1、DRAFT FOR DEVELOPMENT Wood preservatives Determination of the effectiveness against soft rotting micro-fungi and other soil inhabiting micro-organisms ICs 71.100.50 DD ENV 807:200 1 Corrected and reprinted December 2001 Wk seven parts by volume loam, three parts by volume sphagnum peat, two parts by
2、 volume sharp sand plus 0,6 g chalk and 6,O g slow release fertilizer per litre of soil mixture. If the WHC is too high, it can be lowered by modifying the soil with the addition of sand. Page 6 ENV 807:2001 If a natural soil is used, it shall have the turf or top 50 mm removed and shall not be take
3、n from a depth below 200 mm from the original surface. It shall be passed through a sieve of nominal aperture size 12,5 mm. If it is necessary to store the soil prior to use, it shall be stored in closed moisture-proof containers. Before use, thoroughly mix the sample of soil. NOTE 2 The soil should
4、 only be collected in a moist condition. If a horticultural soil is used which is sterilized during its preparation, then 20 % (m/m) of a natural soil, prepared as above, shall be added and the soils thoroughly mixed prior to the start of the test. The soil shall be used only once. NOTE 3 similar st
5、andardized procedure, may be used. If assurance of the virulence of the soil is required, the test procedure using cotton cloth described in annex C, or a 5.2 Products and reagents 5.2.1 Solvents and diluents Water to grade 3 of EN IS0 3696 and, if appropriate, volatile organic liquids leaving in th
6、e wood no residue which would have a toxic effect on the soil inhabiting micro-organisms at the end of the post-treatment conditioning period. NOTE Information on appropriate solvents and diluents should be provided by the supplier. 5.2.2 Reference preservative A copperkhromium preservative with a c
7、omposition equivalent to the following : CuS04.5H20 50,O % (m/m) K2Cr207 48,O % (m/m) Cr03 2,O % (m/m) The preservative shall be prepared from ingredients of at least 95 % (m/m) purity. 5.2.3 Xylene (C6H4(CH3),) mixed isomers, technical grade. 5.3 Apparatus 5.3.1 Conditioning chamber, well ventilate
8、d and maintained at (20 I 2) OC and (65 I 5) % r.h. 5.3.2 Ventilated drying oven, capable of being maintained at (103 I 2) OC. 5.3.3 Desiccators, with efficient desiccant (silica gel for example). 5.3.4 example of glass for organic products and plastics materials for salts containing fluorine. Treat
9、ment vessels, of a material that does not react with either the preservative or solvents or diluents, for 5.3.5 the test specimens. Weights, of a material that does not react with the preservative solutions under test, to provide ballast for 5.3.6 specimens during impregnation. Plastics mesh, of a m
10、aterial that does not react with the preservative solutions under test, for retaining test 5.3.7 Vacuum vessels, fitted with stopcocks. 5.3.8 Vacuum pump, fitted with a pressure gauge and capable of maintaining a pressure of 0,7 kPa. Page 7 ENV 807:2001 5.3.9 Drying vessels, provided with a cover an
11、d containing supports which will give a minimum of contact with the treated test specimens which are to be placed on them. The vessels and supports shall be of a material that does not react with the test solvent or test preservative, for example glass for organic products or of plastic material for
12、 salts containing fluorine. 5.3.10 Culture chamber (incubator or room), dark and maintained at (27 I 2) “C and (70 I 5) % r.h. 5.3.1 1 Vacuum filtration apparatus, comprising vacuum flask, 146 mm diameter Buchner funnel and fitting coarse grade filter papers. 5.3.12 Test containers, made of material
13、 which does not have a toxic effect on the soil inhabiting micro- organisms and provided with a ventilated lid. The depth shall be at least 150 mm, so as to provide at least 30 mm below the test specimens when inserted in the soil to a depth of 80 mm and adequate clearance above the top of the protr
14、uding parts of the test specimens. NOTE not be less than IO). An example of a suitable test container is described in annex D. The exact dimensions are not critical but they determine the number of test specimens in each vessel (which should 5.3.13 Safety equipment and protective clothing, appropria
15、te for the test product, test solvent and reference preservative, to ensure the safety of the operator. 5.3.14 Ordinary laboratory equipment, including a balance accurate to 0,001 g. 6 Sample of the preservative The sample of preservative shall be representative of the product to be tested. Samples
16、shall be stored and handled in accordance with any written recommendations 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 following species shall be used for the test Scots pine (fin
17、us sylvestris Linnaeus) for products intended to be used on softwoods ; beech (Fagus sylvatica Linnaeus) for products intended to be used on hardwoods. NOTE Additional tests may be carried out using other species but, if so, this should be stated in the test report. 7.2 Wood quality The wood shall b
18、e free from cracks, stain, decay, insect damage and 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 may be used. The Scots pine shall be exclusively sapwood containing little resin and ha
19、ving between 2,5 annual growth rings per 10 mm and eight 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 discolouration. It shall have between two annual growth rings per 10 mm an
20、d six annual growth rings per 10 mm. 7.3 Provision of test specimens Condition the wood to (12 I 2) % (mh) moisture content. Prepare planed strips having a cross-section of (IO I 0,l) mm (5 I 0,l) mm. The longitudinal faces shall be parallel to the direction of the grain. The annual rings Page 8 ENV
21、 807:2001 shall have a contact angle of (90 I 15) O 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 (100 I 1) mm long. The specimens shall originate from a minimum of three trees or shall be taken from a st
22、ock of more than 500 specimens and originating from at least five planks. NOTE A moisture meter of the two pronged electrical conductivity type is suitable for assessing moisture content. 7.4 Dimensions and density of specimens The dimensions of each test specimen at (12 I 2) % (m/m) moisture conten
23、t shall be (100 I 1) mm (IO I 0,l) mm (5 f 0,l) mm. For the purposes of calculating the density of the specimens (8.1 .I) and the mass of preservative retained per unit volume of wood (8.1.3), the nominal volume of each test specimen shall be taken as 5,O cm3. In any batch of specimens, the mass of
24、an individual is permitted to differ from the mean value of the batch by f 10(m/m). 7.5 Number and distribution of test specimens The test specimens are divided into s1 treated test specimens. sl,l test specimens treated with the test preservative: these are impregnated with the solutions of the tes
25、t preservative (clause 6) and subjected to attack by the micro-organisms in the soil. Use at least six test specimens for each combination of test preservative concentration, species of wood and exposure period (8.3.1). s1 ,2 test specimens treated with the reference preservative: these specimens ar
26、e impregnated with the solutions of the reference preservative (5.2.2) and subjected to attack by the micro-organisms in the soil. Use at least six test specimens for each combination of reference preservative concentration, species of wood and exposure period. s2 untreated test specimens s2,1 virul
27、ence control specimens : these specimens are not treated, they are of the same species of wood as the treated test specimens, and are subjected to attack by the micro-organisms in the soil. They are used to provide a measure of comparability between tests. Use three virulence control specimens for e
28、ach test container. NOTE 1 The virulence control specimens are assessed after 16 weeks exposure. s2,2 moisture monitoring specimens : these specimens are not treated, they are of the same wood species as the treated test specimens and are planted in the soil to assess that the moisture content level
29、 established in the test specimens is adequate to support active fungal attack. Use three moisture monitoring specimens for each test container. NOTE 2 If the test is to be carried out in eight test containers of the type described in annex D (four containers for Scots pine specimens and four contai
30、ners for beech specimens, (see 8.2.2), each of these containers would require three replicates of the virulence control specimens and three replicates of the moisture monitoring specimens of the appropriate species of wood; this gives a total of 12 virulence control specimens and 12 moisture monitor
31、ing specimens per species of wood. With smaller test containers, lower numbers of replicates are acceptable but each test container should contain at least one replicate virulence control specimen and one moisture monitoring specimen. s3 treated check test specimens for calculation of the correction
32、 values. 3.1 check test specimens treated with the test preservative: these are test specimens treated in exactly the same way as the sl., test specimens, except that after drying, conditioning and leaching, they are allowed to dry fully and are not planted in the soil. Use at least four specimens f
33、or each combination Page 9 ENV 807:2001 of tests preservative concentration and species of wood. Variations in the mass of these specimens make it possible to determine the correction value (CI ) for the variations in mass of the treated test specimens s, resulting from factors other than attack by
34、the soil inhabiting micro-organisms. At a given treating solution concentration, the correction value CI is the mean percentage change in mass of the 3.1 test specimens. 3.2 check test specimens treated with the reference preservative: these are test specimens treated in exactly the same way as the
35、s1,2 test specimens, except that after drying, conditioning and leaching, they are allowed to dry fully and are not planted in the soil. Use at least four specimens for each combination of reference preservative concentration and species of wood. Variations in the mass of these specimens make it pos
36、sible to determine the correction value (C,) for the variations in mass of the reference preservative treated test specimens s1 ,2 resulting from factors other than attack by the soil inhabiting micro-organisms. At a given treating solution concentration, the correction value C2 is the mean percenta
37、ge change in mass of the s3,2 test specimens. Mark each test specimen so that it can be identified throughout the test. NOTE 3 having more than the permitted variation in the quantity of product absorbed (8.1.3). It is advisable to treat more specimens than the minimum number required to allow the r
38、ejection of specimens 8 Procedures 8.1 Preparation of test specimens 8.1 .I Conditioning of specimens before treatment Place the numbered test specimens in the oven (5.3.2) and leave them there for 18 h to 24 h 2). Cool to room temperature in a desiccator (5.3.3) and weigh to the nearest 0,001 g to
39、determine the initial dry mass (mo). Replace the test specimens in the desiccator and store them there in order to keep them dry until impregnation. Calculate the mean density of the specimens of each species using the mean mass and the nominal volume (see 7.4). 8.1.2 Preparation of treatment soluti
40、ons Prepare a series of solutions of at least three concentrations (expressed as % (m/m) of the test preservative (clause 6) in the appropriate solvent or diluent (5.2.1). A solvent or diluent control, that is treatment at concentration O. shall also be included. NOTE 1 It is preferable to use at le
41、ast five concentrations of the test preservative except when there is prior experience of the petformance of the test preservative in the test. It is normal for the treating solution concentrations to be arranged in a geometric or arithmetic progression. NOTE 2 The selection of the treating solution
42、 concentrations (and therefore retentions) of the test preservative should be made giving consideration to the petformance of the reference preservative in the test and the method of calculation of the results (see annex E). It is also necessary to include a retention of the test preservative which
43、fails in the test before the reference preservative fails, to be able to calculate accurately the nominal effective retention of the test preservative (see clause IO). With beech test specimens, the retentions in the test specimens will normally be ranged about the likely retention to be effective i
44、n practice. However, with Scots pine sapwood test specimens, the retentions in the test specimens should be over a range which is much lower than the likely retention to be effective in practice. This is because of the good performance of wood preservatives in this species of wood in laboratory test
45、s and is exemplified by the selection of the treating solution con centrat ions for the reference preservative. Prepare the reference preservative (5.2.2) at the following concentrations in water : In the case of supplementary tests (7.1) using species of wood other than Scots pine sapwood or beech,
46、 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
47、 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. Page 10 ENV 807:2001 Scots pine: 0,l % - 0,16 % - 0,25 % - 0,4 % (m/m) ; beech: 1 ,O % - 1
48、,6 % - 2,5 % - 4,O % (m/m). All treatment solutions shall be freshly prepared. 8.1.3 Impregnation Carry out impregnation of the sets of test specimens with the test preservative solutions in ascending order of concentration starting with the solvent control (concentration = O). Using clean equipment
49、, impregnate the appropriate sets of test specimens with the reference preservative, again in ascending order of concentration. The following procedure ensures the required complete impregnation of test specimens by the test solutions. For each solution place the test specimens, kept dry as described in 8.1.1 and of known mass mo, in one of the treatment vessels (5.3.4) so that as much of their surface as possible is exposed (for example, by stacking them crosswise). Ballast the stack of specimens with the weights (5.3.5) using the plastics mesh (5.3.6) if necessary, to prevent them
