Isooctadecansure

Other Classes -> Stearates

Other Classes -> Stearates

Pharmaceuticals -> Listed in ZINC15

Pharmaceuticals

Lipids -> Unambiguous Lipids

Fatty Acyls [FA] -> Fatty Acids and Conjugates [FA01] -> Straight chain fatty acids [FA0101]

Plastics -> Other functions -> Plasticiser; lubricant

Plastics -> Polyolefin-I; Polyolefin-II

Cosmetic ingredients (Stearic Acid) -> CIR (Cosmetic Ingredient Review)

Emulsifying; Cleansing; Refatting; Emulsion stabilizing

log Kow = 8.23

8.23

0.86 at 68 °F (USCG, 1999) - Less dense than water; will float

0.9408 g/cu cm at 20 °C

Relative density (water = 1): 0.94-0.83

0.86

0.9408 @ 20°C

This chemical does not meet GHS hazard criteria for 68.3% (1405 of 2057) of all reports.

Warning

H315 (25.1%): Causes skin irritation [Warning Skin corrosion/irritation]

P264, P280, P302+P352, P321, P332+P317, and P362+P364 (click each P-code to see the statement)

Aggregated GHS information provided per 2057 reports by companies from 22 notifications to the ECHA C&L Inventory.

Danger

Chemical: Octadecanoic acid

Regulation (EC) No 1333/2008 (amended)

Octadecanoic acid is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Octadecanoic acid are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Status: Active Update: 08-03-2023 https://echa.europa.eu/registration-dossier/-/registered-dossier/15163

Octadecanoic acid: Does not have an individual approval but may be used under an appropriate group standard

This chemical is combustible. This chemical can heat spontaneously. (NTP, 1992)

Combustible.

Combustible

Combustible when exposed to heat or flame.

This TLV Documentation applies only to stearic acid and magnesium, sodium, and zinc stearates. It excludes stearates of other metals. TLV Basis is lower respiratory tract irritation. No acute systemic effects of stearic acid have been reported after ingestion. . . . Sprague-Dawley rats fed stearic acid in their diet at 3000 ppm for 209 days showed 'severe pulmonary infection consisting of tracheobronchitis, lobular pneumonia, lipoid histiocytic response, and abscess formation.' [ACGIH] See Stearic acid.

The U.S.P. product is a mixture of stearic and palmitic acid; [Merck Index] No listed effects of short-term or long-term exposure; Health effects of exposure to the substance have not been investigated. [ICSC] A skin and eye irritant; Dust can irritate nose and throat; Emergency medical treatment: non-toxic ingestion; [HSDB] This TLV Documentation applies only to stearic acid and magnesium, sodium, and zinc stearates. It excludes stearates of other metals. TLV Basis is lower respiratory tract irritation. No acute systemic effects of stearic acid have been reported after ingestion. . . . Rats fed stearic acid at 3000 ppm in their diet for 209 days showed severe pulmonary infection consisting of tracheobronchitis, lobular pneumonia, lipoid histiocytic response, and abscess formation. [ACGIH] Dust can cause eye, nose, and throat irritation; [CAMEO] May cause mild eye irritation; [CHEMINFO] An irritant; [MSDSonline] See STEARATES.

Substance added directly to human food affirmed as generally recognized as safe (GRAS).

Stearic acid is an indirect food additive for use only as a component of adhesives.

The food additive chewing gum base may be safely used in the manufacture of chewing gum in accordance with the following prescribed conditions: (a) The food additive consists of one or more of the following substances that meet the specifications and limitations prescribed in this paragraph, used in amounts not to exceed those required to produce the intended physical or other technical effect. Stearic acid (complying with section 172.860) is included on this list.

Stearic acid is a food additive permitted for direct addition to food for human consumption, as long as 1) the quantity of the substance added to food does not exceed the amount reasonably required to accomplish its intended physical, nutritive, or other technical effect in food, and 2) any substance intended for use in or on food is of appropriate food grade and is prepared and handled as a food ingredient.

Cosmetic Ingredient Review; Final Report on the Safety Assessment of Oleic Acid, Lauric Acid, Palmitic Acid, Myristic Acid, and Stearic Acid. Journal of the American College of Toxicology 6 (3): 321-401 (1987)[Available from, as of November 15, 2017: http://www.cir-safety.org/ingredients]

Residues of stearic acid are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops or to raw agricultural commodities after harvest. Use: Diluent. Limit: None.

Residues of stearic acid are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to animals. Use: Lubricant, component animal tag. Limit: None.

Residues of the following chemical substances are exempted from the requirement of a tolerance when used in accordance with good manufacturing practice as ingredients in an antimicrobial pesticide formulation, provided that the substance is applied on a semi-permanent or permanent food-contact surface (other than being applied on food packaging) with adequate draining before contact with food. (a) The following chemical substances when used as ingredients in an antimicrobial pesticide formulation may be applied to: Food-contact surfaces in public eating places, dairy-processing equipment, and food-processing equipment and utensils. Stearic acid is included on this list. Limit: When ready for use, the end-use concentration is not to exceed 100 ppm.

Fire Extinguishing Agents Not to Be Used: Water or foam may cause frothing.

Use water spray, powder, foam, carbon dioxide.

Fresh air, rest.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth.

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.

Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary.

To fight fire, use carbon dioxide, /or/ dry chemical.

Combustible. Extinguish with dry chemicals, foam, or carbon dioxide. Water may be ineffective on fire. Cool exposed containers with water.

Water or foam may cause frothing.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Avoid breathing dust. Environmental precautions: Do not let product enter drains. Methods and materials for containment and cleaning up: Pick up and arrange disposal without creating dust. Sweep up and shovel. Keep in suitable, closed containers for disposal.

SMALL SPILLS AND LEAKAGE: Should a spill occur while you are handling this chemical, FIRST REMOVE ALL SOURCES OF IGNITION, then you should dampen the solid spill material with 60-70% ethanol and transfer the dampened material to a suitable container. Use absorbent paper dampened with 60-70% ethanol to pick up any remaining material. Seal the absorbent paper, and any of your clothes, which may be contaminated, in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with 60-70% ethanol followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

Product: Offer surplus and non-recyclable solutions to a licensed disposal company. Contaminated packaging: Dispose of as unused product.

1. Liquid acid may be injected at base of incinerator or after mixing with a flammable solvent. Afterburner is suggested for complete combustion. 2. Solid acid may be dissolved in a flammable solvent and burned as above. 3. Solid acid may be packaged in paper or other flammable material and burned in an incinerator.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Avoid breathing dust. Environmental precautions: Do not let product enter drains.

Precautions for safe handling: Avoid formation of dust and aerosols. Provide appropriate exhaust ventilation at places where dust is formed.

Appropriate engineering controls: Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.

Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.

For more Preventive Measures (Complete) data for Stearic acid (6 total), please visit the HSDB record page.

Minimal to mild erythema was observed at a few sites after treatment with a lotion formulation containing 2.8% stearic acid or a 1% aqueous dilution of a bar soap formulation containing 23% stearic acid followed by UVA irradiation. The lotion formulation was applied via 24-hr occlusive patches to the forearm, and treatment sites were irradiated with UVA light for 15 min at a distance of approximately 10 cm, receiving a dose of 4400 uW/sq cm. The bar soap formulation was applied via 24-hr occlusive patches to the infrascapular region of the back, and treatment sites were irradiated with UVA light from Xenon Arc Solar Simulator (150W) with a Schott WG345 filter for 12 min. Similar results were observed at control sites that had received UVA irradiation alone.

A face cream formulation containing 13% stearic acid was tested for photosensitization using 52 human subjects and 4 induction patches and 1 challenge patch. Closed and open 24-hr patches were applied, and treated sites were irradiated with the full Xenon UV light spectrum at 3 times the individuals' predetermined minimal erythemal dose (MED) after removal of each patch and 48 hr later. After the 24-hr challenge patch, treated sites were irradiated with UVA light (Xenon source plus Schott WG345 filter) for 3 min. There were no reactions observed at sites under closed or open patches at either induction or challenge sites.

No reactions were observed in 100 human subjects of a photosensitization study testing an eyeliner formulation containing 2.66% stearic acid. In a 10 induction, 1 challenge occlusive patch /repeat insult patch test/ (RIPT), treated sites were irradiated with UV light from a Hanovia Tanette Mark 1 light source for 1 min at a distance of 1 foot after removal of the 1st, 4th, 7th, and 10th induction patches and after the challenge patch. Approximately 50% of the subjects were designated as "sensitive subjects" because of past experiences of rash or irritation from the use of facial products or because of reaction to a previous patch test with a facial product.

Two skin lotion formulations containing 2.8% stearic acid were tested for phototoxicity. Aqueous preparations of the formulations, 100, 75, 50, and 25%, were applied to four different sites on the backs of 10 male Hartley albino guinea pigs weighing 324-486 g and 284-452 g. These sites were exposed to UVA radiation. Ten control guinea pigs weighing 268-434 and 344-464 g received the same topical applications but no UVA irradiation. Sites were evaluated 1 and 24 hr after treatment. Neither formulation was considered phototoxic to the guinea pigs under these conditions because the control group had signs of irritation that were comparable to the irradiated test group. One guinea pig in the control group of one study died. The test groups reactions ranged from questionable to moderate erythema at 6 (50% preparation) to all 10 sites (75%, 100% preparations). The 25% preparations produced no signs of phototoxicity in either study. The control groups in both studies had questionable to moderate (50-100% sites, 50-75% sites) or considerable erythema (100% site). No irritation was observed at control sites treated with the 25% preparations.

For more Interactions (Complete) data for Stearic acid (9 total), please visit the HSDB record page.

LC50; Species: Lepomis macrochirus (Bluegill) length 40-50 mm; Conditions: freshwater, static, 22 °C; Concentration: 4500 ug/L for 24 hr /formulation/

LC50; Species: Lepomis macrochirus (Bluegill) length 20-30 mm; Conditions: freshwater, static, 22 °C; Concentration: 4330 ug/L for 48, 72 hr /formulation/

LC50; Species: Lepomis macrochirus (Bluegill) length 20-30 mm; Conditions: freshwater, static, 22 °C; Concentration: 4250 ug/L for 96 hr /formulation/

LC50; Species: Gambusia affinis (Western Mosquitofish) length 20-30 mm; Conditions: freshwater, static, 22 °C; Concentration: 8900 ug/L for 24, 48, 72, 96 hr /formulation/

For more Ecotoxicity Values (Complete) data for Stearic acid (9 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 5.1X10+4(SRC), determined from a log Kow of 8.23(2) and a regression-derived equation(3), indicates that the neutral species of stearic acid is expected to be immobile in soil(SRC). The estimated pKa of stearic acid is 4.75(4), indicating that this compound will exist almost entirely in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(5). Volatilization from moist soil is not expected because the compound exists as an anion and anions do not volatilize. Stearic acid is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 7.22X10-7 mm Hg at 25 °C(6). In a modified OECD screening test stearic acid reached 79% of its theoretical BOD in 28 days(7) indicating that biodegradation may be an important fate process in soil(SRC).

FIELD STUDY: In a 1976 field study using samples from agricultural irrigation water, agricultural runoff, streams, and sewage stabilization ponds collected in Yolo and Sacramento Counties, CA, stearic acid, at a concentration of 0.30 mM, did not produce photooxidants after exposure to 5 hours of sunlight(measured as equivalent hydrogen peroxide levels)(1).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 5.1X10+4(SRC), determined from a log Kow of 8.23(2) and a regression-derived equation(3), indicates that neutral species of stearic acid is expected to adsorb to suspended solids and sediment(SRC). The adsorption of stearate, the anion of stearic acid, using relatively nonpolar marine sediment sand surfaces resulted in Kds of 210, 140 and 36, respectively; overall averaging 99% adsorption(4), therefore the stearate is also expected to adsorb to suspended solids and sediment. An estimated pKa of 4.75(5) indicates stearic acid will exist almost entirely in the anion form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process(6). According to a classification scheme(7), an estimated BCF of 10(SRC), from its log Kow(2) and a regression-derived equation(3), suggests the potential for bioconcentration in aquatic organisms is low(SRC). During a 29 day incubation period of freshwater from the Tama River, Japan, the concentration of stearic acid decreased from 536 to 3.7 ug/L, suggesting a half-life of approximately 0.50 days(8). A 5 day theoretical BOD of 43.9 % using a marine water inoculum(9) suggests that biodegradation may be an important environmental fate process in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), stearic acid, which has a vapor pressure of 7.22X10-7 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase stearic is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 17 hours(SRC), calculated from its rate constant of 2.3X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase stearic acid may be removed from the air by wet or dry deposition(SRC). Stearic acid does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight(3).

Stearic acid has been identified in mutton and pork volatiles(1). Mature grains of 15 nonglutinous cultivars each of Indica, Sinica, Javanica, and Japonica brown rice collected in Japan and China in 1984 were determined to have an average of 1.95, 2.00, 1.69, and 1.84 percent stearic acid content, respectively(2). Stearic acid was identified as a volatile component of heated peanut oil(3). The fine aerosol emission rate for stearic acid from a frying hamburger (extralean/regular), from a charbroiled hamburger (extralean), and from a charbroiled hamburger (regular) was determined to be 8.7, 56.3, and 246.9 mg/kg, respectively(4).

ACGIH Carcinogen - Not Classifiable.

ACGIH Carcinogen - Not Classifiable.

The CIR Expert Panel concluded that the following ingredients are safe in the present practices of use andconcentration described in the safety assessment when formulated to be non-irritating and non-sensitizing, which may be basedon a QRA...Stearic Acid...

Safe for use in cosmetics, with qualifications

IDENTIFICATION AND USE: Stearic acid is a solid. It is used in suppositories, coating enteric pills, ointments and for coating bitter remedies. It is also used in manufacturing stearates of aluminum, zinc, and other metals, stearin soap for a liniment invented by Paracelsus, candles, phonograph records, insulators, modeling compounds, impregnating plaster of Paris, in vanishing creams and other cosmetics. Stearic acid is used in animal cell culture. HUMAN STUDIES: The greatest danger from ingestion of large quantities of stearic acid is intestinal obstruction. Skin sensitization is unusual. Aspiration or inhalation of stearic acid could cause chemical pneumonitis. Implantation of stearic acid will cause foreign body reaction. ANIMAL STUDIES: Skin lotion formulations containing 2.8% stearic acid administered at doses of 15 g/kg by gavage to groups of 10 rats resulted in 1 death. Normal behavior and appearance were observed, and there were no gross alterations in surviving rats. No ocular irritation was produced in 6 rabbits by commercial grade stearic acid, whereas mild conjunctival erythema was produced in 3 of 6 rabbits by commercial grade triple-pressed stearic acid. Treatment with 35% stearic acid in corn oil and 50% stearic acid in petrolatum was primarily producing mild conjunctival erythema, which had subsided within 2 days. Intravenous infusion of large doses of stearic acid were thrombogenic in rats, rabbits, and dogs, causing blood platelet aggregation and acute heart failure. When diets containing 5 to 50% stearic acid (as the monoglyceride) were fed to weanling mice for 3 weeks, depression of weight gain was seen above the 10% dietary level. Mortality occurred only with the 50% diet. The effects were less noticeable in adult mice. Rats fed 5% stearic acid as part of a high-fat diet for 6 weeks, or 6% stearic acid for 9 weeks, showed a decreased blood clotting time and hyperlipemia. Rats fed 50 g/kg/day stearic acid for 24 weeks developed reversible lipogranulomas in adipose tissue. No significant pathological lesions were observed in rats fed 3000 ppm stearic acid orally for about 30 weeks, but anorexia, increased mortality, and a greater incidence of pulmonary infection were observed. Single intraperitoneal doses of stearic acid in mice, ranging from approximately 15 to 500 mg/kg, caused no fatalities, but at the highest dose level caused a loss of body weight. In cats, low doses of stearic acid produced elevated pulmonary but decreased systemic blood pressure. Doses greater than 5 mg caused apnea, a fall in blood pressure, and convulsions leading to death. Stearic acid was tested for mutagenicity using the Ames test with Salmonella typhimurium strains TA98, TA100, TA1535, TA1537, and TA1538. Stearic acid had no mutagenic activity over background in the strains tested with and without metabolic activation.

Fatty acids are an important part of the normal daily diet of mammals, birds and invertebrates(1). /Fatty acids/

Annual consumption is 36,500.00 lb. Individual consumption is 0.03093 mg/kg/day.

Stearic acid occurrences in plants(1).

Mature grains of 15 nonglutinous cultivars each of Indica, Sinica, Javanica, and Japonica brown rice collected in Japan and China in 1984 were determined to have an average of 1.95, 2.00, 1.69, and 1.84 percent stearic acid content, respectively(1). Stearic acid is found in low percentages in cotton, coconut, palm kernel, corn, palm, castor, rapeseed, soybean, and sunflower(2).

EPA has released the Interactive Chemical Safety for Sustainability (iCSS) Dashboard. The iCSS Dashboard provides an interactive tool to explore rapid, automated (or in vitro high-throughput) chemical screening data generated by the Toxicity Forecaster (ToxCast) project and the federal Toxicity Testing in the 21st century (Tox21) collaboration. /The title compound was tested by ToxCast and/or Tox21 assays/[USEPA; ICSS Dashboard Application; Available from, as of November 16, 2017: http://actor.epa.gov/dashboard/]

The following link will take the user to the National Toxicology Program (NTP) Test Status of Agents Search page, which tabulates the results and current status of tests such as "Short-Term Toxicity Studies", "Long-term Carcinogenicity Studies", "Developmental Studies", "Genetic Toxicology Studies", etc., performed with this chemical. Testing status for stearic acid is available.[Available from, as of November 3, 2017: https://ntpsearch.niehs.nih.gov/?e=True&ContentType=Testing+Status]

Substance added directly to human food affirmed as generally recognized as safe (GRAS).

Stearic acid is an indirect food additive for use only as a component of adhesives.

The food additive chewing gum base may be safely used in the manufacture of chewing gum in accordance with the following prescribed conditions: (a) The food additive consists of one or more of the following substances that meet the specifications and limitations prescribed in this paragraph, used in amounts not to exceed those required to produce the intended physical or other technical effect. Stearic acid (complying with section 172.860) is included on this list.

Stearic acid is a food additive permitted for direct addition to food for human consumption, as long as 1) the quantity of the substance added to food does not exceed the amount reasonably required to accomplish its intended physical, nutritive, or other technical effect in food, and 2) any substance intended for use in or on food is of appropriate food grade and is prepared and handled as a food ingredient.

Residues of stearic acid are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops or to raw agricultural commodities after harvest. Use: Diluent. Limit: None.

Residues of stearic acid are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to animals. Use: Lubricant, component animal tag. Limit: None.

Residues of the following chemical substances are exempted from the requirement of a tolerance when used in accordance with good manufacturing practice as ingredients in an antimicrobial pesticide formulation, provided that the substance is applied on a semi-permanent or permanent food-contact surface (other than being applied on food packaging) with adequate draining before contact with food. (a) The following chemical substances when used as ingredients in an antimicrobial pesticide formulation may be applied to: Food-contact surfaces in public eating places, dairy-processing equipment, and food-processing equipment and utensils. Stearic acid is included on this list. Limit: When ready for use, the end-use concentration is not to exceed 100 ppm.

Animal cells can de novo synthesize palmitic and stearic fatty acid and their n-9 derivatives. However, de novo synthesis requires the utilization of energy. Palmitic acid (C16) is the immediate precursor of stearic acid (C18). In animal cells, oleic acid is created by the dehydrogenation (desaturation) of stearic acid. Oleic acid is further elongated and desaturated into a family of n-9 fatty acids. The demand for energy used to synthesize n-9 fatty acids can be reduced in cell culture by providing palmitic and stearic acids. In addition, since palmitic and stearic acid are saturated, they are not peroxidized during delivery to the cells.

Stearic acid metabolism via beta-oxidation, omega-oxidation, and (omega-1)-oxidation has been demonstrated in rat liver. Removal of a single acetate moiety can occur to produce palmitic acid, and both this and stearic acid may be desaturated, producing oleic and palmitoleic acids, respectively. After (l4)C stearic acid was injected into rats, about 50 percent of the liver (14)C was recovered as oleic acid, indicating that extensive desaturation occurs. Desaturation occurs only to a small extent extrahepatically but has been detected in adipose tissue and in cells of mammary tissue. Stearic acid is also incorporated into phospholipids, di- and triglycerides, cholesterol, cholesterol esters, and other sterol esters.

Proposed mechanisms for fatty acid uptake by different tissues range from passive diffusion to facilitated diffusion or a combination of both. Fatty acids taken up by the tissues can either be stored in the form of triglycerides (98% of which occurs in adipose tissue depots) or they can be oxidized for energy via the beta-oxidation and tricarboxylic acid cycle pathways of catabolism.

The beta-oxidation of fatty acids occurs in most vertebrae tissues (except the brain) using an enzyme complex for the series of oxidation and hydration reactions resulting in the cleavage of acetate groups as acetyl-CoA (coenzyme A). An additional isomerization reaction is required for the complete catabolism of oleic acid. Alternate oxidation pathways can be found in the liver (omega-oxidation) and in the brain (alpha-oxidation).

Fatty acid biosynthesis from acetyl-CoA takes place primarily in the liver, adipose tissue, and mammary glands of higher animals. Successive reduction and dehydration reactions yield saturated fatty acids up to a 16-carbon chain length. Stearic acid is synthesized by the condensation of palmitoyl-CoA and acetyl-CoA in the mitochondria, and oleic acid is formed via a mono-oxygenase system in the endoplasmic reticulum.

Animal cells can de novo synthesize palmitic and stearic fatty acid and their n-9 derivatives. However, de novo synthesis requires the utilization of energy. Palmitic acid (C16) is the immediate precursor of stearic acid (C18). In animal cells, oleic acid is created by the dehydrogenation (desaturation) of stearic acid. Oleic acid is further elongated and desaturated into a family of n-9 fatty acids. The demand for energy used to synthesize n-9 fatty acids can be reduced in cell culture by providing palmitic and stearic acids. In addition, since palmitic and stearic acid are saturated, they are not peroxidized during delivery to the cells.

Stearic Acid has known human metabolites that include 17-Hydroxystearic acid.

A mild moisturizing body wash with stearic acid, a key component of corneum lipids, and emollient soybean oil has been introduced in the market place. The objectives of this study are to determine the amount and the location of the stearic acid in the corneum after in vivo cleansing by the formulation. Clinical cleansing studies for one and five consecutive days were carried out with the formulation containing soybean oil or petroleum jelly (PJ). The free stearic acid in it was replaced by the fully deuterated variant. The amounts of stearic acid in 10 consecutive corneum tape strips were measured by liquid chromatograph-mass spectroscopy. Separately, electron paramagnetic resonance (EPR) measurements were taken with a porcine skin after a wash by the soybean oil formulation with its free fatty acid replaced by its spin probe analogue, 5-doxyl stearic acid. Deuterated stearic acid was detected in all 10 consecutive layers of stratum corneum and the total amount after five washes with the soybean oil formulation was 0.33 ug/sq cm. The spin probe in cleanser-treated skin was incorporated in a partially ordered hydrophobic region similar to corneum lipids. The probe mobility increased in the temperature region where lipid disorder was expected. The estimated total fatty acid delivered to skin from cleansing is comparable to the amount of fatty acid in a corneum layer. The delivered fatty acid is most likely incorporated in the corneum lipid phase.

It has been noted by several investigators that increasing fatty acid chain length slightly decreased their digestibility; stearic acid was the most poorly absorbed of the common fatty acids.

Fatty acids, /including stearic acid/, originating from adipose tissue stores are either bound to serum albumin or remain unesterified in the blood.

Oleic, palmitic, myristic, and stearic acids are primarily transported via the lymphatic system, and lauric acid is transported by the lymphatic and (as a free fatty acid) portal systems.

Radioactivity has been traced to the heart, liver, lung, spleen, kidney, muscle, intestine, adrenal, blood, and lymph, and adipose, mucosal, and dental tissues after administration of radioactive oleic, palmitic, and stearic acids.

CIR ingredient: Stearic Acid

Used in cosmetics, pharmaceuticals, food additives, waterproofing agents, plastic stabilizers, emulsifiers, and rubber lubricants and dusting agents; Stearic acid occurs naturally in human and animal fats and oils and in some vegetable oils, including cocoa oil. Stearic acid can be prepared from animal fat (triglyceride) by treating with water at high temperature, leading to hydrolysis of triglycerides, or by hydrogenation of unsaturated vegetable oils such as cottonseed oil. [ACGIH]

Present as a glyceride in animal fats and oils and in some vegetable oils; [Merck Index] Used as intermediate for metallic soaps and greases, household soap products, synthetic rubber vulcanization activators, and alkyd and epoxy resins for surface coatings; Also used in cosmetic and pharmaceutical creams and lotions, candles, phonograph records, dental materials, insulators, lubricants, shoe and metal polishes, coatings, food packaging, and modeling compounds; Also used as a synthetic rubber polymerization emulsifier, a release agent in baked goods and confectioneries, a dispersing agent and softener in rubber compounds, a paper sizing ingredient (specialty papers), a textile auxiliary, to make metal stearates (aluminum, zinc, etc.), for impregnating plaster of Paris, to aid incorporation and dispersion of zinc oxide in rubber and paint, and to cure polybutadiene; [HSDB] Stearic acid occurs naturally in human and animal fats and oils and in some vegetable oils, including cocoa oil. Stearic acid can be prepared from animal fat (triglyceride) by treating with water at high temperature, leading to hydrolysis of triglycerides, or by hydrogenation of unsaturated vegetable oils such as cottonseed oil. [ACGIH]

Pulp and Paper Processing [Category: Industry]

For stearic acid (USEPA/OPP Pesticide Code: 079082) there are 0 labels match. /SRP: Not registered for current use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./

Reported uses (ppm):

(1972) 2X10+7 GRAMS

(1975) 2.27X10+7 GRAMS

2023: 250,000,000 - <400,000,000 lb

(1972) 4.35X10+10 GRAMS

(1975) 4.29X10+10 GRAMS

(1984) 2.37X10+8 g

Production volumes for non-confidential chemicals reported under the Inventory Update Rule.[Table#3748]

For more U.S. Production (Complete) data for Stearic acid (6 total), please visit the HSDB record page.

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.

It is produced commercially from hydrolyzed tallow derived from edible sources or from hydrolyzed, completely hydrogenated vegetable oil derived from edible sources.

From high-grade tallows and yellow grease stearin by washing, hydrolysis with the Twitchell or similar reagent, boiling, distilling, cooling, and pressing; from oleic acid by hydrogenation.

/There are/ three types of Stearic Acid distinguished by average Stearic Acid concentration. These Stearic Acids, 37.5%, 42.5%, and 95.0%, have minimum Stearic plus Palmitic Acid concentrations of 89.0%, 94.0%, and 97.5%, respectively. Regular pharmaceutical grade Stearic Acid specifies a 40,0% minimum of either Stearic or Palmitic Acid and a 90.0% minimum for their sum. Purified pharmaceutical grade Stearic Acid specifies a 90.0% minimum Stearic Acid content and a 96.0% minimum for the sum.

Saponified, distilled, single-pressed, double-pressed, triple-pressed, USP, FCC, 90% stearic with low oleic, grade free from chick edema factor, 99.8% pure.

EPA Safer Chemical Functional Use Classes -> Surfactants

Safer Chemical Classes -> Green circle - The chemical has been verified to be of low concern

Fragrance Ingredients

Flavouring Agent -> FLAVOURING_AGENT -> JECFA Functional Classes

Flavoring Agents -> JECFA Flavorings Index

Plastics -> Other functions -> Plasticiser; lubricant

Non-metallic Mineral Product Manufacturing (includes clay, glass, cement, concrete, lime, gypsum, and other non-metallic mineral product manufacturing)

Octadecanoic acid: ACTIVE

Insoluble stearates are formed with many metals. Ointment bases made with stearic acid may show evidence of drying out or lumpiness due to such a reaction when zinc or calcium salts are compounded therein.

Occurs as a glyceride in tallow and other animal fats and oils, as well as in some vegetable oils.

Most commercial stearic acid is 45% palmitic acid, 50% stearic acid, and 5% oleic acid, but purer grades are increasingly used.

Chain length distribution of pure stearic acid, produced by fractional distillation: 5% C(16), 93% C(18), 2% C(20)