
THE STORY OF CALCIUM HYDROXIDE
Calcium Hydroxide: The Strong Alkaline pH Adjuster & Processing Agent
Calcium Hydroxide (Ca(OH)â‚‚), commonly known as slaked lime, is a high-alkalinity inorganic compound used in cosmetics, pharmaceuticals, and industrial formulations as a pH regulator, buffering agent, and processing chemical. It plays a key role in depilatory creams, hair relaxers, dental products, and traditional skincare systems.
Created by Hydrating Quicklime for High-Purity Fine Powder
Calcium Hydroxide is manufactured by adding purified water to calcium oxide (quicklime), followed by drying, micronizing, and sieving to achieve consistent cosmetic-grade texture and purity. TRCkem supplies high-whiteness, low-impurity material suitable for regulated pH-controlled applications.
Neutralize. Process. Control pH.
Key uses in personal-care and pharma formulations:
✅ pH adjuster / alkalizing agent
✅ Used in hair relaxers & depilatory creams to soften keratin bonds
✅ Acts as a buffering base in dental care preparations (e.g., root canal pastes)
✅ Supports emulsification and product stabilization in traditional cold-process creams
✅ Used in some herbal / Ayurvedic paste formulas as a processing medium
Highly Alkaline – Strict Handling & Regulatory Limits Required
• Typical use level: <1% in finished cosmetic formulas (higher only in regulated depilatory/relaxer systems)
• Strongly alkaline (pH ~12.4 in 1% solution) → must be neutralized or safely buffered
• Can cause irritation if used incorrectly — requires PPE during handling
• Allowed in specific product categories under EU, FDA, and BIS regulations, banned in leave-on skincare
• Store sealed, dry, and away from acids or moisture exposure
Formulator’s Queries, We Answered
1. What is Calcium Hydroxide?
Calcium Hydroxide is an inorganic alkaline compound commonly used in personal care products as a pH adjuster, depilatory agent, and skin treatment ingredient. It helps balance acidity in formulations and is widely used in hair relaxers and skincare products.
2. What is the CAS number and INCI name of Calcium Hydroxide?
CAS Number: 1305-62-0
INCI Name: Calcium Hydroxide
3. What are the benefits of Calcium Hydroxide in personal care products?
Calcium Hydroxide is valued for its:
pH adjustment properties: Helps maintain the desired pH level in cosmetic formulations.
Hair relaxing and straightening abilities: Used in chemical hair relaxers.
Antiseptic properties: Helps prevent bacterial growth in certain skincare treatments.
Mild exfoliation: Can aid in removing dead skin cells when properly formulated.
4. How does Calcium Hydroxide work in cosmetic formulations?
Calcium Hydroxide acts as a strong pH adjuster, neutralizing acidity in formulations. In hair relaxers, it breaks down the hair’s protein structure, allowing for straightening effects.
5. Is Calcium Hydroxide safe for all skin types?
Calcium Hydroxide must be used within strict safety limits, as it can be highly alkaline and irritating to the skin at high concentrations. Proper formulation and neutralization are essential to prevent irritation.
6. What types of personal care products contain Calcium Hydroxide?
Calcium Hydroxide is found in:
Hair relaxers and straighteners (especially no-lye formulas)
Depilatory creams (for hair removal)
pH-adjusting skincare products
Dental care (used in some toothpaste and cavity treatments)
7. Can Calcium Hydroxide be combined with other ingredients?
Yes, Calcium Hydroxide is often used with:
Guanidine Carbonate (in no-lye relaxers) to create a gentle formula.
Citric Acid or Lactic Acid to balance pH levels.
Moisturizing agents (such as Aloe Vera or Shea Butter) to counteract potential dryness.
8. Does Calcium Hydroxide cause any side effects?
Calcium Hydroxide is safe when used correctly, but potential side effects include:
Skin irritation in high concentrations.
Eye irritation if it comes into direct contact.
Scalp sensitivity if used improperly in hair relaxers.
9. What is the recommended concentration of Calcium Hydroxide in personal care formulations?
Up to 5% in hair relaxers and depilatory products.
Less than 1% in skincare products for pH regulation.
10. Is Calcium Hydroxide natural or synthetic?
Calcium Hydroxide is naturally derived from limestone but is industrially processed for use in cosmetic and pharmaceutical applications.
11. Where can I purchase high-quality Calcium Hydroxide for formulation purposes?
Calcium Hydroxide is available from cosmetic raw material suppliers. Ensure you choose high-purity, cosmetic-grade Calcium Hydroxide for safe and effective formulations.