Vinasses, residue of fermentation containing biomass of bakers yeast, salt-enriched

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Additional information:

Within the Vinasses category, animal and human data on the sensitisation potential of Vinasses are available for three subgroups of Vinasses, e. g. Vinasses, residue of fermentation, Vinasses, residue of fermentation, salt-enriched and Vinasses, residue of fermentation containing biomass of bakers yeast (Saccharomyces cerevisiae). However, all Vinasses subgroups share a common origin and are therefore constituted of the same components determining their toxicological properties. Thus, read-across is performed based on a category approach (A detailed justification is attached in IUCLID section 13).

A first Local Lymph Node Assay was performed with Vinasses, residue of fermentation in CBA/J mice according to OECD 429 (van Otterdijk, 2010c). Three experimental groups of five female/J mice were treated with test substance concentrations of 25, 50 or 100% w/w on three consecutive days, by open application on the ears. Five vehicle control animals were similarly treated, but with vehicle alone (propylene glycol). The author stated that no irritation of the ears was observed in the presence of brown remnants of the test substance on the ears. However, in all animals treated with the test substance concentration of 100%, increased sizes of the auricular lymph nodes were observed. The ear thickness was not measured. The SI values calculated for the substance concentrations 25, 50 and 100% were 1.6, 1.9 and 9.3, respectively.

 

In a repeat experiment, the identical test substance in concentrations of 25, 50 and 100% caused a slight but noticeable increase in mean ear puncture weights at 100% and yielded SI values of 1.5, 2.1 and 4.0, respectively (Beerens-Heijnen, 2011a).

In addition, a second representative sample of Vinasses, residue of fermentation was tested using the same experimental conditions as already described above with the exception that ear punctures were performed (Beerens-Heijnen, 2011b). In this experiment, test substance concentrations of 25, 50 and 100% resulted in SI values of 2.0, 2.8 and 2.9, respectively, without affecting ear puncture weights.

Moreover, a Local Lymph Node Assay according to OECD 429 including measurements of ear puncture weight was also performed with the test substance Vinasses, residue of fermentation containing biomass of bakers yeast (Saccharomyces cerevisiae) (Beerens-Heijnen, 2011c). Ear skins of 5 female CBA mice were treated with 25μL of the liquid test substance at concentrations of 25, 50 and 100% diluted with propylene glycol for three consecutive days. Mean Disintegrations Per Minute (DPM) /animal values for the experimental groups treated with the test material at 25, 50 and 100% were 468, 465 and 381 DPM, respectively. The mean DPM/animal value for the vehicle control group was 450 DPM. The values were then used to calculate the stimulation index (SI). The SI values calculated for the substance concentrations 25, 50 and 100% were 1.0, 1.0 and 0.8, respectively. No effects on ear puncture weight were observed.

These results indicate that Vinasses are able to elicit an SI ≥ 3 in the Local Lymph Node Assay. However, the results described above cannot clearly be verified as sensitising effects, since skin irritation could also induce an increase of the stimulation index. The fact that stimulation indices above 3 were accompanied by increased auricular lymph nodes and increased mean ear puncture weights, indicative of inflammatory effects, supports this assumption.

Moreover, the Local Lymph Node Assay cannot be considered as a predictive assay for the sensitising properties of UVCB substances since it was developed for and validated by testing of well-defined chemicals.

 

Human data

A number of statements on in-house human experience are available from occupational health physicians confirming that after working with Vinasses for many years, none of the employees has reported any allergic reactions so far, which could be attributed to Vinasses (Brouck and Frimat, 2010; Rasi, 2010; Kosek, 2010; Carton, 2010, Sobkowiak, 2010; Pieters, 2010; Hrušková, 2010; Buhre, 2010). Furthermore, up to now no case of skin sensitisation is published in the literature.

 

Migrated from Short description of key information:
LLNA: positive in 2 tests (EC3 values of 57 and 74, respectively, therefore considered as a weak sensitiser in mice) and negative in 2 tests.
Human experience: not sensitising

Respiratory sensitisation

Endpoint conclusion

Additional information:

This information is not available.

Justification for classification or non-classification

The available data for Vinasses on skin sensitisation is inconclusive according to the criteria of 67/548/EEC (DSD) and 1272/2008/EC (CLP) since (i) the performed Local Lymph Node Assays (LLNA) gave divergent even contradictory results, i. e. two negative and two positive tests, (ii) it is arguable if the LLNA is the appropriate animal test to analyse the sensitisation potential of such a complex UVCB substance and (iii) there are no indications from practical experience that the substance is capable of inducing skin sensitisation in humans. Therefore, in order to assign a reliable classification to the substance, it is proposed to perform a Guinea Pig Maximization Test (GPMT) according to OECD 406.