Urethane Resin M2001

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

march to june 2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study by a laboratory having a GPL certificate.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate on october 1st 2008

Type of study:

mouse local lymph node assay (LLNA)

Test material

Reference

Name:

Unnamed

Type:

Constituent

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

Maximum tested concentration of 75%

No. of animals per dose:

4 animals for the preliminary test, 28 females for the main test

Results and discussion

Any other information on results incl. tables

A homogeneous emulsion was obtained in the fist recommended vehicle, acetone/olive oil (4/1,v/v), at the maximum tested concentration of 75%.

Consequently, the concentrations selected for the preliminary test were 25, 50, 75 and 100%.

Since the test item was non-irritant in the preliminary test, the highest concentration retained for the main test was the maximum praticable concentration (100%).

Systemic clinical signs and mortality.

Neither mortality nor clinical signs were observed during the study.

Local irritation.

An erythema was only noted on day 6 in 1/4 females given the concentration of 25%. No notable increase inear thickness was noted in animals of any group.

Proliferation assay

A significant lymphoproliferation was noted in the positive control group given HCA, the study was therefore considered valid.

A significant lymphoproliferation was noted at the tested concentration of 25, 75 and100%.

The results are presented in the following table:

Treatment	Concentration (%)	Irritation level	Stimulation Index (SI)
Test item	10	non-irritant	0.82
Test item	25	slightly irritant	3.09
Test item	50	non-irritant	1.93
Test item	75	non-irritant	7.97
Test item	100	non-irritant	4.40
HCA	25	-	8.44

In the absence of excessive local irritation, the significant lymphoproliferative responses observed were attributed to delayed contact hypersensitivity.

However, in absence of any clear evidence of a dose-relationship, the EC3 value was not calculable. Nevertheless, as no significant lymphoproliferation was noted at yhe concentration of 10% (SI = 8.82) and in absence of complementary assay, the test item should be at least considered as a weak sensitizer.

Applicant's summary and conclusion

Conclusions:

Under the experimental conditions of this study, the test item Urethane Resin M2001 induced delayed contact hypersensitivity in the murine Local Lymph Node Assay and the test item should be at least considered as a weak sensitizer.