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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

skin sensitisation, other
Type of information:
other: Expert Assessment
Adequacy of study:
weight of evidence
Study period:
March 2022
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Based on structural alerts and QSAR models

Data source

Reference Type:
other: Expert Assessment
Report date:

Materials and methods

Test guideline
no guideline followed
Principles of method if other than guideline:
An expert assesment was performed uses information from the OECD QSAR Toolbox which uses read-across and numerous databases of experimental results to enable the user to fill in data gaps in a logical workflow. Relevant information for the target substance, including probable mechanisms of action and observed/simulated metabolites, is retrieved by profiling to contribute to data gathering and the identification of suitable analogues, and by grouping substances into meaningful categories according to structural similarities. The OECD QSAR Toolbox is outlined by ECHA as one of the in silico tools to reliably predict skin sensitisation.
GLP compliance:
Type of study:
other: Structural alerts and QSAR models

Test material

Constituent 1
Chemical structure
Reference substance name:
4,4'-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]diphthalic anhydride
EC Number:
EC Name:
4,4'-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]diphthalic anhydride
Cas Number:
Molecular formula:
4,4'-(hexafluoroisopropylidene)diphthalic anhydride

Results and discussion

In vitro / in chemico

Key result
test chemical
Run / experiment:
other: N/A
other: QSAR predicition
Remarks on result:
positive indication of skin sensitisation

Any other information on results incl. tables

Profiling returned alerts for “Protein binding alerts for skin sensitisation according to GHS” (Skin sensitization Category 1A;Skin sensitization Category 1A >> Anhydrides (sulphur analogues of anhydrides)), “Protein binding alerts for skin sensitization by OASIS” (Acylation), “Protein binding potency h-CLAT” (Acid anhydride), “Protein binding by OASIS” (Acylation), “Protein binding by OECD” (Acylation), “Protein binding potency GHS” (Moderately reactive (GSH);Moderately reactive (GSH) >> Anhydrides and Lactones (SN2 ring opening)) and “Protein binding potency Lys (DPRA 13%)” (DPRA above 21% (DPRA 13%);DPRA above 21% (DPRA 13%) >> Cyclic acid anhydrides).


Based on substances with the same protein binding mechanism, i.e. "Acylation", according to the "Protein binding alerts for skin sensitisation by OASIS" profile, a positive prediction was obtained with a predictive confidence measured by the p-value of 0.5. The estimation was based on five values and three of them (60%) were equal to the predicted value.

Applicant's summary and conclusion

Interpretation of results:
Category 1A (indication of significant skin sensitising potential) based on GHS criteria
6FDA is expected to be a category 1A skin sensitiser.
Executive summary:

The skin sensitising potential of 6FDA was evaluated by obtaining predictions using the automated workflow in the OECD QSAR Toolbox after a review of the literature did not identify usable experimental data.

As alerts were returned from the initial profiling, predictions were made from Guinea Pig Maximisation Test and the Local Lymph Node Assay (LLNA) with substances leading to acylation upon protein binding according to the "Protein binding alerts for skin sensitisation by OASIS" profiler. The result of the prediction was positive. It was therefore concluded that 6FDA can be expected to induce skin sensitisation. Furthermore, the analogous substances that have been identified and that support this prediction are classified as moderate to strong skin sensitisers, according to the GHS classification regulation and CLP regulation 1272/2008 , they are classified as Skin Sens. Category 1A. Therefore, it can be expected that 6FDA such as its analogues may be classified as Skin Sens. Category 1A.