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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Unfortunately no data is available regarding skin sensitization of 1,3-dioxepane. But data for other cyclic acetals consistently show that no indication for a skin sensitizing potential exists.

1,3,5-trioxane (CasNo. 110-88-3) proofed not to be sensitizing in a guinea pig maximization test (BASF AG, 1989). The study was performed according to the OECD guideline 406 and GLP.

In a supporting guinea pig study 1,3,5-trioxane was tested together with 1,3-dioxolane (CasNo. 646-06-0) and the cyclic tetramer of ethylene oxide (2,4,6,8-Tetraoxanonane, CasNo. 13353-03-2) (Rao, 1981). The assay was performed according to a guinea pig maximization assay (4 inductions, 1 indradermal application of adjuvance, 1 challenge), though reporting of the test results is not very detailed. For all 3 tested acetals no indication for a skin sensitizing potential was identified.

For 1,3-dioxolane additional data of low/undefined quality exists (not included in IUCLID/CSR). In a modified guinea pig assay according to Magnusson and Kligman no dermatitis related to oversensitivity was identified (Czajkowska et al. (1987), Experimental studies of toxic effects of 1,3,5-trioxane and 1,3-dioxolane. I Acute toxic effect. Medycyna Pracy 38: 184-190).

The data-base for evaluation can even be extended to 1,4-dioxane (CasNo. 123-91-1), a cyclic 6-ring with 2 oxygen atoms. Likewise no indication for a skin sensitizing potential was identified in a OECD guideline 406 maximization assay in guinea pigs (BASF AG, 1993; data not shown).

Summarized, a reliable cross reading to a variety of cylic acetalic and non acetalic molecules with 2-4 ring-oxygen atoms can be performed. All sensitization data unambigously shows that no concern for a skin sensitizing potential can be derived for 1,3-dioxepane. By weight of evidence and with respect of animal welfare the performance of an in vivo skin sensitization assay is not indicated.

Nevertheless, similar to 1,3,5-trioxane, 1,3-dioxepane degradation can result in the release of small amounts of formaldehyde (BASF AG, 1998), though to a way smaller extend. In order to protect formaldehyde-susceptible individuals, this observation should be indicated in the hazard communication (MSDS).

Migrated from Short description of key information:
A reliable cross-reading to other cyclic acetals consistently indicates no senitizing potential.

Respiratory sensitisation

Endpoint conclusion
Additional information:
Migrated from Short description of key information:
No data available

Justification for classification or non-classification

In a variety of structurally similar substances no indications for a skin sensitizing potential were identified. Therefore no classification for skin-sensitization is warranted.