Hohenstein supports manufacturers in maintaining microbiological cleanliness for medical devices and their production environments. We verify compliance with ISO 11737, ISO 11607 and AAMI ST72 through testing that confirms the effectiveness of cleaning, sterilization and packaging processes. Our accredited methods provide verified data for product safety, process validation and regulatory submissions across global markets.
Bioburden testing quantifies the total viable microorganisms on a device before sterilization. Results establish the initial microbial load used to validate sterilization processes and monitor routine production control.
Hohenstein determines bioburden through standardized extraction and incubation methods following ISO 11737-1.
The bacterial endotoxin test (BET) or LAL test detects fever-inducing endotoxins from Gram-negative bacteria. It is critical for devices that contact blood or the cardiovascular system.
Testing is performed in line with AAMI ST72, ISO 11737-3 and Ph. Eur. 2.6.14 to demonstrate compliance with global pyrogen limits.
Surface residue analysis verifies the effectiveness of cleaning and processing steps. Using TOC (total organic carbon) and THC (total hydrocarbon) methods, we identify organic residues from lubricants, oils or cleaning agents.
We also perform particulate contamination testing to detect and quantify residual physical particles or fibers that may remain on device surfaces after processing.
These combined analyses provide a complete picture of surface cleanliness and help confirm that devices meet defined acceptance criteria.
Safe use and reuse of medical devices depend on validated cleaning, disinfection and sterilization procedures. Hohenstein supports manufacturers in verifying that these processes consistently achieve the required level of cleanliness and microbiological safety.
Our testing and documentation align with ISO 17664, DIN/TS 5343 and ISO 14971, ensuring global regulatory compliance while supporting FDA submissions.
Validation & Process Review
We review the manufacturer’s Instructions for Use (IFU) and perform cleaning validation according to ISO 17664-1 for critical and semi-critical devices or ISO 17664-2 for non-critical devices. Each validation includes:
Verification Testing
After processing, all acceptance criteria must be met. Hohenstein performs targeted analyses to confirm effectiveness, including:
Reusable Device Reprocessing & End-of-Life Simulation
We evaluate reprocessing procedures (the cleaning, disinfection and sterilization of reusable medical devices) to verify that they maintain safety and performance over time. We simulate repeated reprocessing cycles using standardized or customer-specific methods, such as thermal, chemothermal or chemical disinfection followed by steam sterilization.
These simulations assess device cleanliness, functionality and biocompatibility throughout the validated service life to ensure continued compliance and patient safety.
Residue Detection & Surface Cleanliness
Residue testing confirms that cleaning agents and process aids are effectively removed.
These analyses verify that surfaces meet cleanliness specifications and that no residues remain that could compromise safety or device function.
Sterile barrier systems must prevent microbial penetration throughout storage and handling.
Hohenstein tests porous packaging materials using ASTM F1608 to demonstrate microbial barrier performance as defined in ISO 11607-1.
Monitoring microbiological quality in production areas helps ensure consistent hygiene control and product safety. Hohenstein supports manufacturers with testing that complements routine hygiene monitoring in controlled manufacturing environments such as cleanrooms or preparation areas.
We evaluate the microbiological quality of air, surfaces and water to confirm that environmental controls remain within defined limits. These analyses support compliance with internal hygiene programs and applicable quality management standards.
