THE ENVIRONMENTAL RISK ASSESSMENT OF

BIOCIDES R E G U L AT O RY C H AL L E N G E S AN D

S C I E N T I F I C S O L U T I O N S

Revision of the OECD Emission Scenario Document for Wood Preservatives

Heike Schimmelpfennig SCC GmbH

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Outline

1. OECD Emission Scenario Document (ESD) for Wood Preservatives of 2003

2. Revision of the OECD ESD 2010/2011

3. The next steps…

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Developed by an OECD Expert Group based on a workshop; published by OECD in March 2003 (OECD Series on Emission Scenario Documents No. 2)

Intention: to provide a description of the wood preservative industry

Parts 1 – 4

Adopted at the 14th EU Competent Authority Meeting June 2003 Provides emission scenarios covering environmental compartments of (presumably) highest concern

Introduction to the ESD

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Life cycle steps: application (⇒ industrial/in-situ treatment scenarios)

service life (⇒ treated wood in service)

Application type: penetration / superficial treatment

User type: industrial / professional or amateur

Use classes: UC 1 to UC 5 (degree of exposure / receiving environmental compartment) Most common UC = UC 3

Time scale: day of application / initial and longer assessment period of “service life”

Scenarios provided in the ESD

Differentiation according to:

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…results in:

3 scenarios for industrial applications including storage of treated wood

9 scenarios for treated wood in service depending on UC

7 scenarios for in-situ treatment

3 scenarios for outdoor brushing by amateur and professional users

4 “niche scenarios” (in-situ indoor and outdoor treatments, covering partly also service life)

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Arona Leaching Workshop of 2005 (endorsed during the 19th CA Meeting in July 2005)

Assessment of leaching rates for wood preservatives derived from leaching tests

Default service lives for Time 2 (= longer assessment period)

23rd CA Meeting (in November 2006)

Calculation of the volume of receiving soil

Distance from treated object: formerly 10 cm (horizontal and vertical), now 50 cm

Relevant changes and amendments on EU level between 2003 and 2009

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Groundwater assessment for wood preservatives (endorsed during the 24th CA Meeting in March 2007)

Use of FOCUS scenarios requires adaptation of leaching rate

to an application rate on one hectare

UK holiday village: Number of houses per hectare = 35, reasonable worst case based on urban housing density in the UK

Relevant changes and amendments on EU level between 2003 and 2009 - continued

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1. OECD Emission Scenario Document (ESD) for

Wood Preservatives of 2003

2. Revision of the OECD ESD in 2010/2011

Timeline and scope of the EU project Major amendments (structure and default values) New and adapted scenarios and appendices

3. The next steps…

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Timeline of the EU project

Kick-off meeting in February 2010 Two Steering Group Meetings in 2010 and 2011

Steering Group consists of representatives of COM Competent Authorities Industry

End of project: April 2011

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Scope of the EU project

Revision of Part 1 and Part 2 of the existing OECD ESD of 2003

Task Description

A Evaluation of the application of the OECD ESD in the BPD review programme (focussing on e.g. agreed settings for default parameters and relevant emission scenarios not described in the ESD).

B Evaluation of the experience with the OECD ESD outside the EU.

C Evaluation of the EU-scenario “Exposure assessment for groundwater of wood preservatives” (not part of the OECD ESD of 2003).

D Development of missing scenarios identified under Task A and B.

E Revision of the OECD ESD taking into account the results of Task A to D.

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Major amendments in the structure

Only one document not four parts

Review and amendment of industry- and process descriptions

Chapters were streamlined and “purged” Chapter 1: Introduction Chapter 2: Overview of the wood preservative industry Chapter 3: Principles for env. exposure assessment for wood preservatives Chapter 4: Emission scenarios Appendices 1 to 11

Former Chapter 7 (removal processes in the receiving compartments) was moved to Chapter 3

Tiered approach: “most severe” scenarios to be calculated as first step (relevant on EU level)

Changes only relevant on EU level are specifically highlighted

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Major amendments in default values

Soil volume: calculated based on a 50 cm distance vertically and horizontally from treated object as decided in the 23rd CA meeting (relevant on EU level) Default values for TIME 2 for treated wood in service: as decided in the Arona Leaching Workshop in 2005 (relevant on EU level) Default value for pond volume: ratio bridge surface to water volume beneath: 1:100 instead of formerly 1:2

Groundwater assessment: 16 houses per hectare instead of 35.

In addition inclusion of Fwheaterside = fraction of house surface exposed to rain from which leaching occurs

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New and adapted (additional/niche) scenarios 1. In-situ application by spraying outdoors

2. Termite control scenario: pre-construction foundation- /

post-construction trench treatment

3. Railway sleepers scenario

4. Dock and deck/fence scenario

5. Window frames and exterior doors scenario (as Appendix)

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1. In-situ application by spraying (outdoors)

Based on the ESD for PT10 (house scenario, considering run-off and drift)

Adaptation of the receiving soil area for drift:

Tier 1: soil adjacent to house is uncovered during application – spray drift deposits in a 0.5 m wide band around the house Tier 2: soil adjacent to house is covered during application -

1/3 of the spray drift deposits on a 0.5 m wide band in 1 m distance around the house

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2. Termite control scenario

Revision of the existing scenario based on a proposal by one RMS and applicant; two applications are considered:

Pre-construction foundation treatment Post-construction trench treatment

Default values for (strip) foundation based on the “house” scenario:

Compartments considered for both treatments: soil and groundwater

Life stages considered: application and service live

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2. Termite control scenario – continued

Pre-construction foundation treatment

Phase 1: Treatment of bottom and walls of excavation Phase 2: Treatment of excavated soil Phase 3: Treatment of soil interface Phase 4: Treatment of perimeter

Post-construction trench treatment

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3. Railway sleepers scenario

Service life of industrially pre-treated wooden railway sleepers (UC3)

Soil beneath ballast is considered to be part of the technosphere, the receiving environmental compartment covered by the scenario is therefore groundwater

Two railway lines crossing a field of one hectare

Models under discussion for the exposure assessment: FOCUS -PEARL (including a dilution factor) or HARDspec

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4. Dock and deck/fence scenario

Niche scenario – currently used in the Canadian registration process covering treated wood in service (UC 3) Environmental compartment considered: surface water

(lake/pond of 1 ha surface and 8,000,000 L volume)

Dock: substances leaching from treated wood are directly released to surface water

Deck/fence: substances leaching from land based treated wood structures are indirectly released to surface water via run-off or drainage

Tier 1: 100% of the leached amount from decks and fences drains into the lake

Tier 2: estimation of the drainage by using PRZM/EXAMS models

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New and adapted Appendices

The dimensions relevant for the Termite Control scenario have been added to Appendix 3

Supplement to Appendix 4: (revised) EU-scenario for groundwater assessment

New Appendix 5: Fugacity model - level III proposed as additional Appendix for the exposure assessment of fumigants

New Appendix 6: Window frames and exterior doors scenario

Prepared by industry

Received after a decision taken during the TM in November 2010

The scenario was included as Appendix without further adaptation to the OECD format

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1. OECD Emission Scenario Document (ESD) for Wood Preservatives of 2003

2. Revision of the OECD ESD in 2010/2011

3. The next steps…

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The next steps…

First commenting took place on OECD level Comments and proposals for corrections have been received from four OECD member states and from industry Discussion of the current version of the revised ESD on OECD level in December 2011

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The next steps…

List of open points:

After finalisation of BREF document for wood preservatives, revision of the emission factors for industrial applications

is needed

Revision of unchanged Appendices/Chapters

Scenario for emission to soil from wood in horizontal orientation

Definition of TIME 2 for the storage place scenario

Adaptation of HARDspec for railway sleeper scenario

Definition of protection goal / scale of environmental compartment

Thank you for your kind attention.

heike.schimmelpfennig@scc-gmbh.de phone: +49 671-298 46-164 fax: +49 671-298 46-100 www.scc-gmbh.de

4th SETAC Europe Special Science Symposium Brussels, 25-26 October 2011