Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Toxicological information

Skin sensitisation

Currently viewing:

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
20 Feb - 12 Apr 1996
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP - Guideline study. Refer to endpoint summary Sensitisation and IUCLID Section 13 for reporting and justification of the analogue approach.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1996
Report date:
1996

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method B.6 (Skin Sensitisation)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EPA OPP 81-6 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes
Type of study:
Buehler test

Test material

Constituent 1
Reference substance name:
Cyclohexane
EC Number:
203-806-2
EC Name:
Cyclohexane
Cas Number:
110-82-7
IUPAC Name:
cyclohexane
Details on test material:
- Name of test material (as cited in study report): cyclohexane
- Molecular formula: C6H12
- Molecular weight: 84.16
- Smiles notation: C1CCCCC1
- InChl: 1S/C6H12/c1-2-4-6-5-3-1/h1-6H2
- Substance type: pure substance
- Physical state: clear liquid
- Analytical purity: 99.98%
- Purity test date: 1996-11-01

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Davidson Mill Breeding Labs, Jamesburg, USA
- Weight at study initiation: 314 – 319 g (main study); 307-379 g (screening study)
- Housing: animals were individually housed in stainless steel cages with elevated wire mesh flooring
- Diet: Purina Guinea Pig Diet #5025, ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-27
- Humidity (%): 20-70
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 12 Mar 1996 To: 12 Apr 1996

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
other: induction: 95% ethanol; challenge: acetone
Concentration / amount:
Induction: 10%
Challenge: 10%
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
other: induction: 95% ethanol; challenge: acetone
Concentration / amount:
Induction: 10%
Challenge: 10%
No. of animals per dose:
range-finding test: 20 (in test groups)
main study: 10 (controls), 10 (challenge controls), 20 (in test groups: 9 males and 11 females), 10 (positive controls: 3 males and 7 females), 10 (naive positive controls)
Details on study design:
RANGE FINDING TESTS: three groups of 4 animals (2 males and 2 females) were exposed to 5, 10, 15, 20 and 25% of test substance in 95% ethanol by using the patching technique described in the induction stage. Necrosis was observed after exposure to 25, 20 and 15% concentration of the test substance in 95% ethanol. At 5 and 10% concentration in 95% ethanol, very faint redness was noted in 1/4 animals. Thus, the 10% concentration was chosen for the induction phase. Two groups of 4 animals (2 males and 2 females) were exposed to 5, 10, 15, 20% of the test substance in acetone in order to select appropriate concentrations for the challenge exposure. After treatment with 20% test substance in acetone, very faint redness was observed in 1/4 animals. All other concentrations did not cause any irritations. Based on these results, 10% test substance was chosen for the challenge exposure.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: 6 h
- Test groups: test substance in 95% ethanol
- Control group: 95% ethanol
- Site: left flank
- Frequency of applications: every 7 days
- Duration: 0-21
- Concentrations: 10%

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 28
- Exposure period: 6 h
- Test groups: test substance in acetone
- Control group: test substance in acetone and acetone
- Site: right flank (test substance) and left flank (vehicle)
- Concentrations: 10%
- Evaluation (hr after challenge): 24 and 48 h after patch removal

Challenge controls:
An additional challenge control group (5 males and 5 females) was used and treated with 10% of the test substance in acetone according to the conditions described for the challenge exposure.
Positive control substance(s):
yes
Remarks:
induction: 0.1% 1-chloro-2,4-dinitrobenzene (DNCB) in 50% ethanol/physiological saline; challenge: 0.07% DNCB in acetone

Study design: in vivo (LLNA)

Statistics:
The individual body weight gain was statistically evaluated by analysis of variance (ANOVA) and Neuman Keuls test. Statistical significance was indicated at p < 0.05.

Results and discussion

Positive control results:
0.1% of the positive control test substance DNCB in 50% ethanol/physiological saline induced no or moderate redness in the induction phase of the study. After challenge exposure with 0.07% DCNB in acetone, positive skin sensitisation reactions were seen in 8/10 animals (80%), thus meeting the reliability criteria for the non-adjuvant skin sensitisation test (≥ 15%).

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
induction: 0%; challenge: 10%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: induction: 0%; challenge: 10%. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
induction: 10%; challenge: 10%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
redness was observed in 1 animal
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: induction: 10%; challenge: 10%. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: redness was observed in 1 animal.
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
induction: 0.1%; challenge: 0.07%
No. with + reactions:
8
Total no. in group:
10
Clinical observations:
faint to moderate redness
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: positive control. Dose level: induction: 0.1%; challenge: 0.07%. No with. + reactions: 8.0. Total no. in groups: 10.0. Clinical observations: faint to moderate redness.
Reading:
1st reading
Hours after challenge:
24
Group:
other: challenge control
Dose level:
10%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: other: challenge control. Dose level: 10%. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
1st reading
Hours after challenge:
24
Group:
other: naive positive control
Dose level:
0.07%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: other: naive positive control. Dose level: 0.07%. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
induction: 0%; challenge: 10%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: induction: 0%; challenge: 10%. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
induction: 10%; challenge: 10%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: induction: 10%; challenge: 10%. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
induction: 0.1%; challenge: 0.07%
No. with + reactions:
8
Total no. in group:
10
Clinical observations:
faint to moderate redness
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: positive control. Dose level: induction: 0.1%; challenge: 0.07%. No with. + reactions: 8.0. Total no. in groups: 10.0. Clinical observations: faint to moderate redness.
Reading:
2nd reading
Hours after challenge:
48
Group:
other: challenge control
Dose level:
10%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: other: challenge control. Dose level: 10%. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
other: naive positive control
Dose level:
0.07%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: other: naive positive control. Dose level: 0.07%. No with. + reactions: 0.0. Total no. in groups: 10.0.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
The skin sensitisation potential of cyclohexane was investigated in a GLP-compliant study using a modified Buehler test method in accordance with OECD guideline 406.
9 male and 11 female guinea pigs were induced with 10% cyclohexane in ethanol and challenged with 10% cyclohexane in acetone. The test included concurrent negative (vehicle) and positive controls (1-chloro-2,4-dinitrobenzene, 0.1% in 50% ethanol: 0.9% saline at induction and 0.07% in acetone at challenge).
Induction treatment resulted in no redness (14/20 animals) to very faint redness on some tested animals (6/20 animals). Very faint redness was seen 24 h after challenge in 1/20 animals of the test group and no reactions were observed in any animal at 48 h post-challenge.
No skin reactions were observed in negative control animals. The incidence of sensitisation among the positive control animals was 8/10.
The incidence of sensitisation in cyclohexane-induced and -challenged animals was 0/20.

The study results do not fulfil the classification criteria for skin sensitisation according to Regulation (EC) No 1272/2008 and Directive 67&548/EEC.

CLP: not classified
DSD: not classified