Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

in vitro EPISKIN(TM) 15 min - 42h skin irritation test (OECD439):
The mean tissue viability attained after treatment with WS400101 was 92.8 ± 2.4% and validity of the assay was confirmed, both for the negative and the positive controls. Therefore, WS400101 was predicted to be not irritant to the skin.
Eye irritation, rabbit with neat WS400101:
Mean irritation score 24, 48 and 72 h for each of 3 animals:
1.3 to 2.7 for corneal opacity; 1.0 for iris lesion; 2.7 to 3.0 for redness of conjunctivae; 2.0 to 3.3 for oedema of conjunctivae (chemosis);
In addition, one animal was killed at 9 days after treatment, because of irreversible corneal lesions (opacity grade 3 with area of pannus).
Conclusion: Classification and labelling as “Category 1 (irreversible effects on the eye)" [REGULATION (EC) 1272/2008].

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records
Reference
Endpoint:
skin irritation: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
other: OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method) of 2010
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: L’Oreal. In Vitro Skin Irritation Test: Human Epidermis Model EPISKIN, EPISKIN Skin Irritation Test 15min - 42 hours, Standard Operating Procedure: February 2009 Version 1.8.
Deviations:
yes
Remarks:
An error in the cited SOP was not adopted. Instead, correctly, 10 mg test substance + 90 μL water were used for checking the coloring potential of the test substance
GLP compliance:
yes (incl. QA statement)
Amount / concentration applied:
Types of Treatment in the Main Test
- Negative control: Sterile Dulbecco’s Phosphate Buffered Saline (DPBS) with magnesium and calcium, dose volume 10 µl/tissue sample.
- Test Substance: WS400101, dose 10 µl/tissue sample.
- Positive control: 5% Sodium Dodecyl Sulphate (SDS) in distilled water, dose volume 10 µl/tissue sample.
Duration of treatment / exposure:
15 ± 0.5 minutes with the test substance, negative or positive control at room temperature
Details on study design:
Test System
EPISKIN human epidermis skin constructs consisting of normal, human-derived epidermal keratinocytes and forming a multilayered, highly differentiated model of the human epidermis with a functional multilayered stratum corneum (matrix: collagen type 1 coated with type IV collagen).

Principle of the Test – Main Test
Irritant substances are sufficiently cytotoxic to cause cell deaths in the cell layers. Therefore, cell viability of the multilayers was determined by measurement of mitochondrial dehydrogenase activity assessed by reduction of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) to a soluble, blue coloured, formazan salt. Depending on the percentage of tissue viability attained (compared to negative control viability) a test substance is classified as skin irritating or not skin irritating.

Pre-Tests – Checking for Interference of the Test Substance with the Assay
It was demonstrated, that the intrinsic colour and the colouring potential of the test substance, WS400101, in contact with water did not interfere with the assay. However, direct reduction of MTT by WS400101 itself without the involvement of mitochondrial dehydrogenase activity could not be ruled out, as there was a change of colour in a WS4000101/MTT solution during the pre-test. Therefore in the main test, water killed tissues (which have no metabolic activity but absorb and bind the test substance like viable tissues) were included in addition to the live tissues. In addition, the pH of the test substance was estimated to be approximately 8.5 using pH indicator paper.

Main Test
Each treatment group (test substance, negative/positive controls) comprised 3 live (viable) tissue samples placed into wells of 12 well plates containing 2 mL pre-warmed maintenance medium per well. In addition test substance treated and untreated water killed tissues, each in triplicate, were included in the main test and processed further in a similar manner as the live tissue samples.

Tissue Processing and Quantitative Determination of Cell Viability
Incubation of the tissues prior to treatment in maintenance medium:
- Live tissue samples: ≥ 24 h at 37 ± 2° C in humidified atmosphere of 5% CO2 in air
- Thawed, water killed tissues: ≥ 1 h at room temperature

Positive and negative control preparations and the test substance were dispensed over each assigned tissue sample using a positive displacement pipette and 7 minutes afterwards positive controls were re-spread with a curved flat spatula. Test material was spread over the tissue to make contact with the whole surface of the tissue.

After the 15 ± 0.5 minutes treatment period, residual test substance or positive control substance was removed by rinsing each tissue with 25 mL sterile DPBS and gently swabbing as appropriate. Inserts were blotted on absorbent paper to remove remaining DPBS.

This was followed by incubation of each insert at 37 ± 2° C in humidified atmosphere of 5% CO2 first for 42 ± 1 h in wells each containing 2 mL maintenance medium and then for 3 hours ± 5 minutes in wells each containing 2 mL of 0.3 mg/mL MTT. Finally the tissue samples were processed further and formazan was extracted by vortexing and storage in acidic isopropanol, 500 µL/sample, at 2-8°C in the dark over a minimum of 70 hours. The absorbance was quantitatively determined at 540 nm with acidified isopropanol (0.04 N HCl final concentration) as a blank.
Irritation / corrosion parameter:
other: other: Negative Control Tissue viability as % of OD of negative controls
Value:
100
Remarks on result:
other:
Remarks:
Basis: mean. Time point: Following 42 ± 1 h incubation in fresh maintenance medium, 3 h incubation in MTT solution and ≥70 h formazan extraction. Max. score: 100.0. Reversibility: other: not applicable to the EPISKIN skin irritation assay. Remarks: Mean OD of replicate blanks has been accounted for by subtraction. (migrated information)
Irritation / corrosion parameter:
other: other: WS400101 treated tissue viability as % of OD of negative controls
Value:
92.8
Remarks on result:
other:
Remarks:
Basis: mean. Time point: Following 42 ± 1 h incubation in fresh maintenance medium, 3 h incubation in MTT solution and ≥70 h formazan extraction. Reversibility: other: not applicable to the EPISKIN skin irritation assay. Remarks: Mean OD of replicate blanks and of water killed tissues has been accounted for by subtraction. Therefore, a maximum possible score is not applicable.. (migrated information)
Irritation / corrosion parameter:
other: other: Positive Control Tissue viability as % of OD of negative controls
Value:
26.7
Remarks on result:
other:
Remarks:
Basis: mean. Time point: Following 42 ± 1 h incubation in fresh maintenance medium, 3 h incubation in MTT solution and ≥70 h formazan extraction. Reversibility: other: not applicable to the EPISKIN skin irritation assay. Remarks: Mean OD of replicate blanks has been accounted for by subtraction. An accurate maximum possible score is not applicable.. (migrated information)
Irritant / corrosive response data:
See Table 1
Other effects:
In a pre-test, direct reduction of MTT by WS400101 itself without the involvement of mitochondrial dehydrogenase activity was disclosed. This was accounted for in the main test by inclusion of water killed tissues (which have no metabolic activity but absorb and bind the test substance like viable tissues) in addition to the live tissues.

 

Tabelle 1:  Results of in vitro EpiSkin (TM) Skin Irritation Test

Exposure Period: 15 ± 0.5 minutes

 

OD 540*
Tissue 1

OD 540*
Tissue 2

OD 540*
Tissue 3

OD 540
Mean of Tissue 1, 2 + 3

Tissue Viability
[% of Negative Control
± s.d.]

Negative Control

0.734

0.716

0.753

0.734 ± 0.018

 100.0 ±  2.5

WS400101

0.688

0.707

0.723

0.706 ± 0.017

    92.8 ±  2.4**

Positive Control

0.199

0.295

0.095

0.196 ± 0.100

  26.7 ± 13.6

 

*  OD 540 of individual tissues = Mean Optical Density [wavelength 540 nm] of 2 measurements minus Mean OD of six blanks

   Mean OD of six blanks ± standard deviation (s.d.) = 0.130 ± 0.004

 

** Derived from “true MTT reduction” OD 540 values, thus accounting for possible direct reduction of MTT by the test substance

 

 

Hence assay validity was confirmed both, for the negative and the positive controls, and the test material, WS400101, proved to be not irritating.

 

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: other: criteria specified in the OECD 439 test guideline.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records
Reference
Endpoint:
eye irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 405 (Acute Eye Irritation / Corrosion)
Version / remarks:
of 2002
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)
Version / remarks:
of 2008
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.2400 (Acute Eye Irritation)
Version / remarks:
of 1998
Deviations:
no
Qualifier:
according to guideline
Guideline:
other: Japanese MAFF Test Data for Registration of Agricultural Chemicals, Eye Irritation (2-1-5), 12 Nohsan No. 8147, Agricultural Production Bureau, November 24, 2000.
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Species:
rabbit
Strain:
New Zealand White
Details on test animals or tissues and environmental conditions:
TEST ANIMALS

- Stock supply of healthy adult rabbits
- Number and Sex: 3 females
- Age on day of dosing (Day 1): 41 weeks
- Weight prior to dosing (Day 1): Minimum 3.95 kg, maximum 4.16 kg
- Housing: Individual housing in plastic cages with peforated floor
- Environmental enrichment: Small soft white untreated wood blocks
- Diet : Standard laboratory rabbit diet (125 g/animal/day). In addition, dietary supplement of hay
replaced by a supplement of wholemeal bread as from 2 days prior to dose instillation.
- Water: Drinking water, ad libitum
- Acclimation period: 29 or 30 weeks prior to study start under laboratory conditions.

Routine analysis of the batch of diet used for nutrients, possible contaminants and microorganisms and of the drinking water were conducted or available at the testing facility.


ENVIRONMENTAL CONDITIONS

Air conditioned animal room set at:
- Temperature (°C): 18 ± 2°C
- Relative Humidity (%): 40 to 70%
- Photoperiod: 12 hrs artificial light per 24 hrs

Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
0.1 mL of undiluted test substance was administered into the conjunctival sac of one eye per rabbit (right eye). The contralateral eye (left eye) remained untreated to serve as a control.
Duration of treatment / exposure:
The eyes were not rinsed after treatment, but in two of the three animals (#1 and #3) the treated eye was flushed with saline at 24 and 48 hours after treatment. For the other animal (#2) flushing of the eye with saline was not reported.
Observation period (in vivo):
21 days for two animals, the other animal (# 3) was killed at 9 days after instillation for humane reasons.
Number of animals or in vitro replicates:
3 adult female rabbits
Details on study design:
EYE EVALUATION:

Before treatment start both eyes of each animal were investigated to ensure that there was no pre-existing corneal damage, iridial inflammation or conjunctival irritation.

One animal (the sentinel # 1) was initially treated and in the absence of a severe effect the remaining two animals were committed to the study.

Eyes were evaluated at approximately 1, 24, 48 and 72 hours and 7, 14 and 21 days after test substance instillation adopting the numerical scoring system listed in Table 1 in the field below. The animal killed for humane reasons at 9 days after instillation (Day 10) had a final check for ocular lesions on this day. As from 24 h post treatment staining with fluorescein supported the recognition of corneal lesions.O

Equipment used for eye evaluation: Ophthalmoscope or pencil beam torch
Irritation parameter:
cornea opacity score
Basis:
mean
Remarks:
over 3 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
1.9
Max. score:
4
Reversibility:
not reversible
Remarks:
as in one animal (# 3) area of pannus at 9 days after instillation
Irritation parameter:
cornea opacity score
Basis:
animal #1
Remarks:
mean over 3 time points
Time point:
other: 24, 48, 72 h
Score:
1.3
Max. score:
4
Reversibility:
fully reversible within: 7 days
Irritation parameter:
cornea opacity score
Basis:
animal #2
Remarks:
mean over 3 time points
Time point:
other: 24, 48, 72 h
Score:
1.7
Max. score:
4
Reversibility:
fully reversible within: 7 days
Irritation parameter:
cornea opacity score
Basis:
animal #3
Remarks:
mean over 4 time points
Time point:
other: 48 h, 72 h, 7 days, 9 days
Score:
3
Max. score:
4
Reversibility:
not reversible
Remarks:
as area of pannus at 9 days after instillation
Remarks on result:
other: Animal killed at 9 days after instillation for humane reasons
Irritation parameter:
other: Area of corneal opacity
Basis:
mean
Remarks:
over 3 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
1.9
Max. score:
4
Reversibility:
other: Corneal ulceration or opacity were not evident
Irritation parameter:
iris score
Basis:
mean
Remarks:
over 3 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
1
Max. score:
2
Reversibility:
not reversible
Remarks:
within 9 days in one animal (#3)
Irritation parameter:
iris score
Basis:
animal #1
Remarks:
mean over 3 time points
Time point:
other: 24, 48, 72 h
Score:
1
Max. score:
2
Reversibility:
fully reversible within: 14 days
Irritation parameter:
iris score
Basis:
animal #2
Remarks:
mean over 3 time points
Time point:
other: 24, 48, 72 h
Score:
1
Max. score:
2
Reversibility:
fully reversible within: 7 days
Irritation parameter:
iris score
Basis:
animal #3
Remarks:
mean over 3 time points
Time point:
other: 24, 48, 72 h
Score:
1
Max. score:
2
Reversibility:
not reversible
Remarks:
within 9 days
Remarks on result:
other: Animal killed at 9 days after instillation for humane reasons
Irritation parameter:
conjunctivae score
Remarks:
redness
Basis:
mean
Remarks:
over 3 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
2.8
Max. score:
3
Reversibility:
not fully reversible within: 9 days in one animal (#3)
Irritation parameter:
conjunctivae score
Remarks:
redness
Basis:
animal #1
Remarks:
mean over 3 time points
Time point:
other: 24, 48, 72 h
Score:
2.7
Max. score:
3
Reversibility:
fully reversible within: 14 days
Irritation parameter:
conjunctivae score
Remarks:
redness
Basis:
animal #2
Remarks:
mean over 3 time points
Time point:
other: 24, 48, 72 h
Score:
2.7
Max. score:
3
Reversibility:
fully reversible within: 7 days
Irritation parameter:
conjunctivae score
Remarks:
redness
Basis:
animal #3
Remarks:
mean over 3 time points
Time point:
other: 24, 48, 72 h
Score:
3
Max. score:
3
Reversibility:
not fully reversible within: 9 days
Remarks on result:
other: Animal killed at 9 days after instillation for humane reasons.
Irritation parameter:
chemosis score
Basis:
mean
Remarks:
over 3 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
2.6
Max. score:
4
Reversibility:
not fully reversible within: within 9 days in one animal (#3)
Irritation parameter:
chemosis score
Basis:
animal #1
Remarks:
mean over 3 time points
Time point:
other: 24, 48, 72 h
Score:
2
Max. score:
4
Reversibility:
fully reversible within: 14 days
Irritation parameter:
chemosis score
Basis:
animal #2
Remarks:
mean over 3 time points
Time point:
other: 24, 48, 72 h
Score:
2.3
Max. score:
4
Reversibility:
fully reversible within: 7 days
Irritation parameter:
chemosis score
Basis:
animal #3
Remarks:
mean over 3 time points
Time point:
other: 24, 48, 72 h
Score:
3.3
Max. score:
4
Reversibility:
not fully reversible within: 9 days
Remarks on result:
other: Animal killed at 9 days after instillation for humane reasons
Irritation parameter:
other: discharge
Basis:
mean
Remarks:
over 3 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
2.3
Max. score:
4
Reversibility:
fully reversible within: 14 days
Remarks on result:
other: often mucoid discharge
Irritant / corrosive response data:
In two animals corneal opacity (grade 1 or 2), iritis (grade 1), conjunctival redness (grades 1, 2 and/or 3), chemosis (grades 1 to 2 in one animal and grades 1 to 4 in the other animal) and discharge (grades 1 to 3) were seen until 72 hours or 7 days after instillation. One of these animals was entirely free from ocular findings by 7 days after instillation the other animal by 14 days after instillation.

However, the third animal was more severely affected, in particular regarding corneal and conjunctival findings: Translucent and nacreous areas of corneal opacity were evident from 48 hours after instillation and nine days after instillation an area of pannus formation was apparent. Due to the irreversible nature of these corneal findings, this animal was humanely sacrificed immediately after the examination at nine days after instillation. In addition, an ulcer under the top eyelid was evident at nine days after instillation.
Other effects:
Observation of the animals for defined behavioural criteria led to the conclusion that instillation of the test substance induced practically no initial pain response. Any other signs of systemic toxicity or ill health were not evident.

Signs of reaction to treatment comprised the head of all animals being held slightly to the right on the day of administration, the right periorbital area being sensitive to touch 24 hours after instillation in one animal (#2), and hairloss on the right upper eye lid in two animals (#1 and #3) nine days after instillation or from fourteen days after instillation.
Interpretation of results:
Category 1 (irreversible effects on the eye)
Remarks:
Migrated information Criteria used for interpretation of results: EU
Endpoint conclusion
Endpoint conclusion:
adverse effect observed (irreversible damage)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Effects on eye irritation: irreversible damage

Justification for classification or non-classification

In view of the high viability of WS400101 treated tissue samples during the in vitro skin irritation study, the attained result does not necessitate any classification and labelling regarding skin irritation according to EU classification rules [REGULATION (EC) 1272/2008].

The irreversible corneal lesions in one animal in the in vivo eye irritation study necessitate classification of WS400101 as “Category 1 (irreversible effects on the eye)" [REGULATION (EC) 1272/2008].