A European standard “EN 47 Wood preservatives - Determination of toxic values against larvae of Hylotrupes bajulus (linnaeus) - (Laboratory method)” describes a procedure for determining the toxic values of a wood preservative against larvae of Hylotrupes bajulus (linnaeus) introduced into wood previously treated with full impregnation. These insects damage wooden materials.
-larvalarina-karsi-toksik-degerlerin-belirlenmesi-(laboratuvar-yontemi).jpg "EN 47 Wood Preservatives - Determination of Toxic Values Against Hylotrupes Bajulus (Linnaeus) Larvae - (Laboratory Method)")
This method can be applied to:
This method can be applied regardless of whether the test samples have been subjected to appropriate aging procedures.
For the purposes of this document, the following terms and definitions apply:
This test is based on the following principles:
The preservative sample should be representative of the product to be tested. Samples should be stored and processed in accordance with the written recommendations of the supplier. For sampling of preservatives from bulk supplies, the procedure described in the standard “EN 212 Wood preservatives - General guidance on sampling and preparation for the analysis of wood preservatives and treated timber” should be used.
The reference species Scots pine is used in the tests. Additional tests can be performed using other species, but if so, this must be stated in the test report.
The wood should be free from visible cracks, stains, rot, insect damage and other defects. The wood should not have been stored in water, floated, chemically treated or steamed. The wood should preferably come from trees felled in the winter. The trees should be felled immediately after felling and the timber should be air or kiln dried rapidly at temperatures below 60 degrees. The wood should not have been stored for more than five years.
The wood should be only sapwood with little resin and varying from 10 annual rings per 2,5 mm to eight annual rings per 10 mm. The proportion of latewood in the annual rings should not exceed 30 percent of the whole. It is recommended to use test specimens with similar growth rates in a single test.
Prepare planed strips with a cross-section of 2 mm plus/minus 25 mm × 0,5 mm plus/minus 15 mm, removing at least 0,5 mm from any surface exposed during drying. The longitudinal surfaces shall be parallel to the grain direction. The annual rings shall have a contact angle greater than 10 degrees to the surfaces of the test specimens. In order for the test specimens to be 50 mm plus/minus 0,5 mm long, smooth cross-cuts shall be made to give the end grain surfaces sharp edges and a finely cut surface. Samples shall be taken from at least three trees or taken at random from an initial stock of more than 500 test specimens.
The dimensions of each test specimen after reaching equilibrium in the conditioning chamber shall be 50 mm plus/minus 0,5 mm × 25 mm plus/minus 0,5 mm × 15 mm plus/minus 0,5 mm. For the purpose of calculating the mass of the preservative retained per unit volume of wood, the nominal volume of each test specimen shall be taken as 18,75 cm3. Each test specimen shall be marked in such a way that it can be identified throughout the test.
The number of test samples required is shown in the table provided in the standard. It is recommended to process more test samples than the specified number so that any test samples with abnormally high or low retention values after weighing can be rejected from the lot.
Among the numerous tests, measurements, analyses and evaluation studies carried out for businesses in various sectors, our organization also provides testing services defined in the standard “EN 47 Wood preservatives - Determination of toxic values against Hylotrupes bajulus (linnaeus) larvae - (Laboratory method)” with its trained and expert staff and advanced technological equipment.
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