EN 46-2:2026

• Abstract:

  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.

• Status: Not Published
• Publication Date: 01-Dec-2026
• ICS: 71.100.50 - Wood-protecting chemicals
• Technical Committee: CEN/TC 38 - Durability of wood and derived materials
• Drafting Committee: CEN/TC 38/WG 24 - Insect testing - (beetles - termites)
• Current Stage: 5060 - Closure of Vote - Formal Approval
• Start Date: 24-Sep-2026
• Due Date: 03-Feb-2027
• Completion Date: 24-Sep-2026
• Ref Project: kSIST FprEN 46-2:2026 - Wood preservatives - Determination of the preventive action against recently hatched larvae of Hylotrupes bajulus (Linnaeus) - Part 2: Ovicidal effect (Laboratory method)

• Revises: EN 46-2:2016 - Wood preservatives - Determination of the preventive action against recently hatched larvae of Hylotrupes bajulus (Linnaeus) - Part 2: Ovicidal effect (laboratory method)
• Effective Date: 12-Apr-2023

EN 46-2:2026 is a CEN laboratory standard for assessing the preventive action of a wood preservative against eggs of Hylotrupes bajulus (Linnaeus) when the product is applied as a surface treatment to wood. It is written for laboratories and product developers that need to check whether eggs laid on treated wood hatch, and, when needed, whether the larvae can tunnel through the treated surface and survive in the wood.

What does EN 46-2:2026 specify?

EN 46-2:2026 specifies a laboratory method for determining the ovicidal effect of a wood preservative on eggs of Hylotrupes bajulus on treated wood surfaces. The method applies to water-insoluble chemicals, organic formulations, organic water-dispersible formulations, and water-soluble materials such as salts, and it may be used with specimens that have undergone ageing procedures.

The document is organized into clauses for scope, normative references, terms and definitions, principle, test materials, sampling, test specimens, procedure, expression of results, and test report. Its annexes add practical support material.

Annex	What it covers
Annex A	Example of a test report
Annex B	Technique for culturing Hylotrupes bajulus (Linnaeus)
Annex C	Differentiation of heartwood and sapwood in Pinus species
Annex D	Environmental, health and safety precautions within chemical/biological laboratory

What are the key requirements of EN 46-2:2026?

EN 46-2:2026 is built around exposing treated wood panels to freshly mated Hylotrupes bajulus females and then measuring how many eggs hatch. When ovicidal action is not enough on its own, the standard also uses EN 46-1 to check larval tunnelling and mortality on the same formulation. In practice, that means the test looks at the egg stage first and then follows the biological consequences if larvae do emerge.

• Clause 4 - principle. EN 46-2:2026 requires treated panels to be exposed to freshly mated females, with hatching examined on the treated timber. If ovicidal action is insufficient, larval mortality and tunnelling are checked according to EN 46-1. This matters because the standard separates egg killing from the later survival of larvae.

• Clauses 5 and 6 - test materials and sampling. EN 46-2:2026 uses Hylotrupes bajulus females from cultures, representative preservative samples, grade 3 water from EN ISO 3696, and suitable solvents or diluents. Samples are to be representative of the product and handled according to supplier instructions; bulk sampling follows EN 212. This matters because the test result must reflect the product as supplied, not a poorly chosen sample.

• Clause 7 - test specimens. EN 46-2:2026 uses Scots pine (Pinus sylvestris Linnaeus) as the reference species, with sound sapwood and defined specimen dimensions. The standard also sets specimen numbers for treated pieces, untreated controls, solvent or diluent controls, and additional specimens for tunnelling and mortality checks. This matters because wood quality and specimen count affect penetration, egg-laying, and result validity.

• Clause 8.1 - preparation and sealing. EN 46-2:2026 requires conditioning before sealing, then sealing of the specimen faces according to the treatment method. For water-continuous treatments, paraffin wax is used; for organic solvent systems, a resistant sealant is used. This matters because only the intended surface should be exposed to the preservative and to the insect.

• Clause 8.1.3 - treatment. EN 46-2:2026 allows brushing, pipette application, or dipping, with freshly prepared treatment solutions. The method also requires measuring the applied mass or volume and, for dipping, calculating retained preservative per unit area. This matters because dose is central to comparing products and interpreting performance.

• Clause 8.1.4 and 8.2 - drying, conditioning, and insect exposure. EN 46-2:2026 requires post-treatment conditioning, with longer conditioning allowed for slow-drying products, and ageing according to EN 73 or EN 84 when needed. Females are mated in Petri dishes, exposed to the treated specimens for egg-laying, and examined daily for hatching; if too few eggs are laid, the procedure is repeated. This matters because the insects must see a realistic treated surface, and the test must still produce enough eggs for a meaningful result.

• Clause 8.3 and clause 9 - validity and results. EN 46-2:2026 considers the test valid only if at least 70 % of larvae survive in the untreated controls, and in the solvent or diluent controls where used. Results include egg mortality, larval mortality, and total mortality. This matters because weak control survival would make the test unreliable.

• Clause 10 - test report. EN 46-2:2026 requires a report with the document number, supplier, preservative identity, active ingredient, solvent or diluent, wood species, application method, drying and ageing details, dates, results, and any deviations. This matters because users need a traceable record to compare products or repeat the test.

What terms does EN 46-2:2026 define?

• Representative sample - a sample whose physical and/or chemical characteristics match the volumetric average characteristics of the total volume being sampled.
• Supplier - the sponsor of the test, meaning the person or company providing the wood preservative sample to be tested.
• Hylotrupes bajulus (Linnaeus) - the house longhorn beetle used as the test insect in this standard.
• Ovicidal action - the effect of the preservative on eggs, shown here by whether eggs laid on treated wood hatch.
• Tunnelling ability - the ability of newly hatched larvae to bore into treated wood, which is checked with EN 46-1 when needed.
• Total mortality - the combined outcome based on egg mortality and larval mortality.
• Scots pine (Pinus sylvestris Linnaeus) - the reference wood species used for the test specimens.

Who uses EN 46-2:2026?

EN 46-2:2026 is used by laboratories that test wood preservatives, by manufacturers and formulators of wood-protecting chemicals, and by organizations that evaluate treated timber performance. It is also relevant to quality and technical staff who need controlled laboratory evidence for surface-treated wood products.

The standard supports product development, comparison of formulations, verification of treatment methods such as brushing, pipette application, and dipping, and preparation of test reports for technical review. Annex B is useful to laboratories that culture Hylotrupes bajulus themselves, while Annex C helps when heartwood and sapwood need to be distinguished in Pinus species.

What changed in EN 46-2:2026 from the previous edition?

EN 46-2:2026 supersedes EN 46-2:2016. The foreword states that the update generalizes the sealing requirements for specimens treated with solutions in which an organic solvent is the continuous phase, aligns temperature and humidity requirements with other insect test standards, generalizes imaging facilities for non-destructive recording of tunnels, deletes storage limitations for wood used for specimens, and generalizes dipping specifications in line with other insect standards.

The foreword also notes that test results obtained according to earlier versions, or from tests already started before this version was published, are considered valid.

Which standards are used with EN 46-2:2026?

EN 46-2:2026 cites EN 46-1 as the companion part for larval tunnelling and mortality when eggs hatch on treated wood. It cites EN 73 and EN 84 for accelerated ageing of treated wood before biological testing, which means specimens can be preconditioned to reflect ageing effects before exposure.

EN ISO 835 provides the pipette specification used for liquid application, and EN ISO 3696 provides the water quality requirement for laboratory use. EN 212 is named for sampling preservative from bulk supplies, so it supports representative sampling before testing.

What does the EN 46-2:2026 document contain?

EN 46-2:2026 contains the full laboratory workflow for specimen preparation, sealing, treatment, drying, exposure to insects, and reporting. It also includes the validity check and the way to express egg mortality, larval mortality, and total mortality.

Annex A provides a worked example of a test report, including the kind of data recorded for treated and control specimens. Annex B describes culturing Hylotrupes bajulus, including mating, egg-laying, hatching, larval development, and precautions against enemies and parasites. Annex C gives a practical stain-based method for distinguishing heartwood and sapwood in Pinus species, and Annex D lists environmental, health and safety precautions for chemical and biological laboratory work.

SLOVENSKI STANDARD
oSIST prEN 46-2:2025
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
oSIST prEN 46-2:2025 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 46-2:2025
oSIST prEN 46-2:2025
DRAFT
EUROPEAN STANDARD
prEN 46-2
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.

oSIST prEN 46-2:2025
prEN 46-2:2025 (E)
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
oSIST prEN 46-2:2025
prEN 46-2:2024 (E)
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

oSIST prEN 46-2:2025
prEN 46-2:2025 (E)
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.

oSIST prEN 46-2:2025
prEN 46-2:2024 (E)
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).

oSIST prEN 46-2:2025
prEN 46-2:2025 (E)
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
oSIST prEN 46-2:2025
prEN 46-2:2024 (E)
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) %.
oSIST prEN 46-2:2025
prEN 46-2:2025 (E)
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.
oSIST prEN 46-2:2025
prEN 46-2:2024 (E)
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.
oSIST prEN 46-2:2025
prEN 46-2:2025 (E)
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
...