Alcohols, C16-18 and C18-unsatd., propoxylated

Endpoint summary

Description of key information

Skin irritation/corrosion (OECD 431): not irritating
Eye irritation/corrosion (OECD 437 and 405): not irritating, GLP

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Additional information

In vitro skin irritation/corrosion and eye irritation/corrosion studies with Alcohols, C16-18 (even numbered) and C18 unsaturated, propoxylated, < 2.5 PO (CAS 70955-07-6) were performed. Supporting in vivo studies with structural related substances for read-across were used to cover the endpoint irritation/corrosion.

Skin irritation / skin corrosion

The skin corrosion potential of the test substance was tested in vitro on three dimensional human epidermis model EpiDerm™ 200 according to OECD Guideline 431 under GLP conditions (Remmele, 2012) 50 µL of test substance per insert (6-well plate) with EpiDerm™ 200 was applied. The experiment was performed for 3 (at room temperature) and 60 minutes (in the incubator at 37°C and humidified atmosphere) in duplicate. Negative control tissues were concurrently applied with 50 µL of de-ionized water or with 50 µL of 8 n potassium hydroxide (positive control). After both exposure periods the reconstructed human epidermis was washed. Tissue destruction was determined by measuring the metabolic activity of the tissue after exposure/post incubation using a colorimetric test. The reduction of mitochondrial dehydrogenase activity was measured by reduced formazan production after incubation with a tetrazolium salt (MTT). The viability of cells was therefore assessed using the MTT-assay. The tissues were incubated for about 3 hours in MTT solution. After extraction of the formazan crystals with isopropanol the OD570 was assessed.

The skin irritation potential of the test substance was tested in vitro on three dimensional human epidermis model EpiDerm™ 200 according to OECD Guideline 439 under GLP conditions. 30 µL of test substance per insert (6-well plate) with EpiDerm™ 200 was applied. The experiment was performed for 60 min (overall 25 min at RT and 35 min in the incubator at 37°C) in triplicate. Negative control tissues were concurrently applied with 30 µL of PBS or with 30 µL of 5% SDS (positive control). After both exposure periods the reconstructed human epidermis was washed and incubated for approx. 44 h with a medium change in between. The viability of cells was assessed using the MTT-assay. The tissues were incubated for about 3 hours in MTT solution. After extraction of the formazan crystals with isopropanol the OD570 was assessed.

The EpiDerm™ skin corrorsion/irritation test showed the following results:

The test substance is not able to reduce MTT directly.

Corrosion test:

The mean viability of the test item treated skin resulted to be 100% and 108% after 3 minutes and 1 h exposure period respectively.

Irritation test:

The mean viability of the test item treated skin resulted to be 121% after 1h exposure period with about 42 h post-incubation.

Based on the observed results it was concluded that Alcohols, propoylated (<2.5 PO) does not show a skin irritation potential on the EpiDerm™ skin corrosion/irritation test under the test conditions chosen.

In addition an in vivo study from a structural similar substance alcohol propoxylated (alcohol, C18, 15 PO, CAS 25231-21-4) was taken into account.

In a dermal acute toxicity study performed similar to OECD Guideline 402 with the substance alcohol propoxylated (alcohol, C18, 15 PO, CAS 25231-21-4) 5000 mg/kg bw of the test substance were applied to the clipped skin of 6 male and female New Zealand Albino rabbits of under occlusive conditions for 24 h (Yanagimoto, 1984). The test sites of 3 males and 3 females were abraded. Skin reactions were scored according to Draize, J.H. et al. (1944) after removal of the patch and the skin was washed. The observation period was 14 days.

A very slight erythema was observed in most animals after the exposure period. Under the condition of the study the substance was classified as mils irritant according to the Draize score criteria. However the data are not sufficient to draw a conclusion about the skin irritation potential of the test item.

Eye irritation / eye corrosion

The potential of Alcohols, C16-18 (even numbered) and C18 unsaturated, propoxylated, < 2.5 PO (CAS 70955-07-6) to cause serious damage to eyes was investigate in a BCOP test according to OECD 437 under GLP conditions (Remmele, 2012).

750 µL of 10% test substance preparation (surfactant) was applied to the epithelial surface of isolated bovine corneas. Three corneas were treated with the test substance preparation for 10 minutes followed by a 2 hours post-incubation period.

Corneal opacity was measured quantitatively as the amount of light transmission through the cornea. Permeability was measured quantitatively as the amount of the sodium fluorescein dye passes across the full thickness of the corneas. 

The mean corneal opacity and permeability values of each treatment group were used to calculate an In Vitro Irritancy Score (IVIS). The IVIS could be calculated per treated cornea and finally the mean IVIS per treatment group ± standard deviation was determined:

• IVIS per cornea = corrected opacity change + 15 * corrected permeability OD change

• IVIS per treatment group = mean opacity value + 15 * mean permeability OD value

Test item´s IVIS was -2.2. Negative and positive controls´ IVISs were 2.6 and 169.7 respectively.

A test substance was considered corrosive to the eye if the IVIS is greater than 55 after 10 min exposure and a subsequent 2 h post incubation period.

Based on the findings of the present study and on the evaluation criteria described in the study, it can be concluded that Alcohols propoxylated (< 2.5 PO) does not cause serious eye damage in the Bovine Corneal Opacity and Permeability Test (BCOP Test) under the test conditions chosen.

 

The eye irritation potential of the test substances was investigated in a study performed according to the methods described in the Harbell et al. 2009 (Remmele, 2012).

50 µL of the test substance was applied to a reconstructed three dimensional human cornea model (EpiOcular ™). Two EpiOcular ™ tissue samples were incubated with the test substance for 30 min followed by a 2 h post incubation period.

Negative and positive control tissues were concurrently applied with 50 µL of de-ionized water or methyl acetate, respectively.

After the incubation period the tissues were washed and incubated for 2 h. The viability of cells was assessed using the MTT-assay. The tissues were incubated for about 3 hours in MTT solution. After extraction of the formazan crystals with isopropanol the OD570 was assessed.

The mean viability of the test item resulted to be 107%. As the test substance is considered irritating if the cell viability is lower than or equal to 50% after 30 min exposure and 2 h post incubation, period it was concluded that alcohol propoxylated (<2.5 PO ) does not show an eye irritation potential in the EpiOcular ™ eye irritation test under the test conditions.

 

An acute eye irritation study was conducted with read across substance alcohol ethoxylated (C16-18 and C18 unsatd., ethoxylated, < 2.5 EO (CAS 68920-66-1) according to OECD Guideline 405 and under GLP conditions (Hoyer, 1966). 0.1 mL of the test substance was applied into the lower conjuctivial sac of the right eye of three New Zealand albino rabbits. The left eye served as control.

The eye irritant activity was evaluated by Draize score method. Mortality and abnormal responsed were observed for 14 days at 24 hours interval. The study revealed no irritation, no inflammation and no mortality. Based on the above findings the test item does not indicate any eye irritation.

In addition a further acute eye irritation study was conducted with the read across substance alcohol propoxylates (alcohol, C18, 15 PO, CAS 25231-21-4). 0.1 mL of the test substance was instilled into the right eye of each of six New Zealand White rabbits (Yanagimoto, 1984). No corneal opacity was observed. Slight irritation of the conjunctiva was observed in 5/6 animals.

Justification for selection of eye irritation endpoint:
No study selected as a weight of evidence approach is followed.

Justification for classification or non-classification

According to the classification criteria of Directive 67/548/EEC and Regulation (EC) No 1272/2008 the substance does not need to be classified for skin/eye irritation or corrosion.