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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Key value for chemical safety assessment

Effects on fertility

Description of key information

According to ECHA REACH Fact sheet "INFORMATION REQUIREMENTS FOR REPEATED DOSE TOXICITY AND REPRODUCTIVE TOXICITY – SUBSTANCES OVER 100 (AND 1000) TONNES", ECHA considers registration dossiers for substances ≥ 100 t/y as technically complete even if they do not contain the results of a screening study for reproductive/developmental toxicity if the dossier contains either the results of, or a testing proposal for, a pre-natal developmental toxicity study. The results of a teratogenicity study according to OECD TG 414 is included, screening study for reproductive/developmental toxicity therefore is being waived.

Effect on fertility: via oral route
Endpoint conclusion:
no study available
Effect on fertility: via inhalation route
Endpoint conclusion:
no study available
Effect on fertility: via dermal route
Endpoint conclusion:
no study available

Effects on developmental toxicity

Description of key information

In a prenatal developmental toxicity study with CXN 1-55 in rats by oral gavage, a developmental NOAEL of 300 mg/kg bw/day was found based on skeletal variations (increased incidence of bent ribs and reduced ossification of the skull) at 1000 mg/kg bw/day in absence of maternal toxicity.

Effect on developmental toxicity: via oral route
Endpoint conclusion:
adverse effect observed
Dose descriptor:
300 mg/kg bw/day
Study duration:
Quality of whole database:
The study was performed according to OECD/EC guidelines and GLP principles (Klimisch 1).
Additional information
In rats, the two observed skeletal variations in the prenatal developmental toxicity study are commonly encountered in developmental toxicity studies and often representative of delayed ossification of the fetal bones. Both skeletal variations are considered to be reversible and do not persist postnatally. Increased incidences of bent ribs are often observed secondary to maternal toxicity or reduced fetal weights, indicating a slight developmental delay in the fetuses. Since no corroborating effects (of toxicity) are observed in either the parental females or the fetuses in this study, no conclusion could be drawn if these skeletal variations are indicative of a generalized developmental delay or skeletal dysplasia. No further signs of developmental toxicity were observed in this dose group.

Justification for classification or non-classification

Observed adverse effects in the subchronic toxicity study, namely irregular estrous cycle and the reduction in corpora lutea, accompanied by the delay in fetal development, mandate a classification of CXN1-55 as reproductive toxicant category 2 according to Regulation (EC) No. 1272/2008 on Classification, Labelling and Packaging of Substances and Mixtures.

Additional information