BS EN 12490-1999 Durability of wood and wood-based products D Preservative-treated solid wood D Determination of the penetration and retention of creosote in treated wood1.pdf
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 12490:1999 The European Standard EN 12490:1998 has the status of a British Standard ICS 79.040 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Durability of wood and wood-based products Ð Preservative-treated solid wood Ð Determination of the penetration and retention of creosote in treated wood This British Standard, having been prepared under the direction of the Sector Committee for Building and Civil Engineering, was published under the authority of the Standards Committee and comes into effect on 15 June 1999 BSI 06-1999 ISBN 0 580 32071 5 BS EN 12490:1999 Amendments issued since publication Amd. No.DateComments National foreword This British Standard is the English language version of EN 12490:1998. The UK participation in its preparation was entrusted by Technical Committee B/515, Wood preservation, to Subcommittee B/515/2, Specifications and chemical testing of wood preservatives, which has the responsibility to: Ð aid enquirers to understand the text; Ð present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; Ð monitor related international and European developments and promulgate them in the UK. A list of organizations represented on this subcommittee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled ªInternational Standards Correspondence Indexº, or by using the ªFindº facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 7 and a back cover. CEN European Committee for Standardization Comite  Europe Âen de Normalisation Europa Èisches Komitee fu Èr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12490:1998 E EUROPEAN STANDARDEN 12490 NORME EUROPE ÂENNE EUROPA ÈISCHE NORM November 1998 ICS 71.100.50 Descriptors: wood, sawn timber, wood preservatives, impregnating, creosote, sampling, analysis methods English version Durability of wood and wood-based products Ð Preservative-treated solid wood Ð Determination of the penetration and retention of creosote in treated wood Durabilite  du bois et des mate Âriaux de Ârive Âs du bois Ð Bois massif traite  avec produit de pre Âservation Ð De Âtermination des pe Âne Âtrations et re Âtentions des cre Âosotes dans le bois traite  Dauerhaftigkeit von Holz und Holzwerkstoffen Ð Mit Holzschulzmitteln behandeltes Vollholz Ð Bestimmung der Eindringtiefe und der Teerimpra Ègniero Èlaufnahme in behandeltem Holz This European Standard was approved by CEN on 8 November 1998. 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. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists 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 Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Page 2 EN 12490:1998 BSI 06-1999 Foreword This European Standard has been prepared by Technical Committee CEN/TC 38, Durability of wood and derived materials, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 1999, and conflicting national standards shall be withdrawn at the latest by May 1999. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Contents Page Foreword2 1Scope3 2Normative references3 3Definitions3 4Sampling of creosote-treated wood for the determination of penetration and retention3 5Determination of the penetration of creosote in treated wood4 6Determination of the retention of creosote in treated wood4 7Test report6 Annex A (informative) Sapwood/heartwood boundary determination7 Annex B (normative) Density of some selected timber species that are commonly treated with creosote7 Annex C (informative) Bibliography7 Page 3 EN 12490:1998 BSI 06-1999 1 Scope This European Standard specifies the reference method for determining the penetration and retention of creosote in timber freshly-treated with creosote, principally in order to ascertain whether the treated timber conforms to specifications written in terms of EN 351-1. It also provides guidance on the acquisition of test samples and their handling between sampling and analysis. NOTEIn the day-to-day practice at the plant, other methods (e.g. weighing the charge before and after treatment) can be used for determining the retention, provided that a significant relationship can be established with this method. 2 Normative references This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. EN 351-1, Durability of wood and wood-based products Ð Preservative-treated solid wood Ð Part 1: Classification of preservative penetration and retention. EN 351-2, Durability of wood and wood-based products Ð Preservative-treated solid wood Ð Part 2: Guidance on sampling for the analysis of preservative-treated wood. EN ISO 3696, Water for analytical laboratory use Ð Specification and test methods (ISO 3696:1987). ISO 3131, Wood Ð Determination of density for physical and mechanical tests. 3 Definitions For the purposes of this European Standard, the following definitions apply. 3.1 analytical zone the part of the treated wood which is analysed for assessing the retention requirement (3.6) 3.2 batch clearly identifiable collection of units of preservative-treated wood manufactured to comply with the same defined penetration and retention requirements 3.3 charge all the wood treated together in a single operation 3.4 composite sample collection of all test samples derived from the sampling units taken from the batch in accordance with the chosen sampling plan for the determination of retention 3.5 penetration requirement minimum depth to which the creosote is required to penetrate the wood NOTEThe penetration requirement is expressed in millimetres. 3.6 retention requirement minimum loading of the creosote that is required in the analytical zone (3.1) NOTEThe retention requirement is expressed in kilograms of creosote per cubic metre of treated wood. 3.7 sampling unit one unit (for example a pole, a sleeper, a board or a fence post) of preservative treated wood taken from a batch (3.2) or charge (3.3) of preservative treated wood 3.8 test sample a portion of preservative treated wood taken from a sampling unit, in accordance with the recommendations of EN 351-2 3.9 transition wood wood in a zone between the true sapwood and the true heartwood NOTEThis is distinguishable only in a very few wood species. In general its treatability is similar to that of heartwood. 4 Sampling of creosote-treated wood for the determination of penetration and retention 4.1 General requirements The acquisition of sampling units and test samples shall follow the procedures established in EN 351-1 and EN 351-2. Additionally, when sampling from a freshly treated batch, the wood shall be allowed to cool to ambient temperature before taking test samples. 4.2 Specific requirements for test samples for the determination of penetration The penetration of creosote in each of the test samples shall be determined immediately after sampling, according to clause 5, in order to avoid creosote creeping from the treated to the untreated area. Page 4 EN 12490:1998 BSI 06-1999 4.3 Specific requirements for test samples for the determination of retention A batch to be sampled for the determination of retention shall be sampled at a time less than 30 days after the treatment. NOTE 1The retention requirements defined by the specifier are only applicable to treated wood as produced, not to the treated wood in service. The composite sample for a batch or charge shall comprise test samples taken in accordance with the chosen sampling plan. Sufficient test sample material shall be taken to ensure that at least 1 g of creosote is contained in the composite sample. NOTE 2Wood treated with creosote by vacuum/high pressure processes can normally be expected to contain more than 10 % by mass of creosote. Therefore, it will require approximately 10 g to 12 g of creosoted wood to obtain at least 1 g of creosote in the composite sample. NOTE 3The larger the number of test samples included in the composite sample, the more accurate should be the resultant retention determination. As soon as possible after the test samples have been obtained, and the penetration measured, the wood not included in the specified analytical zone of the test samples shall be removed. The remaining wood constitutes the composite sample for the determination of retention. NOTE 4If the penetration and retention are determined from the same test samples, the penetration should be determined before any wood is removed from the test samples. The composite sample shall be stored in a stoppered glass bottle to prevent any free creosote being lost before the analysis. 5 Determination of the penetration of creosote in treated wood For each of the test samples, measure and record the penetration of creosote in the treated wood, as the distance (in millimetres) of the furthest point from the surface to which creosote can be seen to be present in the wood, in accordance with the general recommendations in EN 351-2. NOTE 1Penetration should be assessed visually from a freshly cut test sample, the colour of the creosote clearly indicating its extent in the treated timber. NOTE 2In some cases the creosote may not penetrate continuously through the early and late wood of the treated timber. NOTE 3If the boundary between the sapwood and the heartwood cannot be distinguished visually, in some cases a chemical method can be used to distinguish between them. Some examples are given in annex A. Where no distinction is possible, all the wood is regarded as sapwood. NOTE 4Occasionnally small zones of sapwood adjacent to the heartwood cannot be treated, for example transition wood. These should be ignored for the purposes of assessing sapwood penetration. 6 Determination of the retention of creosote in treated wood 6.1 Reagents 6.1.1 Water, of grade 3, according to EN ISO 3696. 6.1.2 Chromic acid saturated solution, in concentrated sulfuric acid. 6.1.3 Toluene, C6H5CH3, analytical grade. 6.1.4 Suitable detergent solution, in water. 6.2 Apparatus Ordinary laboratory apparatus and the following (see Figure 1). 6.2.1 Glass round-bottomed flask, capacity 500 ml or 1 000 ml. 6.2.2 Heating mantle, for the glass round-bottomed flask (6.2.1). 6.2.3 Glass Soxhlet-apparatus, capacity 60 ml. 6.2.4 Cellulose extraction thimble, (28 mm diameter and 80 mm height). 6.2.5 Glass water trap, Dean and Stark type, with a capacity of 10 ml, fitted with a stopcock and marked in graduations of 0,1 ml. 6.2.6 Glass reflux condenser, of the ªLiebig-Westº type. 6.2.7 Balance, with an accuracy of 0,01 g. 6.2.8 Glass rod, or rod made of another inert material, with a diameter of about 3 mm and as long as the condenser (6.2.6) and the water trap (6.2.5) together. 6.2.9 Vented drying oven, that can be maintained at (115±5) 8C and operated in a fume cupboard. 6.2.10 Desiccator, with a drying agent of the indicating type (e.g. silica gel). 6.3 Preparation of the water trap and the condenser before the extraction Thoroughly clean the inner surface of the water trap (6.2.5) of the apparatus and the inside surface of the condenser (6.2.6) with a warm solution (50 8C to608C) of detergent (6.1.4). Rinse throughly to remove all trace of detergent with water (6.1.1), and allow to drain for a few minutes. Dry the outer surface of the water trap. Inspect carefully the inner surface of the water trap and condenser. If droplets of water remain on these surfaces, repeat the cleaning operation several times with the detergent solution (6.1.4). If this fails to produce droplet-free inner surfaces, rinse the equipment several times with a saturated solution of chromic acid (6.1.2). CAUTION Care should be taken to prevent contact of the chromic acid solution (6.1.2) with skin or clothing. If contact does occur, wash immediately with copious quantities of water. After treatment with this acid solution, rinse the apparatus thoroughly with water (6.1.1), drain and inspect as before. Repeat the cleaning operation, if necessary. 6.4 Procedure for the extraction of creosote from the composite sample Heat an empty extraction thimble (6.2.4) in the oven (6.2.9) at (115±5) 8C for a minimum of 90 min. Transfer it to the dessicator (6.2.10) and allow it to cool to room temperature. CAUTION Do the following operations in a fume cupboard. Page 5 EN 12490:1998 BSI 06-1999 Transfer about 200 ml of toluene (6.1.3) to the round-bottomed flask (6.2.1) and add approximately 2 ml of water (6.1.1). Assemble the apparatus as in Figure 1. Place the flask (6.2.1) in the heating mantle (6.2.2), apply heat a
