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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Toxic effect type:
dose-dependent

Effects on fertility

Description of key information

A reproductive/developmental toxicity screening test is waived as a pre-natal developmental toxicity study conducted with an analogue source substance is available.

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
Additional information

A reproductive/developmental toxicity screening test for 2,6-diisopropylnaphthalene (CAS No. 24157-81-1) is not necessary according to the specific adaptation option laid down in Regulation (EC) No. 1907/2006 (REACH), Annex VIII, Section 8.7.1, Column 2 as a pre-natal developmental toxicity study conducted with an adequate analogue source substance is available.

Effects on developmental toxicity

Description of key information

Pre-natal developmental toxicity (OECD 414): NOAEL (maternal) = 100 mg/kg bw/day, NOEL (embryo-/fetotoxicity, teratogenicity) = 625 mg/kg bw/day (highest dose tested)

Read-across from analogue source substance bis(isopropyl)naphthalene (CAS No. 38640-62-9)

Link to relevant study records
Reference
Endpoint:
developmental toxicity
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
Refer to the analogue approach justification provided in IUCLID section 13
Reason / purpose for cross-reference:
read-across source
Key result
Dose descriptor:
NOAEL
Effect level:
100 mg/kg bw/day (nominal)
Basis for effect level:
other: maternal toxicity
Remarks on result:
other: Source: CAS No. 38640-62-9, Leuschner, 1993
Dose descriptor:
LOAEL
Effect level:
250 mg/kg bw/day (nominal)
Basis for effect level:
other: maternal toxicity
Remarks on result:
other: Source: CAS No. 38640-62-9, Leuschner, 1993
Key result
Dose descriptor:
NOEL
Remarks:
highest dose tested
Effect level:
625 mg/kg bw/day (nominal)
Based on:
test mat.
Basis for effect level:
other: no effects observed
Remarks on result:
other: Source: CAS No. 38640-62-9, Leuschner, 1993
Abnormalities:
not specified
Developmental effects observed:
not specified
Conclusions:
The treatment of pregnant rats produced no pathologically relevant effects, neither in the dams nor in the offspring. Transient significant reduction in feed consumption and body weight gain were observed during maternal development. With respect to the maternal body weight effect, the NOAEL for maternal toxicity is established to be 100 mg/kg bw/day. Due to the absence of embryotoxic effects, the highest dose tested, 625 mg/kg bw/day, corresponds to a NOEL for embryo-/fetotoxic effects and teratogenicity.
Executive summary:

The developmental toxicity of the target substance is predicted based on an adequate and reliable prenatal developmental toxicity study of a structural analogue source substance. Treatment of pregnant rats with the test substance at 250 and 625 mg/kg bw/day induced a maternal toxic response which was reflected in a reduction in feed consumption and body weight gain. At 100 mg/kg bw/day, the test substance did not cause maternal toxicity. Doses up to 625 mg/kg bw/day did not induce fetotoxicity and did not show teratogenic potential. As explained in the analogue justification, the differences in molecular structure between the target and the source substances are unlikely to lead to differences in the carcinogenic potential.

Effect on developmental toxicity: via oral route
Endpoint conclusion:
no adverse effect observed
Effect on developmental toxicity: via inhalation route
Endpoint conclusion:
no study available
Effect on developmental toxicity: via dermal route
Endpoint conclusion:
no study available
Additional information

No data on developmental toxicity with 2,6-diisopropylnaphthalene (CAS 24157-81-1) are available. The endpoint, therefore, is assessed by means of read-across from the analogue source substance bis(isopropyl)naphthalene (CAS 38640-62-9).

The pre-natal developmental toxicity of bis(isopropyl)naphthalene (CAS No. 38640-62-9) was investigated in a study according to OECD guideline 414 and in agreement with GLP provision (Leuschner, 1993). Groups of 20 pregnant Sprague-Dawley rats were treated by gavage with the test substance in sesame oil at dose levels of 100, 250, and 625 mg/kg bw/day from Day 6 to Day 15 of gestation. A further group of pregnant females was exposed to the vehicle sesame oil only (control). Doses were selected based on a preliminary dose range-finding study. Clinical signs, body weight development, food and water consumption were monitored during the duration of the study. At sacrifice (at Day 20 of gestation) all females were subjected to gross necropsy including examination of the uterine contents. The number of corpora lutea, number, position and type of implantation, placental weight, foetal weight, sex and external and internal macroscopic appearance were recorded. Half of each litter were examined for detailed skeletal development and the remaining half were subjected to detailed visceral examination. No substance-related mortality and no clinical signs were observed in the treated dams. Body weight gain was dose-related inhibited in the dams treated with 250 and 625 mg/kg bw/day. At the  end of the study, the net body weight change was lower than in the controls. Food consumption showed a significant reduction at 250 and 625 mg/kg bw/day. Treatment did not influence drinking water consumption. No substance-related pathological changes were detected at autopsy. Regarding fetal development, no distinct influence on prenatal development was detected. External macroscopic inspection and examination of soft tissue revealed no substance­related variations and/or retardations. Based on these findings and accounting for the maternal body-weight effect, the no-observed-adverse-effect-level (NOAEL) for maternal toxicity was established at 100 mg/kg bw/day. Due to the absence of developmental effects, the highest dose (625 mg/kg bw/day) corresponds to the no-observed-effect-level (NOEL) for embryo-/fetotoxicity and teratogenicity.

Justification for classification or non-classification

According to Regulation (EC) No. 1907/2006 (REACH), Annex VIII, Section 8.7.1, Column 2, a screening test for reproductive/developmental toxicity is not required as a pre-natal developmental toxicity study is available. Under these circumstances, the available data on reproductive and developmental toxicity are considered as sufficient to allow a conclusive evaluation in regard to ‘reproductive toxicity’ as defined in Title 1, Chapter 1 of Regulation (EC) No. 1272/2008 (CLP). The available data on developmental toxicity for the analogue source substance bis(isopropyl)naphthalene (CAS No. 38640-62-9) do not meet the criteria for classification according to the CLP Regulation. Data are, therefore, conclusive but not sufficient for classification. Based on an analogue read-across approach, the target substance 2,6-diisopropylnaphthalene (CAS No. 24157-81-1) is also not expected to exhibit developmental toxicity.

Additional information