Registration Dossier

Administrative data

Description of key information

The test substance containing 34.4% active ingredient was predicted to be non-irritating  to human skin based on the in vitro EST-1000 human skin model for corrosion (3 minutes and 1 hour exposure) and irritation (20 minutes exposure, followed by 42 hours incubation). The same test substance was predicted to be  irritant to human eye based on the in vitro HET-CAM model, however it was negative for severe eye irritation in the in vitro BCOP model. A 35.8% solution was previously tested to be mildly irritant based on the Draize method  in rabbit eyes.  Finally test substance containing 34.4%  active ingredient was tested to be not irritating in rabbit eyes. In conclusion, a subgroup CLP category 2 classification was proposed, with concentration limit of 34% or less for non-classification. 

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:
adverse effect observed (irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Skin irritation

Assessment was performed by a weight-of-evidence approach.

- A first in vitro study was conducted with registered substance to determine potential corrosive properties in an artificial three-dimensional EST-1000 human skin model (Flügge, 2012a). The test item containing 34.4% active ingredient, was applied to the skin surface during two exposure times of 3 minutes and 1 hour. The cell viability was measured by determining the optical density (OD) at a wavelength of 540 nm. In comparison to the negative controls, the mean viability of cells exposed to the test item was 92.2% after a 3-minute exposure period and 74.1% after a 1-hour exposure.The values were well above the cut-off percentage cellviability values distinguishing corrosive from non-corrosive test items of <50% or <15% for a 3-minute or 1-hour treatment, respectively. Therefore, the test item was non-corrosive in this skin model and is predicted to be non-corrosive to human skin.

- A second in vitro study with registered substance was performed to determine potential irritating properties in an artificial three-dimensional EST-1000 human skin model (Flügge, 2012b). The test item containing 34.4% active ingredient, was applied to the skin surface during 20 minutes, followed by refreshment of the medium and incubation for 42 hours. The cell viability was measured by determining the optical density (OD) at a wavelength of 540 nm.The mean viability of the cells exposed to the test item was 104.1% of the mean negative control value. The value was well above the cut-off percentage cell viability value that distinguishes irritant from non-irritant test items of >50% for a 20-minute exposure. The test item was considered to be non-cytotoxic and predicted to be not irritant to skin.

- According to ECHA progress report 2010 (p 32), it is accepted that in vitro methods for skin irritation represent a full replacement of the in vivo method in a tiered testing strategy and in conjunction with in vitro skin corrosivity tests, if necessary. A negative result in the human skin model for irritation does not need to be confirmed by additional testing.

- In conclusion, the test substance was predicted to be non-corrosive and non-irritant to human skin based on the three-dimensional EST 1000 human skin model, therefore no classsifciation is needed.

Eye irritation

- There was a supporting in vivo eye irritation study with test substance containing 35.8% active ingredient tested in three albino rabbits (Tusing, 1955). A single application of 0.05 mL of the undiluted test item was placed in the conjunctival sac of the left eye of each rabbit, while the untreated right eye served as a control. Within 24 hours following eye application, there was a mild degree of eye irritation characterized by erythema, vascularization of the sclera and nictitating membrane, and edema of the lids and nictitating membrane, accompanied by lacrimation and exudate. The eye irritative signs gradually subsided within the next day or two and by the fourth day, and daily thereafter, the eyes of all animals appeared normal. There were no scorings, therefore the study was supportive.

- In a supporting in vitro study, severe eye irritation potential and corrosivity potential of the test item containing 34.4% active ingredient was tested by means of the BCOP test method (Leuschner, 2013).Three corneas were used for each treatment group (test item, negative and positive controls). The test item was used as a 3.44-fold dilution in 0.9% NaCl-solution in order to obtain a 10% w/v dilution of active ingredient, which complies with the guideline requirements for surfactants. 0.9% NaCl solution was used as the negative control and 1% NaOH solution as the positive control item. The test item and the controls were applied to the epithelial surface of the cornea by addition to the anterior chamber of the corneal holder for an exposure time of 10 minutes.The optical density (OD492) or absorbance values were measured at a wavelength of 492 nm. An opacity value of 2.133 and a permeability value of 1.235compared to the negative control were determined. An IVIS 20.67 was calculated. Hence, the test item was not classified as a severe irritant and not corrosive, based on the results of this test. The corneas treated with the positive control item 1% NaOH solution revealed an opacity value of 92.985 and a permeability value of 1.795 compared to the negative control. The IVIS value of 119.90 was well above the cut-off value of 55.1 and, hence, the acceptance criteria for the test were fulfilled. 1% NaOH solution was a severe irritant and corrosive to eyes. The test item, containing 34.4% active ingredient, tested in the in vitro BCOP test method, had an IVIS value of < 55.1 and consequently it was not classified as inducing severe eye damage.

- In another supporting in vitro study the eye irritancy potential was tested with registered substance by means of the chorioallantoic membrane of hens' eggs (HET-CAM) method with a test item containing 34,4% active ingredient (Haferkorn, 2012). Three eggs each were treated with 300 µL/egg. After administration of the test item blood vessels including the capillary system and the albumen were examined and scored for irritant effects (haemorrhage, coagulation and lysis) during 5 minutes. The test item treated eggs revealed an effect with an irritation index (IS) of 10, compared to IS of 19 or 10 for 0.1% NaOH and 0.1% SDS positive controls and no effects in the negative control 0.9% NaCl solution. The test substance was predicted to be irritating.

-In an in vivo eye irritation study (Hansen 2013), a single instillation of 0.1 mL test substance containing 34.40% act. ingr. per animal into the conjunctival sac of the right eye of three rabbits resulted in the following mean 24 -72h scores: 0/4 for cornea, 0/2 for iris, 1.11/3 for conjunctiva and 0.45/4 for chemosis. The fluorescein tests revealed corneal staining in animal no. 2 animals. All findings were reversible within 5 day. There were no systemic intolerance reactions concerning behaviour, body weight and food consumption. Based on the negative findings, the substance can be concluded to be non-irritating to eyes, hence, no labelling is required.

- In conclusion, the registered substance was found to be non-corrosive and non-irritating at tested concentration of 34.4% active ingredient. Nevertheless a subgroup CLP category 2 classification is proposed, however with concentration limit of 34% or less for non-classification.

Conclusion:

- No classification is needed for skin irritation.
- A subgroup CLP category 2 classification was proposed for eye irritation, with concentration limit of 34% for non-classification of registered substance.
- More information on the subgroup classification is provided in the read-across justification, separately attached in Section 13.




Justification for selection of skin irritation / corrosion endpoint:
Although the in vitro study for irritation was selected, the corrosion study was equally valuable in a weight-of-evidence approach.

Justification for selection of eye irritation endpoint:
Key study

Effects on eye irritation: slightly irritating

Justification for classification or non-classification

The substance does not need to be classified for skin irritation according to CLP regulation (No. 1272/2008 of 16 December 2008).

For the eye, the substance is classified as irritating to eyes. According to CLP regulation (No. 1272/2008 of 16 December 2008), the substance is classified as Category 2, with signal word 'warning' and hazard statement: H319-Causes serious eye irritation.  However, a concentration limit of 34% for non-classification can be applied.