Arsen im Holzschutz

Arsenic compounds used in wood preservation are classified as dangerous substances for which a cancerogenic effect to man has clearly been shown. Occupational exposure is possible by working up the preservatives and the impregnated wood. In the area of preservation plants in part a tremendously high contamination of soil by arsenic has been measured. By modern technology the environmental input in the area of the preservation plant could be reduced to a large extent. Although wood impregnated with arsenicals is thought to be relatively safe during its use, considerable proportions of the arsenic from CCA-treated wood can be loaded onto the environment under severe leaching conditions. By burning treated wood without flue gas cleaning 20% to 80% of the arsenic will be emitted to the air. There the arsenic is again present in a form for which a cancerogenic potential has been shown. Waste management problems of treated wood are discussed from a legal, practical and environmental policy point of view, and other sources of emission of arsenic are referred to comparison.     

Arsen im Holzschutz

Arsenic in wood preservation is used all over the world mainly in Copper-Chrome-Arsenic (CCA) wood preservatives by pressure treatment. In the Federal Republic of Germany this use for outdoor wood is not yet forbidden as an exception of a comprehensive ban of the use of arsenical compounds. This regulation originates primarily from an EEC directive. Arsenic content of the CCA salts varies between 11% and 29%, the most common retention is 6 kg salt per m³ of the total volume of treated wood. In the FRG CCA salts are not produced anymore and are used to a relative low extent yet. Although there seems to be a declining trend towards the import of wood treated with arsenicals, in 1988 still approximately 100–200 t of arsenic were introduced to the FRG by this way.     

Arsen im Holzschutz

Arsenic compounds used in wood preservation are classified as dangerous substances for which a cancerogenic effect to man has clearly been shown. Occupational exposure is possible by working up the preservatives and the impregnated wood. In the area of preservation plants in part a tremendously high contamination of soil by arsenic has been measured. By modern technology the environmental input in the area of the preservation plant could be reduced to a large extent. Although wood impregnated with arsenicals is thought to be relatively safe during its use, considerable proportions of the arsenic from CCA-treated wood can be loaded onto the environment under severe leaching conditions. By burning treated wood without flue gas cleaning 20% to 80% of the arsenic will be emitted to the air. There the arsenic is again present in a form for which a cancerogenic potential has been shown. Waste management problems of treated wood are discussed from a legal, practical and environmental policy point of view, and other sources of emission of arsenic are referred to comparison.     

Kupfer-HDO—ein vielseitiger Wirkstoff im Holzschutz

Favourable toxic values of the water-insoluble effective substance Bis-(N-Cyclohexyldiazeniumdioxy)-copper, CU-HDO, for wood-destroying basidiomycetes and soft-rot resulted in the development of water-soluble, chromium-free wood preservative products. Biological tests of water-born formulations based on Cu-HDO showed threshold values after leaching, considerably lower than the values of conventional copper-/chromium-containing wood preservatives, especially for brown rot fungi. Examinations in application engineering with pine and spruce timbers indicated that penetration and distribution of the wood preservative come up to the requirements of an application in hazard class 4. Toxicological values and data on environmental aspects, especially concerning disposal of the impregnated wood, show that this formulation is an interesting alternative to wood preservatives based on conventional copper/chromium compounds.     

Zur Frage des Nachweises der Fluorverbindungen im praktischen Holzschutz

Ohne Zusammenfassung     

Moderne Schneidstoffe im Einsatz

Demands on modern cutter materials such as optimum cut surfaces and simultaneous high cutting capacities with long service lives have been considered in the development of new types of hardalloy and polycristalline diamonds. The performance of cutters made of new hardalloys is demonstrated e.g. in cutting particleboard with circular saws and in sizing of particleboard with milling tools. Test series established the optimum geometry of cutter edge for PKD-edges and determined the influence of edge quality on wear and the relation of edge retreat to feed length. Comparisons of hardalloy cutter service lives were made in different operations on particleboard edges. Service lives showed a relation of hardalloy to PKD of 1∶30 up to 1∶240 in favor of PKD-cutters, as against 50 to 100 times higher costs of investment and maintenance for PKD tools.     

Der Einsatz von Stärke bei der Modifizierung synthetischer Kunststoffe

Native Starch Used for Modification of Synthetic Polymers . Newcompounds were developed by modifiying synthetic polymers with starches. The resulting property profiles allow applications which are not accessible for the initial materials. Three different categories of compounds were produced by use of a corotating, intermeshing twin screw extruder and characterized with regard to their physical and mechanical properties. The first category includes materials which contain starch in their native grain form as a functional filler. The property profile depends on the interaction between the starch surface and the matrixpolymer. which can be improved by an organosilane coating. The two other categories are based on destructurized starch. The starch is modified in the twin-screw kneader by a thermo-mechanical desintegration of the macroscopic starch granules and under the addition of plasticising and softening agents. The created thermoplastically processable moulding compounds can be used directly as a material for special applications. However the more important application of such thermoplastic starches (TPS) is all area of blending or alloying with synthetic polymers. In combination with ethylencopolymers, compounds are obtained, in which TPS forms the disperse phase. Despite of its higher content in the blend, the TPS is embedded in the synthetic polymer matrix, forming small and discrete distributed particles. The resulting mincrostructure and morphology strongly affects the properties of the blends.     

Sind Borverbindungen im Holzschutz effektiv und zeitgemäss?

Abstract Borates are used in wood preservatives for a long time. In technical approvals issued by the building authorities they are characterised as slowly acting. Due to ongoing discussions about the effectiveness of boron as well as reports about failures in practice their effectiveness was again reviewed. It was found that world-wide a huge amount of laboratory tests have been conducted, which need to undergo a re-evaluation under today’s point of view. The results show that for the eradication of insects and fungi a concentration of 3 kg Boric acid /m³ is effective (0.6% BAE). For preventive protection 1 kg (0.2% BAE) would be enough. Thereby penetration and distribution within the wood have to be taken into account. With deeper penetration the larvae in the wood are reached faster. Due to their characteristics as stomach insecticides single insects can survive in the wood even 1-2 years after treatment and emerge at the treated surface. However, there is no risk of a new attack. This is prevented by the boron on the treated surface. Under ecological aspects the disadvantage of the slow effectiveness of boron can be seen as an advantage regarding health aspects.     

Erste ContiRoll-Anlage zur Melamin-Direktbeschichtung im industriellen Einsatz

The particleboard industry in Belgium has once again proven its pioneering spirit in modern industrial production technology. A Belgium enterprise has installed first a double band press, working with the socalled isochoric principle, for coating particleboards with melamine films. The paper describes all condition, the technical data as well as the function of the new plant. Also the problems of the new production unit and their solutions are discussed in detail.     

Zum Einsatz von Pimaricin zur Verhinderung der Schimmelpilz-Entwicklung auf Lebensmitteln

Zusammenfassung Während bereits 9 europäische Staaten sich für die Anwendung des Konservierungsmittels Pimaricin zur Behandlung der Oberflächen von Wurst oder Käsen ausgesprochen haben, ist dieser Stoff in Deutschland nur einem kleinen Kreis bekannt. Der vorliegende Bericht bringt daher zunächst eine Übersicht über die chemischen, physikalischen, mikrobiciden und toxischen Eigenschaften des Pimaricins und danach Beispiele über dessen Verwendung zur Oberflächenbehandlung bei Wurst, Käse und Obst. In einem weiteren Abschnitt wird zur Rechtslage und zu den analytischen Nachweismöglichkeiten Stellung genommen.

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On the use of pimaricin for growth inhibition of moulds in foods

Summary European states already have recommended the application of Pimaricin for conservation of sausage and cheese, this substance is well known only to a few people in Germany. Therefore this review deals with the chemical, physical, microbial and toxicological properties of Pimaricin and it's use for surface treatment of sausage, cheese and fruit. In addition, the legislation and the analytical detection methods are discussed.

     

Zum Nachweis der Kakaoschalen im Kakao

Ohne Zusammenfassung     

Zum Nachweis von Nitraten und Eisen im Wasser

Ohne Zusammenfassung     

Zum papierchromatographischen nachweis des 8-Oxychinolin-Kaliumhydrogensulfats im Rauchtabak

Zusammenfassung Es wird ein Verfahren zum qualitativen Nachweis von 8-Oxychinolin-Kalium-hydrogensulfat in Rauchtabak angegeben, wobei die Identifizierung des mit Wasserdampfdestillation aus dem Tabak abgetrennten 8-Oxychinolins auf papierchromatographischem Wege vorgenommen wird. Das 8-Oxychinolin wird auf den Chromatogrammen mit Eisen(III)-chloridlösung oder mit der Fluorescenzreaktion nachWilson-Tauböck sichtbar gemacht. Es kann auch nach Abtrennung vom Nicotin durch Verwendung von mit Phosphatpuffer imprägnierten Papieren mit Joddämpfen oderDragendorff-Reagens entwickelt werden.     

Beitr?ge zur Analytik von Farbstoffen XII. Mitteilung Nachweis synthetischer und Curcuma-Farbstoffe im Speisesenf

Zusammenfassung Der Nachweis synthetischer- und Curcuma-Farbstoffe im Speisesenf wird beschrieben. Durch Behandeln der Probe mit Aceton werden Fett, Wasser und acetonlösliche Stoffe wie auch Curcuma-Farbstoffe herausgelöst. Saure Farbstoffe lassen sich anschließend durch Desorption vom pflanzlichen Eiweiß und erneuter Adsorption an Polyamidpulver anreichern, so daß diese nach bekannten Verfahren der Papier- oder Dünnschicht-Chromatographie identifizier-bar sind. Es wird ferner die dünnschichtchromatographische Identifizierung der Curcuma-Farbstoffe beschrieben.

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Contribution to the analysis of dyes XII. Detection of synthetic- and curcuma-dyes in mustard

Summary The detection of synthetic- and curcuma-dyes in mustard is described. The desorption of the dyes from the plant-protein, following separation, purification and enrichment by polyamidepowder or carboxymethyl-cellulose is demonstrated. Further described is the thin-layer-chromatography of curcuma-dyes.

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XI. Mitteilung: Fleischwirtschaft50, 946 (1970).

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Den Herren Professoren Dr. B. Eisten, Dr. O. Neunhoeffer und Dr. H. Thaler sowie Herrn Dr. Rendlen danken wir für Hinweise und Ratschläge, der Deutschen Forschungsgemeinschaft, Farbstoffkommission, gilt unser Dank für die Bereitstellung von Forschungsmitteln.