ENV 839:2002
(Main)Wood preservatives - Determination of the protective effectiveness against wood destroying basidiomycetes - Application by surface treatment
Wood preservatives - Determination of the protective effectiveness against wood destroying basidiomycetes - Application by surface treatment
This European Prestandard specifies a method of test for determining the protective effectiveness of a wood preservative, applied to the surface of the wood, against wood destroying basidiomycetes cultured on an agar medium.
The method is applicable to all products which are to be applied by superficial application processes. This includes :
organic solvent-based wood preservatives ; or
organic water-dispersible formulations, as supplied or as prepared in the laboratory by dilution of concentrates ; or
water-soluble products ; or
chemicals which are being studied as active ingredients for application by superficial processes.
NOTE This method may be used in conjunction with an ageing procedure, for example EN 73.
Holzschutzmittel - Bestimmung der vorbeugenden Wirksamkeit gegen holzzerstörende Basidiomyceten - Anwendung mit Oberflächenverfahren
Produits de préservation du bois - Détermination de l'efficacité protectrice vis-à-vis des champignons basidiomycètes lignivores - Application par traitement de surface
La présente Prénorme européenne spécifie une méthode de détermination de l'efficacité protectrice d'un produit de préservation du bois, appliqué par un traitement de surface, vis-à-vis des champignons basidiomycètes lignivores cultivés sur milieu gélosé.
La présente méthode est applicable à tous produits qui sont appliqués par des procédés de traitement de surface. Cela comprend :
les produits de préservation du bois solubles dans les solvants organiques ; ou
des formules organiques hydrodispersables telles qu'elles sont livrées ou obtenues en laboratoire à partir de concentrés ; ou
des produits hydrosolubles ; ou
des produits chimiques étudiés en tant que matières actives pour l'application par des procédés de traitement de surface.
NOTE Cette méthode peut être utilisée conjointement à une épreuve de vieillissement par exemple EN 73.
Wood preservatives - Determination of the protective effectiveness against wood destroying basidiomycetes - Application by surface treatment
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST-TS ENV 839:2004
01-januar-2004
Wood preservatives - Determination of the protective effectiveness against wood
destroying basidiomycetes - Application by surface treatment
Wood preservatives - Determination of the protective effectiveness against wood
destroying basidiomycetes - Application by surface treatment
Holzschutzmittel - Bestimmung der vorbeugenden Wirksamkeit gegen holzzerstörende
Basidiomyceten - Anwendung mit Oberflächenverfahren
Produits de préservation du bois - Détermination de l'efficacité protectrice vis-a-vis des
champignons basidiomycetes lignivores - Application par traitement de surface
Ta slovenski standard je istoveten z: ENV 839:2002
ICS:
71.100.50 .HPLNDOLMH]D]DãþLWROHVD Wood-protecting chemicals
SIST-TS ENV 839:2004 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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EUROPEAN PRESTANDARD
ENV 839
PRÉNORME EUROPÉENNE
EUROPÄISCHE VORNORM
March 2002
ICS 71.100.50 Supersedes ENV 839:1993
English version
Wood preservatives - Determination of the protective
effectiveness against wood destroying basidiomycetes -
Application by surface treatment
Produits de préservation du bois - Détermination de Holzschutzmittel - Bestimmung der vorbeugenden
l'efficacité protectrice vis-à-vis des champignons Wirksamkeit gegen holzzerstörende Basidiomyceten -
basidiomycètes lignivores - Application par traitement de Anwendung mit Oberflächenverfahren
surface
This European Prestandard (ENV) was approved by CEN on 23 December 2001 as a prospective standard for provisional application.
The period of validity of this ENV is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the ENV can be converted into a European Standard.
CEN members are required to announce the existence of this ENV in the same way as for an EN and to make the ENV available promptly
at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the ENV) until the final
decision about the possible conversion of the ENV into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Malta, 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
© 2002 CEN All rights of exploitation in any form and by any means reserved Ref. No. ENV 839:2002 E
worldwide for CEN national Members.
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ENV 839:2002 (E)
Contents
page
Foreword.3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions.5
4 Principle.5
5 Test materials and apparatus .6
5.1 Biological material .6
5.2 Products and reagents.7
5.3 Apparatus .7
6 Sampling of the preservative.8
7 Test specimens .8
7.1 Species of wood.8
7.2 Wood quality.8
7.3 Provision of the test specimens.8
7.4 Dimensions and density of specimens .9
7.5 Number and distribution of test specimens.9
8 Procedure .9
8.1 Preparation of the untreated test specimens.9
8.2 Preparation of the treated test specimens .10
8.3 Exposure to fungi .10
8.4 Culture conditions and duration of test .11
8.5 Assessment of test .11
9 Statement of results .12
10 Test report .12
Annex A (informative) Test fungi .14
Annex B (normative) Methods of sterilization.16
Annex C (informative) Example of a test report.18
Bibliography .21
2
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ENV 839:2002 (E)
Foreword
This document ENV 839:2002 has been prepared by Technical Committee CEN/TC 38 "Durability of wood and
derived materials", the secretariat of which is held by AFNOR.
This document supersedes ENV 839:1993.
This standard includes annexes A and C that are informative and an annex B that is normative.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this European Prestandard: Austria, Belgium, Czech Republic, Denmark, Finland,
France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain,
Sweden, Switzerland and the United Kingdom.
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ENV 839:2002 (E)
Introduction
This European Prestandard specifies a laboratory method of test which gives a basis for assessing the
effectiveness of a wood preservative, when applied as a surface treatment, against wood destroying
basidiomycetes. It tests whether the applied treatment is able to prevent the penetration of the fungi into the
untreated interior of the test specimens under the conditions of test.
This laboratory method provides one criterion by which the value of a product can be assessed. In making this
assessment, the methods by which the preservative may be applied should be taken into account. It is also
recommended that this information be supplemented by data from other relevant tests and above all by practical
experience.
The procedures described in this standard method are intended to be carried out by suitably trained and/or
supervised specialists.
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ENV 839:2002 (E)
1 Scope
This European Prestandard specifies a method of test for determining the protective effectiveness of a wood
preservative, applied to the surface of the wood, against wood destroying basidiomycetes cultured on an agar
medium.
The method is applicable to all products which are to be applied by superficial application processes. This
includes :
organic solvent-based wood preservatives ; or
organic water-dispersible formulations, as supplied or as prepared in the laboratory by dilution of concentrates ; or
water-soluble products ; or
chemicals which are being studied as active ingredients for application by superficial processes.
NOTE This method may be used in conjunction with an ageing procedure, for example EN 73.
2 Normative references
This European Prestandard incorporates by dated or undated reference, provisions from other publications. These
normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For
dated references, subsequent amendments to or revisions of any of these publications apply to this European
Prestandard only when incorporated in it by amendment or revision. For undated references the latest edition of the
publication referred to applies (including amendments).
EN ISO 3696, Water for analytical laboratory use - Specification and test methods (ISO 3696:1987).
3 Terms and definitions
For the purposes of this European Prestandard, the following terms and definitions apply.
3.1
superficial application process
process which does not include particular features or procedures intended to overcome the natural resistance of
wood to penetration by a wood preservative product in its ready to use form
3.2
representative sample
sample having its physical or chemical characteristics identical to the volumetric average characteristics of the total
volume being sampled
3.3
supplier
sponsor of the test
4 Principle
Several series of test specimens of a susceptible wood species are end-sealed with a material to prevent
penetration of the test product into the end grain of the specimens. The end-sealed specimens are treated with the
wood preservative product under test using the process and application rate specified by the supplier.
NOTE Suitable application methods are brushing, pipetting and dipping.
5
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ENV 839:2002 (E)
The treated test specimens are exposed to attack by basidiomycetes in pure culture. The performance of the test
product is assessed in terms of its ability to prevent visible decay and its ability to prevent colonization of the
untreated interior of the test specimens.
5 Test materials and apparatus
5.1 Biological material
The test fungi to be used are as follows :
5.1.1 Obligatory fungus in all cases
Coniophora puteana (Schumacher ex Fries) Karsten (BAM Ebw. 15) on softwood.
Loss in mass of Scots pine sapwood in 16 weeks: a mass fraction of minimum 20 %.
5.1.2 Obligatory fungus for particular hazards
Coriolus versicolor (Linnaeus) Quélet (CTB 863A) on hardwood and/or on softwood as appropriate.
Loss in mass of beech in 16 weeks: a mass fraction of minimum 20 %.
Loss in mass of Scots pine sapwood in 16 weeks: a mass fraction of minimum 15 %.
5.1.3 Two species to be used compulsorily on the basis of the nature of the test product
For all products except creosote-type products :
Poria placenta (Fries) Cooke sensu J. Eriksson (FPRL 280) on softwood.
Loss in mass of Scots pine sapwood in 16 weeks: a mass fraction of minimum 20 %;
Gloeophyllum trabeum (Persoon ex Fries) Murrill (BAM Ebw. 109) on softwood.
Loss in mass of Scots pine sapwood in 16 weeks: a mass fraction of minimum 20 %.
For creosotes and similar products :
Lentinus lepideus Fries ex Fries (BAM Ebw. 20) on softwood.
Loss in mass of Scots pine sapwood in 16 weeks: a mass fraction of minimum 20 %;
Lentinus cyathiformis (Schaeffer ex Fries) Bresadola (CTB 67-02B) on hardwood.
Loss in mass of beech in 16 weeks: a mass fraction of minimum 20 %.
5.1.4 Optional fungi
For specific regional uses or conditions, it is also possible to select other fungi on an optional basis.
NOTE When optional fungi are used, information similar to that given in annex A for the obligatory fungi should be included
in the test report.
5.1.5 Maintenance of strains
The strains shall be maintained and treated (frequency of subculturing, alternation of culture media, etc.) in
accordance with the instructions of their laboratory of origin (see A.2). The parent strain shall be maintained in the
laboratory of its origin so as to conserve and to assure its vigour.
If tests are not undertaken regularly or if a strain shows signs of degeneration a new standard culture of the strain
should be obtained from the laboratory of its origin for each test (see A.2). When new strains are received, the
virulence shall be tested to ensure the strain can achieve the minimum loss in mass (see 5.1.1, 5.1.2 and 5.1.3).
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ENV 839:2002 (E)
5.2 Products and reagents
5.2.1 Culture medium
The culture medium is a malt agar medium with the following composition :
malt extract :
in concentrated form: (50 ± 0,5) g ;
in powder form: (40 ± 0,5) g ;
agar causing no inhibition of growth of fungi :
(20 ± 0,5) g to (30 ± 0,5) g ;
water conforming to grade 3 of ISO 3696 :
quantity to make up to 1000 ml.
Prepare this medium by warming the mixture in a boiling water bath or steam bath, stirring until completely
dissolved.
Place in each culture vessel (5.3.1) a sufficient quantity of the medium to provide a minimum depth of 3 mm to
4 mm when in its in-use position. Close the vessels as specified in 5.3.1 and sterilize in an autoclave at 121 °C for
20 min. Let the vessels cool in their in-use position.
5.2.2 Solvents and diluents
For water soluble or water dispersible preservatives :
water conforming to grade 3 of EN ISO 3696.
For preservatives to be diluted or dissolved in an organic solvent :
suitably volatile liquids that leave no residue in the wood that would have a toxic effect on the fungi at the end
of the post-treatment conditioning period.
NOTE Toluene and xylene of recognized analytical grade have been found suitable.
5.2.3 Fumigant (if necessary)
Xylene technical grade.
5.2.4 End-seal compound
A material resistant to the penetration of the test product and the test fungi, or separate materials for each, and
without any fungistatic or fungicidal activity within the test specimen.
NOTE Two brush coats of Tivosan 6031 diluted 1:1 with acetone or three brush coats of a 2-component epoxy lacquer,
with drying between each application, have been found to be suitable.
5.3 Apparatus
5.3.1 Culture vessels, Kolle flasks or equivalent vessels with a capacity of between 400 ml and 650 ml, providing
2 2
a flat surface area of between 85 cm and 120 cm for the medium.
NOTE 1 Examples of suitable vessels are given in EN 113.
NOTE 2 Kolle flasks are usually plugged with a wad of cotton wool. Other culture vessels are usually fitted with leak proof
lids, the centres of which are pierced with a round hole of up to 15 mm diameter and plugged with a wad of cotton wool.
5.3.2 Drying oven, capable of being controlled at (103 ± 2) °C.
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ENV 839:2002 (E)
5.3.3 Desiccators, with efficient desiccant (silica gel for example).
5.3.4 Conditioning chamber, well ventilated and controlled at (20 ± 2) °C and (65 ± 5) % relative humidity.
5.3.5 Drying supports, that will give a minimum contact with the treated test specimens. The supports shall be of
a material that does not react with the test solvent or test preservative, for example glass for organic products.
5.3.6 Culture chamber, (incubator or room), dark and controlled at (22 ± 2) °C and (70 ± 5) % relative humidity.
5.3.7 Test specimen supports, made of glass, stainless steel or any other inert material, that is to say, with no
risk of having any effect on the culture medium, the fungus, the wood or the test product, or of being itself modified.
Supports may be capable of holding either one or two test specimens. The supports are used to prevent direct
contact of the specimens with the culture medium, but shall not separate them from it by more than 3 mm.
NOTE If abnormally high moisture contents in the test specimens are experienced consistently, use of specimen supports of
approximately 5 mm thick can help to control the problem. If thicker specimen supports are used, this should be recorded in the
test report.
5.3.8 Ordinary laboratory equipment, including a balance capable of weighing to the nearest of 0,01 g and an
autoclave.
6 Sampling of the preservative
The sample of the preservative shall be representative of the product to be tested. Samples shall be stored and
handled in accordance with any written instructions from the supplier.
NOTE For the sampling of preservatives from bulk supplies, the procedure given in EN 212 should be used.
7 Test specimens
7.1 Species of wood
The species of wood to be used shall be susceptible to attack by fungi and shall be readily penetrated by liquids.
The reference species are Scots pine (Pinus sylvestris Linnaeus) representing softwoods and beech (Fagus
sylvatica Linnaeus) representing hardwoods.
Additional tests may be undertaken using other species corresponding to the above characteristics, and of
particular importance for certain countries, but if so this shall be stated in the test report.
7.2 Wood quality
The wood shall be free from cracks, stain, decay, insect damage or other defects. The wood shall not have been
water-stored, floated, chemically treated or steamed.
NOTE Wood that has been kiln dried at temperatures below 60 °C can be used.
The Scots pine shall be exclusively sapwood containing little resin and having between 2,5 and 8 annual growth
rings per 10 mm. The proportion of latewood in the annual rings shall not exceed 30 % of the whole.
The beech shall be even-grained, free from tyloses and discoloration. It shall have between 2 and 6 annual growth
rings per 10 mm.
7.3 Provision of the test specimens
Prepare planed strips having a cross section of (25 0,5) mm (15 0,5) mm. The longitudinal faces shall be
parallel to the direction of the grain. The annual rings shall have a contact angle of (45 ± 15)° to the broad faces.
Make transverse cuts, neatly to give sharp edges and a fine-sawn finish to the end-grain surfaces, to give test
specimens (50 ± 0,5) mm long.
NOTE For treatment, drying and ageing, the test specimens can be retained in planed strips of a length sufficient to
provide one test specimen for exposure to each of the test fungi. Each strip should be end-sealed prior to treatment.
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ENV 839:2002 (E)
The specimens shall originate from a minimum of three trees or shall be taken at random from a stock originally of
more than 500 specimens and originating from at least five planks.
7.4 Dimensions and density of specimens
The dimensions of each test specimen at a mass fraction of (12 ± 2) % moisture content shall be
(50 ± 0,5) mm x (25 ± 0,5) mm x (15 ± 0,5) mm.
NOTE A moisture meter of the two-pronged electrical conductivity type is suitable for assessing moisture content.
2
The total surface area of the faces to be treated is theoretically 40 cm but an allowance shall be made for any
encroachment of the sealing compound on to these faces.
In a batch of specimens to be treated, the density of an individual is permitted to differ from the mean value of the
batch by ± 10 %. This tolerance is increased to ± 20 % for the untreated specimens. The mean density for the
treated test specimens used for the test shall be recorded in the test report.
7.5 Number and distribution of test specimens
The test specimens are divided into :
e treated test specimens :
1
these are the treated test specimens subjected to attack by the wood destroying fungi. Use at least six
test specimens for each combination of preservative, quantity to be applied, preservative concentration,
test fungus and for each timber species.
NOTE The treated test specimens are assessed by visual examination for decay and colonisation by the test fungi. If loss
in mass is to be used as an additional method of assessment, this should be carried out on a parallel series of treated test
specimens; treated check test specimens (see e specimens in EN 113) will also be required.
3
e untreated test specimens :
2
e untreated control specimens : these are untreated test specimens, equal in number to the treated test
2.1
specimens e and of the same wood species, which are placed one in each culture vessel together with a
1
treated test specimen ;
e virulence control specimens: these are untreated test specimens which are subjected to attack by the
2.2
test fungi to monitor vigour. Use six of these for each combination of test fungus and timber species used
in the test.
Mark each specimen so that it can be identified throughout the test.
8 Procedure
8.1 Preparation of the untreated test specimens
Place the numbered untreated test specimens (e and e ) in the oven (5.3.2) and leave them there for 18 h to
2.1 2.2
1)
24 h . Cool to room temperature in a desiccators (5.3.3) and weigh to the nearest 0,01 g to determine the initial
dry mass (m ). Place the specimens in the conditioning chamber (5.3.4) until they need to be sterilized (8.3).
0
NOTE Untreated test specimens are not end-sealed.
1)
In the case of supplementary tests (7.1) using species of wood other than Scots pine sapwood or beech, this drying time
may need to be longer than 18 h to 24 h; the drying time should be such that the test specimens achieve constant mass. This
can be established by selecting at random from the batch being dried 10 test specimens; after drying and cooling as directed,
determine the total mass, return the specimens to the oven and repeat the operation at intervals of not less than 4 h. Constant
mass is achieved when the total mass of the selected specimens does not lose more than 0,05 g between weighings.
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ENV 839:2002 (E)
8.2 Preparation of the treated test specimens
8.2.1 End-sealing
Apply the end-sealing compound resistant to the penetration of the test product (5.2.4) to both end-grain surfaces
of each test specimen to be treated (e ). Allow to dry in the conditioning chamber (5.3.4) for at least 24 h after the
1
last application.
8.2.2 Treatment with the test product
Treat the test specimens on the unsealed longitudinal faces. If application is by brushing or by pipette, calculate the
amount of test product required to treat each face. Apply the amount evenly to each face individually and weigh the
test specimen before (m ) and after (m ) each application to the nearest 0,01 g. Allow to dry between applications.
1 2
Calculate the uptake of preservative solution for each face of each test specimen (m - m ). Calculate the total
2 1
uptake for each test specimen and express it in grams of preservative per square metre of treated surface.
NOTE If the balance has a tare facility, it is easier to tare the balance with the test specimen on it, apply the test product,
and then record the uptake directly.
If application is by dipping, weigh each specimen to the nearest 0,01 g (m ), dip for the required time then remove
1
any excess liquid with absorbent paper. Reweigh each specimen immediately and record the mass after treatment
(m ).
2
Calculate the uptake of preservative solution for each test specimen (m - m ) and express it in grams of
2 1
preservative per square metre of treated surface.
8.2.3 Drying
Following treatment (8.2.2), place the treated specimens on drying supports (5.3.5) in the conditioning chamber
(5.3.4). Invert the specimens twice each week. Dry the test specimens until weighings at 24 h intervals are within
± ,01 g.
NOTE 1 The length of the drying period will vary with the nature of the test product.
If test specimens are to be subjected to an ageing procedure, this shall be carried out after this drying procedure.
NOTE 2 If the test specimens have been retained as planed strips, they should be cross-cut into (50 0,5) mm lengths to
provide individual test specimens at this point.
8.2.4 Final end-sealing
Following drying (8.2.3), apply the fungus resistant end-sealing compound (5.2.4) or, if necessary, additional dual-
purpose end-sealing compound to both end-grain surfaces of each test specimen.
NOTE Additional application of dual-purpose end-sealing compound is most likely to be necessary when the treatment has
resulted in swelling of the test specimens and resultant cracking of the end-seal.
8.2.5 Final conditioning
Place the treated test specimens in the conditioning chamber (5.3.4) for at least 3 days.
8.3 Exposure to fungi
Inoculate the culture medium (see 5.2.1) in the culture vessels (5.3.1) not more than seven days after sterilization
of the medium. The inocula shall be obtained from cultures which are less than four weeks old and which are still
actively growing across the growth medium, or have covered it for less than one week. After inoculation, place the
culture vessels in the culture chamber (5.3.6).
The exposure to fungi shall take place as soon as the mycelium completely covers the surface of the culture
medium. This corresponds to the active phase of development; in no case should this period exceed four weeks.
The fungi shall be free from contamination by other organisms.
Into each culture vessel, introduce aseptically one or two previously sterilized test specimen supports (5.3.7).
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ENV 839:2002 (E)
Place one treated test specimen (e ) and one untreated test specimen (e ), previously sterilized by one of the
1 2.1
procedures given in annex B, on the support(s) in each inoculated culture vessel.
Place the previously sterilized untreated test specimens (e ) two in each inoculated culture vessel.
2.2
8.4 Culture conditions and duration of test
After introducing the test specimens, return the culture vessels to the culture chamber (5.3.6) and leave them there
for 16 weeks.
8.5 Assessment of test
8.5.1 All test specimens
At the end of the test, withdraw the test specimens from the vessels, removing any adhering mycelium. Record
evidence of waterlogging or of inhibition of growth of the test fungus caused by volatile components of the
preservative or contaminating organisms.
8.5.2 Untreated test specimens (e and e )
2.1 2.2
Weigh each specimen to the nearest 0,01 g at the end of the test, (m ). After oven drying to constant mass, weigh
3
each specimen again to the nearest 0,01 g, (m ). Calculate the moisture content of each specimen at the end of the
4
test by expressing its water content (m - m ) as a percentage of its final dry mass (m ).
3 4 4
Calculate the loss in mass of each untreated test specimen by expressing the loss in mass (m - m ) as a
0 4
percentage of the initial dry mass (m ).
0
Calculate the mean loss in mass of the virulence control specimens (e ).
2.2
8.5.3 Examination of the treated test specimens (e )
1
Examine the surface of each treated test specimen and record evidence of visible decay; this process may be
aided by gently probing with a pointed implement, for example a knife with a pointed blade. Clean the surface of
each test specimen of adhering fungus and surface sterilize by lightly flaming or by a momentary dip in a
disinfectant. Split each test specimen longitudinally and parallel to the 15 mm wide faces using an implement which
is sharply tapered to start the split (see Figure 1). It is recognized that the splits will follow the grain of the wood and
thus the slices will not be totally uniform.
NOTE 1 These procedures are designed to prevent transfer of fungal material from the original surface of the test specimens
onto the surfaces created by splitting.
Examine each slice and record evidence of visible decay. If no decay is observed in a test specimen, select three
slices for isolation of the test fungus. The slices shall be taken from the mid-line and approximately 6 mm either
side of the mid-line. From each slice, cut three chips of wood from the central zone. Partly embed each chip in 5 %
malt agar medium in test tubes or Petri dishes and incubate in the culture chamber (5.3.6). Observe for the growth
of the test fungus over a period of 14 days and record.
NOTE 2 A medium selective for the growth of basidiomycetes may be used to prevent the growth of contaminating micro-
organisms.
8.5.4 Validity of resu
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