BS/EN 47-2016 pdf download.Wood preservatives Determination of the toxic values against larvae of Hylotrupes bajulus (Linnaeus) (Laboratory method).
Next, admit air to bring the vacuum vessel back to atmospheric pressure, remove the treatment vessel with its submerged test specimens from the vacuum vessel, cover it and leave it for 2 h, adding further solution as necessary to keep the test specimens fully covered by liquid.
After this impregnation treatment, remove the test specimens one by one, remove excess liquid from their faces by lightly blotting with filter paper (5.2.4), and immediately weigh each to the nearest 0,05 g.
In the case of water-soluble preservatives, for example salts and organic chemicals which are being studied as active substances, calculate the mass of active matter retained by each test specimen from the mass of solution absorbed and its concentration3).
In the case of organic water-insoluble formulations and organic water-dispersible formulations the retention is expressed for each test specimen in terms of the corresponding mass of the formulation retained but, if a concentrate is supplied, the retention is expressed in terms of the solution prepared ready for use as specified by the manufacturer.
Calculate the mass of preservative retained per unit volume of wood in kilograms per cubic metre, for each test specimen.
8.1.3 Drying and conditioning of the test specimens after treatment
Arrange the impregnated test specimens treated with each preservative concentration on their narrow faces, resting on two glass rods, not touching each other in the drying vessel (5.3.10). Place the cover on the drying vessel. Place the drying vessel in the conditioning chamber (5.3.2). Invert the test specimens twice each week during the subsequent drying period, temporarily removing the cover to perform these operations.
To prevent mould growth on test specimens treated with water-diluted preservatives, place a small dish containing the xylene (5.2.1) in the drying vessel (5.3.10).
During the first week retain the cover on the drying vessel.
During the second week uncover the drying vessel progressively each day.
From the beginning of the third week leave the drying vessel fully open. Drying shall be complete at the end of the fourth week.
NOTE The drying and conditioning of the test specimens depend on the nature of the product undergoing testing and on the solvent or diluent used. For slow drying products it may be necessary to extend the conditioning process.
If in the case of slow drying products, the conditioning period is extended, the extended conditioning period shall be stated in the test report.
If the test specimens are to be subject to an ageing procedure, this shall be carried out after this drying procedure.
8.4 Examination of the test specimens
8.4.1 Examination without radiography
After 4 weeks (for larvae in Category 1) or 12 weeks (tor larvae in category 2), cut up the test specimens in the highest concentration.
If all the larvae are dead, cut up the set of test specimens at the next concentration below in the series and proceed in this way until a concentration is reached at which a live larva is first found in a test specimen. Store the remaining test specimens treated at this concentration as well as those treated at lower concentrations for a further 8 weeks in the case of larvae in Category 1 and a further 12 weeks in the case of larvae in Category 2.
Then resume cutting up the treated test specimens. For treated test specimens containing larvae, if a live larva is found, discontinue the second cutting up and keep the remaining treated test specimens for a further 12 weeks if larvae of Category 1, and 24 weeks if larvae of Category 2, following which cut them all up.
At the end of the test period, cut up all the control test specimens.
8.4.2 ExamInation with radiography, (larvae l Category 2)
Using the X-ray apparatus (5.3.13), radiograph all the test specimens after 12 weeks, cut up those test specimens containing larvae presumed dead in order to check their actual state and store those containing live larvae for a further 12 weeks before a further X-ray examination. Resume the examination, keeping those test specimens containing live larvae for a further 24 weeks, following which the test specimens shall be cut up.
8.4.3 Verification of the state of the larvae
If there is any doubt about the state of the live larvae in Category 2 at the end of the test, an additional test shall be carried out with these larvae in untreated test specimens for 4 weeks. Report their ability to bore. Those not able to bore normally shall be considered as moribund and counted as dead.
8.4.4 Validity of the test
The test shall be considered valid if at least 70 % of the larvae inserted into all of the untreated control test specimens, and at least 70 % of those inserted into all of the control test specimens treated with the solvent or the diluent alone, survive. Adult insects shall be included in this percentage. Otherwise, repeat the test.BS/EN 47-2016 pdf download.
BS/EN 47-2016 pdf download
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