Overview - EN ISO 22612:2005 (Clothing for protection against infectious agents)
EN ISO 22612:2005 specifies a laboratory test method for resistance to dry microbial penetration of barrier materials used in protective clothing (e.g., surgical gowns, clean air suits). The standard evaluates the ability of bacteria‑carrying particles (the size range typical of human skin scales) to penetrate fabrics in the dry state. Because of its procedural complexity, EN ISO 22612:2005 is intended for conformity assessment and regulatory evaluation (for example in support of EU Directive 93/42/EEC) rather than routine quality control.
Key topics and technical requirements
- Test principle: Contaminated talc (carrying spores of Bacillus subtilis) is placed on the outside of a test specimen fixed over a stainless steel container; a sedimentation plate inside the container collects any talc or spores that penetrate. The assembly is vibrated to simulate mechanical stress; sedimentation plates are incubated and colonies counted.
- Challenge levels: The method defines two challenge concentrations and two vibration exposure times to provide differing degrees of stress on the barrier material.
- Critical parameters:
- Conditioning and test environment: (20 ± 2) °C and (65 ± 5) % relative humidity.
- Vibration: pneumatic ball vibrator operated at 20 800 vibrations per minute.
- Test specimen size and replication: 200 mm × 200 mm pieces; runs include contaminated samples and an uncontaminated control; results are repeated and averaged (arithmetic mean for valid results).
- Sample aliquot: a measured portion of contaminated talc (0.5 g ± 0.1 g) is used per test container.
- Microbiology: use of Bacillus subtilis spores on talc and recovery on TGE agar; plates incubated (35 °C, 24 h) and colony forming units (cfu) counted.
- Equipment: marble base plate, fixing plate, six stainless steel test containers with sedimentation plate slots, pneumatic vibrator, calibrated air flow meter, and Petri dishes with TGE agar.
- Reporting: material identity, test conditions, deviations, contaminant details and statistical result (geometric or arithmetic means as specified).
Applications and users
- Primary users:
- Manufacturers of medical and protective clothing assessing barrier performance for regulatory submissions.
- Accredited test laboratories performing conformity testing to demonstrate compliance with medical device / PPE directives.
- Regulatory and conformity assessment bodies evaluating claims for resistance to microbial penetration.
- Procurement specialists and R&D teams comparing fabrics and constructions for infection control.
- Practical use:
- Assessing gowns, coveralls, cleanroom suits and packaging where dry particle-borne bacteria are a penetration risk.
- Supporting declarations of conformity to EU Directive 93/42/EEC (medical devices) and relevant PPE directives.
Related standards
- EN 13795 (surgical drapes, gowns and clean air suits) - EN ISO 22612 is intended to be used in conjunction with EN 13795 series where specific product testing requirements are defined.
- Annexes in EN ISO 22612 reference relationships to EU Directives 93/42/EEC and 89/686/EEC for conformity assessment.
Keywords: EN ISO 22612:2005, resistance to dry microbial penetration, protective clothing testing, bacteria‑carrying particles, Bacillus subtilis, TGE agar, barrier materials, surgical gowns, clean air suits.
