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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Administrative data

Description of key information

Skin sensitisation

Based on available read across data (Local Lymph Node Assay (OECD TG 429)), 2,3-Dimethylbutane is not considered to be a skin sensitiser.

Respiratory sensitisation

No data available

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
2000
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: This study is classified as reliable with restrictions because it is an acceptable well-documented publication which meets basic scientific principles.
Justification for type of information:
A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.
Reason / purpose for cross-reference:
read-across: supporting information
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
GLP compliance:
no
Type of study:
mouse local lymph node assay (LLNA)
Species:
mouse
Strain:
not specified
Sex:
not specified
Vehicle:
acetone/olive oil (4:1 v/v)
Statistics:
Results were given in terms of the EC3 value, the concentration of the substance which is expected to cause a 3-fold increase in proliferative activity. EC3 values were determined based on results of previous LLNA tests for the test substance.
Key result
Parameter:
EC3
Value:
> 3
Test group / Remarks:
Concentrations up to 100%
Remarks on result:
other: EC3 > 100%
Parameter:
SI
Test group / Remarks:
Test Concentration 1
Remarks on result:
not measured/tested
Remarks:
The study report refers to 3 concentrations but does not provide specifics on the same. Results refer only to the single highest concentration which is reported as the EC3 value being >100%.
Parameter:
SI
Test group / Remarks:
Test Concentration 2
Remarks on result:
not measured/tested
Remarks:
The study report refers to 3 concentrations but does not provide specifics on the same. Results refer only to the single highest concentration which is reported as the EC3 value being >100%.
Parameter:
SI
Test group / Remarks:
Test Concentration 3
Remarks on result:
not measured/tested
Remarks:
The study report refers to 3 concentrations but does not provide specifics on the same. Results refer only to the single highest concentration which is reported as the EC3 value being >100%.
Interpretation of results:
other: Not sensitising
Conclusions:
Concentrations of up to 100% of test substance are not expected to be sensitising.
Executive summary:

This study was done to determine the concentration of hexane that would be expected to cause sensitisation in humans. Results of previous LLNA experiments were used to calculate the EC3 value, the concentration at which the test substance would produce a 3 -fold increase in the proliferative activity of lymph nodes in the LLNA test. The 3 -fold increase is considered a positive response for sensitisation in the LLNA test. The EC3 value for hexane was determined to be >100% concentration. The test substance is therefore not sensitising.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

There is no skin sensitisation data available for 2,3-Dimethylbutane. However, data is available for structural analogue, n-Hexane. This data is read across to 2,3-dimethylbutane based on analogue read across and a discussion and report on the read across strategy is provided as an attachment in IUCLID Section 13.

 

n-Hexane

In a key study of hexane (Basketter et al., 2000), a local lymph node assay (LLNA) was done to determine the concentration of hexane that would be expected to cause sensitisation in humans. Results of previous LLNA experiments were used to calculate the EC3 value, the concentration at which the test substance would produce a 3 -fold increase in the proliferative activity of lymph nodes in the LLNA test. The 3 -fold increase is considered a positive response for sensitization in the LLNA test. The EC3 value for hexane was determined to be > 100% concentration. The substance was therefore not sensitising.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available
Additional information:

There are no reports of respiratory sensitisation from 2,3-Dimethylbutane in laboratory animals or in humans. However, the read across skin sensitisation study found no indication of skin sensitisation in mice. With these observations, it is presumed that 2,3-Dimethylbutane will not be a respiratory sensitising agent.

Justification for classification or non-classification

Based on available read across data, 2,3-DImethylbutane does not meet the criteria for classification as a skin or respiratory sensitizer under the new Regulation (EC) 1272/2008 on classification, labeling and packaging of substances and mixtures (CLP).