CR 14244:2001
(Main)Durability of wood and wood-based products - Recommendations for measurement of emissions to the environment from treated wood in service
Durability of wood and wood-based products - Recommendations for measurement of emissions to the environment from treated wood in service
This CEN Report is intended to stimulate discussion of the test parameters and the test methodologies to achieve a consensus of opinion. This should allow test methods for emissions from preservative treated wood to be prepared and tested before they become standards. The standards will allow competent authorities and manufacturers of wood preservatives to comply with the requirements of the Biocide Products Directive(BPD.)
Durability of wood and wood-based products - Recommendations for measurement of emissions to the environment from treated wood in service
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-januar-2004
Durability of wood and wood-based products - Recommendations for
measurement of emissions to the environment from treated wood in service
Durability of wood and wood-based products - Recommendations for measurement of
emissions to the environment from treated wood in service
Ta slovenski standard je istoveten z: CR 14244:2001
ICS:
71.100.50 .HPLNDOLMH]D]DãþLWROHVD Wood-protecting chemicals
79.020 Postopki v tehnologiji lesa Wood technology processes
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
CEN REPORT
CR 14244
RAPPORT CEN
CEN BERICHT
October 2001
ICS
English version
Durability of wood and wood-based products -
Recommendations for measurement of emissions to the
environment from treated wood in service
This CEN Report was approved by CEN on 6 July 2001. It has been drawn up by the Technical Committee CEN/TC 38.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2001 CEN All rights of exploitation in any form and by any means reserved Ref. No. CR 14244:2001 E
worldwide for CEN national Members.
Contents
Foreword.3
Introduction .4
1 Scope .5
2 Framework of cases for determination of needs for emission test methods.5
3 Review of methods of measurement of emissions from preservative treated wood .6
4 Characteristics of realistic emission test methods.11
Bibliography .14
Foreword
This document has been prepared by CEN /TC 38, "Durability of wood and wood-based products", the secretariat
of which is held by AFNOR.
The status of this document as CEN Report has been chosen because the most of its content is a review of
methods of measurement of emissions from preservative treated wood in order to stimulate the discussion of the
test parameters and the test methods for emissions to be retained.
Introduction
The regulatory control of biocides and biocidal products (as defined under the UE Directive 98/8/EC, including
wood preservatives, requires increasing amounts of environmentally related information on which to base
decisions.
In the case of wood preservatives (product type 8) this includes the provision of data concerning wood preservative
treated articles.
This data is used to assess whether there is an unacceptable environmental impact likely to arise from the use of
the treated timber product.
Such a risk assessment has to consider potential releases to all environmental compartments, namely air, soil,
surface water, groundwater and sediment.
Many uses of wood preservative products are intended to extend the natural durability based expectation of service
life, sometimes in the order of several decades.
It is therefore necessary to have a means of determining not only absolute values for potential emissions to the
environment but perhaps more importantly the fluxes, or rates of emission during the course of time. They should
be representative.
That is to say they should represent the emissions from in service sized pieces of treated wood.
Flux rates and profiles can then be inserted into mathematical models usually based on defined scenarios .
Such determinations of emission rates will also be invaluable in the development of new products because they will
enable the researcher to identify early in the development of the product whether there are potential problems with
the product in its areas of intended use.
It is quite impractical to mimic all of the biotic and abiotic factors present the natural environment in the laboratory.
It has to be decided if a means can be found which will take into account as many as possible of these factors
together with the large variation in climate and socio-economic factors present in Europe. Is it possible to conceive
of a “surrogate” environment into which to determine emissions?
If it is believed that there is a potential for creating EN standards in this area it is vital that the methods can be
reproduced in any suitably equipped laboratory, whether government, institute or industry. The methods should
also not be costly, but must be cost effective.
Having produced an emission this should then be characterised. This might be through chemical analysis of the
active substances, substances of concern and relevant metabolites; or by some other tests which can indicate
ecotoxicological effects, for example so-called “soup testing”. The next steps would be to identify the environment
‘belonging’ to the treated component and to characterise the physical-chemical behaviour of the active substances,
substances of concern and relevant metabolites in order give an answer about their bioavailability in a given
environment.
These aspects are being considered by other expert groups in the EU and the OECD and should not be considered
part of the remit for CEN/TC 38 to produce standards.
Any proposed standards should also take into consideration of the Technical Guidance Documents (currently being
revised) in place for the Biocidal products Directive (98/8/EC), and the New and Existing Substances Regulations
1 Scope
This CEN Report is intended to stimulate discussion of the test parameters and the test methodologies to achieve a
consensus of opinion. This should allow test methods for emissions from preservative treated wood to be prepared
and tested before they become standards. The standards will allow competent authorities and manufacturers of
wood preservatives to comply with the requirements of the Biocide Products Directive(BPD.)
2 Framework of cases for determination of needs for emission test methods
The following matrix has been established taking into account different documents and works (see [2] to [7]
included).
The aim is to try to link the different end-use categories for treated timber in service, with the Biological Hazard
Classes on one hand and the exposed environmental compartment on the other hand; through this, it is possible to
list the specific cases of emissions from treated timber to the environment (see Table 1).
Table 1 — Specific cases of emissions from treated timber to the environment
Targets Biological Use categories and Exposed Emission data needed First Exposed
Hazard typical scenarios Environmental Non targets
Classes Compartment
Insects HC 1 Internal non structural Indoor Air Emission to indoor Air Human
Bedroom floor
Insects + HC 2 Internal structural Indoor Air Emission to indoor Air Human Environment
Fungi Roofing timber Indoor air organisms
(Bats)
Insects + HC 3 External above ground and Soil by run-off rain Leaching by rain water Environment
Fungi above fresh-water water Soil organisms
Leachate migration into
House cladding Fresh water by run-off Fresh water organisms
soil /surface water
Fence rails rain water
Jetty planks
Insects +HC 4 External in ground contact Soil by run-off rain Leaching by rain water + Environment
Fungi Transmission Pole water Leachate migration into Soil organisms
a Fence post Soil by direct contact soil + Direct emission into
soil
External in freshwater Fresh water by run-off Leaching by rain water + Environment
contact rain water Direct emission into water Fresh water organisms
b Jetty in a lake Fresh water by direct Ground water
Poles contact
Sheet Pilings
Insects + HC 5 External in seawater Sea water by run-off Leaching by rain water + Environment
Fungi + contact rain water Direct emission into sea
Sea Water organisms
Marine water
Sea water by direct
borers
contact
There are two ways to approach the question of the need for emission data to feed in the exposure assessment
calculations in the different scenarios.
The first approach would be to consider globally the emission from the commodity to the environment without any
differentiation of all the mechanisms. This would mean to have one test method for each of the commodities listed
in the reference scenarios ; or, if it is possible to define a worst case scenario for each use category or a model
case, then one test method would be needed for each of the use categories where the conditions are strongly
different ; only may be the cases of HC 1 and HC 2 could be combined (emissions from wood to indoor air) , as well
as HC 4 b and HC 5 where the difference is only the kind of water. This approach looks rather difficult to handle in
a systematic way of producing emission data, as the list of tests needed might change if scenarios are revised.
The second approach would be to consider each possible mechanism of emission to obtain elementary emission
data, and then to combine these (sum up) to calculate the global emission of one commodity to a given
environmental compartment in a scenario.
In this second approach, the list of types of emission data needed is the following :
emission from treated wood to indoor air ;
leaching from treated wood by rain water ;
rain water leachate migration into soil/water ;
direct emission from wood into soil/ground water ;
direct emission from wood into water (fresh water or sea water).
3 Review of methods of measurement of emissions from preservative treated wood
3.1 General
Methods are required for the measurement of emissions from preservative treated wood in service. This document
reviews a number of methods which have been used to measure emissions from preservative treated wood under
laboratory conditions. These methods do not include tests using small specimens or sawdust, or for measuring
emissions from wood during drying after treatment.
The methods are for wood in service in biological HC 2 to HC 5, with exposure to the environmental compartments
of air, soil, ground water beneath soil, fresh water and sea water.
3.2 Air
It is possible that treated wood used in a building could affect air, indoor air, and treated wood outside buildings
could affect outdoor air. The Existing Substances Directive uses a value of 0,01 Pa as the vapour pressure
threshold. Below this vapour pressure a substance is not considered to be volatile and emissions to air are not
considered in the risk assessment. If the substance has a vapour pressure greater then 0,01 Pa, the substance is
considered sufficiently volatile to evaporate and produce a concentration in air. The effect of that concentration
should be considered in a risk assessment. The concentration is used in an equation which predicts deposition on
to surface water and the resulting concentration in the surface water (Predicted Environmental Concentration)
assessed for the risk to aquatic organisms by dividing the PEC by the PNEC (Predicted No Effect Concentration)
from an ecotoxicological test organism (e.g LD Daphnia).
If the PEC / PNEC ratio is greater than 1, there is a potential environmental risk and the tiered approach allows the
PEC to be measured, rather than calculated. As it is not possible to measure the concentration in surface water
which is solely emitted from treated wood, and the emissions from treated wood are likely to be affected by many
parameters, the actual emission from treated wood could be measured.
The ‘Metre cube box’ method has been used for the measurement of formaldehyde emission from wood. The
principle of the test is realistic in that treated wood could be placed in the chamber at a defined temperature and air
at a defined flow rate can be passed over it. Any volatile materials at the temperature of the test will evaporate and
pass out of the chamber. The air will then have to be tested for its environmental effects. If the active ingredient can
be analysed, then it will have to be extracted from the air and chemically analysed. The result can be converted to
an amount of active ingredient emitted in mg/m /day.
If the active ingredient cannot be analysed, or all of the substances emitted from the wood need to be assessed for
their environmental effect, and not just the active ingredient of the wood preservative, then the outlet air will have to
be used in a test which measures the environmental effect of air. It is probably outside the scope of CEN TC/38
Working Group 25 to suggest a suitable test. The OECD Biocides programme is considering methods of
ecotoxicological testing and are considering this issue.
Note that the vapour pressure of 0,01 Pa is the vapour pressure of the components in the dry wood and not of the
components in the treating solution. It is unlikely that any of the components of current wood preservatives used
indoors have components which have a vapour pressure in dry wood of greater than 0,01 Pa, so this test is unlikely
to be required in support of a wood preservative to comply with the data requirements of the BPD.
Meyer and Boehme (1997) (see |13]) determined formaldehyde emission from solid wood using a specially
designed chamber of 1 m . During testing, the temperature was (23 ± 1) °C and the relative humidity was
-1
(45 ± 5) %. The air exchange rate was fixed at 1 h . The chamber was loaded with four solid wood samples
measuring 500 mm by 250 mm by 20 mm, giving a total surface area capable of emission of 1 m (neglecting the
edges). Thus, the ratio of air exchange rate to loading was 1.
...
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