prEN 46-2

SLOVENSKI STANDARD
01-december-2025
Biocidni proizvodi za zaščito lesa - Ugotavljanje preventivnega delovanja proti
hišnemu kozličku Hylotrupes bajulus (Linnaeus) - 2. del: Ovicidni učinek
(laboratorijska metoda)
Wood preservatives - Determination of the preventive action against recently hatched
larvae of Hylotrupes bajulus (Linnaeus) - Part 2: Ovicidal effect (Laboratory method)
Holzschutzmittel - Bestimmung der vorbeugenden Wirkung gegenüber frisch
geschlüpften Larven von Hylotrupes bajulus (Linnaeus) - Teil 2: Ovizide Wirkung
(Laboratoriumsverfahren)
Produits de préservation du bois - Détermination de l'action préventive contre les larves
récemment écloses d'Hylotrupes bajulus (Linnaeus) - Partie 2 : Effet ovicide (Méthode
de laboratoire)
Ta slovenski standard je istoveten z: prEN 46-2
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 46-2:2016
English Version
Wood preservatives - Determination of the preventive
action against recently hatched larvae of Hylotrupes
bajulus (Linnaeus) - Part 2: Ovicidal effect (Laboratory
method)
Produits de préservation du bois - Détermination de Holzschutzmittel - Bestimmung der vorbeugenden
l'action préventive contre les larves récemment écloses Wirkung gegenüber frisch geschlüpften Larven von
d'Hylotrupes bajulus (Linnaeus) - Partie 2 : Effet ovicide Hylotrupes bajulus (Linnaeus) - Teil 2: Ovizide Wirkung
(Méthode de laboratoire) (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 46-2:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Principle . 7
5 Test materials . 7
5.1 Biological material . 7
5.2 Products and reagents . 7
5.3 Apparatus . 7
6 Sampling . 8
7 Test specimens . 9
7.1 Species of wood. 9
7.2 Wood quality . 9
7.3 Provision of test specimens . 9
7.4 Dimensions of test specimens . 9
7.5 Number of test specimens. 9
7.5.1 Test specimens for egg-laying . 9
7.5.2 Test specimens for checking the tunnelling ability and the mortality of the
larvae . 10
8 Procedure . 10
8.1 Preparation of the test specimens . 10
8.1.1 Conditioning of the test specimens prior to sealing . 10
8.1.2 Sealing of test specimen faces . 10
8.1.3 Treatment of the test specimens . 11
8.1.4 Drying and conditioning of the test specimens after treatment . 12
8.2 Exposure of the test specimens to the insects (ovicidal action) . 12
8.3 Validity of the test . 13
9 Expression of results . 13
9.1 Ovicidal test . 13
9.2 Tunnelling control . 14
9.3 Total mortality . 14
10 Test report . 14
Annex A (informative) Example of a test report . 16
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 (informative) 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 46-2:2025) 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 46-2:2016.
Significant technical differences between this document and EN 46-2:2016 are as follows:
a) specifications for sealing faces of test specimens to be treated with solutions in which an
organic solvent is the continuous phase were generalized (5.2.2);
b) requirements for temperature and humidity were aligned with other insect test standards
(5.3.1; 5.3.4; B5; B6);
c) imaging facilities for non-destructive recordings of insect tunnels inside test specimens
were generalized (5.3.11);
d) storage limitations for wood from which test specimens are to be made were deleted (7.2);
e) specifications for dipping (8.1.3.3) were generalized and aligned with other insect
standards.
NOTE Test results obtained according to earlier versions of this document or when the tests had
started before this version of EN 46-2 was published are considered as valid.
The standard EN 46 is composed of two parts:
— EN 46-1, Wood preservatives ― Determination of the preventive action against recently
hatched larvae of Hylotrupes bajulus (Linnaeus) ― Part 1: Application by surface treatment
(laboratory method)
— EN 46-2, Wood preservatives ― Determination of the preventive action against recently
hatched larvae of Hylotrupes bajulus (Linnaeus) ― Part 2: Ovicidal effect (laboratory method)
EN 46 consists of two parts to enable preventive action of wood preservatives, against recently
hatched larvae of Hylotrupes bajulus, which are intended to be applied by surface treatment; Part
1 is required to determine the larvicidal effect of preservatives and Part 2 is required to
determine the ovicidal action of the preservatives after egg-laying of young females.

Introduction
This document describes a laboratory method of test which gives a basis for the assessment of
the preventive action of a wood preservative, when applied as a surface treatment for timber,
against eggs of Hylotrupes bajulus.
In combination with EN 46-1 it provides a means of checking whether larvae may hatch from
eggs laid on the treated wood surface and whether they are capable of boring through the
treated surface and of surviving in the untreated part of the wood.
This document provides information for the sealing of all but one lateral face when specimens
are to be treated by dipping.
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 preventive action of a wood
preservative against eggs of Hylotrupes bajulus (Linnaeus) when the preservative is applied as a
surface treatment to wood.
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; or
— 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 references
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 46-1, Wood preservatives — Determination of the preventive action against recently hatched
larvae of Hylotrupes bajulus (Linnaeus) — Part 1: Application by surface treatment (Laboratory
method)
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 835, Laboratory glassware — Graduated pipettes (ISO 835)
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 and/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
In this laboratory method treated wood panels are exposed to freshly mated Hylotrupes bajulus
females. The hatching ability of the larvae on the treated timber is examined. When the ovicidal
action is insufficient, the mortality of the hatched larvae on or in wood treated with the same
formulation is also established according to EN 46-1.
5 Test materials
5.1 Biological material
5.1.1 Hylotrupes bajulus (Linnaeus) females.
5.1.2 Source of females
The insects shall preferably be obtained from cultures reared as e. g. described in Annex B.
Use only sound and lively insects.
5.2 Products and reagents
5.2.1 Paraffin wax, for fixing the glass plate in all cases and for sealing the end faces as well as
all relevant other faces of test specimens to be treated with solutions in all cases in which water
is the continuous phase (see 8.1.2.1 and 8.1.2.2).
NOTE Paraffin wax with a setting point of approx. 52 °C to 54 °C has been found to be suitable.
5.2.2 Sealant, for sealing the end faces and all relevant other faces of test specimens to be
treated with solutions in all cases in which an organic solvent is the continuous phase (see
8.1.2.1 and 8.1.2.3). The sealant must be resistant to penetration by the wood preservative under
test and the respective solvent. The sealant must not act repellent or insecticidal in the test
specimen.
NOTE Gelatine or two to three coats of a two-component epoxy varnish with a drying step between
each coat has been found to be suitable.
5.2.3 Water, complying with grade 3 of EN ISO 3696 shall be used.
5.2.4 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.
5.3 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) %.
The conditioning of test specimens may 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
relative humidity between (75 ± 5) %.
5.3.5 Petri dishes of glass or polyvinylchloride (PVC), diameter ca. 9 cm for mating the insects
and for egg-laying.
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 Glass plates, (48 ± 1) mm long and (25 ± 1) mm wide, intended to provide a lateral slit
on the test specimens.
5.3.9 Ordinary laboratory equipment, including a balance capable of weighing to an
accuracy of 0,01 g and equipment for applying a liquid product by brushing or by pipette.
5.3.10 Pipette, specified in EN ISO 835 shall be used, or brush.
5.3.11 Imaging facilities e. g. X-ray apparatus, or any other device that offers good images
(2D), of internal tunnels caused by small larvae.
5.3.12 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.
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) .
Additional tests may be carried out using other species but, if so, this shall 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 to 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 surfaces exposed during drying. The longitudinal faces shall be
parallel to the direction of the grain. The annual rings shall have a contact angle of 45° ± 15° 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 (50 ± 0,5) mm long.
The test 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.
Mark each test specimen so that it can be identified throughout the test.
7.5 Number of test specimens
7.5.1 Test specimens for egg-laying
a) Six treated test specimens (no more than two originating from the same tree unless taken at
random from a stock of more than 500) for each preservative, each concentration and each
duration of treatment;
1)
In southern European countries the pine species 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 standard has been
demonstrated in all aspects (development of larvae, resistance of impregnation, etc.).
2)
For special tests, test specimens may be obtained according to a given series. As a result, it may be preferable to
take test specimens from pretreated strips. Where pretreated strips are used details should be included in the test
report.
b) three untreated control test specimens (each originating from a different tree unless taken
at random from a stock of more than 500) for a complete test of any given preservative;
c) three control test specimens treated with the solvent or diluent (5.2.3 or 5.2.4) (each
originating from a different tree unless taken at random from a stock of more than 500) if a
solvent or diluent (including water) is used.
Control test specimens under c) may be omitted if the solvent or diluents is water of drinking
quality.
When dipping is to be used (8.1.3.3) it is advisable to treat more than the specified number of
test specimens so that, after weighing, any test specimens with abnormally high or low
retentions can be rejected from the batch.
To gain further information on a formulation, the manufacturer may find it useful to test a
version of the preservative where the active ingredient(s) has been removed.
7.5.2 Test specimens for checking the tunnelling ability and the mortality of the larvae
In addition to the test specimens for egg-laying at least six test specimens shall be prepared for
each preservative concentration and retention for checking the tunnelling
...