Steareth-20 is a synthetic emulsifier derived from stearic acid (a fatty acid) that helps mix oil and water-based ingredients together in skincare formulas. It's commonly used to create stable, smooth textures in creams and lotions.
Benefits
Stabilizes emulsions to create smooth, consistent product texture
Allows oil and water ingredients to blend effectively
Generally gentler than some alternative detergents used in skincare
Potential concerns
May cause irritation in sensitive skin at high concentrations
Can affect cell viability in laboratory settings at elevated levels, though relevance to normal skincare use is unclear
Science: Research shows Steareth-20 has lower in vitro cytotoxicity compared to harsher detergents like sodium lauryl sulfate, requiring much higher concentrations (70% vs. 1%) to produce cell damage in lab studies. However, these laboratory findings use extreme concentrations not typical in finished skincare products, and actual safety in real-world use remains well-established through decades of cosmetic industry use.
Trisodium EDTA is a chelating agent that binds to metals and minerals in cosmetic formulas, helping stabilize products and prevent them from breaking down. It's used in small amounts (typically under 2%) to maintain product consistency and shelf life.
Benefits
Stabilizes cosmetic formulations and extends shelf life
Prevents discoloration and degradation caused by trace metals
Helps preserve product efficacy over time
Potential concerns
May increase skin penetration of other ingredients by binding to calcium in skin
Should be avoided in inhalable products (sprays, powders) due to potential respiratory concerns
Not intended for ingestion or use in products applied to lips/mouth area
Science: The Cosmetic Ingredient Review Expert Panel confirmed safety in 2023 based on current practices and concentrations. While EDTA is not absorbed through intact skin, it can alter how other chemicals penetrate the skin by chelating calcium, so formulators must carefully consider ingredient combinations.
Sorbic acid is a preservative used in skincare products to prevent the growth of bacteria, fungi, and mold, helping extend shelf life. It's a naturally-derived organic acid that's been safely used in food and cosmetics for decades.
Benefits
Prevents microbial contamination and product spoilage
Effective across a range of pH levels, including mildly acidic formulas
Well-established safety history in food and cosmetic applications
Potential concerns
Can cause transient redness, swelling, and irritation at concentrations as low as 0.1%, particularly on sensitive facial skin
Irritation appears to be mediated by prostaglandin response rather than allergic reaction, so it may affect most people at higher doses
May cause discomfort in individuals with sensitive or compromised skin barriers
Science: Research shows sorbic acid triggers dose-dependent erythema and edema through prostaglandin-mediated inflammation rather than immune sensitization. While physiologically inert at approved preservation levels (typically well below 0.1%), it can provoke irritation responses in human skin, suggesting careful formulation and concentration limits are important for safety.
