Liquid Soap Analyses

Liquid Soap Analyses: All Essential Tests for Product Safety and Performance

Due to increasing hygiene practices, liquid soaps play a significant role in both private and industrial use. However, for the product to be safe, effective, and compliant with regulations, it must undergo comprehensive testing. Analyses conducted in accordance with the EU Cosmetics Regulation (1223/2009), ISO 22716 (GMP), and OECD methods form the basis for manufacturers' quality control processes.

We offer services for all tests performed on liquid soaps, including pH value, viscosity, active ingredient determination, microbiology, heavy metals, stability, foam formation, packaging, and labeling.

Physical and Chemical Analyses

pH Determination: Determines the effect liquid soap has upon skin contact. A skin-compatible pH range reduces the risk of skin irritation. This is also a critical parameter for product stability.

Viscosity Analysis (Brookfield): This test measures the flowability, pumpability, and application properties of liquid soap. It determines the formula's stability and any thickening or thinning tendencies.

Density Measurement: Used for formula verification, quality control, and raw material compatibility. It ensures product consistency in serial production.

Moisture/Dry Matter Determination: Determines the proportion of solid substances comprising the product. It is used for calculating the active ingredient content and is crucial for formula standardization.

Determination of Active Ingredients

Determination of Anionic Active Ingredients: This is the most fundamental component determining the cleansing power of liquid soap. The quantity of surfactants such as SLES and LAS is measured.

Determination of Non-ionic Active Ingredients: These play a crucial role in foam formation, grease-dissolving power, and skin compatibility. They are a critical parameter, especially for products intended for sensitive skin.

Determination of Total Active Ingredients: The total quantity of anionic + non-ionic active ingredients is determined. This reflects product performance and quality standards.

Fragrance and Dye Analysis

The fragrances and dyes used in liquid soaps are examined for:

• IFRA Conformity
• Allergenic Ingredients
• Color Stability
• Volatility and Odor Loss

This analysis ensures the accuracy of both the formula and the labeling information.

Preservative Efficacy Test (Challenge Test)

As liquid soaps are water-based products, there is a high risk of microbial proliferation. Therefore, their preservative efficacy must be demonstrated.

• Staphylococcus aureus
• Pseudomonas aeruginosa
• Candida albicans
• Aspergillus brasiliensis

Microorganisms such as these are inoculated into the product, and the efficacy of the preservative is monitored.

Microbiological Purity

While it is normal for the product to be non-sterile, its microbial load must remain within specified limits.

Tests Performed:

• Total Aerobic Bacteria Count
• Yeast and Mold
• Pathogen Control (if required)

Heavy Metal Analysis

Measurement is performed using ICP-MS/ICP-OES, evaluating the following elements:

• Lead (Pb)
• Cadmium (Cd)
• Mercury (Hg)
• Arsenic (As)

This approach ensures that potential risks originating from raw materials are effectively controlled.

Biodegradability (OECD 301B)

To ensure the environmental compatibility of surfactants used in liquid soaps, a biodegradability test is conducted in accordance with OECD criteria.

• This test demonstrates the duration and extent of the product's degradation in the environment.
• This is crucial for compliance with EU regulations.

Stability Test

The product's shelf life and formulation stability are evaluated.

Under both real-time and accelerated conditions, the following parameters are monitored:

• pH Change
• Change in Viscosity
• Color and Odor Stability
• Phase Separation Control
• Precipitation Formation
• Foaming Behavior

Foam Test

This is one of the most practical tests, reflecting the user-perceived performance of liquid soap.

• Foam Height
• Foam Stability
• Tendency to Disperse
• Parameters such as these are measured.

Color Determination

Color measurement is performed using the CIE Lab* system.

• In serial production, the control of color differences is ensured.

Label & Packaging Compliance Testing

Label Testing:

• Accuracy of INCI List
• Allergen Information
• Warnings
• Net Content
• Batch Number
• Instructions for Use

Packaging Compliance:

• Seal Integrity
• Lid Fit
• Material Interaction
• UV Resistance

This is a crucial step to ensure product safety throughout its shelf life.

Accuracy of Safety Data Sheet (SDS)

The SDS content of the raw materials used is verified:

• Correct Classification
• Pictogram Compliance
• CLP Compliance
• Use of the updated version

This is essential for both occupational safety and regulatory compliance.