prEN 47

SLOVENSKI STANDARD
01-december-2025
Biocidni proizvodi za zaščito lesa - Ugotavljanje toksičnih vrednosti proti ličinkam
hišnega kozlička Hylotrupes bajulus (Linnaeus) (laboratorijska metoda)
Wood preservatives - Determination of the toxic values against larvae of Hylotrupes
bajulus (Linnaeus) - (Laboratory method)
Holzschutzmittel - Bestimmung der Grenze der Wirksamkeit gegenüber Larven von
Hylotrupes bajulus (Linnaeus) - (Laboratoriumsverfahren)
Produits de préservation du bois - Détermination des valeurs toxiques contre les larves
d'Hylotrupes bajulus (Linnaeus) - (Méthode de laboratoire)
Ta slovenski standard je istoveten z: prEN 47
ICS:
71.100.50 Kemikalije za zaščito lesa Wood-protecting chemicals
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2025
ICS 71.100.50 Will supersede EN 47:2016
English Version
Wood preservatives - Determination of the toxic values
against larvae of Hylotrupes bajulus (Linnaeus) -
(Laboratory method)
Produits de préservation du bois - Détermination des Holzschutzmittel - Bestimmung der Grenze der
valeurs toxiques contre les larves d'Hylotrupes bajulus Wirksamkeit gegenüber Larven von Hylotrupes bajulus
(Linnaeus) - (Méthode de laboratoire) (Linnaeus) - (Laboratoriumsverfahren)
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 38.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATIO N

EUROPÄISCHES KOMITEE FÜR NORMUN G

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 47:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative reference . 6
3 Terms and definitions . 6
4 Principle . 6
5 Test materials . 7
5.1 Biological material . 7
5.1.1 Hylotrupes bajulus (Linnaeus) larvae . 7
5.1.2 Source of larvae . 7
5.1.3 Provision of larvae . 7
5.1.4 Choice of larvae in Category 2. 7
5.1.5 Number of larvae . 7
5.2 Products and reagents . 8
5.2.1 Xylene, technical grade. . 8
5.3 Apparatus . 8
6 Sampling . 9
7 Test specimens . 9
7.1 Species of wood . 9
7.2 Wood quality . 10
7.3 Provision of test specimens . 10
7.4 Dimensions of test specimens . 10
7.5 Number of test specimens . 10
8 Procedure. 11
8.1 Preparation of test specimens . 11
8.1.1 Conditioning of test specimens before treatment . 11
8.1.2 Treatment of the test specimens . 11
8.1.3 Drying and conditioning of the test specimens after treatment . 12
8.2 Exposure of the test specimens to the insects . 12
8.2.1 Use of larvae in Category 1 . 12
8.2.2 Use of larvae in Category 2 . 13
8.3 Conditions and duration of the test . 14
8.4 Examination of the test specimens . 14
8.4.1 Examination without imaging facilities . 14
8.4.2 Examination with imaging facilities, (larvae in Category 2) . 14
8.4.3 Verification of the state of the larvae . 14
8.4.4 Validity of the test . 14
9 Expression of results . 15
10 Test report . 15
Annex A (informative) Example of a test report . 17
Annex B (informative) Technique for culturing Hylotrupes bajulus (Linnaeus) . 19
B.1 General . 19
B.2 Obtaining parent beetles . 19
B.3 Mating . 19
B.4 Egg-Iaying . 19
B.5 Hatching of eggs . 20
B.6 Larval development . 20
B.7 Enemies and parasites . 21
Annex C (normative) Differentiation of heartwood and sapwood in Pinus species . 22
C.1 Principle . 22
C.2 Reagents . 22
C.3 Apparatus . 22
C.4 Procedure . 22
Annex D (informative) Environmental, health and safety precautions within
chemical/biological laboratory . 23
Bibliography . 24

European foreword
This document (prEN 47:2025) has been prepared by Technical Committee CEN/TC 38 “Biological
durability of wood and wood-based products”, the secretariat of which is held by SIS.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 47:2016.
The significant technical difference between this document and EN 47:2016 is as follows:
a) requirements for temperature and humidity were aligned with other insect test standards (5.3.1;
5.3.4; B5; B6);
b) imaging facilities for non-destructive recordings of insect tunnels inside test specimens were
generalized (5.3.13);
c) storage limitations for wood from which test specimens are to be made from were deleted (7.2).
NOTE Test results obtained according to earlier versions of this document or when the tests had started
before this version of EN 47 was published are considered as valid.

Introduction
This document describes a laboratory method of testing which gives a basis for the general assessment
of the effectiveness of a wood preservative against Hylotrupes bajulus by determination and comparison
with different classes of larvae, of the concentration at which the product prevents their survival in
totally impregnated wood of a susceptible species.
In this respect it differs from the methods specified in EN 46-1 and EN 46-2 which are intended to
determine whether a preservative applied to the surface is capable of preventing infestation of wood by
these larvae.
This laboratory method provides a criterion by which the value of a preservative can be assessed. In
making this assessment the methods by which the preservative may be applied should be taken into
account. It is further recommended that results from this test should be supplemented by those from
other appropriate tests and, above all, by comparison with practical experience.
When products which are very active at very low concentration are used, it is very important to take
suitable precautions to isolate and separate, as far as possible, operations involving chemical products,
other products, treated wood, laboratory apparatus and clothing. Suitable precautions should include
the use of separate rooms, areas within rooms, extraction facilities, conditioning chambers and special
training for personnel (see also Annex D for environmental, health and safety precautions).

1 Scope
This document specifies a method for the determination of the toxic values of a wood preservative
against the larvae of Hylotrupes bajulus (Linnaeus), introduced into wood treated previously by full
impregnation.
This method is applicable to:
— water-insoluble chemicals which are being studied as active insecticides;
— organic formulations, as supplied or as prepared in the laboratory by dilution of concentrates;
— organic water-dispersible formulations as supplied or as prepared in the laboratory by dilution of
concentrates;
— water-soluble materials, for example salts.
The method is applicable whether or not the test specimens have been subjected to appropriate ageing
procedures.
2 Normative reference
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN 73, Durability of wood and wood-based products — Accelerated ageing of treated wood prior to
biological testing — Evaporative ageing procedure
EN 84, Durability of wood and wood-based products — Accelerated ageing of treated wood prior to
biological testing — Leaching procedure
EN ISO 3696, Water for analytical laboratory use — Specification and test methods (ISO 3696)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
representative sample
sample having its physical or chemical characteristics identical to the volumetric average
characteristics of the total volume being sampled
3.2
supplier
sponsor of the test (person or company providing the sample of wood preservative to be tested)
4 Principle
Impregnation of several sets of test specimens of susceptible wood species with a series of
concentrations of the preservative.
Introduction of Hylotrupes bajulus larvae of a given category into these test specimens and
determination of their survival rate at fixed intervals of time.
Comparison of the results with those obtained with untreated and solvent or diluent-treated control
test specimens. Derivation of the toxic values of the product under test for the category of larvae in
question.
5 Test materials
5.1 Biological material
5.1.1 Hylotrupes bajulus (Linnaeus) larvae
— Category 1 (obligatory test): larvae within a maximum of 3 days of hatching;
— Category 2 (optional additional test): larvae with masses in the range 50 mg to 150 mg.
5.1.2 Source of larvae
The larvae shall preferably be obtained from cultures reared according to the method described in
Annex B.
Otherwise, larvae in Category 2 can be taken from naturally infested wood, in which case they should be
transferred into sapwood of Scots pine and stored for at least 4 weeks under the rearing conditions
specified in Annex B.
Do not use the larvae in the test if they have not fed normally during this storage period.
5.1.3 Provision of larvae
Collect larvae in Category 1 from eggs laid by different females.
Carefully cut out the larvae in Category 2 from the culture blocks and keep them separated from one
another for 2 days to 3 days in the culturing chamber (5.3.1) to check that they are healthy.
5.1.4 Choice of larvae in Category 2
Use only healthy larvae in the test.
NOTE A healthy larva can be recognized by its ivory-white colour, its firm consistency and rounded
appearance, and by the absence of wounds or bites which show up as dark marks. Healthy larvae react to the
touch by vigorous movement and attempts to bite.
Reject any larvae which are shrunken or aged, which have recently moulted, or which are in a pre-pupal
stage.
5.1.5 Number of larvae
The number of larvae per treated and control test specimen shall be six of Category 1 or one of Category
2.
Sort the larvae retained in Category 2 mentioned above.
Do not use larvae weighing more than 150 mg as they may pupate and therefore interfere with the test.
For a single test, use a mixed batch of larvae of Category 1 and for Category 2, as far as possible, use
larvae of similar masses. The number of larvae necessary is given in Table 1.
Table 1 — Number of larvae and test specimens
Larvae in Category 2
Larvae in Category 1
Concentrations
a
Without radiography With radiography
of
Type of test specimen
preservatives
Number of Number of Number of
Number Number Number
test test test
Mass fraction
of larvae of larvae of larvae
specimens specimens specimens
Treated test specimens 1 5 30 10 10 7 7
_ 2 5 30 10 10 7 7
_ 3 5 30 10 10 7 7
_ 4 5 30 10 10 7 7
_ 5 5 30 10 10 7 7
etc.
Untreated control test 0 5 30 10 10 7 7
specimens
Solvent or diluent 0 5 30 10 10 7 7
control test specimens
(including water)
Total for 5 concentrations 35 210 70 70 49 49
a
The use of radiography is only recommended in the case of tests with larvae in Category 2.

5.2 Products and reagents
5.2.1 Xylene, technical grade.
Other products may be used which have been shown suitable for preventing the growth of mould but
not interfere with the test method.
5.2.2 Water, complying with grade 3 of EN ISO 3696 shall be used.
5.2.3 Solvent or diluent, a volatile liquid that will dissolve or dilute the preservative but does not
leave a residue in the wood at the end of the post-treatment conditioning period that has a toxic effect
on the insects.
CAUTION — Do not use benzene or other solvents which pose a health risk.
5.2.4 Cellulose or absorbent cotton wool and filter paper
5.3 Apparatus
5.3.1 Culturing chamber, with air circulation, and controlled at (26 ± 2) °C and at relative humidity
(75 ± 5) %.
5.3.2 Conditioning chamber, well ventilated and controlled at (20 ± 2) °C and at relative humidity
(65 ± 5) %.
NOTE The conditioning of test specimens can be carried out in the laboratory work area (see 5.3.3) provided
that this has the conditions specified for the conditioning chamber (see 5.3.2).
5.3.3 Laboratory work area, well ventilated, where treatment of the test specimens is carried out.
CAUTION — It is essential to follow safety procedures for handling flammable and toxic
materials. Avoid excessive exposure of operators to solvents or their vapours.
5.3.4 Testing chamber, ventilated and air-conditioned, controlled at (22 ± 2) °C and at a relative
humidity of (75 ± 5) %.
5.3.5 Treatment vessels, of a material that does not react with the preservative under test, for
example of glass for organic products and of polyethylene for salts containing fluorine.
5.3.6 Weights, to provide ballast for the test specimens. The weights shall not react with any
materials with which they come into contact during the test.
5.3.7 Safety equipment, protective clothing, protective gloves appropriate for the test product
and the test solvent, to ensure the safety of the operator.
5.3.8 Vacuum vessel(s), fitted with stopcocks, capable of receiving the treatment vessels (5.3.5).
)
5.3.9 Vacuum pump, fitted with a pressure gauge and capable of maintaining a pressure of 700 Pa .
5.3.10 Drying vessel(s), capable of holding sets of five test specimens (7.5), provided with a close-
fitting cover and containing supports that will give minimum contact with treated test specimens to be
placed on them. The vessels and supports shall be of a material that does not react with the
preservative under test, for example glass for organic compounds and polyethylene for products
containing fluorine.
5.3.11 Drill and twist drills, approximately 3,0 mm to 4,5 mm in diameter, and a fine awl. In all cases,
the number of bits shall be sufficient to drill holes to the size of the larvae available; in the case of larvae
of Category 1, use a steel awl.
5.3.12 Ordinary laboratory equipment, including a balance capable of weighing to an accuracy of
0,01 g.
5.3.13 Imaging facilities e.g. X-ray apparatus, or any other device that offers good images (2D), of
internal tunnels caused by small larvae.
6 Sampling
The sample of preservative shall be representative of the product to be tested. Samples shall be stored
and handled in accordance with any written recommendations from the supplier.
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 reference species is Scots pine (Pinus sylvestris Linnaeus) .

1)
100 Pa = 1 mbar.
2)
In southern European countries the species of pine most frequently infested by Hylotrupes bajulus may be used as an
alternative, provided that the suitability of the species for use in the tests specified in this document has been demonstrated in
all aspects (development of larvae, resistance to impregnation, etc.).
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 be free from visible cracks, stain, decay, insect damage and other defects. The wood
shall not have been water-stored, floated, chemically treated or steamed. The wood shall originate from
trees preferably felled in winter. The trees shall be cut immediately after felling and the timber rapidly
air-dried or kiln dried at temperatures below 60 °C.
The wood shall be exclusively sapwood containing little resin and having between 2,5 and 8 annual
rings per 10 mm. The proportion of latewood in the annual rings shall not exceed 30 % of the whole.
It is recommended to use test specimens of similar growth rate within a single test.
7.3 Provision of test specimens
Prepare planed strips having a cross-section of (25 ± 0,5) mm × (15 ± 0,5) mm removing a minimum of
2 mm from any faces exposed during drying. The longitudinal faces shall be parallel to the direction of
the grain. The annual rings shall have a contact angle of greater than 10° to the faces of the test
specimens. Make transverse cuts, neatly to give sharp edges and a fine-sawn finish to the end-grain
surfaces, to give test specimens (50 ± 0,5) mm long.
The specimens shall originate from a minimum of three trees or shall be taken at random from a stock
originally of more than 500 test specimens.
7.4 Dimensions of test specimens
The dimensions of each test specimen after reaching equilibrium in the conditioning chamber (5.3.2)
shall be (50 ± 0,5) mm × (25 ± 0,5) mm × (15 ± 0,5) mm.
For the purposes of calculating the mass of preservative retained per unit volume of wood (8.1.2.2) the
nominal volume
...