Cyclohexane, 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethyl-, homopolymer

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

June 22, 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2011

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test) (2004)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Oligomerisation products of 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate and butan-1-ol and pentan-1-ol and 2-ethylhexan-1-ol, allophanate type

EC Number:

933-047-9

Cas Number:

53880-05-0

Molecular formula:

not applicable (UVCB substance)

IUPAC Name:

Oligomerisation products of 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate and butan-1-ol and pentan-1-ol and 2-ethylhexan-1-ol, allophanate type

Test material form:

solid: particulate/powder

Test animals

Species:

other: Assessment of corrosive potential of the test substance by determination of its cytotoxic effect on an in vitro reconstructed human epidermis (exposure 3 min./room temperature and 60 min./37 °C, subsequently MTT assay).

Details on test animals or test system and environmental conditions:

The experiment was carried out on a reconstructed human epidermis EST-1000 (CellSystems, St. Katharinen, Germany). Inserts were of 0.6 cm² size. The model has a functional stratum corneum with an underlying layer of living cells. The barrier function of the stratum corneum is adequate, as has been shown by the supplier.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: as negative control: physiological saline solution (0.9 % NaCl, 50 µL)

Details on study design:

The corrosive potential of the test item is assessed by determination of its cytotoxic effect on an in vitro reconstructed human epidermis. The test principle is based on the MTT assay reflecting the cell viability after exposure of the epidermal equivalent to topically applied test item.
All tests were performed in triplets for each time point. The test item was applied at a 100 % concentration, i.e. 25 mg per insert (plus 50 µL 0.9 % NaCl-solution to moisten and ensure good contact to the skin), for 3 min. (room temperature) and 60 min. (37 +/- 2 °C, 5 % CO2, maximum huminity).
Cell viability was measured by the amount of MTT reduction, i.e. an OD value following exposure to the negative control substance or the test item.

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 min

Value:

105.54

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not applicable

Remarks on result:

no indication of irritation

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

60 min

Value:

98.4

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not applicable

Remarks on result:

no indication of irritation

Any other information on results incl. tables

Substances are classified as „corrosive (R34)“, if the cell viability of the EST 1000 is decreased by more than 50 % after 3 min. of incubation to the test item, or if the cell viability is less than 15 % after 60 min. of exposure to the test item.

Sample No.	Test item	Time [min.]	% Viability
1-3	control NaCl 0.9 %	60	100.00
4-6	test item	60	98.4
16-18	control NaCl 0.9 %	3	100.00
19-21	test item	3	105.54

The test item was characterized by no significant impact on cell viability after 3 min. or after the 60 min. period.

Applicant's summary and conclusion

Interpretation of results:

other: no corrosive property