Demystifying CI 15850 – The Red Dye in Your Makeup
What Exactly is CI 15850?
CI 15850, labeled as Red 6, Red 7, or their Lake variants on ingredient lists, is a synthetic monoazo dye that delivers vibrant reddish-orange hues. This colorant stars in everything from long-wear lipsticks to blendable cream blushes, prized for its ability to maintain intensity under heat and light.
The Science Behind the Color
Chemical Identity:
Formula: C₁₈H₁₂N₂Na₂O₆S
CAS No.: 5858-81-1
Lake Forms: Combined with aluminum to create insoluble pigments ideal for pressed powders.
Why Lakes?
Unlike water-soluble dyes, lakes (like Red 6 Lake) provide fade-resistant color in oil-based formulations. This explains their dominance in matte lip products and pigmented eyeshadows.
Safety at a Glance
✅ Approved by:
U.S. FDA (with purity requirements)
EU Cosmetics Regulation (EC 1223/2009)
⚠️ Controversies:
Eye Area Caution: Some countries limit concentrations near eyes due to irritation risks.
Inhalation Warning: Not recommended for spray formulations.
Impurity Risks: Low-quality batches may contain heavy metal residues.
Expert Note: A 2021 EU SCCS report flagged insufficient long-term exposure data but confirmed current usage levels as safe.
Why Cosmetic Brands Choose It
Performance: 0.5% concentration achieves opaque coverage – outperforming many plant-based pigments.
Stability: Resists oxidation better than anthocyanins (berry-derived colors).
Budget-Friendly: Costs ~5% of carmine (animal-derived red dye).
Smart Shopping Tips
🧐 Decode Labels:
CI 15850 = Standard dye
Red 6 Lake = Metal-complexed version
🌱 Clean Alternatives: Look for iron oxides (CI 77491) or microbial-based reds in "vegan" lines.
🩹 Patch Test: Apply product behind ears if prone to sensitivities.
The Future of Synthetic Reds
While CI 15850 remains industry-standard, brands like Aether Beauty and Lush now use fermentation-derived pigments. Regulatory shifts may emerge, but for now, this dye continues to color your favorite makeup reliably.