Disodium 4-hydroxy-3-[[2-methoxy-5-methyl-4-[(4-sulphonatophenyl)azo]phenyl]azo]-7-(phenylamino)naphthalene-2-sulphonate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

other: read across from similar substance

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Trisodium 3-[[4-[[6-(anilino)-1-hydroxy-3-sulphonato-2-naphthyl]azo]-5-methoxy-o-tolyl]azo]naphthalene-1,5-disulphonate

EC Number:

228-327-6

EC Name:

Trisodium 3-[[4-[[6-(anilino)-1-hydroxy-3-sulphonato-2-naphthyl]azo]-5-methoxy-o-tolyl]azo]naphthalene-1,5-disulphonate

Cas Number:

6227-20-9

Molecular formula:

C34H27N5O11S3.3Na

IUPAC Name:

trisodium;3-[[4-[(2E)-2-(6-anilino-1-oxo-3-sulfonatonaphthalen-2-ylidene)hydrazinyl]-5-methoxy-2-methylphenyl]diazenyl]naphthalene-1,5-disulfonate

In vitro test system

Test system:

human skin model

Remarks:

EPISKIN Reconstructed Human Epidermis Model Kit

Cell type:

other: reconstructed (RhE)

Details on animal used as source of test system:

The procedure followed is based on the recommended EpiSkin SOP, Version 1.8 (February 2009), ECVAM Skin Irritation Validation Study

Vehicle:

unchanged (no vehicle)

Details on test system:

A 3 mg/mL MTT stock solution was prepared in DPBS. The stock solution was diluted to 0.3 mg/mL with assay medium when required

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Number of replicates:

3

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Tested substance - mean of replicates

Value:

117.53

Vehicle controls validity:

not examined

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Negative control group - mean of replicates

Value:

100

Vehicle controls validity:

not specified

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Results 3

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

Positive control group - mean of replicates

Value:

13.5

Vehicle controls validity:

not specified

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Any other information on results incl. tables

Cell viability determination is based on cellular mitochondrial dehydrogenase activity, measured by MTT reduction and conversion into blue formazan salt that is quantified after extraction from tissues (Mosman T., 1983). The reduction of cell viability in treated tissues is compared to negative controls and expressed as a percentage. The percentage reduction in viability is used to predict the irritation potential.

Each  test  substance  (test  material,  negative  and  positive  controls)  is  topically  applied concurrently  on  three  tissues replicates  for  42 minutes  at  room temperature  (RT,  comprised between  18°C  to  24°C).  Exposure  to  the  test  substance  was  followed  by  rinsing  with phosphate  buffer  saline  (PBS)  and mechanically dried. Epidermis were then transferred to fresh  medium  and  incubated  at  37°C  for  42  additional  hours.  Cell  viability  is  assessed  by incubating  the  tissues  for  3  hours  with  0.3  mL MTT  solution  (1  mg/mL). The  formazan crystals are extracted  using 1.5  mL  isopropanol  for  2  hours  at  RT  and  quantified  by spectrophotometry  at  570  nm wavelength. Sodium  Dodecyl Sulphate (SDS 5%), and PBS treated  epidermis  are  used  as  positive  and  negative  controls, respectively. For each treated tissue,  the  cell  viability  is  expressed  as  the  percentage  of  the  mean  negative  control  tissues. Values under 50% is qualified the test substance as irritant.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Not irritant for skin

Executive summary:

The substance was tested in the EPISKIN™ Reconstructed Human Epidermis Model using triplicate tissues during 15 minutes. Additional controls were included to account for direct MTT interference and color interference. The relative mean viability of the test substance treated tissues was 59.8 %. The test results does not show any effect on skin. The tested substance could be considered as not irritant for the skin and does not required any classification.