Citric Acid Granule

Citric Acid

Citric Acid is a naturally occurring organic acid widely used in cosmetic and personal care formulations for pH adjustment, chelation support, and formulation stability. It is most commonly produced through the fermentation of plant-derived sugars using microbial processes, resulting in a high-purity, bio-based ingredient suitable for cosmetic use. The manufacturing process does not involve ethoxylation or petrochemical modification, supporting its use in clean and modern formulation systems.

From a formulation standpoint, Citric Acid functions primarily as a pH adjuster, allowing formulators to fine-tune products into skin-compatible ranges. Proper pH control is critical for product stability, preservative efficacy, and skin tolerance. Citric Acid also provides secondary chelating benefits by binding trace metal ions, which can help reduce oxidation and improve overall formula stability. Its behavior is concentration-dependent and influenced by buffering systems and total water content.

In finished products, Citric Acid supports product performance without contributing noticeable sensory effects when used at appropriate levels. At very low concentrations, it adjusts pH without irritation, while higher levels are typically reserved for rinse-off products where stronger acidification may be required. Citric Acid is commonly used in cleansers, shampoos, conditioners, lotions, creams, serums, toners, and exfoliating products formulated within safe cosmetic pH ranges.

From a clean standards and safety perspective, Citric Acid has a long history of safe cosmetic use and is widely accepted across global regulatory frameworks. It is biodegradable, non-persistent, and generally well tolerated when formulated correctly. While it is naturally acidic, irritation risk is managed through controlled usage levels and proper pH adjustment, making it suitable for both rinse-off and leave-on applications.

Ingredient Identification

INCI Name: Citric Acid
CAS Number: 77-92-9

Physical & Technical Properties

Appearance: White crystalline powder or granules
Odor: Odorless
Solubility: Freely soluble in water
pKa: Approximately 3.1, 4.8, and 6.4
Functional Role: pH adjuster, buffering agent, chelation support

Typical Usage Levels (Skincare & Personal Care)

Leave-On Products: 0.05–0.5% (pH adjustment only)
Rinse-Off Products: 0.1–1.0%
Cleansers and Shampoos: 0.1–0.8%
Exfoliating Products: Usage depends on final pH and product design

Actual usage levels depend on target pH, formulation buffering capacity, and regulatory considerations.

DIY Education and Formulation Guidance

For DIY formulators, Citric Acid is commonly used as a dilute aqueous solution to allow controlled pH adjustment. It should be added slowly with mixing and followed by pH testing to avoid over-acidification. Because Citric Acid is a strong acid relative to cosmetic pH targets, small adjustments can produce significant pH changes.

Citric Acid should not be confused with chelators such as sodium phytate or EDTA, as its chelating capacity is secondary to its role as a pH adjuster.

Formulation Compatibility & Common Combinations

Citric Acid is compatible with most water-based cosmetic ingredients, including surfactants, humectants, and emulsifiers. It is commonly used alongside preservatives that require acidic pH ranges for optimal performance. In buffered systems, it may be paired with sodium citrate to maintain pH stability.

Shelf Life, Storage, and Packaging

Shelf Life: Typically 36 months when stored under recommended conditions
Storage Conditions: Store in a cool, dry environment away from moisture
Packaging Recommendations: Sealed plastic containers, lined bags, or airtight jars
Handling Notes: Hygroscopic; protect from humidity to prevent clumping

Regulatory & Safety Notes

Regulatory Status: Approved for cosmetic use globally, including the United States and European Union
California Proposition 65: Not listed
EWG Context: Generally categorized as low hazard at cosmetic usage levels
Irritation and Sensitization: May cause irritation at low pH or high concentrations; safe when properly formulated
Clean Beauty Compatibility: Bio-based, biodegradable, and compatible with clean, natural-leaning, and transparency-focused formulation standards