What Is Sd Alcohol 39-C?
Sd Alcohol 39-C is a type of denatured ethyl alcohol. Makers start with regular drinking alcohol that comes from fermenting and distilling crops like corn, sugarcane or grain. To keep people from drinking it, they add a small amount of bitter or unpleasant tasting material listed under the 39-C denaturing formula. The finished liquid is clear, fast evaporating and has the sharp scent most people link with rubbing alcohol.
Cosmetic chemists turned to denatured alcohol in the early 1900s because it dries in seconds, feels weightless and helps mix oils with water. Over the decades it became a go-to helper in many beauty lines, especially when quick dry time or a fresh matte finish were top goals.
Today manufacturers pump the distilled alcohol through columns to reach high purity, remove almost all water, then blend in the 39-C denaturant. The result ships in drums to cosmetic labs where it slides easily into liquid or gel formulas.
You will spot Sd Alcohol 39-C in toners, facial mists, setting sprays, gels, serums, peel-off masks, aftershaves, deodorants, hair sprays, dry shampoos, fragrance mists and nail polish removers. Any product that needs to feel light, dry fast or keep oils evenly mixed can make good use of it.
Sd Alcohol 39-C’s Cosmetic Benefits/Uses
In a formula Sd Alcohol 39-C works hard behind the scenes and gives several practical perks
- Astringent: Leaves a brief cooling sensation, helps tighten the look of pores and cuts surface shine so skin feels freshly toned
- Solvent: Dissolves fragrance oils, plant extracts and film formers which lets the finished product stay clear and evenly blended while helping active ingredients spread in a thin even coat
- Viscosity controlling: Thins heavy mixtures so sprays mist evenly, gels glide on without stickiness and creams set with a light quick-dry finish
Who Can Use Sd Alcohol 39-C
Sd Alcohol 39-C is generally best suited to oily, combination and acne prone skin because its quick evaporation and temporary astringent action can cut surface oil and leave a light matte feel. Normal skin usually tolerates it well when the formula is balanced with hydrators. Those with very dry or sensitive skin may find frequent exposure too stripping since alcohol can pull water from the surface and weaken the skin barrier, which could lead to tightness or irritation.
The alcohol itself is produced by fermenting plant sugars and the 39-C denaturant is synthetic so no animal material is used. This makes Sd Alcohol 39-C acceptable for vegans and vegetarians.
Current research does not flag topical Sd Alcohol 39-C as a specific risk during pregnancy or while breastfeeding. Still, this is not medical advice and anyone who is pregnant or nursing should discuss any skincare product with a qualified healthcare professional before use just to be safe.
The ingredient does not increase photosensitivity and there are no known interactions with sunlight, though sunscreen is always good practice. One practical note: Sd Alcohol 39-C is highly flammable in liquid form so keep products away from open flames and high heat.
Potential Side Effects/Adverse Reactions
Reactions to Sd Alcohol 39-C differ widely between individuals. The effects listed below are possible yet uncommon when the ingredient is used at typical cosmetic levels and in a well-balanced formula.
- Dryness or tightness in the skin especially on already dry or compromised areas
- Tingling or mild stinging upon application particularly on freshly exfoliated or broken skin
- Redness or irritation in sensitive skin types if the formula contains a high alcohol load
- Temporary exacerbation of flakiness in conditions like eczema or psoriasis
- Eye watering or mild respiratory irritation if inhaled from concentrated sprays in a poorly ventilated space
If any of the above reactions occur discontinue use and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 0 / 5 – Sd Alcohol 39-C is considered non-comedogenic because it evaporates almost instantly after application and leaves no oily or waxy residue that could block pores. Its light watery texture does not sit on the skin surface long enough to mix with sebum or dead cells, so it is unlikely to trigger blackheads or pimples.
That makes it generally suitable for people who are prone to acne or frequent breakouts.
One extra point: while the alcohol itself will not clog pores, the full product formula still matters. Heavy oils or film formers paired with Sd Alcohol 39-C can raise the overall comedogenic load, so always look at the complete ingredient list.
Summary
Sd Alcohol 39-C acts as a fast-drying astringent that gives an instant fresh feel, a strong solvent that keeps oils and actives evenly mixed and a viscosity controller that thins formulas so they spread in a light even layer. It does this by flashing off quickly, cutting surface tension and carrying other ingredients in a uniform solution.
Thanks to that quick dry payoff it remains popular in toners, setting sprays, hair sprays and fragrance mists, though brands focused on ultra-gentle care sometimes look for lower-alcohol options.
When used at standard cosmetic levels the ingredient is regarded as safe for healthy skin, with dryness being the main concern for sensitive types. As with any new skincare step it is wise to do a small patch test first to make sure your skin agrees with the full formula.