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.. 7 Test specimens
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 %
For specific regional uses or conditions, it is also possible to select other fungi on an optional basis
When optional fungi are used, information similar to that given in Annex A for the obligatory fungi should be included in the test report
Strains must be preserved and managed according to the guidelines provided by their originating laboratory, including subculturing frequency and media alternation It is essential to maintain the parent strain in its original laboratory to ensure its vitality and conservation.
Regular testing is essential; if a strain exhibits degeneration, a new standard culture should be sourced from the original laboratory for each test Upon receiving new strains, it is crucial to assess their virulence to confirm they can achieve the minimum mass loss.
Products and reagents
The culture medium is a malt agar medium with the following composition:
— agar causing no inhibition of growth of fungi:
— water conforming to grade 3 of EN ISO 3696
— quantity to make up to 1 000 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
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
The material must resist penetration by the tested wood preservative and the test fungi, or utilize separate materials for each, ensuring that there is no fungistatic or fungicidal activity present within the test specimen.
NOTE Three brush coats of a 2-component epoxy lacquer, with drying between each application, have been found to be suitable.
Apparatus
5.3.1 Culture vessels, Kolle flasks or equivalent vessels with a capacity of between 400 ml and 650 ml, providing a flat surface area of between 85 cm 2 and 120 cm 2 for the medium
NOTE 1 Examples of suitable vessels are given in EN 113
Kolle flasks are typically sealed with a cotton wool plug, while other culture vessels are equipped with leak-proof lids that feature a central hole of up to 15 mm in diameter, also plugged with cotton wool.
5.3.2 Drying oven, capable of being controlled at (103 ± 2) °C
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
Drying supports should ensure minimal contact with the treated test specimens and must be made from materials that do not react with the test solvent or wood preservative For instance, glass is an appropriate choice for organic products.
5.3.6 Culture chamber, (incubator or room), dark and controlled at (22 ± 2) °C and (70 ± 5) % relative humidity
Test specimen supports must be constructed from inert materials such as glass or stainless steel to ensure they do not affect the culture medium, fungus, wood, or wood preservative These supports can accommodate one or two test specimens and are designed to prevent direct contact with the culture medium, maintaining a maximum separation of 3 mm.
To address consistently high moisture levels in test specimens, utilizing supports that are approximately 5 mm thick can effectively mitigate the issue It is important to document any use of thicker supports 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
To ensure accurate testing, the wood preservative sample must accurately represent the product It is essential to store and handle the samples according to the supplier's written instructions.
For the sampling of wood preservatives from bulk supplies, the procedure given in EN 212 should be used
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 conducted with other species that match the specified characteristics, which may be particularly relevant for certain countries; any such tests will be clearly indicated in the test report.
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 is characterized by its sapwood, which contains minimal resin and features between 2.5 and 8 annual growth rings per 10 mm Additionally, the latewood proportion in these annual rings is limited to a maximum of 30% of the total.
The beech shall be even-grained, free from tyloses and discoloration It shall have between 2 and 6 annual growth rings per 10 mm.
Provision of the test specimens
Prepare planed strips with a cross section of (25 ± 0.5) mm × (15 ± 0.5) mm, ensuring the longitudinal faces are parallel to the grain direction The annual rings should form a contact angle of (45 ± 15)° with the broad faces Make precise transverse cuts to achieve sharp edges and a fine-sawn finish on the end-grain surfaces, resulting in test specimens that are (50 ± 0.5) mm long.
For effective treatment, drying, and ageing, it is essential to keep the test specimens in planed strips long enough to allow for one specimen to be exposed to each type of test fungus Prior to treatment, each strip must be end-sealed to ensure optimal results.
Specimens must be sourced from at least three different trees or randomly selected from a stock of over 500 test specimens, ensuring they come from a minimum of five planks.
Dimensions and density of test specimens
The dimensions of each test specimen at a mass fraction of (12 ± 2) % moisture content shall be
NOTE A moisture meter of the two-pronged electrical conductivity type is suitable for assessing moisture content
The theoretical total surface area of the faces to be treated is 40 cm²; however, it is important to account for any encroachment of the sealing compound onto these surfaces.
In a batch of test specimens, the density of an individual specimen can vary from the batch mean by ± 10% For untreated test specimens, this tolerance is expanded to ± 20%.
Number and distribution of test specimens
The test specimens are divided into: a) e 1 treated test specimens:
The test specimens, treated with various preservatives, were exposed to wood-destroying fungi For each combination of preservative type, application quantity, concentration, test fungus, and timber species, a minimum of six specimens were utilized.
When conducting dipping tests, it is essential to select a minimum of six test specimens that fall within 10% of the target retention Additionally, supplementary samples should be processed to ensure there are enough properly treated specimens available for testing.
The treated test specimens are evaluated through visual inspection for any signs of surface or interior decay caused by the test fungi If additional assessment for fungal colonization is necessary, it should be conducted on a separate series of untreated test specimens, as outlined in Annex C.
The untreated control test specimens, equal in number to the treated test specimens (e 1) and of the same wood species, are placed in each culture vessel alongside a treated test specimen.
The e 2.2 virulence control test specimens are untreated samples exposed to test fungi to assess their vigor, with six specimens required for each combination of test fungus and timber species Additionally, e 3 treated check test specimens are utilized to calculate the correction value.
Test specimens are treated identically to the e 1 test specimens, with a minimum of six specimens for each combination of preservative, application quantity, and concentration, all from the same wood species After drying, conditioning, and appropriate aging, two specimens are placed in each uninoculated culture vessel The variations in mass of these test specimens allow for the determination of the correction factor (C), which accounts for mass changes in the treated e 1 specimens due to factors other than fungal attack At a specific treating concentration, factor C represents the mass fraction change of the e 3 test specimens.
Mark each specimen so that it can be identified throughout the test
Preparation of the untreated test specimens
Place the untreated test specimens (e 2.1 and e 2.2) in the oven for 18 to 24 hours Afterward, cool them to room temperature in a desiccator and weigh them to the nearest 0.01 g to determine the initial dry mass (m 0) Finally, store the test specimens in the conditioning chamber until they are ready for sterilization.
For supplementary tests involving wood species other than Scots pine sapwood or beech, the drying time may exceed 18 to 24 hours to ensure the test specimens reach a constant mass This can be verified by randomly selecting 10 specimens from the drying batch, drying and cooling them as instructed, and measuring their total mass The process should be repeated at intervals of no less than 4 hours until the total mass of the specimens shows no significant loss.
NOTE Untreated test specimens are not end-sealed.
Preparation of the treated test specimens
Place the numbered test specimens (e 1 and e 3) in an oven set at (103 ± 2) °C for 18 to 24 hours Afterward, cool them to room temperature in a desiccator and weigh to the nearest 0.01 g to determine the initial dry mass (m 0) Finally, transfer the test specimens to the conditioning chamber until they are ready for end-sealing.
Apply a penetration-resistant end-sealing compound to the end-grain surfaces of each test specimen (e 1 and e 3) before treatment with the test wood preservative Ensure the compound dries in the conditioning chamber for a minimum of 24 hours after the final application.
To minimize errors in mass loss due to variations in end seal application, it is essential to apply the end seal as evenly as possible Quality control should aim for a variation within a 10% limit, and implementing an absolute mass correction for all specimens can enhance accuracy.
8.2.3 Treatment with the test wood preservative
Treat the test specimens e 1 and e 3 on their unsealed longitudinal faces When applying the test product using a brush or pipette, determine the required amount for each face and apply it evenly Weigh each specimen before (m 1) and after (m 2) application to the nearest 0.01 g, allowing for drying between applications Calculate the uptake of the wood preservative solution for each face (m 2 - m 1) and express the total uptake for each specimen in grams of wood preservative per square meter of treated surface.
To simplify the process of measuring wood preservative uptake, utilize a balance with a tare function by placing the test specimen on it, applying the preservative, and directly recording the uptake.
For dip application, weigh each test specimen to the nearest 0.01 g (m₁) After dipping for the specified duration, remove any excess liquid using absorbent paper Immediately reweigh each specimen and record the mass post-treatment (m₂).
Calculate the uptake of wood preservative solution for each test specimen (m 2 - m 1) and express it in grams of wood preservative per square metre of treated surface
After treatment, position the test specimens on drying supports in the conditioning chamber Invert the specimens biweekly and continue drying until the weight measurements at 24-hour intervals are within ± 0.01 g.
NOTE The length of the drying period will vary with the nature of the test wood preservative
If test specimens are to be subjected to an ageing procedure, this shall be carried out after this drying procedure
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
Following drying (8.2.4), 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 treated test specimen (e 1 and e 3)
The use of a dual-purpose end-sealing compound may be required if the treatment causes swelling in the test specimens, leading to cracks in the end-seal.
To minimize errors in mass loss due to variations in end seal application, it is essential to apply the end seal as evenly as possible Quality control should aim for a variation within a 10% limit, and implementing an absolute mass correction for all specimens can enhance accuracy.
Place the treated test specimens in the conditioning chamber (5.3.4) for at least 3 d.
Exposure to fungi
Inoculate the culture medium within seven days of sterilization, using inocula from cultures that are less than four weeks old and actively growing or have covered the growth medium for less than one week After inoculation, transfer the culture vessels to the culture chamber.
Fungi should be exposed once the mycelium fully covers the culture medium, marking the active development phase, which must not exceed four weeks It is essential that the fungi remain uncontaminated by other organisms.
Into each culture vessel, introduce aseptically one or two previously sterilised test specimen supports (5.3.7) NOTE 1 For methods of sterilization, see Annex B
Place one treated test specimen (e 1) and one untreated test specimen (e 2.1), previously sterilized by one of the procedures given in Annex B, on the support(s) in each inoculated culture vessel
Place the previously sterilized untreated test specimens (e 2.2) two in each inoculated culture vessel
NOTE 2 If several tests are running in parallel, only one set of virulence test specimens is required
Place two treated check test specimens (e 3) in each uninoculated culture vessel as indicated in 7.5 to establish the correction factor (C).
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.
Assessment of test
After completing the test, carefully remove the specimens from the vessels, ensuring to eliminate any attached mycelium Document any signs of waterlogging or growth inhibition in the test fungus, which may be attributed to the volatile components of the wood preservative or the presence of contaminating organisms.
Weigh each test specimen to the nearest 0.01 g after the test (m₃) After oven drying to a constant mass, weigh each specimen again to the nearest 0.01 g (m₄) Calculate the moisture content by expressing the water content (m₃ - m₄) as a percentage of the final dry mass (m₄).
Calculate the loss in mass of each untreated test specimen by expressing the loss in mass (m 0 - m 4) as a percentage of the initial dry mass (m 0)
Calculate the mean loss in mass of the virulence control test specimens (e 2.2)
To determine the mass loss of each treated test specimen (e 1), calculate the percentage of mass loss by using the formula \((m_o - m_4) / m_o \times 100\) Next, compute the correction factor (C), which represents the average percentage mass loss of the treated check test specimens (e 3) for each concentration of the treating solution Finally, subtract the correction factor (C) from the percentage mass loss of each treated test specimen (e 1) to obtain the corrected mass loss.
NOTE A method for determination of colonisation as an optional means of assessment is mentioned in Annex C and requires an additional series of test specimens
8.5.2 Examination of the treated test specimens ( e 1 )
Inspect the surface of each treated test specimen for visible decay, using a pointed tool like a knife for assistance Longitudinally split each specimen parallel to the 15 mm wide faces with a sharp knife.
Examine each half and record evidence of visible decay
NOTE In the case of white rot fungi, white discoloration (bleaching) and/or dark inhibition streaks are regarded as decay
Reject any treated test specimen (e 1) that exhibits abnormal moisture content, such as being waterlogged, shows signs of contaminating microorganisms, or when the untreated control test specimen (e 2.1) demonstrates a mass loss below the minimum threshold specified in section 5.1.
Reject any treated test specimen showing visible decay which shows evidence of the colonization via a defective end-seal
The test can be evaluated if the mean loss in mass of the virulence control test specimens (e 2.2) is equal to or higher than the minimum value given in 5.1
The validity of data regarding any combination of preservative, application quantity, concentration, test fungus, and timber species is confirmed when results from a minimum of five treated test specimens are accepted.
The effectiveness of the wood preservative is considered sufficient if, at the specified application rate, no more than one test specimen exhibits surface decay and no more than one treated specimen shows signs of internal decay.
Express the results in terms of the application rate as grams of product per square metre of treated area, giving information on how the product was diluted, if appropriate
The test report must include essential information such as the European Standard number and publication date, the supplier's name, and the unique identifier for the wood preservative tested, along with its declared composition It should detail the active ingredient's name and concentration, the wood preservative's density, and the supply date Additionally, the report must specify the solvent used, wood species, average density of test specimens, and the fungi species and strain numbers involved Important procedural details include any dilutions made, treatment methods, quantities of solution applied, drying and storage periods, and any ageing tests conducted The report should also document sterilization methods, exposure dates to test fungi, removal dates, mass loss percentages, visible decay presence, result interpretations, deviations from standard methods, and the responsible organization's name and report issue date, along with the signatures of the testing officers.
The interpretation of a test report requires specialized knowledge in wood preservation, meaning that the report alone does not serve as an approval certificate.
General information on maintenance and acquisition of test strains
Laboratories holding the parent strain should re-isolate the strain after growth on untreated wood if it shows any sign of weakness
Laboratories that conduct regular tests may keep their own strains; however, if any signs of weakness are observed, a new culture should be sourced from the original laboratory It is essential for all laboratories that maintain test fungi to assess virulence at least annually, utilizing virulence control test specimens as outlined in section 8.4.
Regular testing is essential; if a strain exhibits signs of degeneration, a new standard culture should be sourced from the original laboratory for each test.
The laboratory sending test cultures should provide all growth features characteristic of the respective fungus
When transporting cultures, it is crucial to prevent harmful influences, such as freezing during air transport To protect against X-ray exposure, cultures should be packed in aluminum containers or wrapped in aluminum foil International regulations govern the transport of cultures, and information on these regulations can be obtained from recognized culture collections, such as those affiliated with the European Culture Collection Organization.
When new strains are received, the virulence should be tested to ensure it exceeds the minimum given in 5.1.
Maintenance and treatment of test fungi
At least every six months, test strains should be re-isolated from untreated wood which is being actively attacked
NOTE When undertaking tests regularly, the process of re-isolation can be carried out in association with each test to provide cultures for future tests
To conduct virulence control tests for Coriolus versicolor and Lentinus cyathiformis, sterilize two specimens of beech and Scots pine sapwood Alternatively, use two small wood specimens measuring approximately 5 mm (grain direction) × 30 mm × 30 mm, which should also be sterilized Expose the test specimens to the test fungus for six to eight weeks for virulence control specimens or four weeks for smaller specimens, without aging Under sterile conditions, split open the virulence control specimens to remove small wood splinters from the center, embedding them in a 5% malt agar medium in test tubes or Petri dishes to allow fungal growth Transfer the smaller specimens whole into the same agar medium, permitting the fungi to grow out of the wood These cultures will serve for future tests and stock culture maintenance.
The virulence of test fungi must be assessed annually If assessments occur less frequently than once a year, a separate virulence test is required before proceeding with the main tests.
Information regarding obligatory fungi
A.3.1 Coniophora puteana (Schumacher ex Fries) Karsten (Synonym: Coniophora cerebella (Persoon)
Strain: BAM Ebw 15 (Bundesanstalt für Materialforschung und -prüfung - D 12200 BERLIN)
Activity: Fungus causing a brown rot of hardwood and softwood
Simple laboratory culture, rapid growth on malt agar medium, or malt agar-peptone
Maintenance: Store stock cultures at 5 °C to 8 °C
Subculture every six months on malt agar medium
A.3.2 Coriolus versicolor (Linnaeus) Quélet (Synonyms: Polyporus versicolor Linnaeus ex Fries - Polystictus versicolor (Linnaeus) Saccardo - Trametes versicolor (Linnaeus ex Fries) Pilát)
Strain: CTB 863A (Centre Technique du Bois et de l’Ameublement, Allée de Boutaut - BP 227, F 33 028 Bordeaux cedex)
Activity: Fungus causing a fibrous white rot of hardwood
Simple laboratory culture, rapid growth on malt agar medium
Maintenance: Store stock cultures at 5 °C to 20 °C
Subculture every six weeks on malt agar medium
A.3.3 Gloeophyllum trabeum (Persoon ex Fries) Murrill (Synonyms: Lenzites trabea (Persoon ex fries) Fries
- Trametes trabea (Persoon ex Fries) Bresadola)
Strain: BAM Ebw 109 (Bundesanstalt für Materialforschung und -prüfung - D 12200 BERLIN)
Activity: Fungus causing a brown rot of hardwood and softwood
Cultivation in well-ventilated conditions, rapid growth on malt agar medium
Maintenance: Store stock cultures at 5 °C to 8 °C
Subculture every six months on malt agar medium
A.3.4 Lentinus cyathiformis (Schaeffer ex Fries) Bresadola (Synonym: Lentinus degener Kalchbrenner apud
Strain: CTB 67-02B (Centre Technique du Bois et de l’Ameublement, Allée de Boutaut - BP 227, F 33 028 Bordeaux cedex)
Activity: Fungus causing a brown rot of hardwood
Simple laboratory culture, medium rapid speed of growth
Maintenance: Store stock cultures at 5 °C to 20 °C
Subculture every six months on malt agar medium
A.3.5 Lentinus lepideus Fries ex Fries (Synonym: Lentinus lepideus (Fries ex Fries) Fries)
Strain: BAM Ebw 20 (Bundesanstalt für Materialforschung und -prüfung - D 12200 BERLIN)
Activity: Fungus causing a brown rot of softwood
Simple laboratory culture, but fairly slow development on malt agar medium
Maintenance: Store stock cultures at 5 °C to 8 °C
Subculture every six months on malt agar medium
A.3.6 Poria placenta (Fries) Cooke sensu J Eriksson (Synonyms: Poria monticola Murrill - Postia placenta
Strain: FPRL 280 (Building Research Establishment Ltd - Garston, Watford, Herts WD25 9XX - UK)
Activity: Fungus causing a brown rot of softwood
Simple laboratory culture, rapid speed growth on malt agar medium
Maintenance: Store stock cultures at 5 °C to 20 °C
Keep stock cultures on a mass fraction of 5 % malt agar medium and subculture every three months
Ionizing radiation
This method is suitable for all wood preservatives and is especially preferred for organic wood preservatives and those wood preservatives for which the reactivity with epoxyethane is unknown
Place the test specimens individually, or in groups of similarly treated replicates, in polyethylene envelopes (at least 90 μm thick) and seal the envelopes by hot iron welding
Polyethylene sheeting can be utilized by folding it over the test specimen bed and welding along three sides However, using polyethylene tubing sold in rolls is often more practical The test specimens are placed inside this tubing, which is then welded at both ends to secure the specimens.
Send the envelopes thus prepared to an irradiation centre Advice with regard to the packing of the envelopes shall be obtained from the irradiation centre
Subject the envelopes to a dose of between 25 kGy 2) and 50 kGy when using radioisotopes (e.g 60 Co sources) or between 50 kGy and 100 kGy when using electron-accelerators
High-intensity sterilization for a short duration is as effective as low-intensity sterilization over an extended period Following irradiation, the envelopes can be stored safely for several weeks without any negative impact.
Do not open the envelopes until the precise moment when the contents are to be used.
Epoxyethane-based sterilant
This method is not recommended for organic wood preservatives and is unsuitable for products containing boron compounds or chlorinated or phenolic substances
The toxic and explosive nature of this product requires special safety measures Reference should be made to any national regulations governing its use
Place the test specimens individually in low density polyethylene envelopes (thickness of 30 μm to 90 μm) which are sealed by hot iron welding
Test specimens should be placed in an apparatus with a concentration of epoxyethane at 1.2 g/l, under a pressure of 550 kPa, a temperature of 55 °C, and relative humidity of 70% to 80% for 60 minutes After this, ventilate the specimens for 5 days by exposing them to a flow of sterile air.
Do not open the envelopes until the precise moment when the contents are to be used.
Epoxypropane-based sterilant
This method is not recommended for organic wood preservatives and is unsuitable for products containing boron compounds or chlorinated or phenolic substances
The chemical nature of this product requires safety measures Reference should be made to any national regulations governing its use
Test specimens should be placed in a vessel with a concentration of 2 ml of epoxypropane per liter for 24 hours, followed by ventilation with sterile air for a minimum of 2 days.
Lentinus lepideus, a fungus highly sensitive to epoxypropane, should be tested when cultures are no older than 15 days To ensure adequate surface colonization within this timeframe, inoculate each culture vessel at three equidistant points, approximately 20 mm from the center.
Steam
This method shall only be used for preparations known to be heat stable and not volatile in steam
The day prior to planting test specimens in culture vessels, arrange them in suitable glass dishes, ensuring that only specimens treated with the same application rate are placed together To prevent contact between the specimens, use glass or stainless steel rods to separate each one.
Cover the dishes, and place them in a steamer The steam shall circulate round the dishes for 20 min
Leave the dishes to cool, store them for 24 h in a room at ambient temperature and then repeat the sterilization procedure for 10 min
Do not open the dishes until the precise moment when the test specimens are to be placed in the culture vessels
General
Determining whether the test fungus has colonized the interior of specimens can be challenging, particularly with white rot fungi In the initial stages of colonization, the fungus may infiltrate the wooden cells, utilizing the cell contents as a nutrient source before beginning to degrade the wood substance.
In this case tests for the isolation of the test fungus from the interior of the test specimens can provide additional information.
Procedure
If additional assessment through optional tests for the colonization of test fungi is necessary, it should be conducted on a parallel series of treated test specimens.
For each combination of wood preservative, application quantity, concentration, test fungus, and timber species, utilize a minimum of six treated test specimens (c1) alongside an equal number of untreated test specimens (c2), corresponding to the test specimens e1 and e2.1 of section 7.5.
Prepare the test specimens according to 8.1 and 8.2, expose them to the test fungi according to 8.3 and leave them in the culture chamber according to 8.4.
Assessment of test
After completing the test, carefully remove the specimens from the vessels, ensuring to eliminate any mycelium that may be attached Document any signs of waterlogging or growth inhibition in the test fungus, which may be attributed to the volatile components of the wood preservative or the presence of contaminating organisms.
Weigh each test specimen to the nearest 0.01 g after the test (m3) After oven drying to a constant mass, weigh each specimen again to the nearest 0.01 g (m4) Calculate the moisture content of each specimen by expressing the water content (m3 - m4) as a percentage of the final dry mass (m4).
Calculate the loss in mass of each untreated test specimen by expressing the loss in mass (m 0 - m 4) as a percentage of the initial dry mass (m 0)
C.3.3 Examination of the treated test specimens ( c 1 )
Examine each treated test specimen for visible decay, using a pointed implement like a knife for probing Clean the surface of each specimen to remove fungus and sterilize it by lightly flaming or briefly dipping in disinfectant Longitudinally split each specimen parallel to the 15 mm wide faces with a sharply tapered tool, noting that the splits will follow the wood grain, resulting in non-uniform slices.
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 for visible decay and document any findings If a test specimen shows no signs of decay, choose three slices from the mid-line for isolating the test fungus.
Cut three wood chips from the central zone of each slice, ensuring they are 6 mm from the mid-line Partially embed each chip in a 5% malt agar medium within test tubes or Petri dishes, and incubate them in the culture chamber Observe the growth of the test fungus over a 14-day period and document the results.
NOTE 2 A medium selective for the growth of basidiomycetes can be used to prevent the growth of contaminating microorganisms.
Validity of results
Reject any treated test specimen (c 1) that exhibits no visible decay or growth of the test fungus if it shows abnormal moisture content, such as being waterlogged, displays signs of contaminating microorganisms, or if the untreated control test specimen (c 2) has a mass loss below the minimum value specified in section 5.1.
Reject any treated test specimen showing visible decay which shows evidence of the colonization via a defective end-seal
The test can be evaluated if the mean loss in mass of the virulence control test specimens (c 2) is equal to or higher than the minimum value given in 5.1
Data from various combinations of preservatives, application quantities, wood preservative concentrations, test fungi, and timber species are considered valid if results from a minimum of five treated test specimens are accepted.
Statement of results
The results should indicate the application rate of wood preservative in grams per square meter of the treated area, including details on the dilution method used, if applicable.
Figure C.1 ― Splitting and sampling of treated test specimens
Number and date of this European Standard: EN 839:2014
Name and type of the product: Z; organic solution; composition declared
Name and concentration of the active Ingredient: W; a mass fraction of 0,25 %
Density of the product: 0,84 g/ml
Solvent or diluent used: None, supplied ready-to-use
Species of wood used: Scots pine sapwood (Pinus sylvestris L)
Beech (Fagus sylvatica L) Average density of treated test specimens: 485 kg/m 3 (pine); 710 kg/m 3 (beech)
Species of fungi used: Coniophora puteana BAM Ebw 15 )
Gloeophyllum trabeum BAM Ebw 109 ) pine
Poria placenta FPRL 280 ) Coriolus versicolor CTB 863A - on beech
Application of test product: See Table D.2
Storage period after drying: None
Ageing procedures carried out: None
Method of sterilization: Ionizing irradiation
Date of exposure to fungi: 12/12/2014
Date removed from fungi: 03/04/2015; 16 weeks in test
Losses in mass virulence controls: See Table D.1; the test was valid
Assessment of treated test specimens: See Table D.2
Interpretation of results: See Table D.2
Deviations from the standard: None
Report prepared by: Laboratory B, Anytown, UK
Name and signature of the officer(s) in charge: Mr D, Mrs E
The sample of product Z was received by Laboratory B on 19/11/2014
The interpretation of a test report requires specialized knowledge in wood preservation, meaning that the report alone cannot serve as an approval certificate.
Table D.1 — Virulence control test specimens; loss in mass in percentage Test fungus
Individual Mean Minimum required by this prestandard
The test was valid with the mean losses in mass for all fungi exceeding the minimum values required by this European Standard
Table D.2 — Summary of results with Product Z Test fungus
Loss in mass untreated control test specimen
Application of test product by brushing
Condition of treated test specimen g per specimen g/m 2 Visible decay Corrected mass loss
Environmental, health and safety precautions within chemical/biological laboratory
When preparing this standard, consideration was given to the minimization of environmental impacts caused by the use of the methods of analysis
It is the users’ responsibility to use safe and proper techniques in handling materials in the methods of analysis specified in this standard
The following list is not exhaustive but users of this standard may use it as a guide to the use of safe and proper techniques They should:
— investigate if European Directives, transposed European legislation and national laws, regulations and administrative provisions apply;
— consult manufacturers/ suppliers for specific details such as material safety data sheets and other recommendations;
Always utilize safety equipment and wear protective clothing, such as goggles and lab coats, suitable for the test product and chemicals in all laboratory areas to ensure operator safety.
— be careful about flammable materials and substances that are toxic and/ or human carcinogens and generally take care during transportation, decanting, diluting and dealing with spillages;
— use a fume cupboard during preparation of organic solvent solutions;
— store, handle and dispose of chemicals in a safe and environmentally satisfactory manner: including chemicals for laboratory test, test specimens, unused solvents and reagents that have to be disposed of
[1] EN 73, Wood preservatives - Accelerated ageing tests of treated wood prior to biological testing -
[2] EN 113, Wood preservatives - Test method for determining the protective effectiveness against wood destroying basidiomycetes - Determination of the toxic values
[3] EN 212, Wood preservatives - General guidance on sampling and preparation for analysis of wood preservatives and treated timber
[4] EN 1001-1:2005, Durability of wood and wood-based products - Terminology - Part 1: List of equivalent terms
[5] EN 1001-2:2005, Durability of wood and wood based products - Terminology - Part 2: Vocabulary