What Is Alcohol Denat. Sd Alcohol 39?
Alcohol Denat. Sd Alcohol 39 is a form of ethyl alcohol that has been denatured, meaning it has additives that make it undrinkable while preserving its usefulness in cosmetics. The core ingredient, ethanol, is typically produced by fermenting and distilling plant materials such as corn, sugarcane or grain. To meet the United States regulation 27CFR21, this alcohol is then blended with sodium salicylate or salicylic acid, fluid extract of quassin and a small amount of t-butyl alcohol. These denaturants change the taste and smell enough to deter ingestion yet leave the performance of the alcohol intact.
Alcohol has been used in perfumes and personal care preparations since ancient times. Denatured grades like SD Alcohol emerged in the early 20th century when governments sought to prevent beverage use of industrial alcohol without restricting its availability for manufacturing. SD Alcohol 39 quickly became popular with cosmetic chemists because it offers dependable purity, predictable evaporation and compatibility with many raw materials.
Manufacturing starts with large-scale fermentation, where yeast converts plant sugars into ethanol. Distillation purifies the alcohol, after which the precise mix of denaturants is added under controlled conditions. The resulting liquid is clear, fast evaporating and ready for blending into finished products.
You will commonly find Alcohol Denat. Sd Alcohol 39 in facial toners, setting sprays, hair sprays, fragrances, quick-drying hand cleansers, light lotions and certain acne or oil-control treatments. Formulators reach for it whenever they need a lightweight carrier that flashes off the skin without residue.
Alcohol Denat. Sd Alcohol 39’s Cosmetic Benefits/Uses
In cosmetics this ingredient has one main job, yet that role supports several important benefits for both chemists and end users.
As a solvent Alcohol Denat. Sd Alcohol 39 dissolves fragrances, botanical extracts, polymers and other actives that might not mix well with water alone. By keeping these ingredients evenly distributed it helps ensure a stable formula and consistent performance. Its rapid evaporation leaves a refreshing, non-greasy feel that can enhance absorption of follow-up products and speed drying time in sprays or gels, while its inherent sanitizing nature can contribute to an overall cleaner product environment.
Who Can Use Alcohol Denat. Sd Alcohol 39
Products that rely on Alcohol Denat. Sd Alcohol 39 tend to suit normal, combination and oily skin best because its quick-drying nature whisks away excess surface oil and leaves a lightweight finish. Those with very dry, sensitive or compromised skin may find frequent use too stripping since the solvent can pull water from the upper layers and weaken an already fragile barrier.
The alcohol is fermented from plant sources and the denaturants are either synthetic or plant derived so there are no animal-based inputs. That makes it appropriate for vegans and vegetarians.
Topical use during pregnancy or while breastfeeding is generally considered low risk as the ingredient evaporates quickly and systemic absorption is minimal. This is not medical advice and anyone who is pregnant or nursing should confirm the safety of any cosmetic product with a healthcare professional.
Alcohol Denat. Sd Alcohol 39 is not known to cause photosensitivity on its own. However it often appears in formulas that include fragrance oils or botanical extracts that might make skin sun-reactive so daily sunscreen is still a good idea.
Potential Side Effects/Adverse Reactions
Side effects from topical Alcohol Denat. Sd Alcohol 39 differ from person to person. The points below describe what could occur even though most users will not experience any problems when the ingredient is used correctly in a well-balanced formula.
- Dryness or tightness, especially on already dehydrated skin
- Stinging or burning on freshly shaved or broken skin
- Redness or irritation in sensitive skin types
- Disruption of the skin barrier leading to flakiness or rough texture with heavy or repeated use
- Temporary worsening of acne for some individuals due to rebound oil production
- Allergic contact dermatitis, although this is rare
- Respiratory or eye irritation if inhaled in high amounts from aerosol sprays
If any of these effects occur stop using the product and seek guidance from a qualified healthcare provider.
Comedogenic Rating
Rating: 0 / 5
Alcohol Denat. Sd Alcohol 39 flashes off the skin almost as soon as it is applied so it has little to no time to sit in pores and mix with sebum. Because it evaporates rather than leaving a film it does not create the sticky environment that can trap dead cells or bacteria. For those reasons it earns a solid non-comedogenic score of zero.
Most people prone to acne or breakouts can use products containing this type of alcohol without worrying about pore blockage, though overly frequent use could dry skin and trigger rebound oil for a small number of users.
Its rapid evaporation means it will not affect the comedogenic rating of other ingredients in the same formula, but if the product also contains heavy oils those may be the factors to watch.
Summary
Alcohol Denat. Sd Alcohol 39 works primarily as a solvent that dissolves fragrance, polymers and actives then evaporates quickly to leave a light clean feel. This quick flash-off also helps sprays set faster and lotions feel less greasy while its mild sanitizing effect supports product freshness.
Thanks to its reliability, easy sourcing and budget-friendly price it is still a staple in toners, mists, hair sprays and perfumes even as brands explore new low-alcohol options. You will spot it everywhere from drugstore shelves to prestige counters.
When used as intended and in balanced formulas it is considered safe for topical use on healthy skin, though dryness or irritation can occur for some. As with any new cosmetic it is wise to patch test a small area first just to be sure your skin agrees with the product.