### O VERVIEW OF THE OECD HARMONIZATION EFFORTS Michele E. Wingfield, Senior Science Advisor Antimicrobials Division UDM/OECD Workshop November 16, 2011 1

### TOPICS

 Background and Milestones

 Role of the Validation Management Group

 Report on OECD Meeting in Paris

 Key Features of the Method

 Results of the Ring Trials

 Test Guidelines and Guidance Documents

 Changes Due to Comments Received

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### BACKGROUND AND MILESTONES

 1998

– The Taskforce on Biocides surveyed OECD member countries on approaches to regulating biocides. A great deal of interest was expressed in harmonizing efficacy test methods.

 2002

– EPA hosts OECD Workshop

 2003/2004

– Call for tender issued by the European commission

 2006

– Validation Management Group (VMG) established.

 2007/2008

– Ring

- trial designed and executed.

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### BACKGROUND AND MILESTONES

 2008

– Meeting of the VMG to discuss the validation report.

 2009

- TFB agrees to progress the methods to the Working Group of the National Coordinators of the Test Guideline Program (WNT).

 2010/2011

– Two commenting rounds completed on the 4 draft Test Guidelines and the Guidance Document.

 2011

– Test Guidelines and Guidance Document fail to gain approval at the WNT meeting

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### OECD MEETING OF EXPERTS AND REGULATORS

 Held in Paris, France on September 13 & 14, 2011.

 Objectives: to discuss and resolve issues raised at the April 2011 WNT Meeting.

 Major Issues

 Reference standards and proficiency testing

 Applicability to other product types

 Compliance with MAD

 Purpose of the Guidance Document

 Contact time

 Neutralization assay

 Performance Standards 5

### OECD MEETING OF EXPERTS AND REGULATORS

 Presentations given by Dr. Syed Sattar, Mrs. Rhonda Jones and Dr. Stephen Tomasino, on background of the method; concerns raised by ADBAC/DDAC Consortia; and, BEAD collaborative study, respectively.

 Issues resolved: reference standard and proficiency testing, other product types, compliance with MAD, guidance document, contact time, neutralization assay and contact time.

 Unresolved issues: Performance standards

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### OECD MEETING OF EXPERTS AND REGULATORS

 Other issues addressed.

 Carrier quality

 Pseudomonas aeruginosa growth medium

 Reproducibility issues with the inoculum

 Impact of method on concentrates vs. ready

- to use products

 Pre

- collaborative studies

 BEAD collaborative studies and timeline

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### KEY FEATURES OF THE METHOD

 Test design is fully quantitative and “closed” to avoid wash

- off of viable microorganisms.

 Brushed stainless steel disks as the carrier. Simulates surfaces in healthcare settings.

 Default diluent

– 375 ppm hard water.

 5 minute contact time to reflect the realities of field applications.

 Sets 20 2oC as default air temperature.  Includes a standard soil load.

 5% mixture of high molecular weight protein, low molecular weight protein and mucin

 Uses surrogates for all classes of microorganisms

– Hierarchy Approach

 Log reduction measure of performance.

 Promotes data sharing, review sharing, rapid response to pandemics

 Readily amenable to modification 8

## RESULTS OF THE RING

- TRIAL

 27 Laboratories participated in the ring

- trial.

 Test Organisms

 Bacteria

 Pseudomonas aeruginosa
, Staphylococcus aureus
, Enterococcus hirae
 Virus

 Adenovirus
 Mycobacteria

 Mycobacterium terrae
 Fungus

 Aspergillus niger

 Bacterial Spore

 Bacillus subtilis
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## RESULTS OF THE RING

- TRIAL PHASE 1

 Very much learning by doing

 Initiated without training

 Perhaps overly ambitious in number of compounds and organisms

 Positive outcome but high variability

 Drove design of Phase 2

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## RESULTS OF RING

- TRIAL PHASE 2

 

## Improved technical clarity for technicians, changes flowed through to all 5 tests

 

## Inter

- lab variability on par with Phase 1

 

## Intra

- lab variability was lower in Phase 2

 

## Variability decreased with experience

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### C ONTENT OF 

### G UIDANCE 

### D OCUMENT

 Background for Test Guideline development and validation

 Discussion of other product types

 Non

- foaming aerosols, pump sprays, foams and towelettes

 Study Design

 Carriers, soil load, diluent, contact time, concentration and additional microorganisms

 Number of test runs and test days

 Performance standards

 Test Reports

 Proficiency Testing 12

### CHANGES MADE DUE TO COMMENTS RECEIVED

 Annexes

– Have been put in order according to the use in the Test Guideline

– this is to make them more user friendly.
 Defined terms made more consistent throughout the methods (i.e. test organism, working culture)
 Clarified carrier count range to align with performance criteria for log reduction (must be at least 0.5

- 1.5 log higher than performance standard for log reduction)
 Added language to check desiccator system if drying takes longer than 60 minutes
 Added terms to the Material and Equipment sections for each Test Guideline
 Reference to Guidance Document added to the Test Guidelines
 Revised neutralization confirmation assay 13

### GUIDELINE VS. GUIDANCE DOCUMENT

 Test Guidelines are subject to the Mutual Acceptability of Data (MAD)rules.

 Meaning, data generated with an OECD Test Guideline, must be accepted by an OECD member country.

 Guidance documents are not subject to MAD.

 Guidance documents can be used by member countries to develop their own guidelines.

 If the Test Guidelines are not approved, they may become Guidance Documents.

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### GUIDELINES VS. GUIDANCE DOCUMENTS

 Major impact if Test Guidelines are not approved.

 Loss of harmonization

 No one test, one time for the world

 Loss of time conducting 27 laboratory ring

- trial

 Option if Test Guidelines are not approved

– AOAC method

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### QUESTIONS ?

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