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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:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: According to the OECD SIDS document for sodium hydroxide (March 2002), a Klimisch 2 reliability score was assigned since the study is well documented, meets generally accepted scientific principles, and is acceptable for assessment.

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

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:
no
Type of study:
not specified
Justification for non-LLNA method:
NaOH has been used widely and for a long time and no human cases of skin sensitisation have been reported and therefore NaOH is not considered to be a skin sensitiser (EU RAR 2007). Study was conducted in 1995 before REACH regulatory update (2016/863 and 2016/1688).

Test material

Constituent 1
Chemical structure
Reference substance name:
Sodium hydroxide
EC Number:
215-185-5
EC Name:
Sodium hydroxide
Cas Number:
1310-73-2
Molecular formula:
HNaO
IUPAC Name:
sodium hydroxide
Details on test material:
TEST SUBSTANCE
NaOH, Hayashi Pure Chemical Ins., Osaka, Japan

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

Results and discussion

In vivo (non-LLNA)

Results
Reading:
other:
Group:
test chemical
Dose level:
0.063-1.0% (induction) after 7 days 0.125% NaOH
No. with + reactions:
0
Remarks on result:
no indication of skin sensitisation

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

Conclusions:
Not sensitizing