Lye
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Eldereft
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[[WP:UNDO|Undid]] revision 225799937 by [[Special:Contributions/58.69.51.248|58.69.51.248]] ([[User talk:58.69.51.248|talk]]) rm unencyclopedic additon
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{{Wiktionarypar|lye}}
'''Lye''' is a [[corrosive]] alkaline substance, commonly, [[sodium hydroxide]] (NaOH). Previously, lye was among the many different [[alkali]]s leached from [[hardwood]] ashes.<ref>McDaniel, Robert (1997).</ref> In modern day, lye is commercially manufactured using a [[membrane]] cell method, which is an improvement from the previous [[diaphragm]] cell methods of Castner-Kellner, Gibbs, and Nelson.
Solid dry lye is commonly available as flakes, pellets, microbeads, and coarse powder. It is also available as solution, often dissolved in water. Lye is valued for its use in food preparation, [[soap making]], [[biodiesel]] production, and household uses, such as oven cleaner and drain opener. [[Image:Lye.jpg|thumb|Canister of solid dry lye.]]
Lye is being considered for dissolving the tissue of deceased human bodies as an environmentally-friendly alternative to cremation.{{Fact|date=June 2008}}
==Food uses==
Lye is used to cure many types of food, such as: [[lutefisk]], green [[olives]], [[hominy]], [[lye roll]]s, [[century egg]]s, [[pretzels]], ''[[zongzi]]'' (Chinese [[glutinous rice]] dumplings), and [[Chinese noodles]]. In the United States food-grade lye must meet the requirements outlined in the Food Chemicals Codex (FCC),<ref>[http://www.usp.org/fcc/ Food Chemicals Codex]</ref> as prescribed by the US [[Food and Drug Administration]] ([[FDA]]).<ref name=FDA>[http://www.fda.gov/opacom/laws/fdcact/fdcact4.htm US Food and Drug Administration]</ref> Lower grades of lye are commonly used as drain openers and oven cleaners and should not be used for food preparation.<ref>[http://www.certified-lye.com/index.html Certified Lye]</ref><ref name=FDA>[http://www.fda.gov/opacom/laws/fdcact/fdcact4.htm US Food and Drug Administration]</ref>
== Safety ==
Both solid dry lye and lye solutions are [[corrosive]] and will degrade organic tissue.
=== Hazardous reactions ===
Solid [[sodium hydroxide]] or solutions containing high concentrations of sodium hydroxide may cause chemical burns, permanent injury or scarring, and blindness. Lye (sodium hydroxide) may be harmful or fatal if swallowed.
Solvation of sodium hydroxide is highly exothermic, and the resulting heat may cause heat burns or ignite flammables.
Avoid all contact with organic tissue (including human skin, eyes, mouth, and animals or pets). Keep away from clothing. Avoid all contact with [[aluminium]].
The combination of [[aluminium]] and sodium hydroxide results in a large production of hydrogen gas: 2Al(s) + 6NaOH(aq) → 3H<sub>2</sub>(g) + 2Na<sub>3</sub>AlO<sub>3</sub>(aq). Hydrogen gas is explosive; mixing lye (sodium hydroxide) and aluminium in a closed container is therefore dangerous. In addition to aluminium, lye (sodium hydroxide) may also react with [[magnesium]], [[zinc]] (galvanized), tin, [[chromium]], [[brass]], and [[bronze]] to produce [[hydrogen]] gas and is therefore dangerous. Do not allow lye to contact these metals.
Lye may react with various [[sugar]]s to generate carbon monoxide, which is a poisonous gas; mixing sodium hydroxide and [[sugar]] in a closed container is therefore dangerous. Do not allow lye to contact [[sugar]].<ref name=LyeSafety>[http://www.certified-lye.com/safety.html Lye Safety Precautions]</ref>
=== Protection ===
Personal protection for the safe handling of lye includes safety glasses, chemical-resistant [[gloves]], and adequate ventilation. When in the close proximity of lye dissolving in an open container of water, a vapor-resistant face mask is recommended.<ref name=LyeSafety>[http://www.certified-lye.com/safety.html Lye Safety Precautions]</ref>
=== Storage ===
Lye is a [[deliquescent]] [[Salt (chemistry)|salt]] and has a strong affinity for moisture. Lye will deliquesce (dissolve or melt) when exposed to open air. It will absorb a relatively large amount of water from the atmosphere (air) if exposed to it. Eventually, it will absorb enough water to form a liquid solution because it will dissolve in the water it absorbs. Lye should be stored in an airtight resealable container.
[[Hygroscopic]] substances are often used as [[desiccant]]s to draw moisture away from water-sensitive items. Desiccants should never be placed inside a canister of lye because lye has much stronger [[hygroscopic]] properties than activated [[carbon]] and [[silica]] gel (the most common ingredients in commercial desiccant packets) and will pull and absorb the water from the desiccant packets. Do not place desiccant packets inside containers of lye.
Lye should be stored in air-tight plastic containers. The containers should be labeled to indicate the potential danger of the contents and stored away from children, pets, heat, and moisture.<ref name=LyeSafety>[http://www.certified-lye.com/safety.html Lye Safety Precautions]</ref>
==See also==
* [[Sodium hydroxide]], caustic soda
* [[Potassium hydroxide]], caustic potash
* [[Sodium carbonate]], soda ash
* [[Urine]], chamber lye
== Notes ==
<references/>
== References ==
# {{cite web |url=http://www.fda.gov/opacom/laws/fdcact/fdcact4.htm |title=Federal Food, Drug, and Cosmetic Act |format=HTML |publisher=US Food and Drug Administration}}
# {{cite web |url=http://www.usp.org/fcc/ |title=Food Chemicals Codex |format=HTML |publisher=United States Pharmacopeia}}
# {{cite web |url=http://www.certified-lye.com/safety.html |title= Lye Safety Precautions |format=HTML |publisher=Certified Lye}}
# {{cite web |url=http://www.certified-lye.com/ |title=Lye (Sodium Hydroxide) |format=HTML |publisher=Certified Lye}}
# {{cite web |url=http://www.certified-lye.com/MSDS-Lye.pdf |title=Material Safety Data Sheet: Sodium Hydroxide, Solid |format=PDF |publisher=Certified Lye}}
# {{cite book
| last = McDaniel
| first = Robert
| title = The Elegant Art of Handmade Soap: Making, Scenting, Coloring, and Shaping
| publisher = Krause Publications
| location = Iola, WI
| date = 1997
| isbn = 0873418328 }}
[[Category:Bases]]
[[Category:Biodiesel]]
[[Category:Hydroxides]]
[[Category:Hobbies]]
[[Category:Household chemicals]]
[[Category:Deliquescent substances]]
[[Category:Desiccants]]
[[Category:Soaps]]
[[Category:Sodium compounds]]
[[de:Alkalische Lösung]]
[[el:Αλισίβα]]
[[fr:Hydroxyde de Sodium]]
[[it:idrossido di sodio]]
[[nl:Natronloog]]
[[no:Lut]]
[[pl:Ług]]
[[sv:Lut]]