| Identification | More | [Name]
Stearic acid | [CAS]
57-11-4 | [Synonyms]
ACIDUM STEARICUM 50
C18
C18:0 FATTY ACID
CARBOXYLIC ACID C18
CETYLACETIC ACID
FEMA 3035
N-OCTADECANOIC ACID
N-OCTADECYLIC ACID
OCTADECANEDIOIC ACID
RARECHEM AL BO 0157
STEARIC ACID
1-Heptadecanecarboxylic acid
1-Heptadecanecarboxylic acid Ro 5-2807
1-heptadecanecarboxylicacid
400JB9103-88
acideoctadecylique
acidestearique
AdekaFattyAcidSA910
Barolub FTA
BarolubFTA | [EINECS(EC#)]
266-928-5 | [Molecular Formula]
C18H36O2 | [MDL Number]
MFCD00002752 | [Molecular Weight]
284.48 | [MOL File]
57-11-4.mol |
| Chemical Properties | Back Directory | [Appearance]
white flakes | [Melting point ]
67-72 °C (lit.) | [Boiling point ]
361 °C (lit.) | [density ]
0.84
| [vapor pressure ]
1 mm Hg ( 173.7 °C)
| [FEMA ]
3035 | [refractive index ]
1.4299 | [Fp ]
>230 °F
| [storage temp. ]
2-8°C
| [solubility ]
Practically insoluble in water, soluble in ethanol (96 per cent) and in light petroleum (bp: 50-70 °C). | [form ]
powder
| [pka]
pKa 5.75±0.00(H2O
t = 35) (Uncertain) | [color ]
White | [Specific Gravity]
0.84 (80℃) | [Odor]
odorless mild fatty | [Odor Type]
odorless | [Water Solubility ]
0.1-1 g/100 mL at 23 ºC | [JECFA Number]
116 | [Merck ]
14,8804 | [BRN ]
608585 | [Dielectric constant]
2.3（22℃） | [Exposure limits]
ACGIH: TWA 10 mg/m3; TWA 3 mg/m3 | [InChIKey]
QIQXTHQIDYTFRH-UHFFFAOYSA-N | [LogP]
8.22 | [Uses]
stearic acid is an emulsifier and thickening agent found in many vegetable fats. Stearic acid is the main ingredient used in making bar soaps and lubricants. It occurs naturally in butter acids, tallow, cascarilla bark, and in other animal fats and oils. Stearic acid may cause allergic reactions in people with sensitive skin and is considered somewhat comedogenic. | [CAS DataBase Reference]
57-11-4(CAS DataBase Reference) | [NIST Chemistry Reference]
Octadecanoic acid(57-11-4) | [EPA Substance Registry System]
Stearic acid (57-11-4) |
| Safety Data | Back Directory | [Hazard Codes ]
Xi,F | [Risk Statements ]
R38:Irritating to the skin.
R36/37/38:Irritating to eyes, respiratory system and skin .
R11:Highly Flammable. | [Safety Statements ]
S37/39:Wear suitable gloves and eye/face protection .
S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S16:Keep away from sources of ignition-No smoking . | [WGK Germany ]
3
| [RTECS ]
WI2800000
| [Autoignition Temperature]
395 °C | [TSCA ]
Yes | [HS Code ]
38231100 | [Safety Profile]
Poison by intravenous route. A human sktn irritant. Questionable carcinogen with experimental tumorigenic data by implantation route. Combustible when exposed to heat or flame. Heats spontaneously. To fight fire, use CO2, dry chemical. When heated to decomposition it emits acrid smoke and irritating fumes. | [Hazardous Substances Data]
57-11-4(Hazardous Substances Data) |
| Hazard Information | Back Directory | [General Description]
White solid with a mild odor. Floats on water. | [Reactivity Profile]
STEARIC ACID(57-11-4) is incompatible with strong oxidizers and strong bases. STEARIC ACID(57-11-4) is also incompatible with reducing agents. | [Air & Water Reactions]
Slightly soluble in water. | [Health Hazard]
Compound is generally considered nontoxic. Inhalation of dust irritates nose and throat. Dust causes mild irritation of eyes. | [Fire Hazard]
This chemical is combustible. This chemical can heat spontaneously. | [Occurrence]
Stearic acid is naturally present in the glycerides of animal fats and most vegetable oils. Reported found in fresh apple, banana, Vitis vinifera L., melon, tomato, ginger, blue cheeses, cheddar cheese, Swiss cheese, feta cheese, buttermilk, raw fatty fish, raw lean fish, raw shrimp, grapefruit juice, guava, papaya, cucumber, saffron, pork and lamb liver, pork fat, hop oil, beer, cognac, rum, whiskies, sherry, tea, peanut oil, soybean, roast coconut, coconut milk, avocado, passion fruit, rose apple, mushroom, starfruit, fenugreek, mango, cardamom, cooked rice, prickly pear, dill seed, buckwheat, malt, wort, cassava, loquat, shrimp, crab, cape gooseberry and Chinese quince. | [Definition]
A solid
carboxylic acid present in fats and oils as
the glyceride. | [Definition]
ChEBI: A C18 straight-chain saturated fatty acid component of many animal and vegetable lipids. As well as in the diet, it is used in hardening soaps, softening plastics and in making cosmetics, candles and plastics. | [Preparation]
Commercially it is produced by the hydrogenation of the unsaturated 18-carbon fatty acids of soybean, cottonseed or other vegetable oils. When obtained from animal fats by hydrolysis and fractional crystallization, commercial stearic acid is a mixture of solid organic acids, chiefly palmitic and stearic acids. Commercial products containing about 90% stearic acid are produced by hydrolysis and crystallization of a completely hydrogenated vegetable oil or by fractional distillation of fatty acid mixtures obtained from tallow | [Production Methods]
Stearic acid is manufactured by hydrolysis of fat by continuous
exposure to a countercurrent stream of high-temperature water and
fat in a high-pressure chamber. The resultant mixture is purified by
vacuum steam distillation and the distillates are then separated
using selective solvents.
Stearic acid may also be manufactured by the hydrogenation of
cottonseed and other vegetable oils; by the hydrogenation and
subsequent saponification of olein followed by recrystallization
from alcohol; and from edible fats and oils by boiling with sodium
hydroxide, separating any glycerin, and decomposing the resulting
soap with sulfuric or hydrochloric acid. The stearic acid is then
subsequently separated from any oleic acid by cold expression.
Stearic acid is derived from edible fat sources unless it is intended
for external use, in which case nonedible fat sources may be used.
The USP32–NF27 states that stearic acid labeled solely for external
use is exempt from the requirement that it be prepared from edible
sources. Stearic acid may contain a suitable antioxidant such as
0.005% w/w butylated hydroxytoluene. | [Production Methods]
Stearic Acid occurs in many animal and vegetable fats and oils, but it is more abundant in animal fat (up to 30 %) than vegetable fat (typically < 5 % ) . The important exceptions are cocoa butter and shea butter where the stearic acid content (as a triglyceride) is 28 – 45 %.
Stearic acid is prepared by treating these fats and oils with water at a high pressure and temperature (above 200 °C), leading to the hydrolysis of triglycerides. The resulting mixture is then distilled. Commercial stearic acid is often a mixture of stearic and palmitic acids, although purified stearic acid is available.
In terms of its biosynthesis, stearic acid is produced from carbohydrates via the fatty acid synthesis machinery via acetyl-CoA . | [Brand name]
Hystrene 5016 (Witco). | [Aroma threshold values]
Detection: 20 ppm | [Synthesis Reference(s)]
Synthetic Communications, 15, p. 759, 1985 DOI: 10.1080/00397918508063869 | [Pharmaceutical Applications]
Stearic acid is widely used in oral and topical pharmaceutical
formulations. It is mainly used in oral formulations as a tablet and
capsule lubricant, although it may also be used as a
binder or in combination with shellac as a tablet coating. It has
also been suggested that stearic acid may be used in enteric tablet
coatings and as a sustained-release drug carrier.
In topical formulations, stearic acid is used as an emulsifying and
solubilizing agent. When partially neutralized with alkalis or
triethanolamine, stearic acid is used in the preparation of
creams. The partially neutralized stearic acid forms a creamy
base when mixed with 5–15 times its own weight of aqueous liquid,
the appearance and plasticity of the cream being determined by the
proportion of alkali used.
Stearic acid is used as the hardening agent in glycerin
suppositories.
Stearic acid is also widely used in cosmetics and food products. | [Biochem/physiol Actions]
β-Oxidation of stearic acid yields eight FADH2 (flavin adenine dinucleotide) and NADH2 (nicotinamide adenine dinucleotide) molecules and nine acetyl-CoA molecules. | [Safety]
Stearic acid is widely used in oral and topical pharmaceutical
formulations; it is also used in cosmetics and food products. Stearic
acid is generally regarded as a nontoxic and nonirritant material.
However, consumption of excessive amounts may be harmful.
LD50 (mouse, IV): 23 mg/kg
LD50 (rat, IV): 21.5 mg/kg | [Carcinogenicity]
Stearic acid was administered
subcutaneously to several groups of Swiss–Webster mice
at doses of 0.05 or 0.5mg once weekly for 25 weeks (total
dose of 1.3–130 mg), 1.0 mg thrice a week for a total of
10 injections or 1.0 mg twice weekly for a total of 82
injections. No neoplasms were reported in these studies
. In 3 groups of 10–15 BALB/c mice administered
0.05 mg or 0.5 mg stearic acid (twice weekly for 52 or
57 weeks), one pulmonary neoplasm was detected in each
group after 19–21 months.Afewsubcutaneous sarcomas and
one adrenal carcinoma were also reported.No injection
site sarcomas or other carcinogenic effects were reported
by the same authors in a later study of mice injected with
0.05–0.5 mg weekly for 26 weeks. Rats given subcutaneous
injections of 0.05 or 0.5 mg stearic acid weekly for
26 weeks did not develop sarcomas at the site of injection.
When rat fibroblast cells were transfected with an activated
human c-H-ras oncogene and the cells subsequently grown
in a medium supplemented with stearic acid (20–80 mM),
there was a marked increase in the number of transformed
foci. Stearic acid inhibited the colony-forming ability
of four out of five rat and two human tumor continuous cell
lines in vitro. Using rats pretreated with nitrosomethyl urea as
a model for mammary carcinoma, Habib et al. demonstrated
that subcutaneous injection of stearic acid at weekly
intervals prevented tumor development. Increasing levels of
stearate in the diet resulted in decreased mammary tumor
incidence and increased time to tumor in mice. | [Metabolism]
An isotope labeling study in humans concluded that the fraction of dietary stearic acid oxidatively desaturated to oleic acid was 2.4 times higher than the fraction of palmitic acid analogously converted to palmitoleic acid. Also, stearic acid was less likely to be incorporated into cholesterol esters. In epidemiologic and clinical studies stearic acid was associated with lowered LDL cholesterol in comparison with other saturated fatty acids. These findings may indicate that stearic acid is healthier than other saturated fatty acids. | [storage]
Stearic acid is a stable material; an antioxidant may also be added to
it. The bulk material should be stored in a wellclosed
container in a cool, dry place. | [Purification Methods]
Crystallise stearic acid from acetone, acetonitrile, EtOH (5 times), aqueous MeOH, ethyl methyl ketone or pet ether (b 60-90o), or by fractional precipitation by dissolving in hot 95% EtOH and pouring into distilled water, with stirring. The precipitate, after washing with distilled water, is dried under vacuum over P2O5. It has also been purified by zone melting and partial freezing. [Tamai et al. J Phys Chem 91 541 1987, Beilstein 2 IV 1206.] | [Incompatibilities]
Stearic acid is incompatible with most metal hydroxides and may be
incompatible with bases, reducing agents, and oxidizing agents.
Ointment bases made with stearic acid may show evidence of
drying out or lumpiness due to such a reaction when compounded
with zinc or calcium salts.
A number of differential scanning calorimetry studies have
investigated the compatibility of stearic acid with drugs. Although
such laboratory studies have suggested incompatibilities, e.g. with
naproxen, they may not necessarily be applicable to formulated
products.
Stearic acid has been reported to cause pitting in the film coating
of tablets applied using an aqueous film-coating technique; the
pitting was found to be a function of the melting point of the stearic
acid. | [Regulatory Status]
GRAS listed. Accepted as a food additive in Europe (fatty acids).
Included in the FDA Inactive Ingredients Database (sublingual
tablets; oral capsules, solutions, suspensions, and tablets; topical
and vaginal preparations). Included in nonparenteral medicines
licensed in the UK. Included in the Canadian List of Acceptable
Non-medicinal Ingredients. |
| Questions And Answer | Back Directory | [description]
Stearic acid is one of several major long-chain fatty acids comprising oils and fats. It is presented in animal fats, oil and some kinds of vegetable oils as wellin the form of glycerides. These oils, after hydrolysis, produce the stearic acid.
Stearic acid is a fatty acid widely existing in nature and has the general chemical properties of carboxylic acids. Almost all kinds of fat and oil contain certain amount of stearic acid with the content in the animal fats being relative high. For example, the content in the butter can reach up to 24% while the content in vegetable oil is relative low with the value in tea oil being 0.8% and the oil in palm being 6%. However, the content in cocoa can reach as high as 34%.
There are two major approaches for industrial production of stearic acid, namely fractionation and compression method. Add decomposition agent to the hydrogenated oil, and then hydrolyze to give the crude fatty acid, further go through washing with water, distillation, bleaching to obtain the finished products with glycerol as the byproduct.
Most domestic manufacturers use animal fat for production. Some kinds of production technology will result in the incompletion of the distillation of fatty acid which produce stimulating odor at the time of the plastic processing and high temperatures. Although these odor is of no toxic but they will have certain effect on the working conditions and the natural environment. Most imported form of stearic acid takes vegetable oil as the raw materials, the production processes are more advanced; the produced stearic acid is of stable performance, good lubrication property and less odor in the application.
Stearic acid is mainly used for the production of stearates such as sodium stearate, magnesium stearate, calcium stearate, lead stearate, aluminum stearate, cadmium stearate, iron stearate, and potassium stearate. The sodium or potassium salt of stearic acid is the component of soap. Although sodium stearate has a less decontamination ability than sodium palmitate, but its presence may increase the hardness of soap.
Take butter as raw material, go through sulfuric acid or pressurized method for decomposition. The free fatty acids was first subject to water pressure method for removing the palmitic acid and oleic acid at 30~40 ℃, and then dissolved in ethanol, followed by addition of barium acetate or magnesium acetate which precipitates stearate. Then further add dilute sulfuric acid to get the free stearate acid, filter and take it, and re-crystallize in ethanol to obtain the pure stearic acid.
The above information is edited by the chemicalbook of Dai Xiongfeng.
| [Chemical Properties]
Pure product appears as white shiny soft small pieces. It is slightly soluble in water, soluble in alcohol, acetone, easily soluble in benzene, chloroform, ether, carbon tetrachloride, carbon disulfide, amyl acetate and toluene.
| [application]
Stearic acid is widely used in cosmetics, plastics plasticizers, mold release agents, stabilizers, surfactants, rubber vulcanization accelerator, waterproof agent, polishing agent, metal soap, metal mineral flotation agents, softeners and pharmaceuticals as well as other organic chemicals. Stearic acid can also be used as the solvents of oil-soluble paint, crayons lubrication agent, stencil lighting agent and the emulsifier of stearic acid glyceride.
Stearic acid can also be widely used in the manufacturing of PVC pipe, sheet material, profiles and film and is the PVC heat stabilizers with good lubricity and excellent stability against light and heat. In the application of polyvinyl chloride pipe, stearic acid helps prevent the "coke" during the processing and is effective heat stabilizer during PVC film processing while also preventing the discoloration of the finished film discoloration caused by exposure.
Stearic acid has become the additive for lubrication, plasticization and stabilization of the filled masterbatch. Stearic acid can effectively improve the coating activating effect of inorganic powder and increase the flow rate of materials. When there is demand for a large flow rate of the melt for material with inorganic powder accounting for the most part, an appropriate increase in the content of stearic acid can significantly increase the melt flow rate of material. However, the amount of stearic acid used in filled masterbatch also have threshold with its amount being controlled in about 1% of the total mass. If the added amount is over-excessive, it will not only cause the decrease of the quality and the performance of plastic products but also generate sticky substance in the die lip location of the manufacturing equipment of the plastic products, affecting the production efficiency and product quality.
The mono-or multi-alcohol ester of stearic acid can be used as cosmetics, nonionic surfactants and plasticizers. Its alkali metal salt can be dissolved in water and is a major component of soap. Other kinds of salts can be used as waterproofing agents, lubricants, bactericides, coating additives and PVC stabilizers.
| [Uses]
It can be used as natural rubber, synthetic rubber (except butyl rubber) and latex curing active agent. It can also be used as raw material of plastic plasticizer and stabilizer. Medicine: it can be used for the preparation of ointments, suppositories, etc., as well as being used in the manufacture of cosmetics, candles, waterproof agent and polishing agent. The product can be used as a lubricant, defoamers and food additives in the food industry as well as the raw materials of glycerol stearate, stearic acid sorbitol anhydride esters and sucrose esters.
It can also be used as standard reference product for gas analysis as well as the preparation of soap, cosmetics, pharmaceuticals and other organic chemicals.
| [Toxicity]
LD50 i.v. in mice, rats: 23±0.7, 21.5±1.8 mg/kg, L. Or, A. Wretlind, Acta Pharmacol. Toxicol. 18, 141 (1961) | [Limited use]
FEMA (mg/kg): soft drinks: 2.0~ 10; candy: 4000; bakery: 3.5.
GB 2760-2001: candy, gum base agent; take GMP as limit.
| [Production method]
There are two major approaches for industrial production of stearic acid, namely fractionation and compression method. Add decomposition agent to the hydrogenated oil, and then hydrolyze to give the crude fatty acid, further go through washing with water, distillation, bleaching to obtain the finished products with glycerol as the byproduct.
Compression method takes animal oil as raw material. Have animal oil subject to hydrolysis in the catalysis of zinc oxide at pressure of 1.17~1.47 MPa, further go through pickling, washing, distillation, cooling, freezing, press for removal of oleic acid to get the finished products.
Heat the cotton seed oil, rice bran oil, or soybean oil in the presence of a hydrolyzing agent under normal pressure to boiling with hydrolysis of 1.5 h and harden to saturated fatty acid. Oleic acid hydrogenation;
Use the C10~C20 and C18~C20 fraction of the synthetic fatty acid as raw materials, go through melting, pickling (with 1% sulfuric acid) mold, pressing, melting, pickling, dehydrating and crystallization to obtain it.
It can be obtained through the low-temperature segment separation of the mixed fatty acid.
It can also be made through the hydrogenation of oleic acid.
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