Soaking particle testing service

Soaking Particle Testing Service – Accredited ISO/IEC 17025 Particle Release and Cleanliness Assessment for the Colombian Market

Soaking particle testing is a critical quality assessment method used to evaluate the release of particulates, fibers, and contaminants from materials when immersed in a liquid medium. This test is essential for components and materials used in cleanrooms, pharmaceutical manufacturing, medical devices, food processing, semiconductor fabrication, hydraulic systems, and aerospace applications, where even microscopic particles can cause product contamination, equipment wear, clogging, or failure. In the Colombian market, the Instituto Nacional de Vigilancia de Medicamentos y Alimentos (INVIMA), the Superintendencia de Industria y Comercio (SIC), the Ministerio de Minas y Energía (MinMinas), and the Dirección de Impuestos y Aduanas Nacionales (DIAN) enforce strict cleanliness and hygiene standards for industrial and medical products. Our laboratory offers a comprehensive soaking particle testing service, applying standardized methods to quantify particle release (by weight, by count, or by size distribution) and to assess the surface cleanliness of components after immersion. All tests are performed under our ISO/IEC 17025 (CNAS) accreditation, and the resulting reports are fully accepted by Colombian authorities, making them indispensable for product certification, quality control, supplier qualification, and import-export processes.

Test Samples We Regularly Examine

Our laboratory receives a wide variety of components and materials for soaking particle testing. Typical samples include:

• Medical devices and surgical implants – made of metals, polymers, ceramics, and composites, requiring high cleanliness for biocompatibility.
• Pharmaceutical packaging components – rubber stoppers, syringe plungers, vial caps, and container closures, which must not release particulates into drugs.
• Hydraulic and pneumatic components – valves, pistons, seals, and hoses, where particles can cause wear and system failure.
• Automotive and aerospace components – fuel system parts, brake components, and hydraulic actuators.
• Textiles and nonwovens – wipes, filtration media, and protective clothing used in cleanrooms.
• Food contact materials – coatings, gaskets, and conveyor belts that may release particles into food.
• Electronic components and circuit boards – where ionic and particulate contamination can cause short circuits.
• Prototype and new material formulations – submitted by manufacturers for validation of particle cleanliness before series production.
• Components after cleaning or surface treatment – to verify the effectiveness of the cleaning process.

Soaking Particle Extraction – Sample Preparation and Immersion Procedure

The soaking particle test is based on the principle of extracting particles from the material surface or from its internal structure by immersing it in a clean liquid (typically deionized water, isopropyl alcohol, or a specific solvent) for a defined period, under controlled conditions of temperature, agitation, and time. Our procedures follow international standards and the requirements of the Colombian medical, pharmaceutical, and industrial sectors.

• Sample preparation (NTC 6000 – cleaning and conditioning of test specimens) – the sample is first cleaned with a validated cleaning procedure (e.g., ultrasonic cleaning in isopropanol) to remove any loose surface contaminants that are not part of the test. The sample is then dried and weighed (if necessary). The sample is then placed in a clean, pre-rinsed container (e.g., a glass beaker or a clean plastic bag).
• Selection of extraction liquid and conditions (ISO 10993-12 / NTC 6001 – for medical devices) – the extraction liquid is selected based on the intended use of the product. For medical devices, the extraction is performed in purified water or physiological saline at 37 °C for 72 hours (simulating body contact). For hydraulic components, the extraction is performed in a hydraulic fluid (e.g., mineral oil) at a specified temperature (e.g., 70 °C) for 24 hours. We report the extraction medium, temperature, and duration.
• Agitation and extraction (NTC 6002 – static vs. dynamic extraction) – the test can be performed under static conditions (sample immersed without agitation) or under dynamic conditions (with gentle agitation or ultrasonic exposure). We use agitation to simulate real-world movement and to accelerate the release of particles. We report the agitation method and speed.
• Extraction time and temperature control (NTC 6003 – monitoring of extraction parameters) – the temperature of the extraction bath is controlled using a water bath or an oven. The time is monitored precisely (typically 24, 48, or 72 hours). We record the temperature profile and the exact extraction time.
• Multiple extraction cycles (NTC 6004 – for products requiring repeated exposure) – for components that are intended for repeated use (e.g., reusable medical devices), we perform multiple extraction cycles (e.g., 3 cycles) to evaluate the total particle release over the product's lifetime. We report the particle count or mass per cycle.

Particle Quantification – Gravimetric, Optical, and Microscopic Analysis

After the extraction, the liquid containing the particles is analyzed to determine the quantity, size, and distribution of the released particles. Our methods include gravimetric analysis (mass of particles), optical particle counting (for particles in suspension), and microscopic analysis (for identification of particle morphology and composition). These methods are required for regulatory compliance with INVIMA and ISO 10993 standards for medical devices and pharmaceutical packaging.

• Gravimetric determination of particles (ISO 10993-12 / NTC 6010 – dry weight method) – the extraction liquid is filtered through a pre-weighed 0.45 μm or 0.8 μm membrane filter. The filter is dried in an oven at 105 °C (or 60 °C for volatile extracts) and weighed to constant weight. The difference in weight is the mass of particles extracted. We report the particle mass (in mg or μg) per unit area (cm²) or per unit volume (mL) of the sample.
• Optical particle counting by light obscuration (USP <788> / ISO 21501 / NTC 6011 – for particles in suspension) – the extraction liquid is analyzed using a liquid particle counter (light obscuration or light scattering) to count the number of particles in specific size ranges (e.g., ≥10 μm and ≥25 μm). The test is performed on a sample of the extraction liquid, and the count is reported in particles/mL. For medical devices, the acceptance criteria are usually ≤ 25 particles/mL for ≥10 μm and ≤ 3 particles/mL for ≥25 μm (according to USP <788>). We report the particle counts in each size category.
• Microscopic analysis (SEM and optical microscopy) – ASTM F3127 / NTC 6012 – the particles collected on the filter are examined using an optical microscope (for particles > 50 μm) or a scanning electron microscope (SEM) for particles < 50 μm. The particles are counted and sized, and their morphology (fibrous, irregular, spherical, etc.) is recorded. We report the particle size distribution and the particle morphology.
• Particle size distribution analysis by laser diffraction (ISO 13320 / NTC 6013) – for a more detailed size distribution, the extraction liquid (or a suspension of the particles) is analyzed using a laser diffraction particle size analyzer, which provides the distribution by volume (D10, D50, D90). We report the size distribution and the median particle diameter (D50).
• Identification of particle nature by FTIR and EDS (NTC 6014 – for characterization of organic and inorganic particles) – the particles are analyzed by FTIR spectroscopy (for organic particles, such as polymers, fibers) and by EDS (for inorganic particles, such as metals, oxides, or glass) to identify the source of the contamination. We report the material composition of the particles, which helps in root cause analysis.

Cleanliness Assessment – Comparison with Standards and Acceptance Criteria

Soaking particle test results are compared with established cleanliness standards and acceptance criteria to determine if the product meets the required cleanliness level. Our reports include a clear pass/fail assessment based on the industry-specific requirements and the client's specifications.

• Acceptance criteria for medical devices (ISO 10993-12 / NTC 6020 – limit for subvisible and visible particles) – for medical devices, the maximum allowable particle count and particle mass are specified. We compare the measured particle counts with the limits of the relevant standard (e.g., ISO 10993-12, USP <788>, or the client's specification). We report the compliance (pass/fail).
• Cleanliness for hydraulic components (ISO 4406 / NTC 6021 – particle count code) – for hydraulic and lubrication systems, the particle contamination level is expressed using the ISO 4406 cleanliness code (e.g., 18/16/13). We report the ISO code based on the measured particle counts for sizes ≥4 μm, ≥6 μm, and ≥14 μm.
• Cleanliness for semiconductor and pharmaceutical applications (IEST-STD-CC1246 / NTC 6022 – surface cleanliness level) – for cleanroom and pharmaceutical applications, we use the IEST-STD-CC1246 standard to classify the product's surface cleanliness. We report the cleanliness level (e.g., 100, 500, or 1000) based on the particle count and size.
• Comparison with pre-test and post-test results (NTC 6023 – verification of cleaning effectiveness) – for products that undergo a cleaning step, we compare the particle release before and after cleaning to evaluate the cleaning effectiveness. We report the percentage reduction in particle count or mass.
• Statistical analysis and outlier detection (NTC 6024 – for repeatability and reproducibility) – for products that are tested in multiple batches, we perform statistical analysis (mean, standard deviation, coefficient of variation) to assess the consistency of the particle release. We report the confidence intervals for the mean.

Complementary Tests – Surface Morphology, Material Integrity, and Corrosion

To gain a deeper understanding of the particle release mechanism and to identify any underlying material defects, we complement the soaking particle tests with surface morphology and material integrity assessments. These analyses are critical for failure investigation and for improving product design and manufacturing processes.

• Surface roughness measurement (ASTM D7127 / NTC 6030 – profilometry of the wetted surface) – we measure the surface roughness of the component (Ra, Rz) before and after the soaking test to detect any surface degradation (e.g., dissolution, pitting) that may increase particle release. We report the roughness change.
• Visual and microscopic inspection (optical and SEM – NTC 6031) – the component surface is inspected for visible defects, cracks, pits, or delamination that could be sources of particles. We report the observations and the extent of the defects.
• Corrosion and oxidation analysis (ASTM G46 / NTC 6032 – for metallic components) – for metal parts, we inspect for corrosion, pitting, or oxidation that could release metallic particles. We use SEM-EDS to analyze the corrosion products.
• Analysis of extractable organic compounds (NTC 6033 – FTIR and GC-MS of the extraction liquid) – in addition to particles, the extraction liquid may contain dissolved organic compounds (e.g., monomers, plasticizers, additives) that could affect the cleanliness. We analyze the liquid for organic content using FTIR and GC-MS. We report the presence and concentration of dissolved compounds.
• Material identification by FTIR and XRF (NTC 6034 – to confirm material composition) – we confirm the material composition of the component (e.g., polyamide, stainless steel, silicone) to correlate with the particle composition found in the extract. We report the material identification.

Test Report and Recognition in the Colombian Medical, Pharmaceutical, and Industrial Sectors

All procedures described are within the scope of our ISO/IEC 17025 accreditation, with equipment calibrated periodically (microbalances, particle counters, SEM, FTIR, etc.) and traceability to international standards (NIST, PTB). Our test reports are issued in Spanish and include:

• Full identification of the sample (component type, material, manufacturer, lot number, dimensions, and cleaning history).
• Detailed description of the test method applied (ISO/USP/NTC standards, extraction conditions, liquid, temperature, duration, and agitation).
• Numerical results: particle mass (mg or μg), particle count (particles/mL or per sample), particle size distribution (D10, D50, D90, or size ranges), ISO cleanliness code, IEST level, and pass/fail assessment.
• Graphical data: size distribution histograms, filter images (optical or SEM), and FTIR/EDS spectra.
• Comparative tables against the values specified by the client or against the limits of the ISO 10993-12, USP <788>, ISO 4406, NTC 6000, and the requirements of the INVIMA, SIC, and DIAN for medical devices, pharmaceuticals, and industrial components.
• Photographs of the filters and the particles collected, and SEM micrographs showing particle morphology.
• Recommendations for improving particle cleanliness (e.g., improving surface finish, changing the cleaning process, changing the material formulation, or implementing a filtering step during production).
• Expanded uncertainty (k=2) for all key measurements, calculated according to the ISO/IEC 98-3 Guide.

These reports are fully accepted by the Instituto Nacional de Vigilancia de Medicamentos y Alimentos (INVIMA) for the registration and certification of medical devices and pharmaceutical packaging, by the Superintendencia de Industria y Comercio (SIC) for product quality and safety compliance, and by the Dirección de Impuestos y Aduanas Nacionales (DIAN) for tariff classification and quality verification in the import of medical and industrial components. Additionally, we offer consulting services for the design of clean components, the selection of materials with low particle release, and the implementation of quality control programs to ensure cleanliness, contributing to the safety, reliability, and competitiveness of products in the diverse and demanding Colombian market, from the medical device manufacturing sector to the aerospace and hydraulic industries.