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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Remarks:
in vivo
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Justification for type of information:
Sodium hydroxide is both reagents used in the manufacture of Reaction mass of 2-methylpropan-1-ol and sodium O-isobutyl dithiocarbonate and sodium hydroxide . Therefore, sodium hydroxide need to be considered in the assessment of Reaction mass of 2-methylpropan-1-ol and sodium O-isobutyl dithiocarbonate and sodium hydroxide

Data source

Reference
Reference Type:
publication
Title:
A study of skin responses to follow-up, rechallenge and combined effects of irritants using non-invasive measurements
Author:
Park et al.
Year:
1995
Bibliographic source:
Journal of Dermatological Science, 10, 159-165

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Patch testing for 24 hours with visual scoring being recorded by the subjective evaluation method and by the transepidermal water loss method. After the seventh day reading sodium hydroxide (0.125%) was re-applied to all pretested sites and reading was performed on the next day.
GLP compliance:
not specified
Type of study:
not specified
Justification for non-LLNA method:
Patch testing for 24 hours with visual scoring being recorded by the subjective evaluation method and by the transepidermal water loss method. After the seventh day reading sodium hydroxide (0.125%) was re-applied to all pretested sites and reading was performed on the next day.
The irritant response was well correlated to the concentration of the irritant.

Test material

Constituent 1
Chemical structure
Reference substance name:
disodium 2-methylpropan-1-ol [(2-methylpropoxy)methanethioyl]sulfanide hydroxide
EC Number:
904-290-8
Molecular formula:
C5H10OS2.Na
IUPAC Name:
disodium 2-methylpropan-1-ol [(2-methylpropoxy)methanethioyl]sulfanide hydroxide
Test material form:
solid: compact
Details on test material:
NaOH, Hayashi Pure Chemical Ins., Osaka, Japan
Sodium hydroxide is both reagents used in the manufacture of Reaction mass of 2-methylpropan-1-ol and sodium O-isobutyl dithiocarbonate and sodium hydroxide . Therefore, sodium hydroxide need to be considered in the assessment of Reaction mass of 2-methylpropan-1-ol and sodium O-isobutyl dithiocarbonate and sodium hydroxide

In vivo test system

Test animals

Species:
human
Strain:
not specified
Sex:
male
Details on test animals and environmental conditions:
HUMAN VOLUNTEERS
- Age at study initiation: between 20 and 25

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
other: no data
Vehicle:
no data
Concentration / amount:
Concentrations used for induction: 50 µl, 1.0, 0.5, 0.25, 0.125 and 0.063%
Challengeopen allclose all
Route:
other: no data
Vehicle:
no data
Concentration / amount:
Concentrations used for induction: 50 µl, 1.0, 0.5, 0.25, 0.125 and 0.063%
No. of animals per dose:
Number of volunteers: 15 without any previous history of atopy
Details on study design:
MAIN STUDY
A. INDUCTION EXPOSURE
- Control group: yes, distilled water and empty chambers
- Site: back
- Duration: 24 hours (induction and challenge)
- Concentrations: 50 µl, 1.0, 0.5, 0.25, 0.125 and 0.063%


B. CHALLENGE EXPOSURE
- No. of exposures: on day 7, NaOH was reapplied
- Day(s) of challenge: 1
- Concentrations: 0.125%
Positive control substance(s):
not specified

Results and discussion

In vivo (non-LLNA)

Results
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
50 µl, 1.0, 0.5, 0.25, 0.125 and 0.063%
Total no. in group:
15
Clinical observations:
The irritant response was well correlated to the concentration of the irritant. However, increased response was not observed when subclinical doses were rechallenged on the previously patch tested sites.
Remarks on result:
other: see Remark
Remarks:
Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50 µl, 1.0, 0.5, 0.25, 0.125 and 0.063%. Total no. in groups: 15.0. Clinical observations: The irritant response was well correlated to the concentration of the irritant. However, increased response was not observed when subclinical doses were rechallenged on the previously patch tested sites..

Any other information on results incl. tables

The irritant response was well correlated to the concentration of the irritant. However, increased response was not observed when subclinical doses were rechallenged on the previously patch tested sites.

Applicant's summary and conclusion

Interpretation of results:
other: not sensitising
Remarks:
Criteria used for interpretation of results: EU
Conclusions:
Sodium hydroxide is both reagents used in the manufacture of Reaction mass of 2-methylpropan-1-ol and sodium O-isobutyl dithiocarbonate and sodium hydroxide . Therefore, sodium hydroxide need to be considered in the assessment of Reaction mass of 2-methylpropan-1-ol and sodium O-isobutyl dithiocarbonate and sodium hydroxide.
The irritant response was well correlated to the concentration of the irritant. However, increased response was not observed when subclinical doses were rechallenged on the previously patch tested sites.