BS/EN 46-1-2016 pdf download.Wood preservatives Determination of the preventive action against recently hatched larvae of Hylotrupes bajulus (Linnaeus) Part 1: Application by surface treatment (laboratory method).
8.1.3.1.3 ToxIc values
If toxic values are to be determined, prepare a series of at least five concentrations by mass, distributed evenly about the expected toxic values.
A solvent or diluent control, i.e. treatment at concentration = 0, shall also be used. If the approximate toxic values are unknown, the concentrations shall form a widely spaced geometric progression for a first test and a more closely spaced geometric or arithmetic progression for subsequent tests.
All treatment solutions shall be freshly prepared.
8.1.3.2 Treatment by brushing or by pipette
In the laboratory work area (5.3.3) apply the preservative either by brushing or by pipette to the 50 mm x 25 mm lateral face that would have been furthest from the centre of the tree.
Depending on the type of treatment, the volume (application by pipette) or mass (application by brushing) of the treatment solution shall he determined to obtain the surface application specified by the manufacturer. Place the specimens such that the 50 mm x 25 mm lateral face that is to be treated is uppermost and apply the appropriate fluid uniformly to that face.
When the preservative is applied by brush, place the test specimens on a balance while being brushed to determine the amount of preservative applied to the nearest 0,01g.
When the preservative is applied by pipette, move the pipette across the fibre direction and the amount of preservative applied shall be determined to the nearest 0,01 ml.
Several applications can be necessary to apply the required amount. In this case the coats should be applied sufficiently quickly to avoid any solidification of certain substances which can impede the penetration of further coats.
Care should be taken to avoid fluid running off the lateral face being treated.
8.1.3.3 Treatment by dipping
When the treatment of specimens is by dipping all faces, except one 25 mm x 50 mm face, shall be sealed (see 8.1.2).
Weigh to the nearest 0,01 g each sealed test specimen, to obtain its initial mass. Treat each test specimen in the treatment vessel (5.3.5) as follows:
Immerse completely in the solution. The dipping times to be used shall be one of the following, agreed beforehand according to the purpose of the test:
— Either one 10 s period and/or two periods of lOs at an interval of 24 h.
In the case of water-soluble chemicals, for example salts, and water-insoluble chemicals which are being studied as active insecticides, calculate the mass of chemical retained for each test specimen from the mass of solution absorbed and its concentration.
In the case of organic formulations or organic water-dispersible formulations, the retention is expressed for each test specimen in terms of the corresponding mass of the formulation ready for use, 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 area of unsealed wood surface.
8.1.4 Drying and conditioning of the test specimens after treatment
If the end-sealing has been damaged before or after treatment, reject the test specimens concerned from the tests.
After treatment, condition the test specimens for four weeks in the environment specified for the conditioning chamber (5.3.2). Arrange the test specimens on their lateral narrow faces, resting on glass rods, not touching one another. Invert the test specimens twice a week.
NOTE The drying and conditioning of the test specimens depend on the nature of the product under test 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.
lithe test specimens are to be subject to an ageing procedure (according to EN 73 or EN 84), this shall be carried out after this drying procedure.
8.2 Exposure of the test specimens to the insects
After the conditioning period has ended place one of the glass plates (5.3.8) against the treated face of each test specimen.
At one of the 50 mm edges, insert a spacer 0,35 mm thick between the glass plate and the test specimen so as to leave a gap 0,35 mm wide (see Figure 1).
Fix the plate by dipping the transverse faces and the narrow longitudinal face opposite the wedge in the paraffin wax (5.2.1) kept close to melting point so as to seal the openings at the edge of these faces. After cooling remove the wedge. Next place the ten larvae in the gap thus provided in the middle part of the test specimen.BS/EN 46-1-2016 pdf download.
BS/EN 46-1-2016 pdf download
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