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Diss Factsheets

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1998
Report date:
1998

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
yes (incl. QA statement)
Type of study:
Buehler test

Test material

Constituent 1
Chemical structure
Reference substance name:
2,4-di-tert-pentylphenol
EC Number:
204-439-0
EC Name:
2,4-di-tert-pentylphenol
Cas Number:
120-95-6
Molecular formula:
C16H26O
IUPAC Name:
2,4-bis(2-methylbutan-2-yl)phenol
Details on test material:
- Name of test material (as cited in study report): 2,4-di-tert-Amylphenol
- Physical state: liquid
- Analytical purity: 99.61%
- Purity test date: 1998-01-28
- Lot/batch No.: not mentioned
- Date of production: 1998-01-14
- Stability under test conditions: > 1 year
- Storage condition of test material: in tightly closed containers, under exhaust hood

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan Winkelmann, Borchen, Germany
- Age at study initiation: healthy young adults, no details mentioned
- Weight at study initiation: weighing less than 500g
- Housing: conventional, Makrolon Type IV cages (maximum 5 animals per cage)
- Diet (e.g. ad libitum): Ssniff G4 complete feed for guinea pigs ad libitum, supplied by Ssniff Spezialfutter GmbH, Soest, Germany
- Water (e.g. ad libitum): drinking water ad libitum, supplied by Gelsenwasser, Wasserwerk, Haltern, Germany
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 30 - 70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: not mentioned

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
corn oil
Concentration / amount:
induction: 50%
challenge: 25%
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
corn oil
Concentration / amount:
induction: 50%
challenge: 25%
No. of animals per dose:
test animals: 20 (male, main experiment), 3 (female, preliminary test)
control animals: 10 (male), 3 (accompanying group)
Details on study design:
RANGE FINDING TESTS:
Determination of the non-irritant concentration of the test substance with occlusive epicutaneous applications for 6 hours of test substance 5%, 25% and 50% in corn oil and 100% (undiluted). Reading at 30 and 54 hours after application.
Redetermination of the maximum non-irritant concentration for the challenge treatment in the 4th week with 3 additional guinea pigs which had not been treated up to this time. The concentrations and test conditions were the same as in the pilot study. This additional testing was carried out because it was suspected that the sensitivity of the skin changed as the weight of the animals increased. This ensured that the challenge concentration was determined on animals which had approx. the same weights as the 30 animals in the challenge phase.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: occlusive dermal applications for 6 hours, scoring at 30 hours after application
- Test group: receiving test substance (0.3 cm³/patch)
- Control group: receiving vehicle (0.3 cm³/patch)
- Site: left flanks
- Frequency of applications: induction on days 0, 7 and 14
- Duration: 3 weeks
- Concentrations: 50% in corn oil

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: on day 28
- Exposure period: occlusive dermal application for 6 hours
- Test groups: receiving test substance solution and vehicle (0.3 cm³/patch each)
- Control group: receiving test substance solution and vehicle (0.3 cm³/patch each)
- Site: right flanks (front: vehicle, back: test substance solution)
- Concentrations: 25% in corn oil
- Evaluation (hr after challenge): 30 and 54 hours after application
Challenge controls:
same treatment as test group animals
Positive control substance(s):
no

Results and discussion

Positive control results:
The guinea pig strain is judged to be sensitive under the test conditions described.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
30
Group:
other: dermal induction I
Dose level:
50%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
slight reactions on the skin of 4 animals
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 30.0. Group: other: dermal induction I. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: slight reactions on the skin of 4 animals.
Reading:
1st reading
Hours after challenge:
30
Group:
other: dermal induction II
Dose level:
50%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
slight to moderate reactions on the skin of 18 animals
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 30.0. Group: other: dermal induction II. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: slight to moderate reactions on the skin of 18 animals.
Reading:
1st reading
Hours after challenge:
30
Group:
other: dermal induction III
Dose level:
50%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
slight to moderate reactions on the skin of 12 animals
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 30.0. Group: other: dermal induction III. Dose level: 50%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: slight to moderate reactions on the skin of 12 animals.
Reading:
other:
Hours after challenge:
30
Group:
other: challenge treatment
Dose level:
25%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
none contaneous reactions
Remarks on result:
other: Reading: other:. . Hours after challenge: 30.0. Group: other: challenge treatment. Dose level: 25%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: none contaneous reactions.

Any other information on results incl. tables

RESULTS OF PILOT STUDY: The 5 and 25% test substance formulations did not cause any skin irritations on the animals 30 and 54 hours after administration. The 50% formulation caused discrete or patchy erythema in one animal. The undiluted test substance caused intense erythema and swelling combined with scab formation in all animals 30 and 54 h post application.

RESULTS OF TEST

Clinical signs: There were slight reactions on the skin in induction phase I, slight to moderate reactions in induction phases II and III. The challenge treatment with the 25% test compound in vehicle did cause no contaneous reactions within the meaning of contact hypersensitivity on the posterior right flank of all test animals 30 and 54 hours post application.

No clinical effects were observed in the control animals.

Test and control animals showed a normal body weight gain throughout the investigation.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information