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.
Before sending samples for environmental microbial testing, most engineers inquire whether the laboratory covers their specific material or application. At our accredited facility, we specialize in analyzing a wide range of environmental samples, including water, air, soil, and surfaces, to meet international standards and client requirements. Our testing scope is designed to address diverse industrial, commercial, and regulatory needs, ensuring accurate and reproducible results for microbial contamination assessment.
Testing Scope
Our environmental microbial testing services are applicable to various products, materials, and application scenarios where microbial presence or absence is critical. We evaluate liquids such as potable water, wastewater, and industrial effluents; airborne particles in cleanrooms or outdoor environments; soil samples from agricultural or construction sites; and surface swabs from medical facilities or food processing plants. The commonly referenced standards for these tests include ASTM International, ISO (International Organization for Standardization), EN (European Normative Documents), and GB (China National Standards) where applicable.
For water quality testing, we cover parameters like total Coliforms, E. coli, and fecal streptococci as per ASTM D5981 and ISO 16627. Air quality assessment includes microbial load measurement following ISO 22612 for cleanrooms and ISO 18599 for ambient air. Soil and surface testing align with ASTM F2483 and EN 1822 for microbial enumeration. These standards ensure our results are comparable and accepted by global regulatory bodies.
Testing Items and Parameters
We conduct a comprehensive suite of microbial testing items with specific parameters and graded limit requirements. Typical test items include microbial enumeration, identification of pathogenic microorganisms, and resistance testing. Below is a table summarizing parameters for water quality microbial testing:
| Test Item | Typical Parameters | Graded Limit Requirements (Example) |
|---|---|---|
| Total Coliforms | CFU/100mL | <1 CFU/100mL (US EPA standard for potable water) |
| E. coli | CFU/100mL | <0.1 CFU/100mL (EU drinking water directive) |
| Fecal Streptococci | CFU/100mL | <1 CFU/100mL (US EPA standard for recreational water) |
| Pseudomonas aeruginosa | CFU/100mL | Not detected (for sterile products) |
Additional parameters include microbial identification via 16S rRNA gene sequencing, antibiotic resistance profiling, and fungal load analysis. Graded limits are customized based on industry-specific regulations or client-defined acceptance criteria.
Data and Variation Analysis
In assessing parallel-sample and batch-to-batch variation, we employ statistical methods to ensure data reliability. For parallel samples, the relative deviation between duplicates is typically maintained within ±10% for quantitative microbial counts. Acceptance windows are defined as follows: for CFU counts, the mean of two parallel samples must fall within 85-115% of each other. Batch-to-batch consistency is evaluated using control samples, with variation in mean counts across batches limited to ≤15% relative deviation.
Variation analysis includes running method blanks, positive controls, and negative controls to monitor precision and accuracy. Results are presented with confidence intervals, and standard deviations are reported to indicate reproducibility. Our capability narrative follows international guidelines such as ISO/IEC 17025 for accuracy specifications and ASTM E1600 for uncertainty quantification in microbial analysis.
For clients requiring additional validation or specific acceptance criteria, we can perform proficiency testing against international reference materials and provide supplementary variation reports. All data is documented in compliance with ISO 17025:2017 requirements, ensuring traceability and defensibility.
To proceed with environmental microbial testing, please confirm your required test items and sample quantity. We will revert with a formal quotation and expected schedule based on your specifications.