2-Hydroxybenzoic acid
CAS Number: 69-72-7

CAS: 69-72-7

2-Hydroxybenzoic acid
Benzoic acid, 2-hydroxy-
Salicylic acid

Salicylic acid is an important organic synthetic raw material, widely used in medicine, pesticides, dyes, rubber, food and perfumes.
In the pharmaceutical industry, the main drug productions of salicylic acid are sodium salicylate, wintergreen oil (methyl salicylate), aspirin (acetylsalicylic acid), salicylic acid amine, phenyl salicylate.
In dye industry, salicylic acid is used for production mordant pure yellow , direct yellow 3GN, direct yellow GR, direct brown 3GN, acid mordant brown G, acid mordant yellow GG, acid yellow dye complex.
In pesticide production, salicylic acid is used for the synthesis of organic phosphorus pesticide Isocarbophos, intermediate isopropyl salicylate isofenphos methyl and Rodenticide warfarin, coumatetralyl intermediate 4-hydroxycoumarin.
In rubber industry, salicylic acid is used as anti scorching agent and production of ultraviolet absorbent and foaming agent.
Salicylic acid is perfume material, used for the preparation of methyl salicylate, salicylic acid ethyl ester; food preservatives, its sodium Salt is mostly used, now a number of countries have been banned; methyl salicylate can be used as oral cleaning agents, such as toothpaste flavor.

Salicylic Acid is a beta hydroxy acid that occurs as a natural compound in plants.
Salicylic acid has direct activity as an anti-inflammatory agent and acts as a topical antibacterial agent due to its ability to promote exfoliation.

Salicylic acid is an odorless white to light tan solid. Sinks and mixes slowly with water.

How does salicylic acid work?
Salicylic acid works by softening keratin, a protein that forms part of the skin structure. This helps to loosen dry scaly skin making it easier to remove.
When salicylic acid is used in combination with other medicines it takes off the upper layer of skin allowing the additional medicines to penetrate more effectively.

In acne, topical salicylic acid helps slow down shedding of the cells inside the follicles, preventing clogging.
Salicylic acid also helps break down blackheads and whiteheads.

Salicylic Acid is an odourless slightly off-white powder or needle-shape crystal compound with the formula C7H6O3.

With many uses spanning a variety of industries including chemical intermediates, pharmaceuticals and cosmetics, salicylic acid is probably most widely known as the main ingredient in cosmetic face washes, cleaners and exfoliants.
With its ability to safely help remove the outer layer of skin and dissolve skin debris Salicylic Acid is found in a wide range of medicines used to treat a range of dermatological conditions including acne, psoriasis and dermatitis.

Salicylic acid is a monohydroxybenzoic acid that is benzoic acid with a hydroxy group at the ortho position.
Salicylic acid is obtained from the bark of the white willow and wintergreen leaves.
Salicylic acid has a role as an antiinfective agent, an antifungal agent, a keratolytic drug, an EC (L-ascorbate peroxidase) inhibitor, a plant metabolite, an algal metabolite and a plant hormone.
It is a conjugate acid of a salicylate.

SALICYLIC ACID is classified as :
Hair conditioning
Skin conditioning
CAS Number    69-72-7
EINECS/ELINCS No:    200-712-3
Restriction (applies to EU only):    III/98 VI/3
INN Name:    salicylic acid
Chem/IUPAC Name:    Salicylic acid

200-712-3 [EINECS]
200-835-2 [EINECS]
2-Hydroxybenzenecarboxylic acid
2-hydroxybenzoic acid
2-hydroxy-benzoic acid
69-72-7 [RN]
774890 [Beilstein]
Acid, 2-Hydroxybenzoic
Acid, o-Hydroxybenzoic
Acid, ortho-Hydroxybenzoic
Acid, Salicylic
Acide salicylique [French] [ACD/IUPAC Name]
Acido o-idrossibenzoico [Italian]
Acido salicilico [Italian]
Benzoic acid, 2-hydroxy- [ACD/Index Name]
Benzoic acid, o-hydroxy-
Duofilm [Trade name]
Duoplant [Trade name]
Hydroxybenzenecarboxylic acid
Keralyt [Trade name]
Kyselina 2-hydroxybenzoova [Czech]
Kyselina salicylova [Czech]
o-hydroxybenzoic acid
ortho Hydroxybenzoic Acid
Salicylic acid [ACD/IUPAC Name] [Wiki]
Salicylsäure [German] [ACD/IUPAC Name]
Verrugon [Trade name]
4-10-00-00125 [Beilstein]
63-36-5 [RN]
78646-17-0 [RN]
benzoic acid, hydroxy-
Fostex [Trade name]
Freezone [Trade name]
hydroxy benzoic acid
hydroxybenzoic acid
Ionil plus
Ionil Plus shampoo
monohydroxy benzoic acid
o-hydroxy-benzoic acid
Orthohydroxybenzoic acid
ortho-salicylic acid
Phenol-2-carboxylic acid
Retarder W
Salicylic acid 100 µg/mL in Methanol
Salicylic acid ACS grade
Salicylic acid, 99%
Salicylic acid, BP, Ph. Eur grade
Salicylic Acid-d4
Salsonin [Trade name]
水楊酸 [Chinese]

salicylic acid
2-Hydroxybenzoic acid
o-hydroxybenzoic acid
Retarder W
Benzoic acid, 2-hydroxy-
Salicylic acid soap
Salicylic acid collodion
Phenol-2-carboxylic acid
Acidum salicylicum
Orthohydroxybenzoic acid
2-Hydroxybenzenecarboxylic acid
Acido salicilico
Salicylic acid, tech.
Kyselina salicylova
Clear away wart remover
Duofil wart remover
Salicyclic acid
Ionil plus
Dr. Scholl’s corn removers
Kyselina salicylova [Czech]
Dr. Scholl’s callus removers
Dr. Scholl’s wart remover kit
Kyselina 2-hydroxybenzoova
Acido salicilico [Italian]
Advanced pain relief corn removers
Caswell No. 731
2-hydroxy-benzoic acid
Kyselina 2-hydroxybenzoova [Czech]
Advanced pain relief callus removers
Acido o-idrossibenzoico [Italian]
NSC 180
Salicylic acid & Sulfur Soap
CCRIS 6714
HSDB 672
EPA Pesticide Chemical Code 076602
BRN 0774890
Salicylic acid inclusion complex
K 537
ATA fraction 10, ammonium salt
Mediplast pads
Salicylic acid, 99+%
Akurza Lotion
Hydrisalic Gel
Akurza Cream
Salex Lotion
Salex Cream
DuoPlant Gel
DHS Sal Shampoo
P&S Shampoo
Salicylic acid [USAN:JAN]
Acido o-idrossibenzoico
Salicylic acid, 99+%, ACS reagent
salicylicum acidum
Propa pH Peel-Off Acne Mask
phenol derivative, 7
Salicylic acid (TN)
Benzoic acid, 2-hydroxy-, ion(1-)
Benzoic acid, hydroxy-
EINECS 200-712-3
Salicylic acid [USP:JAN]
Salicylic acid (6CI,8CI)
Salicylic acid rs
hydroxy-benzoic acid
ortho-salicylic acid
Fostex (Salt/Mix)
Pernox (Salt/Mix)
Duofilm Wart Remover
Duofilm (Salt/Mix)
Salicylic Acid,(S)
Sebulex (Salt/Mix)
2-hydroxobenzoic acid
Domerine (Salt/Mix)
Sebucare (Salt/Mix)
2-Hydroxybenzoate, I
Natural Salicylic Acid
o-hydroxy benzoic acid
2-hydroxy benzoic acid
Salicylic acid,medicinal
Sulfasalazine Impurity H
Salicylic acid ACS grade
Benzoic acid, o-hydroxy-
Bazuka Extra Strength Gel
Epitope ID:124929
Retarder SAX (Salt/Mix)
EC 200-712-3
Salicylic acid (JP17/USP)
2-Hydroxybenzoic Acid, Natural

Salicylic acid (from Latin salix, willow tree) is a lipophilic monohydroxybenzoic acid, a type of phenolic acid, and a beta hydroxy acid (BHA).
This colorless crystalline organic acid is widely used in organic synthesis and functions as a plant hormone.
It is derived from the metabolism of salicin.

In addition to serving as an important active metabolite of aspirin (acetylsalicylic acid), which acts in part as a prodrug to salicylic acid, it is probably best known for its use as a key ingredient in topical anti-acne products. The salts and esters of salicylic acid are known as salicylates.

It is on the World Health Organization’s List of Essential Medicines, the safest and most effective medicines needed in a health system

Salicylic acid is a beta hydroxy acid. It’s well-known for reducing acne by exfoliating the skin and keeping pores clear.

Salicylic acid is found in a variety of over-the-counter (OTC) products.
Salicylic acid is also available in prescription-strength formulas.

Salicylic acid works best for mild acne (blackheads and whiteheads) and it can also help prevent future breakouts.

Salicylic acid has sterilization ability, 2.5% alcohol solution (called spiritus) is used as a topical medicine in the treatment of tinea manus and tinea pedis, also can be made into ointment.
Sodium salicylate can be used for food preservative or preservatives, also can be used for the preparation of toothpaste, mouthwash.
Salicylic acid has antipyretic and analgesic effects, can cure rheumatism and so on.
It’s all esters can be used as drug and spices.
Methyl salicylate has pleasant aromas of holly, is used for the preparation of perfume and soap flavor.
The methyl salicylate is coated on the skin, can penetrate into the muscle and let out of salicylic acid to release local pain, so it also can be used for the treatment of pain, contusion, sprain and other medication.
Isoamyl salicylate has orchid aroma, benzyl salicylate has weak ester aroma, both can prepare perfume or soap flavor.
The common name of phenyl salicylate is Salo, was hydrolyzed into phenol and salicylic acid in the intestine , is a kind of effective enteral preservatives.
Another Kind drug related to salicylic acid is para aminosalicylic acid (PAS, see “Para amino salicylic acid)
Its sodium and calcium salts are used as anti TB drugs for acute exudative pulmonary tuberculosis (TB) and mucosal tuberculosis, is a weak antimicrobial drug, the effect is only 2% of streptomycin, often combined with streptomycin and isoniazid , in order to enhance the curative effect.
It can be acetylated to the aspirin.

chemical property
1.white needle crystal or crystalline monoclinic edge, spicy.
Salicylic acid is slightly soluble in water, soluble in acetone, turpentine oil, ethanol, ethyl ether, benzene and chloroform.
2.The acidity of salicylic acid is stronger than benzoic acid, it becomes darker in color in the sun.
In the case of iron ion, salicylic acid becomes into purple chelate.
Salicylic acid reacts with ferric chloride to show purple, is unstable to heat, easy to decarboxylation to produce phenol heating to 200 ℃.
In Nature salicylic acid mostly is in the form of methyl existing in birch bark oil, content is up to 96%.
There are existing in cinnamon oil, violet oil, wintergreen oil.
Free salicylic acid only a few exist in plants.
Salicylic acid has double property of phenol and carboxylic acid.
When heated, it is sublimation, and rapid heated, it decomposites to phenol and carbon dioxide.
When react with sodium hydroxide , hydroxyl and carboxyl groups were neutralized to produce the double salt; but with sodium carbonate, only the carboxyl groups are neutralized and build a single salt.
When reacts with alcohol or phenol, it can generate the corresponding carboxylic acid ester.
This product is toxic and irritating to the skin, mucous membrane, and reaction with the body tissue protein, so it is corrosive, from another aspect, it can be sterilized

Salicylic acid belongs to a group of medicines known as keratolytics.
It is used in the treatment of scaly skin diseases where the skin has become thickened, scaly and flaky.
Topical preparations of salicylic acid, either alone or in combination with other medicines, can be used to treat the following common scaly skin conditions:

Viral warts
Seborrhoeic dermatitis
Chronic atopic dermatitis
Lichen simplex

Chemical formula    C7H6O3
Molar mass    138.122 g·mol−1
Appearance    Colorless to white crystals
Odor    Odorless
Density    1.443 g/cm3 (20 °C)[2]
Melting point: 158.6 °C (317.5 °F; 431.8 K)
Boiling point: 200 °C (392 °F; 473 K) decomposes 211 °C (412 °F; 484 K) at 20 mmHg

Sublimation conditions
Sublimes at 76 °C

Solubility in water
1.24 g/L (0 °C)
2.48 g/L (25 °C)
4.14 g/L (40 °C)
17.41 g/L (75 °C)[3]
77.79 g/L (100 °C)[5]

Soluble in ether, CCl4, benzene, propanol, acetone, ethanol, oil of turpentine, toluene

Solubility in benzene
0.46 g/100 g (11.7 °C)
0.775 g/100 g (25 °C)
0.991 g/100 g (30.5 °C)
2.38 g/100 g (49.4 °C)
4.4 g/100 g (64.2 °C)[3][5]

Solubility in chloroform
2.22 g/100 mL (25 °C)[5]
2.31 g/100 mL (30.5 °C)[3]

Solubility in methanol
40.67 g/100 g (−3 °C)
62.48 g/100 g (21 °C)[3]

Solubility in olive oil    2.43 g/100 g (23 °C)
Solubility in acetone    39.6 g/100 g (23 °C)
log P    2.26
Vapor pressure    10.93 mPa[4]
Acidity (pKa)
1 = 2.97 (25 °C)[6]
2 = 13.82 (20 °C)[3]
UV-vis (λmax)    210 nm, 234 nm, 303 nm (4 mg % in ethanol)[4]
Magnetic susceptibility (χ)    −72.23·10−6 cm3/mol
Refractive index (nD)    1.565 (

Salicylic Acid is an organic acid often used as the active ingredients in Anti-Acne skin care preparations.
The active of choice when you’re looking to clear the skin of almost any build up, whether in the pores, or in the tissues.

Salicylic Acid is a Beta Hydroxy Acid (BHA) and it’s activity is completely different from the Alpha Hydroxy Acids (AHA) used in Anti-Aging Skin Care lines.
While the AHA’s are small molecules that can get down into the pores quickly, and efficiently, offering enhanced and rapid cellular turn over, BHA’s are a larger molecule which doesn’t get through the pores as quickly.
The result is that they stay in the pore and continue to work, functioning to break down the build up that is responsible for enlarged pores, acne and inflammatory conditions.

Significantly improve the appearance of acne, Rosacea, & crow’s feet as well as being an excellent agent for pore refinement and any condition that is the result of oil build up in the pores and tissues.

Salicylic acid as a medication is used most commonly to help remove the outer layer of the skin.
As such, it is used to treat warts, psoriasis, acne, ringworm, dandruff, and ichthyosis.

Similar to other hydroxy acids, salicylic acid is a key ingredient in many skincare products for the treatment of seborrhoeic dermatitis, acne, psoriasis, calluses, corns, keratosis pilaris, acanthosis nigricans, ichthyosis and warts.[12]

Uses in manufacturing
Salicylic acid is used in the production of other pharmaceuticals, including 4-aminosalicylic acid, sandulpiride, and landetimide (via Salethamide).

Salicylic acid was one of the original starting materials for making acetylsalicylic acid (aspirin) in 1897.
Aspirin (acetylsalicylic acid or ASA) can be prepared by the esterification of the phenolic hydroxyl group of salicylic acid with the acetyl group from acetic anhydride or acetyl chloride.

Bismuth subsalicylate, a salt of bismuth and salicylic acid, is the active ingredient in stomach relief aids such as Pepto-Bismol, is the main ingredient of Kaopectate and “displays anti-inflammatory action (due to salicylic acid) and also acts as an antacid and mild antibiotic”.[14]

Other derivatives include methyl salicylate used as a liniment to soothe joint and muscle pain and choline salicylate used topically to relieve the pain of mouth ulcers.

Other uses
Salicylic acid is used as a food preservative, a bactericide and an antiseptic.

Sodium salicylate is a useful phosphor in the vacuum ultraviolet spectral range, with nearly flat quantum efficiency for wavelengths between 10 and 100 nm.
It fluoresces in the blue at 420 nm.
It is easily prepared on a clean surface by spraying a saturated solution of the salt in methanol followed by evaporation.

Mechanism of action
Salicylic acid modulates COX1 enzymatic activity to decrease the formation of pro-inflammatory prostaglandins. Salicylate may competitively inhibit prostaglandin formation.
Salicylate’s antirheumatic (nonsteroidal anti-inflammatory) actions are a result of its analgesic and anti-inflammatory mechanisms.

Salicylic acid works by causing the cells of the epidermis to slough off more readily, preventing pores from clogging up, and allowing room for new cell growth. Salicylic acid inhibits the oxidation of uridine-5-diphosphoglucose (UDPG) competitively with nicotinamide adenosine dinucleotide (NAD) and noncompetitively with UDPG. It also competitively inhibits the transferring of glucuronyl group of uridine-5-phosphoglucuronic acid (UDPGA) to the phenolic acceptor.

The wound-healing retardation action of salicylates is probably due mainly to its inhibitory action on mucopolysaccharide synthesis.

17% to 27% salicylic acid used in the form of a paint, and 20% to 50% in plaster form, which are sold for wart and corn removal should not be applied to the face and should not be used for acne treatment.
Even for wart removal, such a solution should be applied once or twice a day – more frequent use may lead to an increase in side-effects without an increase in efficacy.

If high concentrations of salicylic ointment are applied to a large percentage of body surface, high levels of salicylic acid can enter the blood, requiring hemodialysis to avoid further complications.

Chemistry and production

Salicylic acid crystals under the microscope.
Salicylic acid has the formula C6H4(OH)COOH, where the OH group is ortho to the carboxyl group. It is also known as 2-hydroxybenzoic acid.
It is poorly soluble in water (2 g/L at 20 °C).

Salicylic acid is biosynthesized from the amino acid phenylalanine.
In Arabidopsis thaliana it can be synthesized via a phenylalanine-independent pathway.

Sodium salicylate is commercially prepared by treating sodium phenolate (the sodium salt of phenol) with carbon dioxide at high pressure (100 atm) and high temperature (115°C) – a method known as the Kolbe-Schmitt reaction. Acidification of the product with sulfuric acid gives salicylic acid:

Salicylic-Acid General Synthesis V.2.svg
It can also be prepared by the hydrolysis of aspirin (acetylsalicylic acid) or methyl salicylate (oil of wintergreen) with a strong acid or base.

Salicylic acid degrades to phenol and carbon dioxide at 200 – 230°C:

C6H4OH(CO2H) → C6H5OH + CO2
Main article: History of aspirin

White willow (Salix alba) is a natural source of salicylic acid.
Hippocrates, Galen, Pliny the Elder and others knew that willow bark could ease pain and reduce fevers.
It was used in Europe and China to treat these conditions.[25] This remedy is mentioned in texts from ancient Egypt, Sumer and Assyria.
The Cherokee and other Native Americans use an infusion of the bark for fever and other medicinal purposes.

In 2014, archaeologists identified traces of salicylic acid on 7th century pottery fragments found in east central Colorado.
The Reverend Edward Stone, a vicar from Chipping Norton, Oxfordshire, England, noted in 1763 that the bark of the willow was effective in reducing a fever.

The active extract of the bark, called salicin, after the Latin name for the white willow (Salix alba), was isolated and named by the German chemist Johann Andreas Buchner in 1828.
A larger amount of the substance was isolated in 1829 by Henri Leroux, a French pharmacist.
Raffaele Piria, an Italian chemist, was able to convert the substance into a sugar and a second component, which on oxidation becomes salicylic acid.

Salicylic acid was also isolated from the herb meadowsweet (Filipendula ulmaria, formerly classified as Spiraea ulmaria) by German researchers in 1839.
While their extract was somewhat effective, it also caused digestive problems such as gastric irritation, bleeding, diarrhea and even death when consumed in high doses.

Dietary sources
Salicylic acid occurs in plants as free salicylic acid and its carboxylated esters and phenolic glycosides. Several studies suggest that humans metabolize salicylic acid in measurable quantities from these plants.
High-salicylate beverages and foods include beer, coffee, tea, numerous fruits and vegetables, sweet potato, nuts, and olive oil, among others.
Meat, poultry, fish, eggs, dairy products, sugar, and breads and cereals have low salicylate content.

Some people with sensitivity to dietary salicylates may have symptoms of allergic reaction, such as bronchial asthma, rhinitis, gastrointestinal disorders, or diarrhea, and so may need to adopt a low-salicylate diet.

Plant hormone
Salicylic acid is a phenolic phytohormone and is found in plants with roles in plant growth and development, photosynthesis, transpiration, ion uptake and transport.
Salicylic acid is involved in endogenous signaling, mediating plant defense against pathogens.
It plays a role in the resistance to pathogens (i.e. systemic acquired resistance) by inducing the production of pathogenesis-related proteins and other defensive metabolites.

The volatile methyl ester of salicylic acid — methyl salicylate — can also diffuse through the air, facilitating plant-plant communication.
Methyl salicylate is taken up by the stomata of the nearby plant, where it can induce an immune response after being converted back to salicylic acid.

Signal transduction
A number of proteins have been identified that interact with SA in plants, especially salicylic acid binding proteins (SABPs) and the NPR genes (Nonexpressor of pathogenesis related genes), which are putative receptors.

It was first discovered in 1979 that salicylates are involved in induced defenses of tobacco against tobacco mosaic virus.
In 1987, salicylic acid was identified as the long-sought signal that causes thermogenic plants such as the voodoo lily, Sauromatum guttatum, to heat up.


very fine white crystalline powder
assay 99.5% pure
oil soluble
alcohol soluble *
store tightly closed, away from heat sources
shelf 3yrs when properly stored

add to the oil phase
0.5 to 1.0% for sensitive skin products
2.0% for active treatment products

acne / oily skin care lines
clarifying scalp / hair product lines
treatment lines
crusty skin

When creating water based serums / gels / toners, you may pre-dissolve salicylic acid in NatureSilk, or alcohol, to solubilize it before mixing with water or other liquid

* This product is not coated or enhanced.
It will not dissolve, into alcohol, instantly or without effort. It does require mixing in all cases and regardless of solution levels. It will incorporate approximately 10% almost instantly. Beyond a 10% solution you will need to mix it into your alcohol and allow it to rest for approximately one hour or more to incorporate the excess. This process will vary based on the circumstances of your alcohol and equipment. Testing to determine the threshold as it relates to your specific conditions is required.


CAUTION :: As with all of the acids, it is important to let your skin acclimate to their use. For those who’s skin is not used to the acids a slight stinging and redness may result. If this occurs, reduce usage to every other day for 2 weeks, before resuming daily application. If irritation persists, discontinue use. If you experience anything more than a slight stinging, or redness, discontinue use immediately. Any time that you experience discomfort, you can apply a 10% solution of sodium bicarbonate (baking soda) to neutralize the acid, then wash with soap and water to thoroughly remove any acid residue. If irritation develops, or persists, seek medical advise.

Nothing on the Ingredients To Die For website should be considered, or construed, as medical advise.


This medication is used on the skin to treat common skin and foot (plantar) warts.
Salicylic acid helps cause the wart to gradually peel off.
This medication is also used to help remove corns and calluses.
This product should not be used on the face or on moles, birthmarks, warts with hair growing from them, or genital/anal warts.
Salicylic acid is a keratolytic. Salicylic acid belongs to the same class of drugs as aspirin (salicylates).
Salicylic acid works by increasing the amount of moisture in the skin and dissolving the substance that causes the skin cells to stick together. This makes it easier to shed the skin cells. Warts are caused by a virus. Salicylic acid does not affect the virus.

How to use salicylic acid topical

Salicylic acid preparations
Salicylic acid preparations come in many forms and strengths.
Available dosage forms include cream, gel, lotion, ointment, pads, plaster, shampoo, cleanser and topical solution.
Strengths of salicylic acid preparations range from 0.5% up to 30%.
The form and strength chosen depends on the condition that is being treated.

Salicylic acid topical is used to treat many skin disorders, such as acne, dandruff, psoriasis, seborrheic dermatitis of the skin and scalp, calluses, corns, common warts, and plantar warts, depending on the dosage form and strength of the preparation.

This medicine is available without a prescription. Some of these preparations are available only with your doctor’s prescription.

This product is available in the following dosage forms:

Patch, Extended Release

Other names: Benzoic acid, 2-hydroxy-; o-Hydroxybenzoic acid; Phenol-2-carboxylic acid; Psoriacid-S-Stift; Retarder W; Rutranex; Salicylic acid collodion; Salonil; 2-Hydroxybenzoic acid; Acido salicilico; Keralyt; Kyselina 2-hydroxybenzoova; Kyselina salicylova; Orthohydroxybenzoic acid; Duoplant; Freezone; Ionil; Saligel; Compound W; 2-Hydroxybenzenecarboxylic acid; 2-Carboxyphenol; o-Carboxyphenol; Advanced pain relief callus removers; Advanced pain relief corn removers; Clear away wart remover; Dr. Scholl’s Callus Removers; Dr. Scholl’s Corn Removers; Dr. Scholl’s Wart Remover Kit; Duofil Wart Remover; Ionil plus; Salicylic acid soap; Stri-Dex; Benzoic acid, o-hydroxy-; NSC 180; Trans-Ver-Sal; Domerine; Duofilm; Fostex; Pernox; Salicylic acid & Sulfur Soap; Sebucare; Sebulex; component of Fostex medicated bar and cream; component of Keralyt; Retarder SAX; component of Solarcaine first aid spray; component of Tinver; 7681-06-3; 8052-31-1; Salicyclic acid; Domerine (Salt/Mix); Duofilm (Salt/Mix); Fostex (Salt/Mix); Pernox (Salt/Mix); Salicylic acid & Sulfur Soap (Salt/Mix); Sebucare (Salt/Mix); Sebulex (Salt/Mix); component of Fostex medicated bar and cream (Salt/Mix); component of Keralyt (Salt/Mix); Retarder SAX (Salt/Mix); component of Solarcaine first aid spray (Salt/Mix); component of Tinver (Salt/Mix)

physical property
It is white crystalline powder, odorless, first bitter taste then sweet. Exists in the nature of willow bark, the leaves and sweet birch.
The chemical formula of C6H4 (OH) (COOH), the melting point is 157-159 ℃.
In the light, it gradually discolorated.
The relative density is 1.44.
The boiling point is about 211℃/2.67kPa. Sublimation at 76℃. Under the common pressure, it rapid thermal decomposited to phenol and carbon dioxide. Soluble in ethanol, ethyl ether, chloroform, benzene, acetone, turpentine oil, insoluble in water. 1g salicylic acid was dissolved in 460ml water, 15ml boil water, 2.7ml ethanol, 3ml acetone, 3ml ether, 42ml chloroform, 135ml benzene, 52ml glycerol turpentine, about 60ml glycerol and 80ml petroleum ether. Adding sodium phosphate, borax can increase the solubility of salicylic acid in water. PH of Salicylic acid aqueous solution is 2.4. Alicylic acid reacts with ferric chloride aqueous solution to generat special purple.
Active Ingredients for Acne Medications
Salicylic acid—a beta hydroxy acid that also sloughs dead cell buildup within the follicle, acts as a mild antibacterial, and has soothing properties.
Salicylic acid is regarded to be less irritating than benzoyl peroxide and has less allergy potential, but it is also less aggressive in treating acne.
It is often used for treating milder forms of acne. The concentration in OTC drugs is limited to 2 percent. Salicylic acid is also used as a performance ingredient exfoliant in smaller concentrations, without making a drug claim.
pharmacological action
Salicylic acid is widely used, eczema, psoriasis, salicylic acid can be used in acne, dandruff.
The concentration of 3%~6% can be used to horny, higher than 6% of salicylic acid can damage to tissue .
Below 40% of concentration is suitable for the treatment of thick cocoon, corns and warts. Salicylic acid can also be added in the treatment of acne and dandruff.
Nowadays many famous cosmetic ingredients: in 1993, Clinique CLINIQUE first launched 1% salicylic acid in soft water cream, immediately became one of Clinique’s most successful products; In 1998, SK-II crystal induced skin cream added 1.5%BHA ingredients to the original, and salicylic acid has effect of treatment pores and cutin like the egg peeling analogy that caused the market boom; open access Olay popular products activating cream also contains 1.5% BHA components. However, due to the high concentration of salicylic acid, it has a certain degree of damage, cosmetics containing salicylic acid concentration has generally been limited between 0.2%~1.5%, containing salicylic acid cosmetics shall be added to the note of warning signs to determine the safety of long-term use and children under 3 years of age also shall not be used.
Contrast with the beauty effect of acid
Salicylic acid (BHA) is extracted from willow bark , holly leaf, also called plant acid; Tartaric acid (AHA) was extracted from sugarcane; two different raw materials extract acid. The two can control the oil, cutin, remove acne, shrink pores, light print. More than 50% concentration of the acid change skin can be operated by only the doctor of Department of Dermatology, and no matter how much concentration of salicylic acid, skins are classified as medical treatment, it is worth noting that a few people are not suitable for the use of any concentration of salicylic acid, so the general beauty salon is not executed, below 40% of salicylic acid in the acid skin beauty salon is allowed in law, in contrast, Tartaric acid is safer than salicylic acid. As for the effect of salicylic acid, salicylic acid only locked in the superficial stratum corneum, just play a simple treatment and blocking effect, changing the skin is only temporary, while the tartaric acid into the true cortex changed fundamentally. The skin can be cured, the dermal damage formation pox pits, salicylic acid becomes incapable of action, so it can not be called salicylic acid skin, can only be called salicylic acid treatment. The safety of salicylic acid and tartaric acid and skin effect are different, because tartaric acid is not toxic, use from low to high (8%-15%-20%-30%-40%), slowly adaption is not burn the skin, disfigured and any side effects. While salicylic acid is toxic, high concentration is not suitable for use in the face, there are certain restrictions on the concentration, the concentration can be used to the skin in the 3%-6%, higher than 6% salicylic acid is corrosive to the skin, a high concentration of 40% salicylic acid has strong corrosion properties of keratin.
1.Salicylic acid namely ortho hydroxy benzoic acid (o-hydroxybenzoic acid) is a kind of important organic synthetic raw material.
In pesticide production, it is used for synthetic organic phosphorus pesticide Isocarbophos, isofenphos methyl intermediates isopropyl salicylate and Rodenticide warfarin, kill rats ether intermediate 4-hydroxy coumarin; in the pharmaceutical industry, salicylic acid was used as antiseptics, also as intermediates of acetylsalicylic acid (aspirin) and other drugs; it is also an important raw material of dye, spices, such as rubber industry .
2.It is mainly used as raw materials of aspirin feedstock and pesticide aqueous amine and phosphorus products, can also be used in dye industry, refining and chemical reagent, etc.
3.Used in the pharmaceutical industry for the antipyretic, analgesic, anti-inflammatory, diuretic drugs, industrial dye used for direct of azo dyes and acid mordant dyes, but also for spices, etc.
4.Used as complexing indicator and preservative.
5.Verification for aluminum, boron, cerium, copper, iron, lead, manganese, mercury, nickel, silver, titanium, tungsten, vanadium, sulfite, nitrate and nitrite.
Determination of aluminum, copper, iron, thorium, titanium and uranium.
Alkali method and iodometry titration standard. The fluorescent indicator. Complexometric indicator.
6.Salicylic acid is an important raw material of medicine, spices, dyes, rubber auxiliaries and other fine chemicals.
In the pharmaceutical industry, salicylic acid itself is used as antiseptics, for local cutin hyperplasia and skin fungal infection.
As for pharmaceutical intermediates, it is used for production of ethenzamide, diuretin, acetylsalicylic acid (aspirin), sodium salicylate and salicylamide, glibenclamide niclosamide, salicylic acid, phenyl ester, ethyl p-hydroxybenzoate, bismuth subsalicylate, sulfasalazine and other drugs. In the dye industry, it is used for the production of direct yellow GR, direct grey BL, direct light brown RT, acid mordant brown G, acid mordant yellow GG dye. Salicylic acid esters are used as spice, for example, methyl salicylate can be used as toothpaste and other oral spices and other spices and food spices. Used in rubber industry production antiscorching agent, ultraviolet absorbent and foaming agent and water. Salicylic acid can also be used as a phenolic resin curing agent, textile printing and dyeing pulp preservatives, synthetic fiber dyeing of the expansion agent (agent) and so on.

Methods of production
1. The phenol and sodium hydroxide react to produce phenol sodium, distillation and dehydration, CO2 carboxylation reaction to obtain sodium salicylate, then using sulfuric acid and produce crude product.
The crude product through the sublimation refined to the finished product.
Raw materials consumption quota: phenol (98%) 704kg/t, alkali burn (95%) 417kg/t, sulfate (95%) 500kg/t, carbon dioxide (99%) 467kg/t.
2.The preparation method of the method is that the sodium salt of phenol and carbon dioxide can be obtained by acidification.
phenol and liquid caustic soda are produced into solution of the sodium salt of phenol, vacuum drying, and then to 100℃, slowly put to the dry carbon dioxide, when the pressure reaches 0.7~0.8MPa, stop passing carbon dioxide, warming up to 140 to 180℃. After the reaction with water, sodium salicylate dissolved and decolorization, filtering, coupled with the sulfuric acid, namely precipitation salicylic acid, after filtering, washing and drying to obtain the product.

Salicylic acid (from Latin salix, willow tree, from the bark of which the substance used to be obtained) is a mono hydroxy benzoic acid, a type of phenolic acid and a beta hydroxy acid. This colorless crystalline organic acid is widely used in organic synthesis and functions as a plant hormone. It is derived from the metabolism of salicin. In addition to being an important active metabolite of aspirin (acetylsalicylic acid), which acts in part as a prod rug to salicylic acid, it is probably best known for its use in anti-acne treatments. The salts and esters of salicylic acid are known as salicylates.

Chemical Properties
Salicylic acid has the formula C6H4(OH) COOH, where the OH group is ortho to the carboxyl group.
It is also known as 2- hydroxybenzoic acid. It is poorly soluble in water (2 g / L at 20 °C).
Aspirin (acetyl salicylic acid or ASA) can be prepared by the esterification of the phenolic hydroxyl group of salicylic acid with the acetyl group from acetic anhydride or acetyl chloride.

Chemical Properties
2-Hydroxybenzoic acid is odorless or has a slight phenolic odor with an acrid taste.

Chemical Properties
Also known as o-hydroxybenzoic acid,C6H4(OH)(COOH) is a white powder with an acrid taste that is stable in air but gradually discolored by light.
Soluble in acetone, oil of turpentine, alcohol, ether,benzene; slightly soluble in water,and combustible. Derived by reacting a hot solution of sodium phenolate with carbon dioxide and acidifying the sodium salt thus formed. Used in the manufacture of aspirin and salicylates, resins, dyestuff intermediate, prevulcanization inhibitor, analytical reagent,and fungicide.

Chemical Properties
Salicylic acid is a white to tan crystalline solid; needles.

Unripe fruits and vegetables are natural sources of salicylic acid, particularly blackberries, blueberries, cantaloupes, dates, raisins, kiwi fruits, guavas, apricots, green pepper, olives, tomatoes, radish and chicory; also mushrooms. Some herbs and spices contain quite high amounts, although meat, poultry, fish, eggs and dairy products all have little to no salicylates. Of the legumes, seeds, nuts, and cereals, only almonds, water chestnuts and peanuts have significant amounts.

The Greek physician Hippocrates wrote in the 5th century BC about a bitter powder extracted from willow bark that could ease aches and pains and reduce fevers . This remedy was also mentioned in texts from ancient Sumer , Lebanon , and As syria .
The active extract of the bark, called salicin, after the Latin name for the white willow (Salix alba), was isolated and named by the German chemist Johann Andreas Buchner in 1826. Raffaele Piria, an Italian chemist was able to convert the substance into a sugar and a second component, which on oxidation becomes salicylic acid.
Salicylic acid was also isolated from the herb meadowsweet (Filipendula ulmaria, formerly classified as Spiraea ulmaria) by German researchers in 1839. While their extract was somewhat effective, it also caused digestive problems such as gastric irritation, bleeding, diarrhea, and even death when consumed in high doses.

Salicylic acid is known for its ability to ease aches and pains and reduce fevers. These medicinal properties, particularly fever relief, have been known since ancient times, and it is used as an antiinflammatory drug.
In modern medicine, salicylic acid and its derivatives are used as constituents of some rubefacient products. For example, methyl salicylate is used as a liniment to soothe joint and muscle pain, and choline salicylate is used topically to relieve the pain of mouth ulcers. As with other beta hydroxy acids, salicylic acid is a key ingredient in many skin-care products for the treatment of seborrhoeic dermatitis, acne, psoriasis, calluses, corns, keratosis pilaris, and warts.

Although toxic in large quantities, salicylic acid is used as a food preservative and as bactericidal and an antiseptic . For some people with salicylate sensitivity even these small doses can be harmful .
Sodium salicylate is a useful phosphor in the vacuum ultraviolet with nearly flat quantum efficiency for wavelengths between 10 to 100 nm . It fluoresces in the blue at 420 nm. It is easily prepared on a clean surface by spraying a saturated solution of the salt in methanol followed by evaporation.

salicylic acid is a beta-hydroxy acid with keratolytic and antiinflammatory activity.
It helps dissolve the top layer of stratum corneum cells, improving the look and feel of the skin.
Salicylic acid is an effective ingredient in acne products and as such is widely used in acne soaps and lotions.
Because it is lipid soluble, it can more easily reduce sebaceous follicle blockage by penetrating the pores and exfoliating the cellular buildup.

Salicylic Acid is antimicrobial, anti-septic, enhances the activity of preservatives, and can be used to adjust the pH of products.
For the treatment of aging skin, Salicylic Acid appears to help improve skin wrinkles, roughness, and tone.
In addition, Salicylic is a useful ingredient for products formulated to treat psoriasis, callouses, corns, and warts-cases where there is a buildup of dead skin cells.
When applied topically, it is reported to penetrate 3 to 4 mm into the epidermis.
A small amount of salicylic acid can convert to copper salicylate, a powerful anti-inflammatory.
When used at high concentrations, salicylic acid may cause skin redness and rashes.
This is a naturally occurring organic acid, related to aspirin.
Salicylic Acid is found in some plants, particularly the leaves of wintergreen, willow bark, and the bark of sweet birch.
Salicylic acid is also synthetically manufactured.

Salicylic Acid is an Impurity of Acetylsalicylic Acid (A187780).
Acetylsalicylic acid Impurity B.

non-steroidal anti-inflammatory drugs

ChEBI: A monohydroxybenzoic acid that is benzoic acid with a hydroxy group at the ortho position.
It is obtained from the bark of the white willow and wintergreen leaves.

A crystalline aromatic carboxylic acid. It is used in medicines, as an antiseptic, and in the manufacture of azo dyes. Its ethanoyl (acetyl) ester is aspirin.
See aspirin; methyl salicylate.

Production Methods
Salicylic acid may be obtained (1) from oil of wintergreen, which contains methyl salicylate, or (2) by heating dry sodium phenate C6H5ONa plus carbon dioxide under pressure at 130 °C (266 °F) and recovering from the resulting sodium salicylate by adding dilute sulfuric acid.

Salicylic acid is a β-hydroxy acid that penetrates into the sebaceous gland and has comedolytic and anti-inflammatory properties.
It can be used as an adjunctive therapy and is found in cleansers, toners, masks, and peels.
Salicylic acid is keratolytic and at concentrations between 3% and 6% causes softening of the horny layers and shedding of scales.
It produces this desquamation by solubilizing the intercellular cement and enhances the shedding of corneocytes by decreasing cell-to-cell cohesion.
In concentrations >6%, it can be destructive to tissue.
Application of large amounts of the higher concentration of salicylic acid can also result in systemic toxicity.
Salicylic acid is used in the treatment of superficial fungal infections, acne, psoriasis, seborrheic dermatitis, warts, and other scaling dermatoses.
When it is combined with sulfur, some believe that a synergistic keratolytic effect is produced.
Common preparations include a 3% and 6% ointment with equal concentration of sulfur; 6% propylene glycol solution (Keralyt); 5% to 20% with equal parts of lactic acid in flexible collodion for warts (Duofilm, Occlusal); in a cream base at any concentration for keratolytic effects; as a 60% ointment for plantar warts; and in a 40% plaster on velvet cloth for the treatment of calluses and warts (40% salicylic acid plaster).

Prepared by heating sodium phenolate with carbon dioxide under pressure

Production Methods
Salicylic acid is biosynthesized from the amino acid phenylalanine. In Arabidopsis thaliana it can also be synthesized via a phenylalanine – independent pathway.
Sodium salicylate is commercially prepared by treating sodium phenolate ( the sodium salt of phenol ) with carbon dioxide at high pressure (100 atm ) and high temperature (390K) -a method known as the Kolbe-Schmitt reaction. Acidification of the product with sulfuric acid gives salicylic acid :
It can also be prepared by the hydrolysis of aspirin (acetylsalicylic acid) or methyl salicylate (oil of winter green) with a strong acid or base.
brand name
Advanced Pain Relief Callus Removers (Schering-Plough HealthCare); Advanced Pain Relief Corn Removers (Schering-Plough HealthCare); Clear Away Wart Remover (Schering-Plough HealthCare); Compound W (Whitehall-Robins); Dr. Scholl’s Callus Removers (Schering-Plough HealthCare); Dr. Scholl’s Corn Removers (Schering-Plough HealthCare); Dr. Scholl’s Wart Remover Kit (Schering-Plough HealthCare); Duofilm Wart Remover (Schering-Plough HealthCare); Duoplant (Stiefel); Freezone (Whitehall-Robins); Ionil (Galderma); Ionil-Plus (Galderma); Salicylic Acid Soap (Stiefel); Saligel (Stiefel); Stri-Dex (Sterling Health U.S.A.).

Synthesis Reference(s)
The Journal of Organic Chemistry, 27, p. 3551, 1962 DOI: 10.1021/jo01057a035
Tetrahedron Letters, 37, p. 153, 1996 DOI: 10.1016/0040-4039(95)02120-5

General Description
Odorless white to light tan solid. Sinks and mixes slowly with water.

Air & Water Reactions
Sublimes and forms vapor or dust that may explode [USCG, 1999].

Reactivity Profile
Salicylic acid is a carboxylic acid.
Carboxylic acids donate hydrogen ions if a base is present to accept them.
They react in this way with all bases, both organic (for example, the amines) and inorganic.
Their reactions with bases, called “neutralizations”, are accompanied by the evolution of substantial amounts of heat.
Neutralization between an acid and a base produces water plus a salt.
Carboxylic acids with six or fewer carbon atoms are freely or moderately soluble in water; those with more than six carbons are slightly soluble in water.
Soluble carboxylic acid dissociate to an extent in water to yield hydrogen ions.
The pH of solutions of carboxylic acids is therefore less than 7.0.
Many insoluble carboxylic acids react rapidly with aqueous solutions containing a chemical base and dissolve as the neutralization generates a soluble salt.
Carboxylic acids in aqueous solution and liquid or molten carboxylic acids can react with active metals to form gaseous hydrogen and a metal salt.
Such reactions occur in principle for solid carboxylic acids as well, but are slow if the solid acid remains dry.
Even “insoluble” carboxylic acids may absorb enough water from the air and dissolve sufficiently in Salicylic acid to corrode or dissolve iron, steel, and aluminum parts and containers. Carboxylic acids, like other acids, react with cyanide salts to generate gaseous hydrogen cyanide.
The reaction is slower for dry, solid carboxylic acids.
Insoluble carboxylic acids react with solutions of cyanides to cause the release of gaseous hydrogen cyanide.
Flammable and/or toxic gases and heat are generated by the reaction of carboxylic acids with diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides. Carboxylic acids, especially in aqueous solution, also react with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), to generate flammable and/or toxic gases and heat. Their reaction with carbonates and bicarbonates generates a harmless gas (carbon dioxide) but still heat. Like other organic compounds, carboxylic acids can be oxidized by strong oxidizing agents and reduced by strong reducing agents. These reactions generate heat. A wide variety of products is possible. Like other acids, carboxylic acids may initiate polymerization reactions; like other acids, they often catalyze (increase the rate of) chemical reactions.

Respiratory alkalosis, hyperkalemia, hyperthermia, dehydration, convulsions, shock, res- piratory paralysis, respiratory acidosis, lesions and death from respiratory collapse; fetotoxic.

Health Hazard
Inhalation of dust irritates nose and throat. Vomiting may occur spontaneously if large amounts are swallowed.
Contact with eyes causes irritation, marked pain, and corneal injury which should heal.
Prolonged or repeated skin contact may cause marked irritation or even a mild burn.

Mechanism of action
Salicylic acid has been shown to work through several different pathways.
It produces its anti – inflammatory effects via suppressing the activity of cyclo oxygenase (COX), an enzyme which is responsible for the production of pro – inflammatory mediators such as the prostaglandins. Notably, it does this not by direct inhibition of COX, unlike most other non-steroidal anti-inflammatory drugs (NSAIDs), but instead by suppression of the expression of the enzyme (via a yet-un elucidated mechanism) . Salicylic acid has also been shown to activate adenosine monophosphate-activated protein kinase (AMPK), and it is thought that this action may play a role in the anticancer effects of the compound and its prod rugs aspirin and salsalate. In addition, the anti diabetic effects of salicylic acid are likely mediated by AMPK activation primarily through allosteric conformational change that increases levels of phosphorylation. Salicylic acid also uncouples oxidative phosphorylation which leads to increased ADP:ATP and AMP:ATP ratios in the cell. Consequently, salicylic acid may alter AMPK activity and subsequently exert its anti-diabetic properties through altered energy status of the cell.
Even in AMPK knock – out mice, however, there is an anti-diabetic effect demonstrating that there is at least one additional, yet – unidentified action of the compound.

Side effects
Salicylic acid’s side effects include erythema and scaling.

Safety Profile
Poison by ingestion, intravenous, and intraperitoneal routes. Moderately toxic by subcutaneous route.
An experimental teratogen. Human systemic effects by skin contact: ear tinnitus.
A skin and severe eye irritant.
Experimental reproductive effects. Incompatible with iron salts, spirit nitrous ether, lead acetate, iodine. Used in the manufacture of aspirin.
When heated to decomposition it emits acrid smoke and irritating fumes.

Potential Exposure
Used as a topical keratolytic agent; in manufacture of aspirin, salicylates, resins, as a dyestuff intermediate; prevulcanization inhibitor; analytical reagent; fungicide, antiseptic, and food preservative.

Veterinary Drugs and Treatments
Often combined with sulfur, salicylic acid shampoos are often employed to treat patients with seborrheic disorders (seborrhea sicca and oleosa) exhibiting mild to moderate scaling, with mild waxy and keratinous debris.
In higher concentrations, topicals such as Kerasolv? Gel (6.6% salicylic acid) can be used to remove localized excessive tissues associated with hyperkeratotic disorders, such as calluses and idiopathic thickening of the planum nasale and footpads.
Salicylic acid has mildly antipruritic, antibacterial (bacteriostatic), keratoplastic and keratolytic actions.
Lower concentrations are primarily keratoplastic and higher concentrations, keratolytic.
Salicylic acid lowers skin pH, increases corneocyte hydration and dissolves the intercellular binder between corneocytes.
Salicylic acid and sulfur are thought to be synergistic in their keratolytic actions.

Purification Methods
It has been purified by steam distillation, by recrystallisation from H2O (solubility is 0.22% at room temperature and 6.7% at 100o), absolute MeOH, or cyclohexane and by sublimation in a vacuum at 76o. The acid chloride (needles) has m 19-19.5o, b 92o/15mm, the amide has m 133o (yellow needles from H2O), the O-acetyl derivative has m 135o (rapid heating and the liquid resolidifies at 118o), and the O-benzoyl derivative has m 132o (aqueous EtOH). [IR: Hales et al. J Chem Soc 3145 1954, Bergmann et al. J Chem Soc 2351 1950]. [Beilstein 10 IV 125.]

Plant hormone
Salicylic acid (SA) is a phenolic phytohormone and is found in plants with roles in plant growth and development, photosynthesis, transpiration, ion uptake and transport.
SA also induces specific changes in leaf anatomy and chloroplast structure. SA is involved in endogenous signaling, mediating in plant defense against pathogens.
It plays a role in the resistance to pathogens by inducing the production of pathogenesis-related proteins .
It is involved in the systemic acquired resistance (SAR) in which a pathogenic attack on one part of the plant induces resistance in other parts.
The signal can also move to nearby plants by salicylic acid being converted to the volatile ester, methyl salicylate.

iron salts; lead acetate; iodine.
Forms an explosive mixture in air.
Salicylic acid Preparation Products And Raw materials

Raw materials
Caustic Soda(liquid)30%-48%  Sodium salicylate Phenol CARBON DIOXIDE Sodium hydroxide Sulfuric acid