"A practical supplier guide to Salicylic acid (CAS 69-72-7): what the beta-hydroxy acid is (C7H6O3, MW 138.12, EINECS 200-712-3, mp 158-161 C, density 1.44, ethanol-soluble, 2-8 C storage), how its keratolytic and lipophilic action clears pores and fades marks, typical 0.5-2% use levels in acne and exfoliating formulas, pH setting with citric acid, smart pairings with kojic acid, alpha-arbutin, vitamin C, GHK-Cu, squalane, mild surfactants and Argireline, plus EU SCCS/1675/25 safety limits and buyer COA notes."
-Deshangchemical-chemechemi
Salicylic Acid (CAS 69-72-7): The BHA That Clears Pores and Fades Marks Without the Hype
Walk down the acne-care aisle of any pharmacy and you will see the same active on half the labels: salicylic acid. Listed on our product page under CAS 69-72-7, it is one of the oldest and best-understood ingredients in cosmetic and topical use, yet it keeps earning its place in modern formulations. For a contract manufacturer or private-label brand, the appeal is simple: it is affordable, stable, well-documented, and it does a job that few other single ingredients can — it works inside the pore, not just on the surface.
What the material actually is
Salicylic acid is a beta-hydroxy acid (BHA), which means the hydroxyl group sits one carbon away from the carboxyl group. That small structural detail is what makes it lipophilic — it dissolves in oil — and that is why it behaves differently from water-soluble alpha-hydroxy acids like glycolic or lactic acid. The spec sheet on our product page carries the identifying data a buyer needs before quoting or sampling:
| CAS | 69-72-7 |
| Molecular formula | C7H6O3 |
| Molecular weight | 138.12 |
| EINECS | 200-712-3 |
| Melting point | 158–161 °C (lit.) |
| Density | 1.44 |
| Solubility | ethanol: 1 M at 20 °C, clear, colorless |
| Storage | 2–8 °C, sealed, protected from light |
It arrives as a fine white-to-off-white crystalline powder with a faint characteristic odor. Because the melting point is high and the material is a solid at room temperature, it is easy to handle in a dry goods warehouse and ships without the cold-chain headaches that peptides or some enzymes demand. We keep it at 2–8 °C to preserve assay, but short transit at ambient temperature does not compromise the material.
How it works on skin
The reason salicylic acid is the default clarifier in acne products comes down to three actions. First, it is keratolytic: it loosens the bonds between corneocytes, the dead cells on the skin surface, so they shed instead of packing into a plug. Second, because it is oil-soluble, it follows sebum down into the follicle and helps clear the comedone — the clog that becomes a blackhead or whitehead. Third, it carries a mild anti-inflammatory effect, which is why a 0.5–2% leave-on application takes down the redness around a breakout better than a scrub ever will.
That combination is hard to replicate. An abrasive cleanser scrapes the top layer but never reaches the plug; a water-soluble acid exfoliates the surface but does not travel into the oily pore. Salicylic acid does both at once, which is why formulators keep coming back to it for toners, spot treatments, and wash-off masks.
Where it goes in the formula
Use levels are well established by regulators. For leave-on skincare aimed at acne and gentle exfoliation, 0.5–2% is the standard band, and both the U.S. FDA and China's National Medical Products Administration accept it as a safe concentration in that range. Higher strengths change the job: 3–10% preparations are used for dermatological conditions such as tinea, psoriasis, and cracked skin (under professional guidance), and around 30% is reserved for in-office chemical peels performed by trained staff. As a preservative, the cap is 0.5% in food and cosmetics, where it also inhibits microbes and extends shelf life.
Salicylic acid is most stable and effective in a slightly acidic system, roughly pH 3–4. It dissolves readily in ethanol and propylene glycol, and it can be built into gels, toners, and emulsions. A small amount of Citric Acid Anhydrous (CAS 77-92-9) is the clean way to set that pH without adding color or odor, and it doubles as a chelator that keeps the water phase stable.
Pairing it with other actives
Salicylic acid rarely carries a formula alone. It sits comfortably next to actives that cover the rest of the clarifying-and-brightening story:
- Kojic Acid (CAS 501-30-4) and Alpha-Arbutin (CAS 84380-01-8) — brightening agents that fade the post-acne marks salicylic acid helps clear, so a single routine can address both the blemish and the shadow it leaves.
- L-Ascorbic Acid (CAS 50-81-7) — vitamin C antioxidant support that protects the formula and helps even tone alongside the BHA.
- GHK-Cu Copper Peptide (CAS 49557-75-7) — a signal peptide aimed at repair and firmness, useful in a post-breakout recovery step.
- Squalane (CAS 111-01-3) — the emollient carrier that cushions the skin and offsets the drying feel of an exfoliating acid.
- Sodium Lauroylsarcosinate (CAS 137-16-6) — a mild amino-acid surfactant for the cleanser that precedes a salicylic acid treatment.
- Argireline (CAS 616204-22-9) — an anti-wrinkle peptide for a leave-on product that pairs clarifying and anti-aging in one step.
Handling, storage, and safety notes
The powder is low acute toxicity by mouth (oral LD50 greater than 500 mg/kg in rats), but it is corrosive to skin and mucous membranes in concentrated form and can seriously damage the eyes on contact. In the lab, handle it as a dust: avoid breathing it in, keep it away from the eyes, and wash any contact off promptly. Store the sealed material at 2–8 °C away from light.
For finished goods, watch the regulatory ceiling. The European Union's latest assessment (SCCS/1675/25 opinion) restricts children's products: it bars salicylic acid in some rinse-off hair products at 3%, in certain 2% leave-on products, and caps body lotion at 0.5%. Pregnant and breastfeeding customers are generally advised to avoid high concentrations, since it is classified as a category-2 reproductive toxin at elevated exposure. For most adult skincare at 0.5–2%, the material sits well inside the accepted safe window.
What to check before you buy
When you request a quote, ask for the COA (identity, assay, and microbiology), pack size, and lead time. For cosmetic-grade supply you want a supplier who can show consistent assay and batch traceability, plus the documentation your QA team needs for a finished-product filing. Beyond cosmetics, the same CAS feeds the aspirin supply chain, serves as an anti-scorching agent in rubber, acts as a metal-ion color developer in electroplating and dyes, and enters spice synthesis — so grade and impurity profile matter for the end use.
For the active itself, see the Salicylic acid product page for current assay, pack size, and COA details. If you are building a clarifying, brightening, or anti-aging line and want to discuss use levels, pH, or a paired acid-plus-peptide system, our team can help you spec the combination.
