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An unexpected intense blue line appears when a white paper screen is used to demonstrate the spectral lines of a mercury lamp with a diffraction grating. The line is not present when a plastic screen is used and is due to the fluorescence of the whitening agents in the paper.

Following the introduction of fluorescent whitening agents (FWA) to the detergent industry, the development and introduction of new products proceeded rapidly. Research chemists synthesized hundreds of new fluorescent compounds in an effort to market :improved and/or lower-cost whiteners. The driving force behind these research efforts was the high degree of competition in a new and rapidly expanding market. Fluorescent whitener usage continued to expand in the U.S. until the early 1970s when a number of factor,~ resulted in significant reductions in whitener levels and the removal of synthetic fabric whiteners from many detergents. As total whitener volume declined, the next decade witnessed a reduction in the number of whitener suppliers through mergers and withdrawals from the market. This trend continued through the mid1980s (1). During this period, research in the whitener field also declined dramatically. The remaining manufacturers focused on addressing toxicological and environmental issues that were raised in the early 1970s, while product ranges were reduced to those compounds maintaining viable usage volumes in the marketplace. Concurrently, there was little innovation in the detergent industry itself as detergent manufacturers were preoccupied with rising raw material costs and finding suitable phosphate builder substitutes. Few new detergents or significant new formulations were introduced during this period. Although it is difficult to pinpoint a specific time or event, a new period of innovation in the detergent industry began in the early 1980s and has been accelerating since. In addition to a multitude of new or improved products from the traditional detergent manufacturers, companies with no previous participation in the market are introducing new and innovative brands. These new and often complex formulations, both physically and chemically, have spurred renewed R&D efforts in the whitener field. In addition to improved versions of existing FWA, some new products will require totally new compounds to deliver optimum whitening performance.

The stabilities, both on wool and in solution, of several commercial fluorescent whitening agents (FWAs) were examined. Stability in solution was found to vary considerably. However, the photoye/lowing rates of wool whitened with these compounds were found to be similar, suggesting that the photodegradation pathway in solution is probably different to that on wool. The stabilities of two pyrazolines were also examined, and in accordance with previous results it was found that the stabilities of these compounds in solution did not relate to the photoye/lowing rates of wool whitened with them. The photoye/lowing of whitened wool was also followed by diffuse reflectance spectroscopy. The sample was illuminated by monochromatic light and the presence of FWAs on the fabric detected by an increase in transmission. This apparent increase is due to the fluorescence contributing to the reflected light. Using such a method the presence of an FWA can be easily verified and its photodegradation followed.

A number of heavy-duty detergent additives, collectively referred to as “minor additives,” are ingredients which are individually present in minor amounts but which can contribute significantly to the performance and marketability of detergent products. In this paper, additives which will be discussed include fluorescent whitening agents (FWA), soil antiredeposition agents and perfumes.

Sodium 2-(4-styryl-3-sulphophenyl)-2 H -naphtho[1,2- d ]triazole (I), disodium 4,4′-bis-[(4-anilino-6-morpholino-1,3,5-triazin-2-yl)amino]stilbene-2,2′-disulphonate (II), disodium 4,4′-bis-([4-anilino-6-( N -methyl-2-hydroxyethylamino)-1,3,5-triazin-2-yl]amino)stilbene-2,2′-disulphonate (III) or disodium 4,4′-bis-(2-sulphostyryl)biphenyl (IV) fed daily to albino rats for 2 yr at dietary levels of 40, 200 or 1000 ppm produced no adverse effects. Fibrous peritonitis was noted in some beagle dogs fed various levels of compound I over a 2-yr period. This finding represented the healing stage of an inflammatory process, which apparently resulted from the presence of residual caustic soda from a manufacturing step when unbuffered compound I was fed to the dogs for the first 30 wk of the 2-yr study. There were no other significant observations definitely attributable to the ingestion of the material. Compounds II, III and IV had no adverse effects when fed to dogs for 2 yr at dietary levels up to 2000 ppm. Accumulation of the compounds in the dog tissues was negligible. When fed to male and female albino rats throughout a three-generation reproduction study at dietary levels up to 1000 ppm, none of the compounds caused any toxic effects. The reproductive performance of the animals was not adversely affected, and no malformations were observed in the progeny. No histopathological changes were seen in parental animals from each generation or in the F 3b progeny.

Different chemically treated wools have been exposed to radiation in the presence of different aqueous reductive bleaching agent solutions. It was observed that thiourea dioxide gave the best performance and, in the case of wool serge, led to a fabric having a better light fastness. An interesting beneficial synergistic effect was uncovered when the reducing agents were used in conjunction with formaldehyde. Biphenols (models for dityrosine) have also been padded onto wool and exposed to light in the wet state to mimic the photoyellowing of dityrosine. 0, 0′-Biphenol-treated wool was exposed to light in the presence of the reducing agents and these were found to decrease the amount of discoloration produced by degradation of 0, 0′-biphenol.

To test the yellowing tendency of FWAs for polyester on exposure to nitrogen oxides, McEwan and Murdoch proposed a rapid test using an unrealistically high concentration of these gases. Our studies have shown that this test induces yellowing reactions that are associated with the high nitrogen oxide concentration, but which do not occur under practical conditions.

—A fluorescence spectral study has been made of the photochemical behaviour of two types of fluorescent whitening agents, a naphthotriazolylstilbene and a bistriazinylaminostilbene, in single fibres of wool. The photodecomposition of each molecule of the naphthotriazolylstilbene is accompanied initially by the photooxidation of up to 7 residues of trp in the fibre. Amino acid analyses show that his and met residues are also photooxidized. Inhibition of the photooxidation of these amino acids by sodium azide suggests that singlet oxygen is involved in the reaction.

The rate of photoyellowing, when wet, of wool cloth bleached conventionally with hydrogen peroxide and then with stabilized sodium dithionite depends on the pH of the dithionite bleaching bath. Between pH 3.5-7.5, the lower the pH. the higher the lightfastness. The enhanced photostability of damp fabric which has been dithionite-bleached at pH 3.5 is not fast to washing. Indeed, when washed under certain conditions, the wet wool becomes particularly sensitive to sunlight yellowing. These effects become very apparent on fabric treated with a fluorescent whitening agent. Cloth treated with sodium metabisulfite behaves similarly. The photostability of dry wool is not affected by bleaching or washing conditions. The lightfastness on wet and dry cloth of a selection of commercial fluorescent whitening agents is compared here.

Ultraviolet absorption and fluorescence spectroscopy have been used to determine the nature and extent of photo-decomposition of fluorescent whitening agents in polymer films and in surface-whitened wool. Irradiation of the coumarin (I) in polymer films at 365 nm gives rise to a mixture of photodimers which rapidly revert to I on irradiation at wavelengths less than 320 nm. Irradiation of the stilbene (II) at 365 nm also gives a photodimer which absorbs strongly around 350 nm, but this reverts only slowly to II on irradiation. Fluorescence studies indicate that there is an increase in the degree of aggregation of I in polymer films with increasing whitener concentration, and that the kinetics of whitener photodecomposition change from first-order at low whitener concentration (0.0025%) to second-order at the higher concentration (2.5%) used in surface-whitening. The coumarin (I) is more stable to light in poly(vinyl acetate) film cast from formic acid than in films cast from less polar solvents, probably because of differences in the degree of whitener aggregation. The photostability of I in poly(vinyl acetate) film is also improved if the film is heated for short periods or stored at room temperature for longer periods.

This survey presents a comprehensive coverage of the literature on fluorescent whitening agents for the period 1974 to mid-1982. It is intended to serve researchers in the field by providing an up-to-date summary of the published literature on the synthesis, textile applications and analysis of fluorescent whitening agents. The survey does not cover the use of fluorescent whitening agents as additives for soaps and detergents. The latter part of the survey describes the light fading reactions of five technologically important classes of fluorescent whitening agent. Recent progress in understanding the photochemical processes that are responsible for fading, and the factors that influence the light stability of fluorescent whitening agents in a polymeric environment, are summarized.

In 1975, the Forest Service (USDA) recommended use of the adjuvant Shade as a UV absorber in spray mixes of TM BioControl-1, the nuclear polyhedrosis virus (NPV) of Orgyia pseudotsugata (McDunnough). Because Shade is no longer available commercially, we evaluated suitable substitutes compatible with the NPV of O. pseudotsugata . Materials tested included two lignosulfonates, a disulfobenzophenone, and two fluorescent whitening agents. Shade was also tested as a reference standard. The materials were evaluated by exposing virus-absorber mixtures to UV radiation from high-intensity mercury sun lamps. We used a new technique that permitted individual handling of samples, on sterile disposable Teflon pads, through various steps of the test procedure. Two of the materials, Tinopal DCS (a stilbene fluorescent whitening agent) and Raymix powder (a lignosulfonate), protected O. pseudotsugata NPV against UV radiation equally or better than did Shade. Both UV absorbers are soluble in cold water, with pH near neutrality.

Sulfonated 2-pyrazolines containing two, three, and four phenyl groups have been synthesized and examined as fluorescent whitening agents for wool. Although the photostability of these whiteners increases as the number of phenyl substituents is increased, the rate of photoyellowing of wool containing these whiteners has been found to be independent of the whitener used. The rate of photoyellowing of wool treated with the diaryl-2-pyrazoline (Ha) increases with increasing whitener concentration up to 0.4% owf and then remains constant up to a concentration of 1.6% owf—the highest level studied.

This article is based on a CIE Technical Report that describes an intercomparison of measurements of the (total) spectral radiance factor (SRF) of luminescent materials. Seven luminescent specimens were provided as painted panels: two were white containing fluorescent whitening agents and five were chromatic [green, yellow, orange (two), and red]. The SRFs were measured with direct specimen illumination by a source simulating CIE D65. The SRFs that would have been obtained under D65 illumination were calculated by a method selected from among those previously studied by the committee. Data sets from four laboratories (one supplying two sets) gave useful results. The mean CIELAB color difference from the mean of the five data sets was 2.6 units averaged over all data sets and specimens, with a range among specimens from 1.9 to 3.4 units and among data sets from 1.5 to 4.2 units. The mean color difference from the results of an arbitrary reference laboratory was 3.6 units averaged over all data sets and specimens, with a range among specimens from 3.0 to 4.2 units and a range among data sets from 2.1 to 5.3 units. Maximum values of the SRFs varied considerably among the data sets, from 11.4% to 33.6% among the samples. It was the CIE Technical Committee's feeling that these results are representative of the present state of the art for this measurement, despite the relatively poor performance seen.

Fluorescent whitening agents (FWAs) are incorporated into household detergents at approximately 0.5% dry weight in order to maintain fabric whiteness during laundering. Seven different FWAs are currently used in American detergents produced by the major manufacturers. In 1974, 11 million 1b of these seven compounds were used in detergent manufacture and had the potential for appearing in laundry effluent. As such, FWAs can be identified routinely in sewage. The concentration in various natural waters and in fish caught in polluted waters is commonly on the order of 10 ppb. Only trace quantities have been found in drinking waters. All seven compounds show a low fish toxicity, low biodegradability, and a low potential for bioconcentration. Considerable information is available on the mammalian toxicity of FWAs. Tests of oral toxicity including mutagenicity, teratogenicity, and carcinogenicity which have been completed using high daily doses do not indicate any need for concern. Studies of effects resulting ...

Several stilbenes have been shown to sensitise the formation of singlet oxygen, which is capable of oxidising indole residues, e.g. tryptophan. Some stilbenes were found to quench singlet oxygen, e.g. disodium 4,4′-diaminostilbene-2,2′-disulphonate. Such materials have been shown to be capable of sensitising the photoyellowing of wool and proved to be no more stable than conventional stilbene fluorescent whitening agents.

Fluorescent whitening agents (FWAs) area special class of fluorescent dye. Their physical characteristics are such that special illumination (standard illuminant D65) resembling average daylight is necessary for colorimetric determination. With the aid of this illuminant, modern methods of measurement can determine the visual sensation “whiteness” in quantitative terms as selectively as required for practical purposes Methods of assessing whiteness should be flexible enough to allow for the particular “whiteness preference” of an observer or group of observers, i.e. a country. There are considerable advantages in relating levels of whiteness to a physically existing white scale — at its simplest it need only span the range of whiteness values encountered in a mill's production range — hence this should always be an objective. Formulae have been devised for this purpose. An easy-to-follow description of the methods based on them is given here. It is a fairly simple matter to adapt existing whiteness measuring systems to these methods, particularly where the necessary computing aids are concerned The results obtainable are well worth the effort. These methods can be used for other substrates besides textiles. Problems still unsolved and moves to standardize whiteness assessment internationally are also reported.

Skin tumours were produced in hairless mice after several months of daily exposure to ultraviolet radiation from a solar simulator. The carcinogenic effect was enhanced by pretreating mice with 8-methoxypsoralen (tumours appearing sooner and in larger numbers). Other mice were pretreated with one of two substituted-stilbene fluorescent whitening agents (FWAs). Neither FWA produced phototoxicity or enhanced photocarcinogenesis.

Photoisomerization of four purified stilbene–derived fluorescent whitening agents in methanol solution, followed by removal of residual trans–isomer, has afforded the pure cis–isomers in good yield. Measurement of the u. v. absorption characteristics of the pure isomers has yielded data that now permit the determination, for any single FWA studied, of both the total concentration of FWA in solution and of the cis. trans isomer ratio.

Introduction Interest has been expanding in 1,3,5-triphenyl-2pyrazoline (TPP) and its derivatives. Recent studies have shown that these compounds possess some interesting physical and chemical properties. They are strongly fluorescent (LEAVER, RIVETT 1974; STRAHLE et al. 1976), for which the nearly planar conjugated n-system Ar-N-NZC-Ar in the pyrazoline ring is responsible. They are photoconductive, and readily form a glassy state at near or above room temperature which is kept for quite a long period of time (SANO et al. 1976). They have been used as fluorescent whitening agents for wool and certain synthetic fibers (WAGNER et al. 1966). Some derivatives of TPP have found a successful application for use in electrophotography (MELZ et al. 1977).

The photofading behaviors of the fluorescent whitening agents (F.W.A.) on cellophane film were examined by both spectrophotometry and thin-layer chromatography. F.W.A. examined were four types of N, N'-disubstituted 4, 4'-diamino-stilbene-2, 2'-disulfonates ; benzoylamino type (B) phenylureido type (U), triazinylamino type (D), and triazolyl type (T).It was found that there were two steps in photofading; the rapid fading step and the slower fading step. The rate of the rapid fading step varied depending on the types of F.W.A. in order U>D>B ≥T. It was confirmed that the rapid photofading in the case of B or U type of F.W.A. is mainly attributable to the trans.→ cis photoisomerization.

WittigReactions of Phosphoniomethylaryl Compounds with Sulfonated Aromatic and Heteroaromatic Aldehydes Bis (triphenylphosphoniomethyl)aryl dichloride derivatives react with aromatic or heteroaromatic aldehydes which have a sulfonic or carboxylic group attached to the ring system, to yield stilbene compounds of a betaine-type structure. These betaines are reacted further with various aromatic or heteroaromatic aldehydes yielding asymmetrically substituted derivatives in excellent yields. This new method is widely applicable to the preparation of water-soluble, fluorescent whitening agents of the bis-stilbene type.

Two indicators of septic tank effluent were measured in a groundwater quality survey of an unsewered, semi‐rural community. The selected indicators were fluorescent whitening agents and sodium tripolyphosphate (STP). Other water quality determinands indicated that the groundwater was of good chemical quality for drinking purposes but, in about half of the wells, levels of total coliform bacteria exceeded New Zealand Board of Health recommended guidelines for drinking water. Fluorescent whitening agents and/or STP were detected in 17% of the samples and concentrations of STP correlated significantly (P

The optical properties of a series of thiazole and benzothiazole styryl derivatives are reported. The effect of lengthening the conjugative system in several thiazolyl- and benzothiazolyl-vinyl stilbenes which were prepared and tested as fluorescent whitening agents is discussed.

The yellowing of wool is a complex phenomenon which is induced by a variety of agencies such as light, heat and aqueous chemical reactions. Yellowing of wool by light depends critically on the wavelength distribution of the light (u. v. region), humidity and the type of prebleach given to the wool; if fluorescent whitening agents (FWAs) are employed in the bleaching process then the sensitivity to photo-yellowing is drastically increased. The copious amount of work carried out to overcome this complex situation will be summarised and the important role of the aromatic indole amino acid, tryptophan, will be detailed. In contrast to photoyellowing, exposure of wool to visible blue light (maximal effect 420–450 nm) promotes photobleaching of the yellow pigments, giving rise to complaints of colour change, especially in wool products dyed to pastel colours. To remove natural yellowness, chemical bleaching of wool is usually carried out by using hydrogen peroxide, the usage of which should be carefully controlled because of its fibre damaging characteristics. Optimisation of wool peroxide bleaching procedures has therefore been the subject of much work and these studies will be reviewed. Bleaching of wool with reducing agents is often practised either as an alternative to peroxide bleaching or more usually as an aftertreatment of peroxide-bleached wool to improve the whiteness and stability to light. Trade practice in the field of wool bleaching has recently been critically reviewed; the results and recommendations of this assessment will be given. More recently, significant progress has been made in the field of selective dark fibre bleaching and in the bleaching of heavily pigmented wools (e.g. karakul) using methods based on ferrous ion mordanting.

Wool fabrics can be whitened by treatment with a solution containing both a fluorescent whitening agent and a polymer. After drying, this leads to the distribution of the whitener in a polymer film which surrounds the fibers, Many whitener/ polymer systems lead to good whitening, but few provide white wool of satisfactory stability to light. The nature of the polymer, as well as that of the whitener, influences the photostability of the surface-whitened fabric. The most light- stable systems give surface-whitened fabrics which yellow in simulated sunlight less rapidly than conventionally-whitened fabrics, the difference being very pronounced for exposure in the wet state. This result is attributed to the fact that whiteners cannot sensitize the photoyellowing of wool if insulated from the fiber in a polymer film. Most whitener/ polymer systems give a whitening effect which is durable to laundering but not to drycleaning. However, durability to drycleaning (as well as to laundering) can be achieved by using reactive whitener/polymer systems in which the whitener is covalently linked to a polymer which can be crosslinked at a later stage.

Fluorescent whitening agents (FWAs) have been manufactured since 1950 in Japan. Now, they are used very widely in the fields of paper, textile, and detergent industries.Discussions were given to the results of medical surveys and studies on the safety of the FWAs derived particularly from diaminostilbene disulphonate.The FWAs can be considered to be safe both in chronic and acute toxicities.Further, possibility of the FWAs' contamination to human skin or table-wares from papers and textiles was examined.The results showed that the degrees of contamination were very small or negligible.As a conclusion, the FWAs are practically nontoxic even if they are taken into human bodies, though they can not migrate to human skin from papers or textiles containing the FWAs.

White, as a color sensation, can be determined by colorimetric methods of measurement. With other than colorimetric methods, no satisfactory correlation between measured value and visual assessment can be expected. The contribution of hue, saturation and luminosity to the degree of whiteness as found by six formulas widely used in industry was analyzed and the results were plotted in the form of a graph. An easy-to-use nomogram for whiteness determination was developed, based on the CIE 1931 2°-color system. Another nomogram is presented which provides an easy means to determine the hue of a sample treated with fluorescent whiteining agents (FWAs). The new whiteness determination is based on the measurement of true tristimulus values for fluorescent samples using the new International Commission on Illumination standard illuminant D 65. The magnitude of the just perceptible difference in whiteness was determined in a panel test using 11 samples and 22 observers. The results were evaluated statistically. Pending standardization of an illuminant, not only for colorimetric measurements, but also for visual assessment of white samples containing FWAs, it would scarcely seem possible to arrive at a more accurate determination of degrees of whiteness. All visual rankings of fluorescent white substrates are widely scattered around a mean value for the different phases of natural daylight. The relative energy emitted by artificial daylight lamps in the near UV region is insufficient in many cases. Xenon lamps are quite satisfactory for instrumental evaluation. In an internationally approved system, with a known hue preference, it would be possible to compare an objective measured value with each subjective result obtained by visual evaluation.

Since the discovery of industrial bladder cancer by Rehn in 1895, many incidences of the occupational bladder cancer have been reported with the progress of dyestuff industry. On the other hand, various industrial bladder carcinogens have been found in aromatic amines of dyestuff intermediates experimentally and epidemiologically. The biochemical mechanisms that the metabolites of the parent aromatic amines have more potent carcinogenic action than the parent chemicals have been found. From these findings, some chemicals being slightly changed in their chemical structure were produced and it was found that these chemicals were usefull for dyestuff intermediates as well as quite safe for cancer induction. It is very necessary for the prevention that new aromatic amines should be checked in order to know whether they are carcinogenic or not. From this point of view, 5-aminoacenaphtene and 5-nitroacenaphthene, the intermediates of fluorescent whitening agents, were examined by the author, and it was proved experimentally that these new aromaiic amines have carcinogenic action to mice.

Bei der Zerlegung der Lichtremission eines gelblich getonten Gewebes stellt man fest, das die Remission im blauen Gebiet niedriger als in den ubrigen Spektralgebieten liegt. Dieser Blaudefekt kann durch Anwendung optischer Aufheller (z. B. Blankophore) bei gleicher Remission kompensiert werden, ohne das die Gesamtremission geschwacht wird, was bei den fruher ublichen Blauemitteln der Fall ist. An Hand kurvenmasig dargestellter Mesweite werden die Bewertung der Aufheller besprochen und Nachweis-Methoden fur die verschiedenen Handelstypen angegeben. Valuation and Detection of Optical Whitening Agents The analysis of the light reflected by a yellowish fabric shows that reflection in the blue range is lower than in other spectral ranges. This blue-deficiency can be compensated by optical whitening agents (e. g. Blankophore) in the green to red range, without reducing the total reflectance as in the case of the usually applied blue deyes. Graphs of corresponding measurements are given and the merits of these agents are discussed, also some possible methods of distinguishing between various types.

Die durchgefuhrten Untersuchungen betreffen die Auswaschbarkeit von Hautfett aus Chemiefaser-Erzeugnissen und Baumwolle und die Bestimmung des Restfett-Gehaltes in den beiden verschiedenen Gewebearten. Der Einflus der Lagerungs- und Trocknungsbedingungen auf den Weisgehalt hautfetthaltiger Gewebe und die Wirkung von Waschmitteln mit optischen Aufhellern auf den Weisgrad werden untersucht. Composition and Behaviour of Wash-Dirt III The experiments undertaken deal with the determination of washability of the skinfats from the manufactures made from cotton and chemical fibres and the determination of fat which still remains in the fabric. The influence of conditions of storage and drying on the whitening agent of the fabrics contaminated with skinfats and the action of detergents containing optical whitening agents on the degree of whiteness have been investigated.

Uptake of fluorescent whitening agents from aqueous and organic systems by polyester fibers and films under various conditions was investigated. Different factors influencing the correlation between uptake of the fluorescent whitening agents and their performance in laundry liquors are discussed on the basis of the presented data. The results indicate that fluorescent whitening agents normally used for whitening other synthetic fibers can also have valuable additional effects on polyester. Furthermore the results are discussed in terms of the possible mechanisms of whitening.

In recent years some of the aromatic amines such as 5-nitroacenaphthene and 5-aminoacenaphthene have been in use in industry as intermediates of fluorescent whitening agents.Experiments were made on mice, by the author, to investigate possibilities of carcinogenicity and the results are as follows: these chemicals injected intraperitoneally into mice for 18 months induced malignant tumours such as leukemia, recticulum cell sarcoma, etc. in about 40% of the mice and wax pellets containing 5-aminoacenaphthene, when implanted in the bladders of mice revealed a mild carcinogenic effect on the ephithelium.These results suggest that the use of these new aromatic amines in modern industry should be revaluated in order to prevent occupational bladder cancer that may occur among industrial workers.

スチルべン系螢光増白染料は,光によりトランス型からシス型に異性化する。4,4′-ジアミノスチルベン-2,2′-ジスルホン酸については紫外線照射後の水溶液よりシス異性体を分離した。この異性体は熱反応により再びトランス型にもどる。光異性化は可逆的であって,トランスまたはシスいずれの異性体からも同一の平衡混合物が得られ,かつトランス-シス間の平衡の位置は照射光のスペクトル分布に支配される。また分離したシス異性体とフェニルイソシアネートとの反応により, シス型のフェニルウレイド誘導体を合成することができる。この場合にも光変化は可逆的であることを認めた。トリアジン誘導体およびベンゾイルアミノ誘導体も光異性化するが,後者の平衡は著しくトランス側に片寄っている。

Among bis-substituted derivatives of sodium 4, 4′-diaminostilbene 2, 2′-disulfonate (1), the following types of fluorescent whitening agents were synthesized : acylamide type (3; with an unconjugated substituent group adjacent to the carbonyl group, (3) -a ; with a conjugated substituent group, (3) -b), ureide type (5), triazinylaminotype (8), and naphthotriazole type (10).Solution of each derivative of 1.00×10-5 mol/l was irradiated at 30±0.2°C for one hour under UV light (360 mμ). The UV absorption and fluorescence spectra of the solutions were also examined before and after the irradiation.Results : In view of fluorescence intensity and stability to light in solution, these derivatives were classified into three types.1. Derivatives whose fluorescence intensity increases with the value of emax, but with poor photostability… (3) -a, (5), (8).2. Derivatives whose fluorescence intensity and the value of emax are both large, and with good photostability… (10).3. Derivatives whose fluorescence intensity is very poor considering the value of emax, but with good photostability… (3) -b.

Ausgedehnte Laboratoriums-Prufungen und praktische Versuche haben keinerlei verstarkte Korrosion bei Anwesenheit optischer Aufheller erkennen lassen, auch nicht bei nachfolgender Chlorbleiche und anschliesender Behandlung mit Thiosulfat. Influence of Optical Whitening Agents on the Corrosion of Copper. Detailed laboratory experiments and practical tests did not show any increased corrosion in the presence of optical whitening agents, not even with subsequent chlorine-bleaching, followed by treatment with thiosulfate.

Sulfonated aromatic aldehydes strongly sensitize the yellowing of wool by simulated sunlight, especially for exposure in the wet state. Compounds of this class are formed when stilbene-type fluorescent whitening agents are irradiated, either in solution or on wool. The possibility that these sulfonated benzaldehyde derivatives are responsible for the accelerated photoyellowing of fluorescently whitened wool is discussed. It is concluded that they may be important in the photoyellowing of whitened fabrics in the wet state, although they play little part in the photoyellowing of dry fabrics.

Skin tumours were produced in hairless mice after several months of daily exposure to ultraviolet, visible and infra-red radiation from a long-arc xenon-lamp solar simulator. Mice were bathed in an aqueous detergent suspension of a test compound (or the vehicle alone) prior to each light exposure. The carcinogenic effect was enhanced by pretreatment of mice with 8-methoxypsoralen (tumours appearing sooner and in larger numbers). Pretreatment of mice with any one of four substituted-stilbene fluorescent whitening agents did not produce phototoxicity or enhance photocarcinogenesis.

The ultimate choice of a whitener or whitener system for a specific formulation often represents a compromise between the optimum technical performance desired and economic considerations. This overview provides an introduction to fluorescent whitening agents to those new to the field of laundry product formulations and, perhaps, serves as a refresher course for the more experienced formulator. In actual practice, the selection of an optimum whitener system is based on extensive laboratory trials and evaluations.

Erythema was produced on the skin of hairless mutant mice by a single exposure to lowpressure mercury-vapour (germicidal) ultraviolet lamps. The acute reaction was not affected by pretreatment of the skin with 20 μg of a fluorescent whitening agent (FWA), disodium 4,4-bis-(4,6-dianilino-1,3,5-triazin-2-yl)-aminostiIbene-2,2′-disulphonate, applied topically in 20 μl methanol. Skin tumours were produced in hairless mice during several months of daily exposure to the same lamps. Slightly fewer tumours, with a slightly longer latent period, were produced in mice similarly irradiated but pretreated daily with FWA as above. Thus, under the test conditions used, the FWA was not phototoxic, nor did it enhance photocarcinogenesis.