1、BRITISH STANDARD BS 1982-0: 1990 Fungal resistance of panel products made of or containing materials of organic origin Part 0: Guide to methods for determinationBS1982-0:1990 This British Standard, having been prepared under the directionof the Wood PreservationStandards Policy Committee, was publis
2、hed underthe authority of the BoardofBSI and comes intoeffecton 3 1October1990 BSI 08-1999 First published as BS1982 June1953 Second edition September1968 Third edition as BS1982-0 October1990 The following BSI references relate to the work on this standard: Committee reference WPC/10 Draft for comm
3、ent 87/52050 DC ISBN 0 580 18438 2 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Wood Preservation Standards Policy Committee (WPC/-) to Technical Committee WPC/10, upon which the following bodies were represented: Association of Consu
4、lting Scientists British Pest Control Association British Wood Preserving and Damp-proofing Association Chemical Industries Association Department of the Environment (Building Research Establishment) Timber Research and Development Association Amendments issued since publication Amd. No. Date Commen
5、tsBS1982-0:1990 BSI 08-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Nature of the problem 1 3 Health and safety considerations 1 4 Limitations of test methods 2 5 Analysis of hazard in service 2 6 Types of fungal attack in service 3 7 Range of tests 3 8 Cont
6、rol substrates 3 9 Choice of test procedure 4 Table 1 Degree of hazard of decay caused by fungi 2 Publication(s) referred to Inside back coverBS1982-0:1990 ii BSI 08-1999 Foreword This Part of BS1982 has been prepared under the direction of the Wood Preservation Standards Policy Committee. BS1982 wa
7、s published in1968 as a single standard including three test methods. This revision provides a fuller consideration of the possible hazards to organic based panel products and has been divided into Parts to allow each method to be kept up-to-date separately. The following Parts supersede BS1982:1968
8、, which is withdrawn. Part0: Guide to methods for determination; Part1: Method for determination of resistance to wood-rotting Basidiomycetes; Part2: Method for determination of resistance to cellulose-decomposing microfungi; Part3: Methods for determination of resistance to mould or mildew. Technic
9、al Committee38 Durability of wood and wood-based products of the European Committee for Standardization (CEN) has just commenced work, under a mandate from the Commission of the European Economic Community (EEC), on the classification of biological hazards and durability of timber, performance of tr
10、eated timber, and the performance testing of preservatives. With the publication of European Standards arising from this work, this Part of BS1982 will be amended, revised or withdrawn so as to remove any conflicting aspects. A British Standard does not purport to include all the necessary provision
11、s 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, pagesi andii, pages1 to4, an inside
12、back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS1982-0:1990 BSI 08-1999 1 1 Scope This Part of BS1982sets out general considerations to be taken into a
13、ccount in the selection of test methods for the assessment of fungal resistance of panel products, made of or containing materials of organic origin, in a variety of hazard situations. The term “panel product” is used to include materials variously known or described as board or sheet materials, bui
14、lding boards, composite boards, rigid sheet materials, etc. It includes not only wood-based panel products such as plywood, particleboards and fibre building boards, but also products made of or containing other ligno-cellulosic fibres such as bagasse, flax and straw. BS6100-4.3 and BS4261 give guid
15、ance on terminology. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Nature of the problem Many of the panel products used in building construction are made from or contain raw materials of organic origin. Nearly all such products are susceptibl
16、e in some degree to fungal attack if their moisture content rises sufficiently to sustain fungal growth. Most materials of organic origin are also in some degree hygroscopic and, if they are exposed for any length of time to an atmosphere of high relative humidity, their moisture content rises until
17、 it reaches equilibrium with the surrounding atmosphere. The minimum moisture content at which fungi will develop depends on the temperature and the species of fungus concerned as well as the nature of the panel products. Panel products, notably plywood, may be used constructionally in high hazard s
18、ituations, for example decking of bridges and induced draught cooling towers, planking of boats, pontoons and lock or dock gates. In industrial buildings in which processes are carried out that involve humidification of the atmosphere, either deliberately or accidentally, the relative humidity of th
19、e atmosphere may become sufficiently high for fungal growth to develop on susceptible materials. Panel products used for insulation of external walls and roofs may, in cold weather, become saturated by condensation. Condensation and fungal growth are likely to be troublesome, for example in weaving
20、sheds, dye-houses, breweries, ice-cream factories and swimming baths. In farm buildings housing livestock similar conditions of high humidity may arise. Formerly, in temperate countries, in properly-designed, well-maintained houses heated by solid-fuel fires with open flues, the relative humidity of
21、 the internal atmosphere seldom rose and remained above the minimum for growth long enough for fungi to become established. However, in dwellings built since the1940s, the increasing use of central heating coupled with reduction of ventilation by the absence of open flues has introduced novel conden
22、sation hazards and concomitant risks of growth of fungi. The new industrial techniques of building construction with improved insulation to conserve energy, besides leading to greater use of panel products, also tend to reduce incidental ventilation and so introduce further condensation risks. These
23、 condensation problems are in addition to the ordinary risks of accidental wetting of components during construction and exposure to moisture in service through conditions of occupancy, accident or inadequate building maintenance. Resistance to the growth of fungi is therefore a desirable characteri
24、stic for panel products used in building construction. 3 Health and safety considerations 3.1 Conduct of tests Because the procedures involve handling and working with micro-organisms, either in pure or mixed culture or from natural populations, it is important that personnel trained in microbiology
25、 should perform those parts of the test involving handling of organisms and infected test specimens. It is essential that personnel should be familiar with the general recommendations on personnel safety given in BS2011-2.2J, in particular Nationalappendix Z, and have appropriate equipment and facil
26、ities available. 3.2 In service considerations Prevention of fungal growth on panel products can be important in respect of occupational and environmental health and safety. The presence of mould growth can lead to a build-up of populations of fungus-eating insects and disturbance of heavy mould gro
27、wths can yield air-borne spores which, if inhaled in quantity, can induce allergic reaction in sensitive individuals. If panel products with a structural function are attacked by decay fungi, the safety of occupants and operators may be at risk.BS1982-0:1990 2 BSI 08-1999 4 Limitations of test metho
28、ds If it is suspected that panel products contain bonding agents which are not moisture resistant, so that significant loss of strength may occur as a result of wetting alone, the product should be tested using the methods described in BS5669prior to those for rot resistance described in Parts1 and2
29、 of this standard. Testing for the resistance to cellulose-attacking fungi of non-rigid sheet building materials, such as damp-proof membranes and breather papers, should be carried out by the soil burial test procedure in BS6085. If disfigurement in the form of blue or grey stains caused by fungi g
30、rowing beneath surface finishes is of concern, it should be regarded as “blue stain in service” and assessed by the procedure described in BS7066-1 and BS7066-2. 5 Analysis of hazard in service 5.1 Usage and use situation For panel products used decoratively, the major hazard as a result of wetting
31、or exposure to high atmospheric humidity is mould growth. Insulation materials lose their function if moisture penetrates and may suffer loss of integrity through attack by decay fungi. In constructional usage, loss of strength through fungal attack needs to be considered as well as the possible str
32、ength loss directly consequent on wetting. According to location in or on the building, an assessment can be made of the risks of wetting and hence the degree of hazard likely to be caused by decay fungi. Four categories based on those agreed by the European Homologation Committee 1)2)are given in T
33、able 1. The nature of the hazard in a particular situation can be modified by the type of design used. 5.2 Nature of the panel products components The type of bonding agent used needs to be taken into consideration. If non-durable adhesives, i.e.adhesives which fail under the influence of moisture,
34、are used in panel products construction, the products should not be considered for use in high hazard situations. In contrast, the bonding agent in cement based boards is unaffected by moisture alone and, by virtue of its alkalinity, gives protection against fungal attack to non-decay resistant base
35、 materials. Another feature of panel products which may need to be taken into consideration is their response to conditions in their environment. Normal softwood hardboard at100% r.h. equilibrates to a moisture content which is too low to support growth of wood-rotting Basidiomycetes. In contrast, s
36、olid softwood equilibrates to a moisture content which is about the limiting value for such attack. In contact with liquid water, softwood hardboard wets up much more slowly than pine sapwood but dries out at about the same rate as solid wood. Thus under fluctuating marginal conditions, hardboard is
37、 inherently much less at risk than comparable solid wood. The fungal resistance of the wood components of panel products assumes importance only when the bonding agent is durable. Wood based panel products are then at least as resistant to decay as the timber from which they are made. Hardwoods are
38、inherently more susceptible than softwoods to attack by microfungi and this is also true of panel products made from these two types of timber. Table 1 Degree of hazard of decay caused by fungi 1) See “The EHC Reference Document1984” edited on behalf of EHC by KOMO, Sir Winston Churchill-Iaan273, Po
39、stbus240,2280AE, Rijswijk (ZH), Netherlands. 2) A European Standard classifying biological hazards is in preparation and this Part of BS1982 will be amended to align with it when it is published. Decay Conditions Examples No decay Possible decay hazard Decay hazard High decay hazard Interior use in
40、permanently dry conditions Neither in ground contact nor directly exposed to weathering; possibility of temporary wetting Exposed to the weather or to condensation, but not in ground contact Permanent ground contact or exposed to continuous severe wetting Upper floor materials Internal linings Sheat
41、hing Ground floor materials Kitchen and bathroom floors Flat roof decking and insulation External cladding Farm building partitioning Cooling tower wallingBS1982-0:1990 BSI 08-1999 3 6 Types of fungal attack in service 6.1 General For practical purposes fungal growth on panel products containing org
42、anic materials can be considered as belonging to one of the two types described in6.2 and6.3. 6.2 Fungi which cause decay and breakdown of wood and other ligno-cellulosic materials These fungi are referred to as “wood-rotting fungi” and include the following. a) Wood-rotting Basidiomycetes, a group
43、that includes those fungi which commonly cause decay in buildings including the dry rot fungus Serpula lacrymans and wet rot fungi, e.g.Coniophora puteana. b) The cellulose-attacking microfungi including those which cause the decay of wood commonly known as soft rot. Chaetomium globosum is a well kn
44、own example of this large group of fungi. 6.3 Other microfungi These fungi, commonly referred to as moulds or mildew, grow on a variety of organic materials causing unsightly surface discolorations. The damage caused by these organisms may be disfiguring rather than structural. Many materials that a
45、re themselves resistant to mould growth may become infected if their surface is contaminated with traces of food stuffs or other organic matter. NOTESome preservative treatments which confer resistance to wood-rotting Basidiomycetes do not render the material proof against moulds and cellulose-attac
46、king microfungi. It should also be noted that treatments which render materials immune to fungal attack do not necessarily render them resistant to insect attack. 7 Range of tests 7.1 Resistance to wood-rotting Basidiomycetes (Part1) The method in Part1 is a soil/block test. This is preferred to an
47、agar/block test which, while convenient, is not suitable for some types of panel product, e.g.phenol formaldehyde (PF) bonded plywood and chipboard. 7.2 Resistance to cellulose-decomposing microfungi (Part2) The method in Part2 involves small stakes partially buried, vertically, in unsterile soil. T
48、he moisture gradient which occurs in these stakes allows the test fungi to attack in the area of most suitable moisture content. 7.3 Resistance to mould or mildew (Part3) The methods in Part3 provide for separate tests for high and low moisture hazard; tests are also possible with or without additio
49、nal nutrients. 7.4 Resistance to leaching in water or to evaporative loss If the panel product is to be used externally in an exposed situation where weathering can occur, additional information about its resistance to leaching may be obtained by subjecting it to the leaching procedure described in BS5761-2 before exposing it to the fungus using the methods described in other Parts of this standard. Resistance to evaporative loss, e.g.of incorporated preservatives, can similarly be determined if the panel product is subjected to the test described in BS5761-1 befo
