading about this very subject on another board yesterday.

Quote

I also am sure to have white vinagar opened and within reach, just in case, because it's said to neutralize lye


I'm not sure exactly how this myth got started, but it is not correct. Here's some info from 2 MSDS sheets, one for a 50% solution and one for dry.

http://www.setonresourcecenter.com/msds ... d046de.htm
Material Safety Data Sheet
CAUSTIC SODA <50% , SODIUM HYDROXIDE SOLUTION

SECTION V - Reactivity Data

Stability Conditions to Avoid: MIXTURE WITH WATER, ACID OR INCOMPATIBLE MATERIALS CAN CAUSE SPLATTERING AND RELEASE OF LARGE AMOUNTS OF HEAT

SECTION VI - Health Hazard Data

Emergency/First Aid Procedures: [SKIN] IMMEDIATELY WASH EXPOSED SKIN WITH PLENTY OF SOAP AND WATER WHILE REMOVEING CONTAMINATED CLOTHING AND SHOES. GET IMMEDIATE MED ATTEN. WASH CLOTHING BEFORE REUSE AND THROW AWAY SHOES WHICH CANNOT BE THOROUGHLY CLEANED.

http://www.jtbaker.com/msds/englishhtml/s4034.htm
Material Safety Data Sheet
SODIUM HYDROXIDE

3. Hazards Identification

Emergency Overview
—————————————
POISON! DANGER! CORROSIVE. MAY BE FATAL IF SWALLOWED. HARMFUL IF INHALED. CAUSES BURNS TO ANY AREA OF CONTACT. REACTS WITH WATER, ACIDS AND OTHER MATERIALS.

4. First Aid Measures
Skin Contact:
Immediately flush skin with plenty of water for at least 15 minutes while removing contaminated clothing and shoes. Call a physician, immediately. Wash clothing before reuse.

Notice that both say the sodium hydroxide reacts with acid. Vinegar is acidic, albeit mild (white vinegar has maybe 5% acetic acid). But acid is acid, and even a small amount can react with lye and cause even more injury (would you deliberately aggravate a burn injury?).

Both say the proper procedure for skin contact is to flush/wash the skin with plenty of water, and nothing about neutralizing the lye. Both are saying massive dilution is the way to go.

From theAgency for Toxic Substances & Disease Registry
http://www.atsdr.cdc.gov/MHMI/mmg178.html

Incompatibilities

Sodium hydroxide dissolves easily in water generating a great deal of heat. It reacts with acids (also generating a lot of heat); halogenated organic compounds; metals such as aluminum, tin, and zinc; and nitromethane. Sodium hydroxide is corrosive to most metals.

Immediately brush any solid material from clothes, skin, or hair while protecting the victim's eyes. Quickly remove contaminated clothing and flush exposed areas with water for at least 15 minutes. Double-bag contaminated clothing and personal belongings. Use caution to avoid hypothermia when decontaminating children or the elderly. Use blankets or warmers when appropriate.

Flush exposed or irritated eyes with plain water or saline for at least 30 minutes. Remove contact lenses if easily removable without additional trauma to the eye, otherwise sodium hydroxide trapped beneath the lens will continue to damage the eye. If pain or injury is evident, continue irrigation while transferring the victim to the Support Zone.

In cases of ingestion, do not induce emesis. Do not administer activated charcoal or attempt to neutralize stomach contents.

Victims who are conscious and able to swallow can be given 4 to 8 ounces of milk or water; if the patient is symptomatic, delay decontamination until other emergency measures have been instituted.
Consider appropriate management of chemically contaminated children at the exposure site. Provide reassurance to the child during decontamination, especially if separation from a parent occurs.

That being said, I will forever use copious amounts of water...

 

[MikeInPdx]

I am of the copious amounts of water school too. As far as your soaping equipment goes, if you don't need it right away and wait 24 hours, the remaining raw soap will saponify and help with the cleaning.

 

[carebear]

Adding an acid to a base gets you a chemical reaction that releases HEAT - a lot of it - which burns. AND putting an acid, even a weak one, on a wound HURTS. I strongly suggest, based on both reading and experience, that you rinse rinse rinse.

Back in my days in the lab I got some KOH solution on my face right under my eye (I was wearing gloves, so didnt' notice it was on my hand) and goggles - and when I pushed up my goggles a bit I touched my face). OMG it hurt. I had my face under the faucet and was doing just fine rinsing away when some good samaritan got out her trusty vinegar and put some on my face. THAT is when I started to scream (briefly - I got my face away from her and back under the faucet).

Then if you feel the need you can use a diluted vinegar solution but after rinsing with copious amounts of water - but at that point I don't think it would be necessary. Remember, if you have a burn the vinegar will hurt.

IF, however, its an oily mix with lye (as in raw soap) I suggest rinsing and washing with soap - yes soap is also somewhat caustic, but in my experience it helps get that caustic oily mix off your skin faster. Which is my goal.

Vinegar for cleaning surfaces - that I could buy into (but I don't bother, water works well)

 

[DeeAnna]

I think this thread from 2009 deserves a bump. Please do not use vinegar to neutralize lye on the skin. Use water -- lots of it.

 

[Hazel]

Bumping again because it needs to re-stated.

 

[Derpina Bubbles]

Yep, rinsing with heaps of water is the answer, but in an emergency, if you can drink it, you can rinse with it.

I had an accident with caustic soda last year while cleaning drains. I had goggles, gloves, apron and the rest of my full PPE kit on. I slipped and landed on my butt while carrying the lye pearls. They went all over me from head to toe including in my hair. I removed all my contaminated PPE gear. I didn't know about the stray pearls in my hair and when I put a shirt on these fell from my hair into my eyelashes, obviously then into my eyes. I rinsed my eyes in the shower immediately. If I hadn't rinsed immediately I'd be blind. It eats the proteins in your eyes. The emergency room used saline rinse for about an hour. I was sent to an Ophthalmologist who told me that there is seconds between being blind or not with this stuff in your eyes.

He said anything you can drink, you can rinse your eyes with in an emergency. Even juice, lemonade, whatever. If that's all you can get, use it. Obviously sterile solution is better but if you don't have anything next to you but milk, soda or iced tea go for it. He told me that would apply to caustic burns anywhere on your body in an emergency. It makes sense.

*Of course, you shouldn't handle caustic soda without running water nearby in the 1st place.

 

[DeeAnna]

I hear you, Derpina. No argument from me -- any liquid in an emergency is far better than leaving lye on the body. I'm really glad you reacted correctly when you got the lye in your eyes. Unlike you, some people panic and end up doing exactly the wrong thing. Uck, that must have hurt something awful! I had a similar experience years ago (acid in the eyes) and know what you're talking about.

If I could stamp out just one incorrect "fact" that seems to be widespread in the soaping world, however, it would be the irresponsibly wrong advice to affirmatively choose vinegar, not water, to treat a lye splash to the body.

Water should always be the first choice ... and lots of it!!! Sheer volume is important to dilute the lye quickly, to minimize the heating created by the lye as it reacts with body tissues and with the water, and to flush the lye out of body tissues.

If I somehow got lye on my body and the only liquid close to hand was a jug of vinegar, I'd use it in a heart beat ... but I'd also be rushing to the nearest sink or shower.

 

[Hazel]

Derpina - That must have been really scary and I'm glad you're okay.

 

[Derpina Bubbles]

Yep, water is the go and lots of it. Rinsing for 30mins minimum is what's needed. Seems like a lot but it keeps eating away at the tissues like you said. I image the acid must have felt the same. It's weird how you read about vinegar in some soap books but caustic soda safety directions will tell you to rinse with water.

 

[Derpina Bubbles]

Derpina - That must have been really scary and I'm glad you're okay.

Thanks Hazel. I was home alone, smacked into a few walls on the way to the shower, rang a few wrong numbers trying to get the ambos. Did I keep my cool? Nope lol. Just have some slightly damaged eyelids and eyelash follicles. So lucky.

 

[Susie]

You are extremely smart and very collected under pressure. That is what saved you. I am a nurse, and have seen what happens when people don't get to enough water fast enough.

 

[Lin]

I had heard the myth and had a jug of vinegar prepared with my first batch of soap.... When I then came across how its a myth and why, I thought OMFG DUH. And felt stupid. My boyfriend and I both knew better but didn't use our chemistry knowledge about the exothermic reaction. So even knowing better you can read it as an instruction and believe it! I'm glad I quickly came across it being false and had that "duh" moment quickly, before years of soaping or having an accident.