Milchsure Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
VISKOSE, FARBLOSE BIS GELBE FLüSSIGKEIT ODER FARBLOSE BIS GELBE KRISTALLE.
CHEMISCHE GEFAHREN
Mittelstarke S?ure.
ARBEITSPLATZGRENZWERTE
TLV nicht festgelegt (ACGIH 2005).
MAK nicht festgelegt (DFG 2005).
AUFNAHMEWEGE
Aufnahme in den K?rper durch Inhalation des Aerosols und durch Verschlucken.
INHALATIONSGEFAHREN
Nur ungenügende Angaben vorhanden über die Geschwindigkeit, mit der eine gesundheitssch?dliche Konzentration in der Luft beim Verdampfen bei 20°C erreicht wird.
WIRKUNGEN BEI KURZZEITEXPOSITION
WIRKUNGEN BEI KURZZEITEXPOSITION: Die Substanz reizt die Haut und die Atemwege und ver?tzt die Augen. ?tzend beim Verschlucken.
LECKAGE
Ausgelaufene Flüssigkeit in abdichtbaren Beh?ltern sammeln. Ausgelaufene Flüssigkeit vorsichtig mit schwach alkalischer L?sung, z.B. Dinatriumcarbonat neutralisieren. Dann mit viel Wasser wegspülen.
R-S?tze Betriebsanweisung:
R38:Reizt die Haut.
R41:Gefahr ernster Augensch?den.
R34:Verursacht Ver?tzungen.
S-S?tze Betriebsanweisung:
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S39:Schutzbrille/Gesichtsschutz tragen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn m?glich, dieses Etikett vorzeigen).
S36/37/39:Bei der Arbeit geeignete Schutzkleidung,Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.
Chemische Eigenschaften
Lactic acid, CH3CHOHCOOH, also known as 2-hydroxypropanoic acid, is a hygroscopic liquid that exists in three isometric forms. I-lactic acid is found in blood and animal tissue as a product of glucose and glycogen metabolism. d-Iactic acid is obtained by fermentation of sucrose (corn refining), The racemic mixture is present in foods prepared by bacterial fermentation or prepared synthetically. Lactic acid is soluble in water,alcohol,and ether. It is used as a solvent, in manufacturing confectionery, and in medicine.
Occurrence
Reported found in Papaver somniferum L.; it is a constituent of wine and sour milk; the two optically active
isomers are found in muscular tissues and are formed by the action of lactic acid–producing bacteria in several fermentation processes. Also reported found in guava, grapes, melon, wheat bread, cheeses, yogurt, milk, cream, buttermilk, egg, cooked beef,
cognac, cider, sherry, grape wine, beer, grape brandy, whiskey, cocoa, coffee, tea, mango, sake, wort, dried, bonito, cassava, Bourbon
vanilla, chicory root, Cape gooseberry and cherimoya.
Verwenden
lactic acid (sodium lactate) is a multi-purpose ingredient used as a preservative, exfoliant, moisturizer, and to provide acidity to a formulation. In the body, lactic acid is found in the blood and muscle tissue as a product of the metabolism of glucose and glycogen. It is also a component of the skin’s natural moisturizing factor. Lactic acid has better water intake than glycerin. Studies indicate an ability to increase the water-retention capacity of the stratum corneum. They also show that the pliability of the stratum corneum layer is closely related to the absorption of lactic acid; that is, the greater the amount of absorbed lactic acid, the more pliable the stratum corneum layer. Researchers report that continuous use of preparations formulated with lactic acid in concentrations ranging between 5 and 12 percent provided a mild to moderate improvement in fine wrinkling and promote softer, smoother skin. Its exfoliating properties can help in the process of removing excess pigment from the surface of the skin, as well as improving skin texture and feel. Lactic acid is an alpha hydroxy acid occurring in sour milk and other lesser-known sources, such as beer, pickles, and foods made through a process of bacterial fermentation. It is caustic when applied to the skin in highly concentrated solutions.
Definition
ChEBI: A 2-hydroxy monocarboxylic acid that is propanoic acid in which one of the alpha-hydrogens is replaced by a hydroxy group.
Vorbereitung Methode
Lactic acid is prepared by the fermentation of carbohydrates, such
as glucose, sucrose, and lactose, with Bacillus acidi lacti or related
microorganisms. On a commercial scale, whey, corn starch,
potatoes, or molasses are used as a source of carbohydrate. Lactic
acid may also be prepared synthetically by the reaction between
acetaldehyde and carbon monoxide at 130–200°C under high
pressure, or by the hydrolysis of hexoses with sodium hydroxide.
Lactic acid prepared by the fermentation of sugars is levorotatory;
lactic acid prepared synthetically is racemic. However, lactic
acid prepared by fermentation becomes dextrorotatory on dilution
with water owing to the hydrolysis of (R)-lactic acid lactate to (S)-
lactic acid.
Allgemeine Beschreibung
A colorless to yellow odorless syrupy liquid. Corrosive to metals and tissue. Used to make cultured dairy products, as a food preservative, and to make chemicals.
Air & Water Reaktionen
Soluble in water.
Health Hazard
Inhalation of mist causes coughing and irritation of mucous membranes. Ingestion, even of diluted preparations, has a corrosive effect on the esophagus and stomach. Contact with more concentrated solutions can cause severe burns of skin or eye.
Brandgefahr
Combustible material: may burn but does not ignite readily. When heated, vapors may form explosive mixtures with air: indoors, outdoors and sewers explosion hazards. Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form.
Pharmazeutische Anwendungen
Lactic acid is used in beverages, foods, cosmetics, and pharmaceuticals
as an acidifying agent and acidulant.
In topical formulations, particularly cosmetics, it is used for its
softening and conditioning effect on the skin. Lactic acid may also
be used in the production of biodegradable polymers and microspheres,
such as poly(D-lactic acid), used in drug delivery
systems.
Lactic acid is also used as a food preservative. Therapeutically,
lactic acid is used in injections, in the form of lactate, as a source of
bicarbonate for the treatment of metabolic acidosis; as a spermicidal
agent; in pessaries for the treatment of leukorrhea; in infant feeds;
and in topical formulations for the treatment of warts.
Industrielle Verwendung
lactic acid showed good depressing effect on hornblende, pyroxene and biotite during
flotation of hematite and ilmenite minerals.
Sicherheit(Safety)
Lactic acid occurs in appreciable quantities in the body as an end
product of the anaerobic metabolism of carbohydrates and, while
harmful in the concentrated form , can be
considered nontoxic at the levels at which it is used as an excipient.
A 1% v/v solution, for example, is harmless when applied to the
skin.
There is evidence that neonates have difficulty in metabolizing
(R)-lactic acid, and this isomer and the racemate should therefore
not be used in foods intended for infants aged less than 3 months
old.
There is no evidence that lactic acid is carcinogenic, teratogenic,
or mutagenic.
LD50 (guinea pig, oral): 1.81 g/kg
LD50 (mouse, oral): 4.88 g/kg
LD50 (mouse, SC): 4.5 g/kg
LD50 (rat, oral): 3.73 g/kg
Lager
Lactic acid is hygroscopic and will form condensation products
such as polylactic acids on contact with water. The equilibrium
between the polylactic acids and lactic acid is dependent on
concentration and temperature. At elevated temperatures lactic acid
will form lactide, which is readily hydrolyzed back to lactic acid.
Lactic acid should be stored in a well-closed container in a cool,
dry place.
Inkompatibilit?ten
Incompatible with oxidizing agents, iodides, and albumin. Reacts
violently with hydrofluoric acid and nitric acid.
Regulatory Status
GRAS listed. Accepted for use as a food additive in Europe.
Included in the FDA Inactive Ingredients Database (IM, IV, and SC
injections; oral syrups and tablets; topical and vaginal preparations).
Included in medicines licensed in the UK. Included in the
Canadian List of Acceptable Non-medicinal Ingredients.
Milchsure Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
