Reaction mass of 1-hydroxydecan-3-one and 3-(hydroxymethyl)nonan-2-one and nonan-2-one

Endpoint summary

Description of key information

Skin corrosion: Corrosive after 60-minute exposure, but not 3-minute exposure based on an OECD TG 431 test.

Skin irritation: Irritating based on an OECD TG 439 test.

Eye corrosion/irritation: Causes serious eye Irritation based on an OECD TG 438 test.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Skin corrosion

The skin corrosive potential of the test substance was tested in vitro using the EpiDerm™ model after a treatment period of 3 and 60 minutes. The study procedures were according to OECD TG 431 and GLP principles. The principle of the assay was based on the measurement of cytotoxicity in reconstructed human epidermal cultures following topical exposure to the test substance by means of the colorimetric MTT reduction assay. The mixture of 50 μL test item per 1 mL MTT medium showed reduction of MTT as compared to the solvent. The test item turned blue/purple. For quantitative correction of results, the part of absorption due to the non-specific reduction of MTT (NSMTT) was determined by using killed tissues. Therefore, two tissues per treatment period were treated with the test item or left untreated, respectively. NSMTT was calculated relative to the negative control of living tissues (NC) per treatment period. In the 3 min experiment NSMTT was 2.5%, in the 60 min experiment 1.0%. NSMTT was ≤ 30% relative to the negative control of living epidermis. This means that the test item was washed away almost completely before the addition of the MTT solution. The true MTT metabolic conversion (TODTT) of the test item treated living tissues (TM) was corrected for each treatment period. The mixture of 50 μL test item per 300 μL Aqua dest. and per 90 μL isopropanol showed no colouring as compared to the solvent. Therefore, non-specific color (NSC) equalled 0%. The test item showed non-specific reduction of MTT, but no relevant colouring potential after mixture with aqua dest. and with isopropanol. Therefore, no additional controls for correction of possible false-negative results were necessary. The test item showed corrosive effects. The mean relative tissue viability (% negative control) was reduced below 15% (4.2%, NSMTT-corrected) after 60 min treatment but not below 50% (101.4%, NSMTT-corrected) after 3 min treatment. The test item is therefore corrosive when exposure last longer than 3 minutes.

Skin irritation

The skin irritation potential of the test substance was tested in vitro using the EpiDerm™ model after a treatment period of 60 minutes followed by a post-exposure incubation period of 42 hours. The study procedures were according to OECD TG 439 and GLP principles. The principle of the assay was based on the measurement of cytotoxicity in reconstructed human epidermal cultures following topical exposure to the test substance by means of the colorimetric MTT reduction assay. Triplicate tissues were treated with 30 µL undiluted test item for an exposure period of 60 minutes. Concurrent positive (5% SDS solution in aqueous solution) and negative (Dulbecco’s Phosphate Buffered Saline) controls were included. The optical density was measured at 570 nm. The mixture of 30 μL test item per 1 mL MTT medium showed reduction of MTT compared to the solvent. The mixture turned blue/purple. The coloured test material or MTT reducing substance was classified as “Irritant” i.e. mean tissue viability is < 50%. Therefore, no correction procedures were necessary. The mixture of 30 μL of the test item per 300 μl aqua dest. and per 300 μL isopropanol showed no colouring detectable by unaided eye-assessment. Therefore, non-specific colour (NSC) equalled 0%. The test item showed non-specific reduction of MTT, but no relevant colouring potential after mixture with aqua dest. and with isopropanol. Therefore, no additional controls for correction of possible false-negative results were necessary. The test item showed irritant effects. The mean relative tissue viability (% negative control) was ≤ 50% (2.7%) after 60 min treatment and 42 h post-incubation. The substance is irritating to skin.

Eye irritation

An in vitro eye irritation study of the test item was performed in isolated chicken’s eyes. The irritation effects of the test item were evaluated according to the OECD TG 438 guideline and the classification scheme of Schutte et al (2009). After the zero reference measurements, the eyes were held in a horizontal position and the test item was applied onto the centre of the cornea such that the entire surface of the cornea was covered in all cases. After 10 seconds exposure time, the surface of the eyes was rinsed with physiological saline solution. Three eyes were treated with 30 μL test item. The three positive control eyes were treated in a similar way with 30 μL of 5% (w/v) Benzalkonium chloride solution. The negative control eye was treated with 30 μL of physiological saline (0.9% (w/v) NaCl solution). Corneal thickness, corneal opacity and fluorescein retention were measured and any morphological effects (e.g. pitting or loosening of the epithelium) were evaluated. The results from all eyes used in the study met the quality control standards. The negative control and positive control results were within the historical control data range in experiment. Thus, the study was considered to be valid. Slight corneal swelling change (mean = 13.0%) was observed during the four-hour observation period on test item treated eyes. Moderate cornea opacity change (mean = 2.00) was observed. Severe fluorescein retention change (mean = 2.83) was noted. No other morphological effect was observed. Based on this in vitro eye irritation assay in isolated chicken eyes with Methyl Lavender Ketone, according to Schutte et al (2009), the test item is considered to cause serious eye irritation.

Justification for classification or non-classification

Based on the results of the available in vitro skin studies, the substance has to be classified as corrosive (Skin Corr 1B or 1C) as corrosivity was observed after 1 hour exposure, but not after 3 minutes exposure. As the subcategories 1B and 1C cannot be distinguished based the data available, the substance will be classified Skin Corr 1B and shall be labelled with H314: Causes severe skin burns and eye damage according to EU CLP (EC 1272/2008 and its amendments).

Based on the results of the available in vitro eye study, and according to the classification scheme of Schutte et al (2009), the substance has to be classified as Eye Irrit. 2 and shall be labelled with H319: Causes serious eye irritation according to EU CLP (EC 1272/2008 and its amendments).