5. CI 77499 - Black Iron Oxide
Black Iron Oxide, identified by the Color Index code CI 77499, is an inorganic, hydrophobic pigment. Being hydrophobic, it repels water, making it less likely to mix with water-based solutions. In simple terms, it's water-repellent and not derived from organic materials. Black Iron Oxide, typically in its second oxidation stage, is often categorized under iron oxides. Its chemical formula, Fe3O4, uniquely contains iron in the +2 and +3 oxidation states.
Color-wise, Black Iron Oxide has a rich, warm hue, lighter than Carbon Black, and tends to shift towards warmer tones over time. This difference in color intensity between Black Iron Oxide and Carbon Black is largely due to their particle sizes - larger particles like Black Iron Oxide appear lighter, while smaller particles like Carbon Black appear darker.
Interestingly, Black Iron Oxide is synthesized in laboratories to ensure purity and prevent heavy metal contamination. Although its formula occurs naturally in iron ore, today's Black Iron Oxide is predominantly lab-produced.
According to the Environmental Working Group's (EWG) Skin Deep database, Black Iron Oxide has a 'fair' hazard score, ranging between 2-4, indicating general acceptance in cosmetology.
An intriguing aspect of Black Iron Oxide (Fe3O4) is its magnetic properties. There have been instances where magnets have adhered to pigment bottles containing it. However, this magnetic trait doesn't suggest harmful heavy metal content. The magnetic nature of Fe3O4 might theoretically affect Magnetic Resonance Imaging (MRI), but such an impact would require quantities far exceeding those used in Powder Brows, Hairstrokes, or Microblading treatments.
Historically, Black Iron Oxide was extracted from iron ore, which could contain traces of other metals. Today's lab-synthesized version has virtually eliminated these concerns, and experts generally debunk claims of heavy metal presence in the synthesized form.
Finally, Black Iron Oxide pigments often include glycerine. Glycerine serves two purposes: as a binder, it loosely holds pigment particles together, and as a solvent, it influences the pigment's consistency. This gives it a different behavior than pigments with other binders like shellac.