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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:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Justification for type of information:
Part of research on methods to improve LLNA.
Lactic acid assessed (note lactic acid canbe used as a negative control in some methods)

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2011

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Principles of method if other than guideline:
As well as the standard method of using radioactivity to assess activity of the local lymph nodes, the research included asessment of cell counts in the lymph nodes
GLP compliance:
yes
Type of study:
mouse local lymph node assay (LLNA)

Test material

Constituent 1
Chemical structure
Reference substance name:
Lactic acid
EC Number:
200-018-0
EC Name:
Lactic acid
Cas Number:
50-21-5
Molecular formula:
C3H6O3
IUPAC Name:
2-Hydroxypropanoic acid
Specific details on test material used for the study:
Work performed with lactic acid.
Lactic acid and lactates dissolve to form lactate ions and the acid is considered to be a suitable surrogate for assessment of the salt.

In vivo test system

Test animals

Species:
mouse
Strain:
CBA
Sex:
female
Details on test animals and environmental conditions:
Temperature 20–24 °C and a relative humidity of 30–70%, with a 12 h light–dark cycle
Tap water and food were given ad libitum.

Study design: in vivo (LLNA)

Vehicle:
dimethyl sulphoxide
Concentration:
5.0, 10, 25 %
No. of animals per dose:
Three
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:
Positive

In vivo (LLNA)

Results
Key result
Parameter:
EC3
Value:
0
Remarks on result:
not determinable
Remarks:
No indication of positive effects

Any other information on results incl. tables

Lactic acid led to local skin irritation in the high and mid dose groups.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
Lactic acid proved negative by both methods used for evaluation.
Substances known to be positive sensitisers gave positive responses as expected demonstrating validity of the work.