DEAS 325: 2023 
ICS 71.100.50  
 
© EAC 2023                                                                                                                        Second  Edition 2023  
 DRAFT EAST AFRICAN STANDARD  
Wood preservatives and treated timber — Guide to sampling and 
preparation of wood preservatives and treated timber for analysis  
EAST AFRICAN COMMUNITY  
 DEAS 325: 2023 
ii © EAC  2023 – All rights  reserved  
 Copyright notice  
This EAC document is copyright -protected by EAC. While th e reproduction of this document by 
participants in the EAC standards development process is permitted without prior permission from EAC, 
neither this document nor any extract from it may be reproduced, stored or transmitted in any form for 
any other purpos e without prior written permission from EAC.  
Requests for permission to reproduce this document for the purpose of selling it should be addressed 
as shown below or to EAC’s member body in the country of the requester:  
© East African Community 2022  — All rights reserved  
East African Community  
P.O. Box 1096 , 
Arusha  
Tanzania  
Tel: + 255 27 2 162100  
Fax: + 255 27 2162190  
E-mail: eac@eachq.org  
       Web: www.eac -quality.net  
Reproduction for sales purposes may be subject to royalty payments or a licensing agreemen t. 
Violators may be prosecuted . DEAS 325: 2023 
© EAC 2023 – All rights reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4 Field of application  ................................ ................................ ................................ ................................  1 
5 Health and safety hazards  ................................ ................................ ................................ ....................  2 
6 Guidance on sampling preservatives  ................................ ................................ ................................ .. 2 
6.1 General  ................................ ................................ ................................ ................................ ...................  2 
6.1.1  Number of items in consignment  ................................ ................................ ................................ ........  2 
6.1.2  Choice of materials for sample container  ................................ ................................ ...........................  2 
6.1.3  Storage of samples  ................................ ................................ ................................ ...............................  2 
6.2 Sampling of solid preservatives  ................................ ................................ ................................ ..........  3 
6.2.1  Sampling device  ................................ ................................ ................................ ................................ .... 3 
6.2.2  Procedure  ................................ ................................ ................................ ................................ ...............  3 
6.3 Sampling of preservatives in paste form  ................................ ................................ ............................  4 
6.3.1 Sampling  ................................ ................................ ................................ ................................ ................  4 
6.3.2  Procedure  ................................ ................................ ................................ ................................ ...............  5 
6.4 Sampling of liquid preservatives  ................................ ................................ ................................ .........  5 
6.4.1  Sampling device  ................................ ................................ ................................ ................................ .... 5 
6.4.2  Procedure  ................................ ................................ ................................ ................................ ...............  5 
7 Guidance on sampling treated timber  ................................ ................................ ................................ . 5 
7.1 General  ................................ ................................ ................................ ................................ ...................  5 
7.2 Suggested sampling procedures  ................................ ................................ ................................ .........  6 
7.2.1  Determination of average retention  ................................ ................................ ................................ ..... 6 
7.2.2  Determination of lateral zone loadings  ................................ ................................ ...............................  6 
7.2.3  Determination of core loading  ................................ ................................ ................................ .............  7 
7.2.4  Thin section samples  ................................ ................................ ................................ ............................  8 
7.2.5  Sawdust sampling  ................................ ................................ ................................ ................................ . 8 
8 Method for the determination of the moisture content of the  preservative -treated timber  ...........  9 
8.1 Selection of sample  ................................ ................................ ................................ ...............................  9 
8.2 Procedure  ................................ ................................ ................................ ................................ ...............  9 
8.3 Calculation  ................................ ................................ ................................ ................................ ...........  10 
9 General considerations in sampling for analysis  ................................ ................................ ............  10 
Bibliography  ................................ ................................ ................................ ................................ ......................  11 
 DEAS 325: 2023 
iv © EAC  2023 – All rights  reserved  
 Foreword  
Development of the East African Standards has been necessitated by the need for harmonizing requirements 
governing quality of products and services in the East African Community. It is envisaged that through 
harmonized standardization, trade bar riers that are encountered when goods and services are exchanged 
within the Community will be removed.  
The Community has established an East African Standards Committee  (EASC)  mandated to develop and 
issue East African Standards  (EAS) . The Committee is co mposed of representatives of the National 
Standards Bodies in Partner States, together with the representatives from the public and private sector 
organizations  in the community .  
East African Standards are developed through  Technical Committees that are r epresentative of key 
stakeholders including government, academia, consumer groups, private sector and other interested parties. 
Draft East African Standards are circulated to stakeholders through the National Standards Bodies in the 
Partner States. The com ments received are discussed and incorporated before finalization of standards, in 
accordance with the Principles and procedures for development of East African Standards.  
East African Standards are subject to review, to keep pace with technological advan ces. Users of the East 
African Standards are therefore expected to ensure that they always have the latest versions of the standards 
they are implementing .  
The committee responsible  for this document is Technical Committee EASC /TC 022, Wood, timber and th eir 
products . 
Attention is drawn to the possibility that some of the elements of this document may be subject of patent 
rights. EAC shall not be held responsible for identifying any or all such patent rights.  
This second  edition cancels and replaces the first edition ( EAS 325:2002 ), which has been technically rev ised.  
 DRAFT EAST AFRICAN STANDARD  DEAS 325:2023 
 
© EAC 2023 – All rights reserved  1 
 Wood preservatives and treated timber — Guide to sampling and 
preparation of wood preservatives and treated timber for analysis  
1 Scope   
This East African Standard gives guidance on the gen eral procedures to be followed in the sampling and 
preparation for analysis of preservatives and preservative -treated timber.  
No attempt has been made here to define rigidly any detailed methodology to be followed in operations in 
these areas because this can depend upon the nature of the preservative, the method of treatment, and the 
particular requirements of relevant approval authorities . 
2 Normative references   
There are no normative references in this document.  
3 Terms and definitions   
No terms and def initions are listed in this document.  
ISO and IEC maintain terminological databases for use in standardization at the following addresses:  
— ISO Online browsing platform: available at http://www.iso.org/obp  
4 Field of  application   
4.1 This East African Standard is applicable to the provision of appropriate samples for analysis which may 
be used to check the content of active components in preservative formulations, and to determine the identity, 
location and concentrat ion of preservatives in treated timber. The techniques described may be employed in a 
wide variety of applications ranging from laboratory research through to the checking of preservatives or 
preservative -treated timber for arbitration purposes. In most ca ses it is possible, by chemical analysis, to 
determine whether or not a sample of timber has received a preservative treatment and the results can often 
give an indication of the type of treatment the wood has received when due consideration is given to ot her 
relevant factors, such as timber species and heartwood/ sapwood ratio, in the samples under test.  
4.2 No attempt has been made in this East African Standard, to lay down detailed procedures to be 
adopted for control purposes at manufacturing plants whe re large volumes of preservative are to be sampled.  
4.3 Furthermore, the objectives of each analysis, and the demands of the individual analytical technique, 
may impose their own requirements with regard to sampling and subsequent handling. Therefore, it i s 
essential that the sampling plan for each operation should be devised in the light of the particular objective, 
using professional judgment based on experience.  DEAS 325: 2023 
2 © EAC  2023 – All rights  reserved  
 5 Health and safety hazards  
5.1 All preservatives may be considered potentially toxic both to  man and to the environment and shall be 
handled with care and in accordance with the specific recommendations for safety agreed with national and 
international authorities. The manufacturer’s instructions should also be observed.  
5.2 In handling solid tim ber after treatment, protective gloves shall be worn if the timber is still wet or 
contains solvent. Once the timber has dried, unless blooming of the preservative on the surface is noted, no 
special precautions are necessary in handling food or smoking.  
5.3 When treated, timber is machined or mechanically sanded or sawn, an efficient dust extraction system 
should be used, or, failing this, the operator shall be provided with, and shall wear, appropriate respiratory 
protection.  
5.4 The organic solvents comm only used for applying preservatives are flammable and it is essential that 
care be exercised in handling such materials.  
6 Guidance on sampling preservatives  
6.1 General  
The method of sampling chosen should ensure that the sample obtained is as representa tive as possible of 
the total consignment.  
6.1.1  Number of items in consignment  
The least number of containers, e.g. drums to be sampled from any given consignment of preservative 
materials irrespective of whether the materials are solid or liquid, should be the nearest whole number to the 
square root of half the total number of drums in the consignment (see Table 1).  The drums to be sampled 
should be taken at random  
Table 1 — Sampling of drums   
Number of drums in 
consignment (x)  √(x/2)  Number of drums to 
be sampled  
10 2.24 2 
20 3.16 3 
50 5.00 5 
100 7.07 7 
 
6.1.2  Choice of materials for sample container  
It is essential in all cases that the sample container and its closure be made from material which is inert to the 
particular  preservative under investigation. Thus, glass bottles are unsuitable for bi -fluoride solutions and 
polyethylene containers should not be used for petroleum solvents.  
6.1.3  Storage of samples  
Prior to analysis, samples should be stored in a cool dark place . DEAS 325: 2023 
© EAC 2023 – All rights reserved  3 
 6.2 Sampling of solid preservatives  
6.2.1  Sampling device  
A suitable sampling device for the purpose of sampling the preservative in a drum is a sampling spear of 
internal diameter 32 mm and sufficiently long to reach the bottom of the drum.  
6.2.2  Proced ure 
6.2.2.1  Before sampling, mix the contents of the drum as thoroughly as possible. Take great care to 
minimize the moisture picked up by the sample during sampling, mixing and reducing processes.  
6.2.2.2  Using the sampling device, take five samples (see Figure 1), one from the centre of the drum and 
the other, four from points on a pair of diameters at right angles to each other, which are mid -way between the 
central and the side of each drum selected for testing (operation). Ensure that the sampling spea r reaches the 
bottom of the drum. Combine the five samples of approximately 400 g each in a clean, dry airtight container of 
about 2.5 kg capacity. (Operation 2)1. If necessary, grind the whole of the bulk sample to pass a test sieve of 
nominal aperture si ze 2.00 mm, ensuring that no residue is left on the sieve.  
6.2.2.3  Mix the sample well (operation 3A). Transfer the entire sample to a clean dry surface and heap 
into a cone (operation 3, cone 1): Turn over to form a new cone until the operation has been c arried out three 
times (operation 3, cone 4). Form each conical heap by depositing material on the apex of the cone so that 
the portions which slide down the side are distributed as evenly as possible, and that the centre of the cone is 
not displaced. If s ome of the larger aggregates of the mixture roll and scatter round the base, either push them 
back to the edge of the heap or break them and distribute them evenly over the heap.  
6.2.2.4  Flatten the final cone from the mixed contents of the container by re peated vertical insertions of 
the edge of a board, commencing about the centre and working radial round the cone, lifting the board clear of 
the material after each insertion. Carry out this operation so that the flattened heap is of uniform thickness and 
diameter and the centre coincides with the centre of the original cone (operation 4).  
6.2.2.5  To ascertain the homogeneity of the contents of a drum, individual spear samples may be 
analysed . 
 DEAS 325: 2023 
4 © EAC  2023 – All rights  reserved  
 
 
Figure 1 — Sampling of a solid preservative  
6.2.2.6  Quarter t he heap along two diameters which interest at right angles, using a suitable divider. 
Shovel one pair of opposite quarters into a cone and reject the remainder (operation 5). Mix the cone three 
times (operation 5, cone 8) as described above, flatten the co ne and quarter along two diameters (operation 
6). 
6.2.2.7  Repeat these operations until a reduced sample of about 200 g remains (operation 7). 
Immediately enclose the test sample in an airtight container until required for analysis.  
6.3 Sampling of preserv atives in past e form  
6.3.1  Sampling  
A suitable device is a wide – mouthed sampling can of about 500 ml capacity fitted with a long, stiff handle so 
that it can be submerged in the material to be sampled. It should also carry a removable lid to which a seco nd 
stiff handle is attached, so that when the can is immersed in the paste the lid can be removed, allowing the 
can to fill.  
A stout steel stirring rod, suitable for stirring the contents of a drum is also required.  DEAS 325: 2023 
© EAC 2023 – All rights reserved  5 
 6.3.2  Procedure  
Thoroughly mix the prese rvative in each drum before the samples are taken. Displace any settled material 
from the base of the drum using the stirring rod. Reclose the drum and homogenize the contents by rolling 
and shaking the drum. Mechanical agitation should be used if availabl e. Re -open the drums and test the 
contents for uniformity by probing with the steel rod. Continue alternate stirring, shaking and rolling until the 
contents are of a homogenous consistency.  
Take three sample from each drum with the sampling can, one from j ust below the surface of the preservative, 
the second at a position about halfway between the surface and the base of the drum and the third from near 
the base. Pour the tree samples from each drum into a clean glass or plastic container and mix together.  
NOTE  Should homogenization prove to be impossible, it will be necessary to dissolve or disperse the whole contents 
of the drum and take aliquot portions for analysis.  
6.4 Sampling of liquid preservatives  
6.4.1  Sampling device  
A suitable sampling device con sists of a thick - walled glass tube of about 13 mm internal diameter, cut to a 
length suitable for extracting the treatment solution to a depth about 600 mm. The actual length of the tube will 
depend on the container to be sampled  
To ensure retention of th e liquid column when the tube is withdrawn from the solution, the bottom end of the 
tube should be softened in a flame and the glass allowed to collapse until the opening is reduced to about 6 
mm diameter.  
6.4.2  Procedure  
Insert the glass tube vertically i nto the well -mixed liquid in the can to be sampled, and allow the liquid to reach 
its natural height in the glass tube. Place the thumb on the upper end of the tube to prevent escape of the 
liquid from the tube while it is being lifted. Lift the tube from the can and insert the end into the sample bottle. 
Allow the liquid to drain into the sample bottle by removing the thumb. If required, bulk the sample from the 
various cans. Mix and remove a suitable volume for analytical purposes. Seal the sample can.  
7 Guidance on sampling treated timber  
7.1 General  
7.1.1  The effectiveness of any treatment depends on the introduction of suitable quantities of preservative 
to a sufficient depth below the surface of the wood to protect from biological attack, and to combat  existing 
infection. The degree of protection required varies with the severity of the environment to which the treated 
timber is exposed.  
7.1.2  The penetration of preservatives into the timber is governed by three main factors:  
a) The properties of the prese rvative.  
b) The method of applying it to the timber.  
c) The permeability of the timber itself: this property varies markedly with species and, even within a 
single timber, regions of different permeability (e.g. heartwood/ sapwood) may be present.  
7.1.3  In pract ice, therefore, a wide range of preservative distribution 'profiles' is encountered within treated 
timber and any methods designed for the detailed examination of such materials should make provision not 
only for the detection and/or measurement of active components but also for the determination of their 
location within the timber samples or wooden members. The exact sampling technique to be employed in any DEAS 325: 2023 
6 © EAC  2023 – All rights  reserved  
 particular case will depend on the factors enumerated above and should also take account of, where r equired, 
the product's end use and location.  
7.1.4  The primary requirement of any sampling system is that the samples taken should be as 
representative as possible of the main stock of treated wood. These should be selected so as to avoid knots, 
splits and  other growth irregularities.  
7.1.5  Samples consisting entirely of heartwood should be avoided unless the timber under test is all 
heartwood, otherwise the analytical results will indicate a value which is too low.  
7.1.6  Similarly, samples consisting entir ely of the more permeable sapwood should be avoided unless the 
timber under test is all sapwood or loading of the sapwood only has to be determined, otherwise the results 
will indicate a value which is too high. It should be borne in mind also that preserv ative enters timber most 
rapidly through the end grain, and relatively high loadings are obtained in these areas.  
7.1.7  The effect of end penetration on the overall loading of a stick will thus depend on the length of the 
stick while the contribution of la teral penetration to this total will vary with the cross -sectional area of the 
timber. It is therefore import ant that the dimensions of the wood components to be sampled are taken into 
account when deciding the sampling procedure to be adopted.  
7.1.8  The n umbers and distribution of samples to be taken should be decided for each analysis (see Clause 
1). Clearly, pressure -impregnation of a permeable timber will result in a relatively even distribution of 
preservative within the wood while, at the other extrem e, dipping or brushing an impermeable species will 
provide only a thin, less uniform, 'envelope' of preservative which is confined to the outermost layers of the 
wood. It is evident, in this latter case, that more extensive sampling may be required to give  meaningful 
results. When sampling of constructional timber has to be undertaken, it is important to ensure that no 
structural weakening arises as a result of this process, and sampling may have to be limited on this account. 
The advice of an experienced s pecialist in the building field should be sought before commencing operations.  
7.1.9  In many situations, samples have to be taken from preservative -treated timber which has been 
subjected to further processing such as painting or gluing, or which has been otherwise contaminated on the 
surface. In such cases, care has to be taken to avoid interference in the subsequent analysis by excluding 
such extraneous material form the sample.  
7.2 Suggested sampling procedures  
7.2.1  Determination of average retention  
Cut a complete cross -section, 6 mm thick, from the timber. The sample should be taken, if possible; at least 
300 mm from the end. In all cases, and especially in shooter billets, it is essential to take into account the 
effects of any penetration through the  end grain.  
7.2.2  Determination of lateral zone loadings  
7.2.2.1  Cut a sample of the required lateral depth at least 300 mm from the end. If profiles of penetration 
at different depths are required, it will be necessary to eliminate edge effects. For examp le, if radial 
penetration profiles are required, zones contaminated by tangential penetration should be avoided (see Figure 
2). DEAS 325: 2023 
© EAC 2023 – All rights reserved  7 
 
 
Figure 2 — Example of a sampling technique for the study of radial penetration  
7.2.2.2  Depending on the purpose of the test, i t may be desirable that the sample consists of sapwood 
only, or of heartwood only. If both are present, it may be necessary to distinguish between them before 
selecting analytical samples from the block, if possible.  
7.2.3  Determination of core loading  
7.2.3.1 Cut a cross -section of 50 mm in the longitudinal direction form the timber at least 300 mm from 
the end. Dry the section to a moisture content between 8 % and 18 % by air drying or in an oven (see 6.2) at a 
temperature of less than 60 °C. Special prec autions should be observed when dealing with volatile 
preservatives and oven drying may not be suitable (see Clause 7). From the centre of this 50 mm section cut 
a 6 mm section and cut from it the one -ninth core as illustrated in Figure 3.  DEAS 325: 2023 
8 © EAC  2023 – All rights  reserved  
 
 
Figure 3 — Preparation of 1/9 core section to determine core loading  
7.2.3.2  If the timber to be sampled already has moisture content between 8% and 18%, the 6 mm section 
for core preparation can be cut directly.  
7.2.4  Thin section samples  
7.2.4.1  Preservatives in treat ed wood are usually not evenly distributed, and it is often required to 
determine preservative loading over very small areas. To do this, cut sections up to 0.2 mm in thickness, on a 
microtome, from air -dry specimens sawn form the bulk of the treated wood or from borings taken with a 
Mattson borer. It is also possible to cut sections with a wood plane, but this method is not so accurate.  
7.2.4.2  Samples may also be taken using Forstner auger bit which produces thin shavings and results in 
a smooth – sided, flat bottomed hole of well defined area. If incremental borings are taken it is possible to 
examine the distribution of preservative with respect to depth, though this method is not as accurate as that 
using a microtome because of the possibility of compre ssing the wood during sampling.  
7.2.4.3  To obtain a representative sample, it is necessary to include both early and late wood in the thin 
sections taken for analysis. This is because concentration gradients of preservative can occur across the 
annual ring s. Sections taken from the radial and transverse faces of the sample will contain both early and late 
wood but sections cut form the tangential face may contain only one or the other.  
7.2.4.4  To make up a representative sample from the tangential face, thi n sections should be cut over 
several annual rings, provided there is sufficient depth of preservative penetration to allow this.  
NOTE  In order to avoid loss of sample, it is necessary for the preparation of thin section samples (5.2.5) and for 
sawdust sam pling (5.2.6) to be carried out in a draught -free environment; appropriate precautions should be taken to 
protect the operator (see clause 3).  
7.2.5  Sawdust sampling  
7.2.5.1  Samples may be cut as solid sections (which may afterwards be converted to sawdust , for 
example by pulverizing the dry sample in a beater mill or hammer mill) or they may be produced as sawdust 
directly from the piece of timber under study (see note following 5.2.5). Since the preservative, by virtue of its 
original location within the timber, may well be concentrated in sawdust particles of a particular size, it is 
important that no fraction be rejected before analysis. The product may be homogenized, for example by 
continuing grinding until all the sample passes a test sieve of nominal  aperture size 425 μm and mixing well 
before taking aliquot portions.  DEAS 325: 2023 
© EAC 2023 – All rights reserved  9 
 7.2.5.2  Care should be taken to minimize the risk or evaporative losses or degradation of organic 
preservatives due to excessive generation of heat in the conversion process.  
7.2.5.3  The fastest method of sampling it to make a clean uniform saw cut through the cross -section of a 
specimen and collect the sawdust produced for analysis. During sawing, it is important that the sawblade is 
held rigidly so that sideways motion of the blade is v irtually eliminated. An unrepresentative sample will be 
obtained if there is any variation in the width of the saw cut through the specimen.  
7.2.5.4  To ensure a uniform cut, modify a mitre machine to allow easy sawdust collection by fitting it with 
a shall ow V -shaped bed containing a simple gripping device over which the saw is supported on four rods 
(see Figure 4). Fit the machine with a medium cut blade with four to five points per centimetre.  
7.2.5.5  Saw the specimen through, whilst it is held firmly mou nted on the saw bench, and collect the 
sample by brushing the sawdust into a tared beaker for weighing.  
 
Figure 4 — Modified mitre machine for the preparation of the sawdust sample  
8 Method for the determination  of the moisture content of the preservative -treated 
timber  
8.1 Selection of sample  
8.1.1  If the average moisture content of a piece of treated timber is require d, cut a sample consisting of a 
full cross -section 13 mm to 19 mm thick, not less than 300 mm from one end. Using a test borer  consisting o f 
a hollow auger and extractor, bore from the sapwood face to the centre of the section or  to the specified depth 
(see note) if the cross -section exceeds 6,000 mm2.  
NOTE  The depth to be utilized for large cross -section members should be specified in the co mmodity specification.  
8.1.2  If the information is required on the moisture content of the analytic al samples, matched material or 
sample aliquots may be employed, but not the samples to be used for chemical analysis.  
8.1.3  If the sample cannot be weighed at once, put it into a stoppered we ighing bottle or other airtight 
container immediately after it has been prepared (see 4.1).  
8.2 Procedure   
8.2.1 Weigh the sample as soon as possible after preparation (m1) and place it in an oven which has 
already been a djusted to a temperature of between 100 °C and 105 °C. Remove the sample periodically, cool DEAS 325: 2023 
10 © EAC  2023 – All rights  reserved  
 it in a desiccator and reweigh (m2). Repeat the drying, cooling and weighing at  suitable intervals until any 
further loss in mass is at a rate not exceeding 0.1g/24  h, or for samples in excess of 20 g dry mass until the 
loss between two successive weighings is not greater than 0.5 % 24 h.  
NOTE  Some loss of preservatives by volatilization or degradation may be incurred during this process and this may 
lead to somewhat  higher values for moisture content. In calculating the results, therefore, allowances should be made for 
such evaporative losses as well and for any degradation of the preservatives.  
8.2.2  If the timbers have a high content of volatile substances that are  non-miscible with water, such as may 
arise with creosote treatment, is may be preferable to use a Dean and Stark distillation method for the 
determination of moisture content.  
NOTE 2  It is advisable for the drying oven to be in a fume cupboard to avoid ex posure of personnel to any fumes.  
8.3 Calculation  
Calculate the moisture content, w, as a percentage of the dry mass, from the following formula:  
 
where  
m1 is the mass of sample when wet in grams  
m2 is the mass of sample after drying in grams  
9 General c onsiderations in sampling for analysis  
9.1 Analytical samples isolated by the methods outlined in clauses 4 and 5 may be converted, by a variety 
of techniques, into a form suitable for further processing.  
9.2 Subsequent operations may include preparation o f the wood surface, conversion to sawdust, chemical 
digestion, extraction, etc.  
9.3 The precise procedures to be followed depend on the requirements of the analytical methods.  However, 
reference has already been made (5.2.6 and 6.2) to important considerat ion, the need to ensure homogeneity 
of the sample and to avoid, as far as possible, losses of preservative by evaporation.  
9.4 Drying under ambient conditions is therefore recommended and moisture content determinations 
should not normally be carried out o n the samples selected for further analysis. In addition, migration of 
aqueous or organic solvents during the drying process may well cause redistribution of the active components 
within sol id wood samples and it may be necessary to use a freeze - drying te chnique in distribution studies.  DEAS 325: 2023 
© EAC 2023 – All rights reserved  11 
 Bibliography  
EAS 325:2002 , Wood preservatives and treated timber — Guide to sampling and  preparation of wood 
preservatives and treated timber for analysis  
 DEAS 325: 2022    
 
© EAC 2022 – All rights reserved