Reasons for choosing our testing services
ZHONGXI Testing has obtained inspection qualification certifications from multiple countries and regions worldwide. We possess a senior testing team and advanced testing methods, providing independent, impartial, and professional third-party verification services for global carbon projects.
Internationally recognized authority
Certified by multiple international standards such as CNAS, VCS, and GS, with reports universally applicable worldwide.
Global service capability
Covering 140+ countries and regions, it supports on-site detection and remote verification in multiple languages.
Professional experimental methods
Adopt standard experimental methods to ensure accurate and reliable data.
A well-defined testing scope is the first sign of a competent laboratory. In our capacity as a CNAS/CMA-accredited third-party testing and inspection facility, we specialize in, a critical evaluation method for identifying potential allergenicity in materials intended for human or animal contact. This service is essential for product development, regulatory compliance, and risk mitigation in industries ranging from pharmaceuticals to cosmetics and consumer goods.
Testing Scope
Our covers a broad range of products, materials, and applications. We test chemical substances, pharmaceuticals, cosmetics, personal care products, and industrial materials that may elicit allergic reactions. The scope includes testing for both primary skin sensitization ( Patch Test) and systemic sensitization (Intravenous Challenge). Applicable materials span from individual chemical compounds to complex formulations. Testing is available for various grades of materials, including raw ingredients, intermediates, and final products. Application scenarios encompass new product development, batch release verification, and competitive product analysis. Commonly referenced standards for this testing include ISO 10993-5 (Evaluation of irritation and skin sensitization), OECD Guidelines for the Testing of Chemicals (e.g., Guideline 404), and China's GB/T 16170 (Dermal sensitization test - Guinea pig method).
Testing Items and Parameters
Our includes specific test items with well-defined parameters and graded limit requirements. The primary test methods are the Buehler Patch Test for local sensitization and the Maximization Test with Challenge for systemic sensitization. Typical test parameters and acceptance criteria are outlined in the table below:
| Test Parameter | Typical Concentration/Volume | Acceptance Criterion |
|---|---|---|
| Buehler Patch Test Dose 1 | 0.5 mg test material in 0.25 mL vehicle | Mild reaction in <15% animals at 48 hours |
| Buehler Patch Test Dose 2 | 5 mg test material in 0.25 mL vehicle | No significant reaction in <10% animals at 48 hours |
| Maximization Test Initial Dose | 100 mg test material in 0.5 mL saline | ≥50% animals with moderate reactions at 24/48 hours |
| Maximization Test Challenge Dose | 10 mg test material in 0.5 mL saline | ≥50% animals with positive responses (prick reaction or papule) |
Additional parameters include observation scoring (0-4 scale), clinical photography, and histopathological analysis of excised skin. Results are categorized as non-sensitizing, sensitizing, or potent sensitizing based on OECD and ISO guidelines. We report parameters with graded limits aligned with regulatory requirements from regions such as the EU, US, and China.
Data and Variation Analysis
In assessing, we rigorously evaluate parallel-sample and batch-to-batch variation through statistical analysis. For parallel-sample testing, relative deviation between duplicate or triplicate samples is calculated using coefficient of variation (CV). Typically, we maintain a CV below 10% for sensitization parameters, ensuring method precision. Batch-to-batch variation is analyzed by comparing results across consecutive batches of identical materials using analysis of variance (ANOVA). Acceptance windows for variation are established based on historical data and reference materials, typically requiring sensitization response rates to remain within ±20% of the mean across batches. Statistical metrics including p-values and effect sizes are reported to quantify significance. All variation data is presented in capability reports alongside standard deviation, mean values, and control material comparisons, providing clients with comprehensive assessment of reproducibility and reliability.
Our data analysis approach follows internationally recognized principles for sensitivity testing variability, ensuring that results are statistically valid and reproducible across different test runs and material batches. This methodology provides clients with confidence in their material safety assessments and regulatory submissions.
For your specific testing needs, we invite you to confirm your required test items and sample quantity. We will revert with a formal quotation and expected schedule tailored to your requirements.