Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Key value for chemical safety assessment

Skin sensitisation

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

Justification for read across

Skin Sensitisation

Type of read across:one-to-one

Test Compound (with data):CAS: 174350-05-1

Dossier Compound (without data):CAS:

The read across is based on the following similarity measures:

(1) Chemical similarity
The test compound (CAS: 174350-05-1) provides all main chemical features present in the dossier compound (CAS:82991-48-8). Both substances share typical structural features for liquid crystals, i.e. one phenyl ring coupled via single bond to a cyclohexyl ring.

The test compound shows a flour substitution (n=2) at the phenyl ring that is missing in the dossier compound. In addition the phenyl ring of the test compound shows a para alkoxy substituent while the dossier compound shows a pentyl chain at the same position at the phenyl ring. The cylohexyl ring of both compounds shows a para alkyl substitution (Test Compound: n=3, Dossier Compound: n=5).

Overall, this yields a chemical similarity score of 0.43 (Tanimoto).

(2) Physicochemical similarity
The chemical similarity yields almost identical physicochemical key parameters relevant for bioavailability as listed in the table below.

(3) Similar Effects in Biological Systems
Both compounds have been tested in biological assays for the acute oral toxicity and for mutagenicity in bacteria. The studies were performed according to GLP and the methods applied were fully compliant with the OECD TG.
The LD50 of both compounds exceeds 2000 mg/kg bw/day. Both compounds were not mutagenic in the OECD 471 studies.

The table below lists the similarity measures applied for this read across.


Table 1. Comparison of the similarity measures applied for Test and Dossier compound


Test Compound
CAS: 174350-05-1

Dossier Compound
CAS: 82991-48-8

Cyclohexyl phenyl core



Terminal substitution at the cyclohexyl ring



Terminal substitution at the phenyl ring



Liquid crystalline properties



Fluor Substitution at the phenyl ring

yes (n=2)


Water solubility

130 µg/L
(EU A.6)

46 µg/L
(EU A.6)


> 5.7
(OECD 117, EU A.8)

> 6.5
(OECD 117, EU A.8)

Acute Oral Toxicity in Rats

LD50 > 2000 mg/kg bw/d
(OECD 423)

LD50 > 5000 mg/kg bw/d
(OECD 401)

in vitro Genotoxicity

negative (OECD 471)

negative (OECD 471)

Read Across

Skin Sensitisation

(OECD 429)

Negative (Read Across)


The Dossier Compound shows a data gap for Skin Sensitisation; however, a chemical analogue provides data for these endpoints. Both the Dossier Compound and the Test Compound show chemical similarity and almost identical physicochemical parameters leading to similar bioavailability. The response in biological assays was comparable; i.e. the LD50 exceeds 2000 mg/kg bw/d and negative data on mutagenicity in vitro.

Based on these finding it is justified to use the data from the chemical analogue (Skin Sensitisation: negative (GLP, OECD TG 429)) to fill the data gap for the dossier compound.

Migrated from Short description of key information:
This study used for this read across was performed according to GLP and the methods applied are fully compliant with OECD TG 429.

Justification for selection of skin sensitisation endpoint:
For this endpoint a one-to-one read across was performed to a chemical similar compound of the same chemical class with a comparable phys. chem. profile and similar response in biological assays. The relevant study was performed according to GLP and the methods applied are fully compliant with OECD TG 429.

Justification for classification or non-classification

According to the results of the sensitisation test, a classification and labelling is not required for this substance.