OECD Environmental Emission Scenarios: Wood Preservatives (PT 8) Hannu Braunschweiler Finnish Environment Institute (SYKE) EU course “Exposure scenarios in Risk Assessment of Wood Preservatives and Rodenticides” 9-10 October 2003, ECB, Ispra
Feb 24, 2016
OECD Environmental Emission Scenarios: Wood Preservatives (PT 8)
Hannu BraunschweilerFinnish Environment Institute (SYKE)
EU course “Exposure scenarios in Risk Assessmentof Wood Preservatives and Rodenticides”
9-10 October 2003, ECB, Ispra
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OECD Emission Scenario Document for Wood Preservatives Developed in the OECD Expert Group on the basis of a workshop,
published by OECD in March 2003• OECD Series on Emission Scenario Documents No. 2• Parts 1-4
Some of the scenarios have been tested in the EUBEES-2 project, primarily with regard to usability
Adopted at the 14th EU Competent Authority meeting June 2003:• “CAs recommend its use with the note that the ESD is a living document.”• “The ESD can be revised in the light of new knowledge, experience
gained in its application, and data from real measurements made by industry.”
The ESD is available also through http://ecb.jrc.it/biocides/
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Life-cycle of a wood preservativeProduction of a.s.
Formulation of B.P.
Private/professional use “in-situ”*
Product application (processing)*
Industrial preventive use*
Product application (processing)*
Service life of treated wood (“wood-in-service”)*
Waste treatment(*) Recovery
*) Life-cycle stage covered in the ESD
Potential environmental exposure from wood preservative applications
Emission scenario Soil Ground water
Waste water
Surface water
Air
Preventive applications (before wood-in-service, and professional and amateurs also "in-situ") Automated spraying or dipping, industrial sawmill + + + + + Industrial vacuum pressure + + + + + Double vacuum, industrial joinery + + + Manual or mechanised dipping (large scale joinery) + Dipping (small scale joinery) + + + + + Spraying or injection (indoors) + + Brushing (indoors), amateurs or professionals + Brushing (outdoors), amateurs or professionals + + + + Injection or wrapping (outdoors), professional + + + Termites prevention of foundation + + + + Curative applications (remedial, "in-situ") Spraying or injection (indoors) + + Brushing (indoors), amateurs or professionals + Brushing (outdoors), amateurs or professionals + + + + Fumigation, professional + Injection or wrapping (outdoors), professional + + + Termites prevention of foundation + + + +
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Detailed scenarios in the ESD Focus of the emission scenarios
• Estimation of local emissions to primary receiving environmental compartments and local environmental concentrations within them from:1) industrial preventive treatments2) treated wood in service3) in situ treatments (curative and preventive)
Two options for calculation of Clocal• without removal processes of the substance (Ch. 4-6)• with removal processes in the receiving compartment
(e.g. due to degradation, volatilisation, leaching to groundwater ) -> modified formulas in Chapter 7
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Time scales of the scenarios Local emissions and concentrations from treated
wood• Storage of industrially treated wood:
a) initial assessment = 30 days (TIME1)b) longer assessment period, > 30 days (TIME2)
• Treated wood-in-service:a) initial concentration; immediately after the last application
(e.g. at the end of the application day)b) 30 days; covers the initial leachingc) during the rest of the service life (> 30 days). Depending
on the characteristics of the active ingredients and the service life of treated commodities, time periods of several years of service life can be used
Structure of the ESDChapter 2 Overview of the treatment types and processes, different
wood preservatives and uses of treated wood
Chapter 3 Background and approaches behind the scenarios and calculations
Chapter 4 Three scenarios for emissions from industrial preventive applications
Chapter 5 Scenarios for emissions during the service life of industrially treated wood, summary of leaching test requirements
Chapter 6 Scenarios for emissions from preventive and curative in-situ treatments, by professionals and/or amateurs, cover treatments and wood-in-service
Chapter 7 Approach for emissions from treated wood as a function of time and taking into account removal processes of substance (e.g. leaching and degradation)
Appendixes General requirements for leaching tests, full description of wood-in-service scenarios, guidance for calculation of fluxes, description of some ground water calculation models, examples of emission calculations, glossary etc.
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Industrial preventive treatment
3 scenarios• Automated spraying processes• Dipping/immersion processes• Pressure processes
For all 3 scenarios, emissions take place during• Treatment process• Post-treatment conditioning• Storage of treated wood prior to shipment
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Preventive industrial processes: compartments of concernApplication/Scenario
Process(* Storage of treated wood(**
Air Waste water
Surface water
Soil Ground water
Surface water
Automated spraying
+ + (+) + + +
Immersion/ dipping
+ + (+) +(1 +(1 +(1
Pressure processes
+ + (+) +(1 +(1 +(1
(**No emissions to air and wastewater(1 Not relevant for joineries
(*No emissions to soil
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Preventive industrial processes/ storage of treated wood: assumptions Realistic worst-case:
• storage area is uncovered and unpaved• default values for the parameter AREAwood-treated and emission
factors (F)• default value for rainfall 3 rain events, 60 min each, every third
day, with a precipitation of 4 mm.h-1 => corresponds to 1460 mm.y-1; the leaching test should mimic this rainfall pattern
Storage begins after post-treatment conditioning Emissions are cumulative during the storage time and also
from the application phases Degradation processes should be taken into account
Storage of treated wood: General equations
Emission during application
Leaching during storage
Concentration in soil
Emission to surface water
FAREAQElocal treatedwoodai
TIMEAREAAREAFLUXQ storageowoodstoragetimestorageleach exp,,
)1(,,runoff
soil
timestorageleachsoil F
MQ
Clocal
runofftimestorageleach
ersurfacewat FTIME
QElocal ,,
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Storage of treated wood scenario: example of input values and outputInput data *Qai = 15 g/m2
#AREAwood-treated = 2000 m2/d #F = 0.03 *$FLUXstorage = 128 mg/m2/d #AREAwood-expo = 11 m2/m2
#AREA storage = 79 m2
#TIME1 = 30 d #Msoil = 13430 kg ww #F runoff = 0.5
Results Elocal = 0.9 kg/d Qleach,storage,time = 3.34 kg
Clocalsoil = 124 mg/kg ww
Elocalsurfacewater = 0.056 kg/d
* Value to be set # Default value
$ This is the leaching rate
Emission Scenario for automated spraying
No 1: Emission Scenario for anti-sapstain application in automatic spraying (sawmill)
Facility drain
WWTPinfluent
effluent
Run-o
ff
Mix Tank
Spray Box
Drip padwood wood
Stored timber
Rain
recycling
Air driftGenerally roofed
Surface water
estuary
soil
Ground water
Air deposition
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Automated spraying scenario: assumptions Realistic worst-case:
• emissions to air occur directly due to spray drift / evaporation from the spray box and from the treated wood after it
• cemented floors, run-off recycled; unintentional spills, floor & equipment cleaning, washing waters etc. go to facility drain => to the sewage treatment plant
• default emission factors (F) depend on water solubility and vapour pressure (given as pick-lists)
All industrial spraying applications covered, 2 plant sizes Emission to surface water only via dry deposition; not yet quantified Emissions are cumulative from the application phases and also
during the storage time
Automated spraying scenario
Parameter/ variable Symbol Unit DefaultsInput:Wood area treated per day AREAwood-treated m2.d-1 2.000 or
20.000Application rate: quantity of a.i.applied per m2 of wood area
Qai kg.m-2 Dossier
Fraction released to facility drain Ffacilitydrain - from pick-list
Fraction released to air Fair - from pick-list
Fraction of spray drift deposition Fdrift - 0.001
Output:Local emission rate to air Elocalair kg.d-1
Local emission rate to facility drain Elocalfacilitydrain kg.d-1
)( driftairaitreatedwoodair FFQAREAElocal
ainfacilitydraitreatedwoodainfacilitydr FQAREAElocal
Emission Scenario for automated dipping
Facility drain
WWTP influent
effluent
soil Dip Tank
Drip pad wood wood
Rain
recycling
Air
( mostly no roof )
Surface water
Ground water
Run- off
Stored timber
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Automated dipping scenario: assumptions and calculations All industrial and professional dipping / immersion
applications covered: sawmills and joinery / carpentry Assumptions and calculations are much the same as for the
spraying scenario; the differences are:• no spray drift to air: emissions to air occur due to evaporation
from the dipping bath, co-distillation with solvent and from saw dust / dried salts
• calculations based on volume of treated wood (100 m3.d-1) instead of area; conversion formulas provided
No direct emission to surface water from the process, only from storage
Emission Scenario for industrial pressure processes
Facility drain
WWTPinfluent
effluent
Mix Tank
Pressur Vessel Drip padwood wood
Rain
recycling
Air
roof
Surface water
soil
Ground water
Run-
off
(*)
(*) relevantfor oil and organicnot relevantfor salt products
Stored timber
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Industrial pressure processes scenario: assumptions and calculations All industrial pressure applications covered with 2 plant volumes
• vacuum pressure: wood volume treated per day 30 m3.d-1 • double-vacuum & low pressure: daily wood volume 15 m3.d-1
Assumptions and calculations are much the same as for the spraying scenario; the differences are:• no spray drift to air: emissions to air occur due e.g. releases at
cease of vacuum, evaporation losses, aerosol air drifts and from saw dust / dried salts
• calculations based on volume of treated wood (see above) instead of area
No direct emission to surface water from the process
Use classes of treated wood, the emission scenarios & relevant compartments
( )
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Scenarios for treated wood in service 4 relevant use classes with 10 detailed scenarios
• UC3 Wood not covered and not in contact with soil: 4 scenarios• UC4a Wood in contact with soil: 2 scenarios• UC4b Wood in contact with fresh water: 2 scenarios• UC5 Wood in contact with salt water: 1 scenario
House scenario represents a worst case compared to the fence and noise barrier because of the highest wood to soil ratio• Recommended to use the house scenario preferentially
• Use the fence scenario as a further option• Noise barrier scenario resembles the fence but includes a emission
route to a sewage treatment plant (70% of emission)
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General assumptions in thewood-in-service scenarios All scenarios require that leaching rate (FLUX [kg/m2/d]) be
established, e.g. from leaching tests Cumulative amount leached over certain time (Q*
leach,time [kg/m2]) is estimated from FLUX
General equations used for emissions during storage apply also for the scenarios of treated wood-in-service
Default values given for leachable treated wood area and volumes of receiving compartments
The primary receiving environmental compartment is considered to be soil or water (including STP)
Emissions to the air are considered negligible from environmental point of view
Use class 3: Emission Scenario for Timber Cladded House (with receiving soil compartment)
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Timber Cladded House: assumptions The primary receiving environmental compartment is considered
to be soil via rain run-off Leaching rates to be used should be from a test with wood in
direct contact with water• Summary of test requirements is in Section 5.3.2.1 and
requirements for the design of such a leaching test is given in Appendix 1
Emissions are cumulative over the assessment period, therefore Clocal represents the concentration at the end of the assessment time period
Emitted quantity calculated may be fed into groundwater models
Timber Cladded House scenario
Parameter/ variable Symbol Unit DefaultsInput:Leachable wood area AREAhouse m2 125
Duration of assessment period TIME1, TIME2 d 1: 302: to be set
Cumulative quantity of a.i. leached out of 1 m2 of treated wood over the assessment period
Q*leach,time kg.m-2 Dossier
Wet soil volume Vsoil m3 0.50
Bulk density of wet soil Fair kgwwt.m3 1700
Output:Cumulative quantity of a.i. leached over the assessment period
Qleach,time kg
Concentration in local soil at the end of assessment period
Clocalsoil,leach,time kg.kgwwt-1
*,, timeleachhousetimeleach QAREAQ
soil
timeleachtimeleachsoil M
QClocal ,
,, soilsoil RHOV
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Timber Cladded House: example of input values and results
Results Qleach,time1 = 0.13 kg (over 30 d)
Clocalsoil,leach,time1 = 591 mg/kgww (D = 0.025 m)
Clocalsoil,leach,time1 = 147 mg/kgww (D = 0.1 m)
Clocalsoil,leach,time1 = 28 mg/kgww (D = 0.5 m)
Input data AREAhouse = 125 m2
Soil “width” = 0.1 m (default) Soil depth = 0.1 m (default) Msoil = 850 kgww
TIME1 = 30 d Q*
leach,time1 = 1006 mg/m2
Use class 3: Emission Scenario for noise barrier (with receiving environmental compartments)
Use class 3: Emission Scenario for garden fence (with receiving soil compartment)
Use class 4a: Emission Scenario for Transmission Pole (with receiving soil compartment)
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Transmission Pole scenario: assumptions and calculations Recommended to use the transmission pole scenario preferentially
• Use the fence post scenario as a further option if e.g. required due to preservative type
The primary receiving environmental compartment is soil which has cumulative emissions from:• rain run-off from above soil part of the pole• permanent contact with the soil water phase for below ground part
Assumptions and calculations are much the same as for the cladded house scenario; main differences are:• separate above and below soil wood areas (5.5 and 1.6 m2)
• leaching rates to be used should be from a test with wood in direct contact with water or in contact with soil (for below ground part only)
Use class 4a: Emission Scenario for fence post (with receiving soil compartment)
Use class 4b: Emission Scenario for Jetty in Lake (with receiving water compartment)
Jetty : 1.5 m wide, 8 m long.
Posts : 8, 2 m long, 20 cm diameter, 1 m in water.
Planks : 2.5 cm thick.
Supports : 5 cm thick, 20 cm wide
Primary EnvironmentalCompartment for Emissions
Fresh water : Lake 100 m diameter, 2m deep= 1.6 x107 litres
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Jetty in Lake scenario: assumptions For Use Class 4b, two scenarios available: jetty in a lake and a sheet piling in a
small stream or waterway• The jetty scenario is a worst case with respect to the higher wood surface area • The sheet pilings scenario represents a worst case because of the wood being
exposed mainly under water The primary receiving environmental compartment is a circular pond which has
cumulative emissions from:• planks exposed to rain (usually treated for Use Class 3)• poles all in permanent contact with water (treated for Use Class 4b)
Leaching rates to be used should be from a test with wood in direct contact with water
General assumptions similar to the house scenario
Jetty in Lake scenario
Parameter/ variable Symbol Unit DefaultsInput:Leachable wood area: planks or poles AREAplanks
AREApoles
m2 16.210.0
Duration of assessment period TIME1, TIME2 d 1: 302: to be set
Cumulative quantity of a.i. leached out of 1 m2 of treated wood over the assessment period
Q*leach,time kg.m-2 Dossier
Water volume Vwater m3 1.6*104
Output:Cumulative quantity of a.i. leached over the assessment period
Qleach,time kg
Concentration in local surface water at the end of assessment period
Clocalwater,leach,time kg.m-3
*,, )( timeleachpolesplankstimeleach QAREAAREAQ
soil
timeleachtimeleachsoil M
QClocal ,
,, waterV
timeleachwater ,,
Use class 4b: Emission Scenario for sheet pilings in a small streaming waterway
• There are 5 poles on both sides per meter waterway length.• The waterway is 1 km long, 1.5 m deep and 5 m wide, with the residence time of 20 days.
Use class 5Emission Scenario for Harbour Wharf
• The wharf is 100 m long with walling and kerbing extending the full length.• The walling is doubled at the front and back of the fender piling. • Piles with associated rubbing strips are spaced at 5 m intervals.• The receiving compartment is the seawater at up to 5 m distance from the wharf.
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Wharf scenario: assumptions The primary receiving environmental compartment is salt
water in an intermediate-sized wharf Seawater has cumulative emissions from:
• planks exposed to rain (usually treated for Use Class 3)• poles all in permanent contact with seawater (treated for Use
Class 5) The contact time of wood with the water and therefore the
concentration is determined by the water residence time Leaching rates to be used should from a test with wood in
direct contact with seawater (submerged poles) and with de-ionised water (planks above water)
Wharf scenario
Parameter/ variable Symbol Unit DefaultsInput:Leachable wood area: planks or poles AREAplanks
AREApoles
m2 296911
Duration of assessment period TIME1, TIME2 d 1: 302: to be set
Cumulative quantity of a.i. leached out of 1 m2 of treated wood over the assessment period
Q*leach,time kg.m-2 Dossier: separate value
for poles and planks
Water volume along wharf Vwater m3 1000
Residence time of the seawater TAUseawater d 0.5
Output:Cumulative quantity of a.i. leached over the assessment period
Qleach,time kg
Concentration in local seawater at the end of assessment period
Clocalseawater,leach,time kg.m-3
seawatertimeleach
polestimeleach
plankstimeleach TAUTIME
QAREA
TIMEQ
AREAQ
**,
*,
,
soil
timeleachtimeleachsoil M
QClocal ,
,, waterV
timeleachseawater ,,
Potential exposure of environmental compartments from professional and amateur in-situ treatments
Chapter 6
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Accounting for removal processes in water and soil Removal processes in the receiving compartment are
degradation, volatilisation, leaching to groundwater (for soil) or sedimentation (in surface water)
In a first tier estimation these can be ignored (Ch. 4-6) For a second tier the removal processes can be estimated
e.g. according to TGD and taken into account in the estimation of the concentrations in water or soil• Guidance on how to calculate emissions from treated wood as
a function of time and taking into account removal processes of the substance is given in Chapter 7
• The longer time span proposed: 1 year or longer (up to 10 yr)
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General remarks on the ESD Guidance given on appropriate leaching tests for treated wood and
especially how to use different kind of leaching test results Some guidance given for calculation of the emissions from treated
wood that may reach groundwater in soil• Applicability of PEARL and PELMO groundwater models discussed: regarding
scenarios for treated wood-in-service and storage In the scenario description Tables, the input and output data are
divided into three groups:• A: “data Set” data to be supplied by the notifier; no default value is set. Note:
Symbol “S” used for this group in the EU ESDs & spreadsheets• D “Default” parameter has a standard value (most defaults can be
changed by the user);• O “Output” parameter is the output from a calculation (most output
parameters can be overwritten by the user with alternative data);
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Conclusions on the OECD ESD ESD covers use scenarios and environmental compartments of
(presumed) highest concern Based on empirical data & default values but has not been
validated; only the applicability of the equations has been tested Can be used when no other overriding data are available (c.f.
TGD) Specific data on use pattern and emission rate should be used by
applicants whenever possible Results from emission estimates should feed into exposure
assessment in accordance with the Technical Guidance Document on risk assessment• combined with some generic emission estimates according to the TGD
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Revised TGD: relevant exposure assessment issues More complete life cycle assessment Release estimation
• emissions from long-life articles• emissions from waste disposal including
recovery Unintentional uses: calculation of
background concentrations
ARTICLEUSE
CHEMICALUSE
PRODUCTION
FORMULATION
PRIVATE USE(article production)
INDUSTRIAL USE(article production)
ARTICLES
WASTE DISPOSAL- Incineration- Landfilling- Recovery
<< PROCESSING >>
SERVICE LIFE
ARTICLES
Waste remaining in the environment
CHEMICAL PRODUCTIONINTERMEDIATES- non-isolated intermediates- isolated intermediates stored on-site- isolated intermediates with controlled transport
Waste remaining in the
environment
Urban soil
Service life > 1 year EXAMPLE: Chemical X as an additive to a material in shoe
sole.
Accumulation of long-life articles in the society
Steady state at year 2004 Service life of the shoe = 5 year
tonnes / year
1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009year
Introduced to the market
= Annual input of X from production = Remaining amount of X in the society year 2,3,4,5 (corrected for reduction due to emission)
annual flow of substance X in molecular form
jgf
Emissions from long life articles
L O C A L S C A L E
URBAN /IND. SOIL
SURFACEWATER
AIR
Incinerationsites
Landfills
C O N T I N E N T A L / R E G I O N A L S C A L E
“Service life”
Accumulated amount of substance X in the society
a b
STP
Annual input from: - “production”- “formulation”- “industrial / professional use”
dc
Explanation of symbols: annual flow of substance X in form of articles / materials
e
i
h
k
Acc. amount of X in “Waste remaining in the environ."
Emission at Steady state when “input” = “output”
…for society: a = [b + c + d + e + f + g + h]…for “waste remaining in the environment”: h = [i + j + k]
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Emissions scenario for long-life articles
Calculations of diffuse emissions at regional / continental scale
1) Estimate service life2) Estimate emission factors (F)3) Calculate accumulation 4) Calculate annual release
F < 1%/year simplification
Local scale: for the municipal STP• Indoor emissions• Outdoor emissions via storm water
(IC 5, Personal/Domestic)
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Emission equations
kTservice
y
yi,totalkk FQtotte_steadystaQtot_accum
1
1)1(
Simplification when the emission factor is low (<1 %/year):
Qtot-accum_steady statek = Qtotk * Tservice
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“Unintentional sources” / Cumulative effects (TGD, Part II, App. XIII) The rapporteur should list other sources which can give rise to
exposure by the substance being assessed• Evaluation report should include available information on these
sources: other PTs, non-biocidal uses For biocides, only sources which include substances of natural
origin or releases from other biocidal uses should be taken into account as “cumulative effects” in the risk assessment
Cumulative effects are to be taken into account in the PECregional which provides the background concentration to be incorporated in the PEClocal• PECregional to be calculated with EUSES using generic
assumptions