ISO 4768

Testing of anti-biofilm activity on plastics and other non-porous surfaces in accordance with ISO 4768.

Overview

ISO 4768 describes a test method for assessing the anti-biofilm activity of treated plastics and other non-porous surfaces.

The method is particularly suitable for functionalised surfaces, coatings and material development where biofilm formation is to be investigated under defined conditions. It is intended as a screening method for material development.

The standard uses crystal violet staining followed by photometric absorbance measurements to quantify biofilm formation. An additional or alternative assessment based on recovered culturable microorganisms can be agreed as a project-specific adaptation.

The test design can be tailored to the study objective, sample type, sample dimensions, incubation conditions, test organism or required readout. Studies with conditions or readouts that differ from the standard are described as adapted tests based on ISO 4768.

Typical applications

Anti-biofilm surfaces

For surfaces treated to reduce biofilm formation, microbial attachment or biofilm-associated growth.

Non-porous materials

For plastics, coatings and comparable smooth, solid, non-porous surfaces.

Material development

For comparative studies, formulation optimisation and assessment of material or surface properties that inhibit biofilm formation.

Frequently asked questions

What does ISO 4768 assess?

ISO 4768 assesses the anti-biofilm activity of treated plastics and other non-porous surfaces. The focus is on limiting biofilm formation under defined test conditions.

How are ISO 4768 results assessed?

The standard quantifies biofilm formation using crystal violet staining and photometric absorbance measurements. Recovery and enumeration of culturable microorganisms, expressed as colony-forming units (CFU), can be included as an additional or alternative readout in an adapted study.

What is the difference between ISO 4768 and ISO 22196?

ISO 22196 assesses antibacterial activity on plastics and other non-porous surfaces. ISO 4768 assesses anti-biofilm activity. Recovery and enumeration procedures may be included in an adapted biofilm study where appropriate.

Can testing be adapted to customer-specific surfaces?

The suitability of adaptations is assessed for the material, surface, sample dimensions, incubation conditions, test organism and required readout. Tests described as being in accordance with ISO 4768 must meet its requirements; deviations are identified as part of an adapted study.