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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was conducted according to O.E.C.D. Testing Guideline No. 429 with GLP compliance and peer review.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2008
Report date:
2008

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
not specified
GLP compliance:
yes
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
As per IUCLID5 Sections 1.1 -1,4,

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
CBA/CaOlaHsd female mice were acquired from Harlan Winkelmann GmbH, Borchen, Germany and housed individually in Makrolon type 1 cages. The animals were six to ten weeeks of age upon reciept. The animals were maintained under conditions of 20 - 24 degrees C, 30 - 70% relative humidity with a light/dark cycle of 12 hr. Tap water and feed were provided ad libitum.

Study design: in vivo (LLNA)

Vehicle:
other: Acetone
Concentration:
0.3, 1.0 and 3.0% w/v.
No. of animals per dose:
6
Details on study design:
Twenty five uL of the test substance preperation was applied to both ears of the mice for three consecutive days. The control group received 25 uL of vehicle. Concentration and stability of the test substance in vehicle was monitored GC analysis.

Three days following the last dermal treatment the mice were injected intravenously (I.V.) with 20 uCi of [3H]-thymidine via the tail vein. Approximately five hr after the 3H-thumidine injection, the mice were sacrificed and the auricular lymph nodes were harvested. The weight of each animal's lymph nodes was determined. Lymph node response was accessed by measuring the cellular content and amount of 3H-thymidine incorporated into the lymph node cells as indicators of cellular proliferation.

Single cell suspensions were prepared from pooled lymph nodes of each animal by passing them through iron mesh (mesh size 200 um) into 6 mL of phosphate-buffered physiological saline. To determine cell counts the suspensions were dilluted 1:500 and counted with a Casy-Counter. The rest of the lymph node cell suspension was washed twice with phosphate-buffered saline by centrifugation and resuspension. The washed suspension was precipitated with 5% trichloroacetic acid and transfered to scintillation fluid for the measurment of 3H-thymidine incorporation
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)
Statistics:
The Estimated Concentration for a Stimulation Index (SI) of 1.5 or 3-fold was determined by linear regression analysis.

Results and discussion

Positive control results:
Lymph node cell counts reached 1.64-fold the control background level at 10% wt/ and 3H-thymidine DPM was 2.84-fold the concurent control value at 10% wt/v.

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: 0.94 - 0.3 % wt/v, 1.67 - 1.0% wt/v and 4.65 - 3.0% wt/v.
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: No data.

Any other information on results incl. tables

Lymph Node Cell Counts

____________________

0.3%              0.92

1.0%              1.21

3.0%              2.0

Applicant's summary and conclusion

Interpretation of results:
sensitising
Remarks:
Migrated information based on both lymph nodecell count SI and DPM SI.
Conclusions:
1,6-Hexanediol Diglycidylether (HDDGE) is a dermal sensitizer in the mouse LLNA assay. The authors concluded that Estimated Concentration for HDDGE based on DPM data was 1.9% wt/v and judged HDDGE to have moderate dermal sensitizing potential based on the outcome of this study. Based on E.C.H. A. guidance (RIP 3.2 Chapter R.8, Section R.8.4.3.1 and Appendix R 8-10 page 128) and adjustment of the dermal penetration mouse to human skin (Boogaard, et. al., 2000) the resulting worker dermal DMEL/DNEL for skin sensitization is 22.6 ug/cm2.
Executive summary:

1,6-Hexanediol Diglycidylether (HDDGE) was evaluated for skin sensitizing potential in a mouse LLNA O.E.C.D. 429 Testing Guideline study with GLP compliance including test substance stability and concentration verification. HDDGE was found to be a dermal sensitizer in the mouse LLNA assay. The authors concluded that the Estimated Concentration 3 for HDDGE based on DPM data was 1.9% wt/v and judged HDDGE to have moderate dermal sensitizing potential based on the outcome of this study. The Worker Dermal DMEL/DNEL based on the results of this study was estimated to be 22.6 ug/cm2.