Wood Protection in Europe: Developments ... - ACS Publications

website of the European Commission "The Biocidal Product Directive aims to harmonize ... which fulfill their additional requirements / traditional rul...
3 downloads 0 Views 2MB Size
Chapter 34

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

Wood Protection in Europe: Developments Expected up to 2010 Hans Leithoff, Piet Blancquaert, Mark van der Flaas, and Alex Valcke Janssen Pharmaceutica N . V . , Turnhoutseweg 30, B-2340 Beerse, Belgium

Introduction In the past the wood preservation market in Europe was scattered and characterized by wide differences in national regulations and regional traditions. At this time the main criteria in the development of new wood preservatives were efficacy and economics. At present, however, all developments of wood preservatives in Europe are preliminary dependant on the European Biocide Directive 98/8/EC (BPD (1)). Its main objectives are summarized in the following sentences on the official website of the European Commission "The Biocidal Product Directive aims to harmonize the European market for biocidal products and their active substances. At the same time it aims to provide a high level of protection for humans, animals and the environment." (2). In the future, only active substances and biocidal products assessed and authorized according to the B P D regulations can be placed on the European market. Therefore, this article focuses on the impact of the ongoing B P D assessments on wood preservation in Europe. The history of bans and restrictions on classical all-purpose wood preservatives like PCP, creosote, and C C A , which were the first widely used preservatives, is also considered (3). These restrictions/bans accelerated the development of alternative biocides/preservatives, but the efficacy of the newer biocides is limited to certain target organisms compared to the broad efficacy of the earlier biocides. Later biocides consequently have a much better toxicological and ecotoxicological profile (4). A further development of this tendency might be a so called "fit for purpose" product targeted to specific uses and/or market segments and the expected service life of the treated end-use product (5, 6). 564

© 2008 American Chemical Society

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

565 Furthermore, although the B P D will result in harmonization some country specific differences within the European Union (EU) will remain and still have to be considered. It is impossible to address these differences in detail, but, some general background information is given here in the introduction to illustrate the situation: Prior to the implementation of B P D a tremendous but not complete harmonization of the classification and efficacy testing of wood preservatives was achieved mainly by activities of the European Committee of Standardization ( C E N T C 38) and the affiliated national committees. Consequently, within the last 30 years a number of European standards were published (7). However, the existing national differences with regard to product registration and/or approval and the related evaluation schemes prevented a single European assessment of wood preservatives and are at present still strong barriers for the free trade of wood preservatives within Europe. The B P D has clearly the objective to pull down these barriers, but, while the approval of active substances is controlled by the European Commission, the wood preservative products are going to be authorized at the member state level. To facilitate and harmonize the authorization of these products, the principle of mutual recognition has been included in the B P D : One member state evaluates and authorizes the biocidal product and based on this first evaluation, other member states will authorize the product for their national market and can limit their authorization due to administrative aspects only. At the other hand a number of powerful and independent regional or even national associations/agencies established a variety of voluntary approval schemes and provide quality control schemes for the product and its production (e.g. N W P C in Denmark, Finland, Norway and Sweden; C T B P in France; R A L G Z 830 in Germany). Furthermore, approval boards like DIBt (Deiitscher Industrieverband fur Bautechnik, Germany) grant national approvals required for products employed in a particular area and/or application. Likely such organizations will try to maintain at least some business also after fiill implementation of the B P D . Some organizations already indicated that they intend to ensure superior quality by selecting those B P D authorized products which fulfill their additional requirements / traditional rules (8). +

Biocidal Products Directive (BPD) Concept and Structure of B P D To achieve harmonization of authorizations and registrations with regard to biocidal products in the E U , the Council and Parliament agreed to unify the assessment of the active substances and biocidal products and so adopted in

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

566 1998 the Biocidal Products Directive 98/8/EC (/). The B P D defines that the assessment is not done centrally but by the individual agencies (Competent Authorities = CA) of the member states (Rapporteur Member States = RMS). In the first phase the active substance itself is assessed, and in a second phase the biocidal product, the wood preservative, will be assessed and authorized at member state level when it is considered effective and safe for man and the environment.

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

First stage: Assessment of the active substance In case the active substance is considered as unacceptable, a non-inclusion decision will be adopted and published. It will impose a deadline for the member states to withdraw the substance and products that employ it from the European market. This phase-out period will be 6 to 12 months. In case of a positive assessment the biocide will be listed in Annex I of the B P D for the use in a specific product types (e.g. in product type 8 = wood preservation). In that process the list of endpoints is fixed (e.g. Acceptable Operator Exposure Level or A O E L for human risk assessment and the Predicted No Effect Concentration or P N E C for environmental risk assessment), and - i f necessary - mitigation measures or restrictions on use may be required. A decision for Annex I listing is published as a Commission Directive addressed to the member states and provides binding rules of the biocidal product authorizations, the second stage. The applicant, (in most cases the manufacturer of an active substanee, pays an application fee covering the work done by the R M S . The fees vary from around 100,000 € to 350,000 €. To allow a harmonized implementation of the B P D by the C A ' s of all member states, guidance documents and guidelines were developed and adopted. These include the Technical Notes for Guidance (TNsG, (9)) and the Technical Guidance Documents (TGDs (10)). The latter are also used for the assessment of new and existing chemicals. Where the B P D and its related Commission Directives and Regulations are legally binding documents, the guidance documents are not legally binding. The (existing) active substance evaluation is done by the C A of the R M S decided by the Commission (for new active substances the applicant can select the RMS). Before the full evaluation starts, the dossier is checked in a process that can take up to six months. Once considered complete, the scientific evaluation starts and should not last for more than 12 months. Only when data gaps are discovered during the evaluation period the clock can be stopped to allow the generation of the additional data required. The applicant cooperates quite closely with the R M S during the whole process.

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

567 Once the C A has finalized its Competent Authority Report (CAR) it is sent to the Commission, circulated to the other C A ' s and made publicly available on the Commissions website. This public version does not contain the confidential parts and can be found at: http://forum.europa.eu.int/Public/irc/env/bio_reports/ library?l=/wood_preservatives_l&vm=detailed&sb=Title As the experience and expertise in the 27 member states is not yet at the same level, the CARs are discussed during one or more Technical Meetings (TM). These meetings take place three to five times per year and are intended to obtain a high quality of the evaluations, development of further guidance and harmonization of interpretations. Participants at the T M s are the technical and scientific experts of the RMSs. Following the T M discussions on an active substance, the C A R is transformed into an Assessment Report and a proposal for Annex I inclusion (or non-inclusion) is prepared. The proposal then goes to the C A meeting (gathering four times per year in Brussels) for further discussions and for other considerations like politics and economics. The final decision is taken at the Standing Committee for Biocidal Products (SCBP) by qualified majority voting (see Figure 1). From the description of the process above, it should be clear that this is a time consuming exercise, and in view of the end of the transitional period on 14 May 2010, the Commission and the member states are under considerable time pressure. For wood preservatives only, dossiers on 38 active substances were submitted and only one decision had been taken before the end of 2006 (sulfuryl fluoride (77). A decision on 5 to 10 substances is expected by the end of 2007.

The second stage: Product authorization. In this second stage, an applicant submits a dossier on an existing wood preservative he wants to keep on the market to a member state before the effective Annex I inclusion of the active substance(s) in his product. This dossier includes a confirmation that the active substance(s) used in the product has (have) the same specifications as the Annex I listed substance(s), a letter of access to the protected data and an application fee (estimated to be around 40,000 to 50,000 €), product data including efficacy, leaching behavior, and a human and environmental exposure and risk assessment. The dossier is assessed by the R M S (chosen by the applicant but preferably the R M S of the active substance) using comparable timelines as for the active substance (three months for completeness check followed by 12 months evaluation). This first member state can grant an authorization and the applicant can use this first authorization within two months to apply for another E U member state for authorization for the same product by the principle of mutual

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

Figure 1. Timeline for BPD decision on Annex I listing of active substances and the subsequent product authorization under the BPD.

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

Os 00

(SI

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

569 recognition. The use of mutual recognition is necessary to allow for the full implementation of the B P D and reduce the workload of all parties involved. Mutual recognition should be mainly an administrative act and refusal needs to be substantiated by the member state. In case no product dossier has been submitted or it has been considered incomplete, the products concerned will go into a phase-out period and be withdrawn from the market within one year after the Annex I listing of the active substance(s). For no more than 2 years following the Annex I listing of the active substance shall products that remain on the market be re-authorized at national level under the B P D requirements (see Figure 1). This is a very challenging goal and a comparable approach under the directive 91/414/EEC, the so-called sister directive of the B P D regulating plant protection products, has been shown to be unrealistic. As the first phase, the evaluation of the existing active substances, is not yet finalized and may be further delayed all parties involved have some years to prepare and to make the system work. The first set of compounds with broader use than sulfuryl fluoride consists of the organic fungicides dichlofluanid, tebuconazole, propiconazole, tolylfluanid and IPBC. Decisions on these compounds are expected by late 2007 with publication early 2008, so that effective Annex I listing of these substances can be foreseen for early 2010. Wood preservative dossiers for existing products based on these fungicides need to be submitted no later than the effective listing of the last active substance in the product entering Annex I. In case an insecticide is also included in a preservative system, the submission will be delayed until that insecticide is also listed on annex I. None of the insecticides submitted under PT 8 has progressed as far as some of the fungicides in the approval process. Dossiers of new wood preservatives based on annex I listed active substances can be submitted any time after the annex I listing but can only be marketed once national authorization has been granted by a member state.

New Active Substances Wood preservatives based on new active substances (new active substances are substances not listed in Annex II of Commission Regulation 1048/2005 (72), see above) can only be marketed after Annex I inclusion of the new active substance or following provisional approval. This provisional approval can be granted at member state level for a period of three years during the evaluation period of the new active substance. This way new active substances can enter the market more rapidly and gradually as mutual recognition does not apply in this case. However, a formal submission for provisional approval must be submitted in all member states where the applicant intends to market his product during the evaluation period.

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

570 The provision for provisional approval did not exist in national biocide schemes and comes from the plant protection products directive 91/414/EEC. It should be noticed that the current proposal to amend this directive, the provisional approval provision, has been deleted. As the preparation of the amendment of the B P D starts in 2007 it can be expected that within 5 to 10 years this provision will also be deleted.

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

1 September 2006 Commission Regulation 2032/2003 of 4 November 2003 (75, 14) giving further direction for the 10-year review program also defines the date when all non-defended active substances and biocidal products including them must be taken off the market: 1 of September 2006. Specifically for wood preservatives this means that only the active substances for which a complete dossier was submitted can stay on the market (see Table 1). Use of all other actives should have been discontinued. Some member states have granted additional phase-out periods, although the EÙ Commission repeatedly indicated that the date was known sufficiently in advance so that national measures should have been taken to remove the non-defended substances from the market. st

Chromium: A Biocide or a Non-biocidal Additive for Fixation Only? Chromium was identified as an active substance but no Chromium dossier for PT8 was submitted under the B P D . Legally, this requires the withdrawal of all chromium-containing wood preservatives from the E U market by 1 of September 2006. However, reflecting the function of chromium as a fixation agent in wood preservatives as well as the definition of the required "sufficient efficacy under real-use conditions", this interpretation was not at all common sense in the CA-meeting (75). It was also impossible to agree on chromium as non-biocidal additive. Therefore, the European Commission judged chromium in principle as an active ingredient which, consequently, has to be withdrawn from the E U market. But on the product level the European Commission referred the assessment whether chromium is an active or fixation compound in a particular wood preservative to the national level of each Member States' C A . In case suitable data shows chromium to be "non efficient under real-use conditions " against target organisms it can be assessed as a fixation agent and, by this, manufacturers got temporary approval to maintain chromium-containing products in Germany, Sweden, the Nederlands and Austria. Other countries such as United Kingdom, Belgium and France judged data presented as incomplete or not convincing and phased out chromium containing wood preservatives by 1 of st

st

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

571 September 2006 (76). However, as the B P D also requires human and environmental exposure and risk assessments of "substances of concern" (substances that are classified under the Dangerous Substances Directive, 67/548/EEC and its amendments and Adaptations to Technical Progress (77)), a substantial amount of data on chromium will still need to be submitted.

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

Impact of BPD on Product Development until 2010 Considering the facts related to B P D as explained above, it is obvious that many ongoing development projects are regulatory driven. The most prominent aspect is the identity and number of actives available for wood preservation in near future. Under these circumstances the list of active ingredients under review for PT 8 (wood preservation), listed in Table I, becomes a logical starting point for further discussion. Considering some very common actives previously used but not supported under the B P D , this table allows us to address some changes which have already happened or are to be expected and are caused directly or indirectly by B P D .

Actives to be withdrawn from the market Only 40 of the active ingredients listed for PT 8 in the Annex 5 of the second review regulation E C 2032/2003 (13, 14) are still supported (see Table I, see also 27). In consequence a number of wood preservatives / active ingredients had to be withdrawn from the market by 1 of September 2006. Only some of them can be discussed here: st

Arsenic /CCA Although the use of arsenic was already restricted to certain applications, before September 2006, C C A could still be used for some important but severe hazard applications like transmission poles or some industrial/professional applications (3). Furthermore, most probably C C A will not be replaced mid term by arsenic-free but chromium-containing wood preservatives (see above). A shift to chromium-free wood preservatives was already seen in 2004 (18). In some heavy duty Use Class IV applications the end users judged chromium- and copper-based wood preservatives as very important non-replaceable wood preservatives, mainly due to an excellent record of good performance derived directly from practice. For such applications it is likely that some end customers are going to import the treated wood from non E U countries (which is still

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

572 Table I. Biocides in the review process for inclusion in Annex I of the B P D for PT8 (wood protection) by 31st August 2006 (14, 31, 32). type

generic name

CAS number

insecticide* ins. term.

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

Cyproconazole

fungicide** SS

533-74-4

DCOIT

64359-81-5

Dichlofluanid

1085-98-9

Fenpropimorph

67564-91-4

SR

X

? X

X

(X)

X

Guazatine triacetate 115044-19-4

X

X

X

(X)

X

X

IPBC

55406-53-6

K-HDO

66603-10-9

Potassium sorbate

24634-61-5

X

Propiconazole

60207-90-1

X

Tebuconazole

107534-96-3

Thiabendazole

148-79-8

Tolylfluanid

731-27-1

Sorbic acid

110-44-1

Bifenthrin

82657-04-3

X

X

Chlorfenapyr

122453-73-0

X

X

Clothianidin

210880-92-5

X

X

Cypermethrin

52315-07-8

X

X X

(X)

(X) X

X

X

80844-07-1

X

Fenoxycarb

72490-01-8

X

insecticides

Flufenoxuron

101463-69-8

X

Permethrin

52645-53-1

X

X

Thiacloprid

111988-49-9

X

X

Thiamethoxam

153719-23-4

X

X

Sulphury! difluoride

2699-79-8

(X)

X

(X)

(X)

X

Etofenprox

X

X X

organic

Legend see Table I.

BAS

94361-06-5

Dazomet

organic fungicides

BS

fumigation X

(Continued).

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

573 Table I. (Continued). generic name

type

CAS number

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

copper

SS

BS

BAS

SR

-

(X)

(X)

X

X

(X)

(X)

-

(X)

(X)

X

X

(X)

(X)

(X)

(X)

X

X

(X)

(X)

(X) (X)

(X)

X

X

(X)

(X)

X

X

(X)

(X) (X)

(X) X

X

X

(X)

(X)

(X) X

Bardap 26

94667-33-1

TMAC

61789-18-2

Boric acid

10043-35-3

(X) X

Diboron trioxide

1303-86-2

X

12280-03-4

X

X

(X)

(X)

X

1330-43-4

X

X

(X)

(X)

X

Copper dihydroxide 20427-59-2

X

X

X

X

X

1317-38-0

X

X

X

X

X

12069-69-1

X

X

X

X

X

CuHDO

312600-89-8

X

X

X

X

X

Creosotes

8001-58-9

X

X

X

X

X

Disodium octaborate tetrahydrate Disodium tetraborate, anhydrous

Copper oxide

Copper(II) containing carbonate-copper(II) compounds hydroxide (1:1)

others

ins. term. BKC

Laurylamine 2372-82-9 ammonium dipropylendiamine compounds polymeric Betain 214710-34-6

boron

fungicide**

DDAC quaternary

compounds

insecticide*

(X)

X

X

* **

Insecticide with efficacy against: ins. = wood boring insects; term. = termites Fungicides with efficacy against: S S = sap-stain; B S = blue stain; Bas = wood decaying basidiomycetes, SR = soft rot fiingi X cross in bold: Spectrum of the single active derived from BPD dossier / draft evaluation report see: http://forum.europa.eu.int/Public/irc/env/bio_reports/library7H/woodj3re _1 &vm=detailed&sb==Title X cross: Spectrum of the single active derived from literature or registrations (X) cross in brackets: Either efficacy claimed but the compound is usually not used as single active or: efficacy not claimed, but active is used in practice (e.g. in two way products)

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

574 allowed) or switch to completely non wood materials like concrete, steel, or polymeric products.

TBTO

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

T B T O was used mainly in solvent borne wood preservatives for joinery and cladding. It was recognized quite early that T B T O was not supported under the B P D and was/is replaced mainly by a combination of an azole (propiconazole/ tebuconazole) plus a moldicide (e.g. IPBC, dichlofluanid).

Sodium Pentachlorophenol (Na PCP) Independent of BPD, Na-PCP was already banned before 2006 in most European countries. In France, Ireland, Portugal, Spain and U K the use was permitted with strong restrictions (17/ Therefore, Na-PCP has already been replaced by a number of other actives, depending on the specific application.

Fluor salts These compounds have essentially been discontinued even before implementation of the B P D , mainly due to some disadvantages including corrosivity and high depletion.

Copper sulphate, dicopper oxide Used mainly in chromium containing wood preservatives but, in many cases, already replaced by other copper compounds, defended under the B P D .

Deltamethrin and Cyjluthrin Organic insecticides used in various wood preservatives. Both are going to be replaced by other pyrethroids or by neonicotinoids, pyrroles or insect growth regulators already undergoing B P D approval. However, due to the mode of action insect growth regulators are not suitable as a preventive termiticide in wood protection.

Actives Available on the European Market Table I lists 40 actives being reviewed for wood preservation and gives a general overall view on their spectrum of activity against wood destroying or inhabiting organisms. In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

575 However, the number of actives is may be a bit misleading because three entries ( B K C , D D A C and T M A C ) cover a whole group of similar quaternary ammonium compounds (Quat). On the other hand, some actives listed are mainly used in very special applications, e.g. sulfuryl difluoride (fumigation), potassium sorbate, sorbic acid (sap stain products) or K - H D O (engineered wood). Others are used only in solvent borne formulations like dichlofluanid and tolylfluanid. Most of the actives listed are quite well known in wood preservation and thus their efficacy, spectrum of activity and applications can be obtained in more detail from existing literature or registrations. There are only a limited number of actives which have a very broad spectrum and can be used to control all target organisms. However, it is remarkable that a broad spectrum of an individual biocide is not automatically linked to its use as single active ingredient in final wood preservative formulations. Approx. 1300 products mentioned in documents available from Austria, France, Germany, the Netherlands and the United Kingdom (20 - 24) were used to screen the compositions under this aspect (multiple registration in several countries included). From these products the majority (53%) contain only one active ingredient while 28% contain two actives, 15% contain three actives and only 3% contain four actives, but, none contains more than four actives. Although it has to be considered that a lot of entries in these lists are only registered but are either not sold or have a very limited market share, these data can be used to characterize the typical design of wood preservatives. For example, it was observed that products which contain only one active ingredient claim in most cases a very limited use spectrum, e.g. pure curative insecticide for U C I and II only or efficacy against blue stain only. Obviously the use of a single active ingredient is most commonly employed in a targeted product. Here the highly effective biocides with a limited but targeted spectrum can be used at a very low dosages and therefore provide strong economical and toxicological benefits. Two-way combinations are used either to: a) assemble actives with completely different spectra like an insecticide and a fungicide, e.g. combination of an azole with an insecticide or b) optimize the efficacy of a broad spectrum biocide by adding an active ingredient with a spectrum limited to target organisms which otherwise could be controlled only with a much higher dosage, e.g. combination of an azole with a strong blue stain agent or c) optimize the efficacy by combining two broad spectrum biocides with somewhat complementary spectra or synergistic effects, e.g. the combination of copper with Quats or boron. d) improve formulations, e.g. combination of two boron compounds. Two way combinations do not necessarily provide protection against fungi and insects. Quite often the combination of two actives is used to only optimize

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

576 fungicidal efficacy. Interestingly, the combination of two insecticides seems to be very uncommon. In case of three- and four-way formulations, biocides with similar spectrum of activity as mentioned above are employed, however, often two quite similar actives are combined with a third (and possibly a fourth) complementary biocide (e.g. two fungicides combined with an insecticide), but combinations of three broad spectrum biocides were recorded as well (e.g. combination of a boron compound, a copper compound and a Quat). Three- and four-way formulations usually claim to protect the timber against fungal decay as well as insect attack. Four way combinations usually consist of one insecticide and three fungicides, of which one fungicide usually inhibits predominantly blue stain and/or mold fungi. However, in many cases the combination was used more to optimize the efficacy against fungi or the properties of the formulation than to optimize the insecticidal efficacy. It is likely that the number of products with more than three active ingredients will increase, although the development of such formulations can be relatively complicated and the registration might require more effort. Two main reasons may explain this statement: • By combining highly targeted biocides the final formulation can benefit from complementary or synergistic effects which will result in superior efficacy and consequently lower retentions compared to products using fewer actives. • The strict risk assessments for human health and environment will favor formulations which are effective at low retentions. Even in cases where the total amount of active ingredients is similar to a product with only one active, the combination of actives with different modes of action might result in a considerable better assessment due to the lower amount of the individual actives, their limited spectrum and consequently a lowered effect on non-target organisms. At the first view it seems that 40 actives should provide sufficient combinations for any future development. But, from 14 organic fungicides listed only 5 are frequently mentioned in the registrations: dichlofluanid, IPBC, propiconazole, tebuconazole and tolylfluanid, with dichlo- and tolylfluanid only used in solvent borne systems. A similar situation counts for the organic insecticides: Here only four (cypermethrin, fenoxycarb, flufenoxuron and permethrin) of 11 actives are frequently listed. Furthermore, only the two pyrethroids are termiticides. Under the aspect "combination of actives", the four boron compounds listed are so similar in their mode of action and spectrum that they should be summarized as one group where their individual value is mainly related to special formulation issues. The same is valid for the three inorganic copper compounds. This illustrates that due to the special character of the individual

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

577 actives the number of real options for future development is more limited than would be anticipated simply from the number of active ingredients. Based on the situation described, some major shifts in products used in U C III & IV can be expected while the influence on products used in U C I and II will likely be much less (21 - 23). At this time, the major wood preservatives used in U C IV are based on a mixture of Cu-HDO, didecylpolyoxyethylammoniumborate (polymeric betain) or Quats with copper carbonate and boron compounds, as well as the combination of azoles with copper compounds plus an insecticide (e.g. a boron compound). Creosote can also be employed, but some legal restrictions limit its use to severe industrial applications like railway ties and utility poles (17). Due to the very limited number of inorganic actives still available, future development will focus on organic biocides. These allow the development of products optimized for the intended use and with an efficacy strongly focused on the target organisms. At the same time water borne systems will replace more and more solvent borne formulations. Therefore, formulation issues in general, especially with respect to long term efficacy and leaching behavior, will become a key issue. It is likely that more effort will be taken to optimize formulations with all types of non biocidal additives.

Role of Biocide-free Treatment Methods and Materials Only four major types of biocide free treatments and materials shall be mentioned here: Heat treatment, Acetylation, Resin treatments and Wood Polymer Composites (WPCs). A l l three chemical methods as well as the WPCs are currently commercially available in Europe. Numerous literature is available on properties and benefit of these materials and describe the different processes used (e.g. 25 - 28). Within this chapter the discussion will be restricted to the three following aspects: a) Durability of commercially available products; b) Marketing concept commonly used in European; and c) Market segment addressed.

Durability of the Commercially Available Biocide-Free Products Most of the commercially available products do not claim full protection against decay and insects, but use the durability classification as described in E N 350-1/EN 460 (29, 30) for natural timbers. Most products are classified as durability class 2, some even as durability class 1. In many cases full protection could be achieved, but an adjustment of the treatment parameters to maximum durability would cause an unacceptable decrease in mechanical properties or a

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

578 dramatic and unacceptable price increase. Therefore, the final product reflects a compromise between the different properties and thus marketing emphasized the low maintenance and improved durability as well as the anti shrinking efficiency (ASE), higher dimensional stability, low equilibrium moisture content or water uptake, the improved hardness, the color change, etc.

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

Marketing Concept for Introduction in the European Market Most of the recently launched products use the concept of selling a "final product" and avoid focusing too much on the treatment method or the chemicals used. The aim is always to give the treated wood an individual name and characterize it as new material or a kind of new wood species with characteristic and unique properties.

Market Segment The main market segments are exterior decking, cladding, garden furniture, window frames and doors. A l l products approach the high quality, high price segment. The use of the material for load bearing structures, e.g. for frames is in many cases not intended (price) or excluded (not compliant with national building regulations national approval so not). With regard to the given description there is no need for a separate characterization of WPC, although it differs strongly from treated timber with regard to the production processes, many physical properties and appearance. By creating a new product profile with unique characteristics these new products gained acceptance by the customer and consequently market share. One of the main driving forces behind their developments was the aim to create an improved material with high durability without employing biocides. However, for customers durability is only one of many desired properties and, for example, the appearance or the low maintenance claim might be more important. These biocide-free products might be seen as direct competitors to preservative-treated wood. However, considering the price and the market segment these materials most likely compete with highly durable and expensive tropical timbers like Bankirai (Shorea spp.) than with the classical biocidetreated softwood. But these materials might been considered as a kind of trendsetter. Their performance might become a benchmark and create expectations which are challenging to achieve with traditional wood preservation techniques. Although the efficacy of future preservatives is often assumed to be the dominant performance criterion, other properties shortly might become much more important to consumers for certain applications. The

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

579 marketing of WPC decking products which claim low maintenance and excellent weathering resistance of the exposed wood surface might illustrate this.

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

Summary Due to the ongoing implementation of the BPD, most mid term development of wood preservatives in Europe is regulatory driven. A maximum of 40 active ingredients will be available, some of which are of limited value due to their special characteristics. Organic active ingredients may play a key role in designing targeted and highly efficient wood preservatives which will likely consist of two or more actives. The B P D mandate should not be viewed as a threat but as an opportunity to prove that the biocides used in wood preservation are safe and treated timber can be used without negative impact to human health and the environment. This will help to develop wood preservatives which will reinforce the image of wood as a natural, valuable, high-tech and sustainable resource and could be an important element in competing with new materials like WPC or chemically modified timbers.

References 1.

Directive 98/8/EC of the European Parliament and of the Council of 16 February 1998 concerning the placing of biocidal products on the market (30 of August 2006: http://ec.europa.eu/environment/biocides/pdf/ dir_98_8_biocides.pdf) Citation: http://ec.europa.eu/environment/biocides/index.htm Council directive of 27 July 1976 on the approximation of the laws, regulations and administrative provisions of the Member States relating to restrictions on the marketing and use of certain dangerous substances and preparations (76/769/EEC) consolidated text: C O N S E L E G : 1976L0769 16/03/2004) (30 of August 2006: http://ec.europa.eu/enterprise/chemicals/ legislation/markrestr/consolid_1976L0769_en.pdf) Pallaske, M. Chemical wood protection: Improvement of biocides in use. Presentation given at COST Action E22, Estoril / Portugal March 22 23 2004 (30 of August 2006: http://www.bfafh.de/cost37.htm) Van Acker, J. The way forward: Testing and specifying wood protective systems. Presentation given at COST Action E22, Reinbeck / Germany November 8 - 9 2001 (30 of August 2006: http://www.bfafh.de/ inst4/43/ppt/3forward.pdf) Van Acker, J.; Stevens, J . M . Increased biological durability differs for traditional wood preservation and new non-biocidal systems (NBS). th

2. 3.

th

4.

nd

rd

5.

th

th

6.

th

th

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

580

7.

International Research Group on Wood Preservation, Stockholm, 2000 IRG/WP 00-20212, 11 pp. Willeitner, H. Historical perspective of wood preservation and the use of standard test methods to evaluate efficacy. Presentation given at COST Action E37, Oslo / Norway June 20 of 2005 (30 of August 2006: http://www.bfafh.de/inst4/45/ppt/4history.pdf) Peek, R.-D. Prufbestimmungen des DIBt. oral communication, Sept. 2006. Technical Notes for Guidance. (31 of January 2007: http://ecb.jrc.it/biocides.) Technical Guidance Documents. (31 of January 2007: http://ecb.jrc.it/tgd/) Commission Directive 2006/140/EC of 20 December 2006, OJL: 414/78 of 30.12.2006 Commission Regulation (EC) 1048/2005 of 13 June 2005. OJL 178/1 of 09.07.2005 Commission Regulation (EC) 2032/2003 of November 2003. OJ L 307 24.11.2003. Commission Regulation (EC) No 2032/2003 as amended by Regulation 1048/2005 ((31 of January 2007: http://ec.europa.eu/environment/biocides/ pdf/consol_reg_2032_2003.pdf) Guidance document agreed between the Commission services and the competent authorities of Member States on the role of chromium in wood preservation. Brussels 04.07.2005. (30 of August 2006: http://ec.europa.eu/environment/biocides/pdf/nfg_cr_040705.pdf) Conclusions reached by member Sates competent authorities regarding the efficacy of chromium as a biocidal active substance in wood preservation products - Interim report. CA-Sept06-Doc.8.2 Dangerous Substances Directive, 67/548/EEC and its amendments and Adaptations to Technical Progress. (31 of January 2007: http://ecb.jrc.it/assessment-of-chemicals/) Hughes, A . The tools at our disposal. Presentation given at COST E22 Estoril/Portugal 22 - 23 March 2004. (18 of September 2006: http://www.bfafh.de/inst4/43/pdf/7tooldis.pdf) Irmschler, H.-J.; Quitt, H . Holzschutzmittelverzeichnis. Erich Schmidt Verlag, Berlin. 2006,286 pp. Österreichisches Holzschutzmittelverzeichnis2006.editor: Arbeitsgemeinschaft Holzschutzmittel, Wien, Austria 128 pp. Pesticide bluebook. Wood preservatives. (18 of September 2006: http://www.hse.gov.uk/pesticides/bluebook/section12.pdf) Pesticide database of college voor de toelating van bestrijdingsmiddelen. (18 of September 2006: http://www.ctb.agro.nl) Produits de Traitement Certifies CTB-P+ (18 of September 2006: http://www.ctba.fr/documentjproduit/Listes%20P+%20nov03.pdf) th

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

8. 9. 10. 11. 12. 13. 14.

th

st

st

st

15.

th

16.

17.

st

18.

nd

20. 21. 22 23.

rd

th

th

th

24.

th

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

581 25. Proceedings of the first European Conference on Wood preservation. Ghent, Belgium 3 - 4 April 2003, 414 pp 26. Proceedings of the second European Conference on Wood preservation. Göttingen, Germany 6 - 7 October 2005 27. Erster Deutscher WPC-Kongress. 8th - 9th November 2005 Köln, Germany 28. Proceedings of Wood Plastic Composites Conference. 14 - 16 of September 2004, Vienna, Austria. 29. E N 350-1 : 1994 Durability of wood and wood-based products - Natural durability of solid wood - Part 1 : Guide to the principles of testing and classification of the natural durability of wood. 30. E N 460 : 1994 Durability of wood and wood-based products - Natural durability of solid wood - Guide to the durability requirements for wood to be used in hazard classes 31. Active substance in PT8 and 14 for which at least one dossier was submitted by 28 March 2004. (30 of August 2006: http://ec.europa.eu/environment/biocides/pdf/040430_received_dossiers.pdf 32. Active substance in PT8 and 14 for which no dossier was submitted by 28 March 2004, but which have been taken over by new participants. (30 of August 2006: http://ec.europa.eu/environment/biocides/pdf/take_over.pdf) rd

th

th

th

Downloaded by UNIV OF ARIZONA on August 4, 2012 | http://pubs.acs.org Publication Date: April 2, 2008 | doi: 10.1021/bk-2008-0982.ch034

th

th

th

th

In Development of Commercial Wood Preservatives; Schultz, T., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.