What Is Sodium/Aluminum/Iron/Sulfate/Citrate/Hydroxide?
Sodium/Aluminum/Iron/Sulfate/Citrate/Hydroxide is a blended mineral complex created when aluminum sulfate and ferric sulfate are neutralized with sodium hydroxide in the presence of citric acid. The result is a stable salt mixture that combines aluminum iron sodium sulfate and citrate ions with a touch of hydroxide left over from the reaction. Chemists first explored this mix while looking for a milder alternative to traditional alum blocks used for odor control and water purification. Its ability to fight germs absorb moisture and scatter light soon caught the eye of cosmetic formulators who began adding it to deodorants and skin treatments in the early 2000s.
Manufacturing starts with food or pharmaceutical grade aluminum sulfate and ferric sulfate dissolved in water. Sodium hydroxide is added slowly to raise the pH and trigger controlled precipitation. Citric acid is then introduced to chelate any free metal ions and improve skin feel. The slurry is filtered dried and milled into a fine off-white powder. Because it is water dispersible and heat stable it slips easily into many product formats such as roll-on deodorants, clarifying masks, mattifying moisturizers, creamy sunscreens and after-shave lotions.
Sodium/Aluminum/Iron/Sulfate/Citrate/Hydroxide’s Cosmetic Benefits/Uses
This ingredient packs several helpful roles into one powder
- Antimicrobial: Limits the growth of odor-causing bacteria on skin which helps keep products fresh and extends wear time
- Deodorant: Neutralizes sweat acids and curbs bacterial activity reducing body odor without heavy fragrances
- Humectant: Attracts and holds water at the skin surface adding a light boost of hydration and preventing a tight dry feel
- Opacifying: Scatters light to make formulas appear creamier and to blur minor skin imperfections for a soft-focus finish
- Uv Absorber: Helps absorb a portion of UV rays supporting the overall sun-filter system in daytime products
Who Can Use Sodium/Aluminum/Iron/Sulfate/Citrate/Hydroxide
This mineral complex is generally well tolerated by most skin types including oily combination normal and even mildly dry skin thanks to its light humectant effect. Very sensitive or highly reactive skin may find the astringent metal salts a bit too stimulating which could lead to temporary redness or tightness so these users should approach with caution.
Sodium/Aluminum/Iron/Sulfate/Citrate/Hydroxide is synthetic and contains no animal derived components which makes it suitable for both vegans and vegetarians.
Current safety data shows no specific risk for pregnant or breastfeeding people when the ingredient is used topically at cosmetic levels. That said this is not medical advice and anyone who is pregnant or nursing should discuss all personal care products with a qualified healthcare provider to be extra safe.
The ingredient does not increase photosensitivity. In fact its mild UV absorbing ability can offer a tiny boost to overall sun protection when combined with dedicated sunscreen filters. No notable interactions with common actives like niacinamide or hyaluronic acid have been reported.
Potential Side Effects/Adverse Reactions
Responses to topical Sodium/Aluminum/Iron/Sulfate/Citrate/Hydroxide differ from person to person. The points below outline potential side effects that could occur though most users will not experience them when the ingredient is formulated and used correctly.
- Mild stinging or warmth on freshly shaved or broken skin
- Temporary dryness if layered with multiple mattifying or alcohol based products
- Gradual surface buildup leaving a faint powdery film on skin or fabric
- Discoloration of light fabrics if the product is not fully dry before dressing
- Rare contact irritation in individuals sensitive to aluminum or iron compounds
- pH shift in very acidic routines which can reduce the effectiveness of nearby actives
If any irritation or other adverse effect develops stop use promptly and consult a healthcare professional for guidance.
Comedogenic Rating
Rating: 1/5 – Sodium/Aluminum/Iron/Sulfate/Citrate/Hydroxide is a water-soluble mineral complex that does not form an oily film on skin so it has very little tendency to clog pores. The trace hydroxide and citrate components rinse away easily and the powder sits on the surface rather than sinking into follicle openings. That said the ingredient can leave a light residue if used in very high concentrations which is why it is not given a perfect zero.
Because its pore-clogging risk is minimal most people who are prone to acne or breakouts can use products with this ingredient without worry.
One extra point worth noting is that formulas pairing the complex with heavy silicones or waxes could raise the overall comedogenic profile even if the ingredient itself is low so always look at the whole ingredient list.
Summary
Sodium/Aluminum/Iron/Sulfate/Citrate/Hydroxide works as an antimicrobial deodorant humectant opacifier and mild UV absorber. In practice the aluminum and iron salts curb bacterial growth while the sodium component boosts solubility and the citrate helps bind stray metals improving skin feel. Its fine particulate nature scatters light for a soft matte look and the mineral matrix grabs a bit of water adding light hydration.
The complex is still a niche addition rather than a mainstream favorite showing up mainly in specialty deodorants clarifying masks and a handful of sunscreen blends. Formulators like its multitasking ability but the name length and metal content keep it from mass popularity.
Current data indicates it is safe for topical use at cosmetic levels with only rare irritation reports. As with any new skincare ingredient it is wisest to patch test a small area first to rule out personal sensitivities before full application.