Leucophor 1111X

Endpoint summary

Description of key information

no bioaccumulation potential

Key value for chemical safety assessment

Bioaccumulation potential:

no bioaccumulation potential

Additional information

There are no experimental data available on the Leucophor 1111X, thus a read across approach with structural analogous substances Stilbene Fluorescent Whitening Agents has been proposed.

In general, Stilbene Fluorescent Whitening Agents are organic salts with high molecular weight, solids with high thermal stability, low Kow and high to very high water solubility. They do not show acute toxic effects after oral, inhalation and dermal administration. They are neither irritant to skin nor eyes, nor genotoxic in-vitro and in-vivo, nor sensitizing. Subacute and chronic toxicity investigation did not reveal relevant toxic effects. They are mainly excreted in the faeces in a few hours by oral administration and practically not absorbed by skin, therefore no systemic effects are expected.

Results were reported by Black et al. (1977) about the intestinal absorption and skin penetration of analogous substance 04. Two groups of 9 rats each were treated by oral gavage with 0.5 ml of a solution containing 0.007 % tritiated substance in 1 % (w/v) detergent (alkyl benzene sulphonate and sodium tripolyphosphate) or in an aqueous solution. All animals were placed in separate metabolic cages and urine and faeces samples were collected every 24 hours for up to 4 days. At scheduled necropsies after 24, 48 and 96 hours blood samples were taken by heart puncture and selected organs were sampled for radioanalysis. The bulk of radioactivity from both treatment groups was excreted in the faeces, mostly during the first 24 hours. Small amounts were present in the urine. Recovery of radioactivity was essentially complete after 48 hours (total recovery > 92 % with 48 hours). No significant amount of radioactivity was found in urine, blood and faeces samples from 16 rats treated topically with 0.2 ml of a solution containing 0.007 % tritiated substance in 1 % aqueous detergent. In two rats, treated topically with 0.5 ml of a solution containing 0.43 mg/ml tritiated test material in ethanol, however small amounts of radioactivity were detected in faeces, large and small intestines and their contents as well as in the content of the stomach. Only minor amounts of radioactivity were found in the liver, bladder, kidneys, and heart of one of the treated animals. Approximately 0.1 % of the applied dose (i.e. approximately 0.01 μg/cm²) had been absorbed through the skin during two days.

Absorption, distribution and excretion experiments were conducted in rats and the results has been published by Mücke et al. (1975). Following an oral dose of ¹⁴C-labeled analogous substance 08 in water at 5.9 mg/kg bw to rats of both sexes, rapid and complete excretion of radioactive material was observed, with an excretion half-life ranging from 7 to 13 hours. Faeces were practically the only route of excretion (more than 95 % of the administered radioactive material was excreted within 48 hours), indicating, in combination with the short half life times that no significant amounts were absorbed from the gastro-intestinal tract. No radioactivity was found in blood, liver kidney, brain, muscle, or fat 96 hours after dosing (limit of quantification 0.005 - 0.01 ppm equivalents). The total recovery of radioactivity was 97.5 % and 95.2 % of the orally applied dose for males and females, respectively.

Black (Black J.G., 1977), studied the oral toxicokinetic with radiolabelling of the aniline moiety and they found the radioactivity completely in the faeces. Muecke (Muecke W., 1975) instead, labelled the triazine ring and found in the faeces both the isomers cis and trans.

As a consequence the whole molecule, included the aniline or suphonated aniline moieties are not metabolised.

In the study performed by Muecke (1975) both the substances (also studied by Black) analogous 04 and 08 were tested in the same conditions, administered in water solution by gavage. In both cases a rapid and complete excretion of radioactive material was observed: after application of the morpholino derivative the radioactive material was completely extractable from faeces with methanol in the form of unchanged parent compounds, while the methyl hydroxyethyl derivative was not extractable. The author comments that the behaviour is not surprising since the substance is known to bind to cellulose.

This comment suggests that the behaviour of the two substances may be different regarding bioavailability during administration in food. Nevertheless, the reliability of the comment is doubtful since both derivatives are recommended for cotton (cellulose) treatment with good fastness. The following further consideration needs to be evaluated: based on this hypothesis, it seems that the methylhydroxy derivative would not be bioavailable if administered with food in long-term studies and there would be a difference between morpholino and methylhydroxylamino derivative.

This difference is not confirmed by the study of Lyman et al. (F. L. Lyman, 1975), during which both compounds (analogous 04 and 08) were administered to dogs in food. Tissue samples were taken from representative male and female dogs used in the 90 days and 2 years oral toxicity studies: in each tissue (liver, muscle, fat, kidney, brain, blood) no difference in residues for both compounds were found. The administered doses were given in significant amounts, namely 2000 ppm (from 50 mg/Kg/day). In most cases residues were below the detection limit (the maximum detected quantity was of 0.09 ppm in the muscle), demonstrating that adsorption is generally very low and accumulation also excluded.

Furthermore, the extraction from faeces in the Muecke (1975) study was performed with methanol at room temperature; it has to be considered that the stomach environment is a strongly acid environment, with at least 37 °C temperature. In those conditions, even if a physical adsorption on the food may take place, bioavailability would be again granted by the chemical environment.

All the substances used in a read across approach are Stilbene derivatives Fluorescent Whitening Agents salts. They display similar structural and physicochemical properties: all of them exhibit high degree of dissociation in water and very low octanol/water partition coefficients because to a higher affinity with water phase than the octanol one. They are all very soluble in water, due to the presence of sulphonated groups in the molecules. The read across approach can be considered as reliable and representative. Further details about the justification for read across approach are given in the report attached to the Section 13 of this dossier.