Dibenzo[b,f]cyclohepten-1-one

Endpoint summary

Description of key information

LD50 was estimated to be 2125 mg/kg bw when rats were orally exposed with 1H-dibenzo[a,d][7]annulen-1-one.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

Data is predicted using OECD QSAR toolbox version 3.4 and the supporting QMRF report has been attached

Qualifier:

according to guideline

Guideline:

other: as below

Principles of method if other than guideline:

Prediction is done using QSAR Toolbox version 3.4

GLP compliance:

not specified

Test type:

other: No data

Limit test:

no

Specific details on test material used for the study:

- Name of the test material: 5H-Dibenzo(a,d)cyclohepten-5-one
- IUPAC name: 1H-dibenzo[a,d][7]annulen-1-one
- Molecular formula: C15H10O
- Molecular weight: 206.243 g/mole
- Substance type: Organic
- Smiles: c12c(ccc3c(c1=O)cccc3)cccc2

Species:

rat

Strain:

not specified

Sex:

not specified

Details on test animals or test system and environmental conditions:

No data

Route of administration:

other: Oral

Vehicle:

not specified

Details on oral exposure:

No data

Doses:

No data

No. of animals per sex per dose:

No data

Control animals:

not specified

Details on study design:

No data

Statistics:

No data

Preliminary study:

No data

Sex:

not specified

Dose descriptor:

LD50

Effect level:

2 125 mg/kg bw

Based on:

test mat.

Remarks on result:

other: 50 % mortality observed

Mortality:

No data

Clinical signs:

other: No data

Gross pathology:

No data

Other findings:

No data

The prediction was based on dataset comprised from the following descriptors: LD50
Estimation method: Takes average value from the 6 nearest neighbours
Domain  logical expression:Result: In Domain

(((((("a" or "b" or "c" )  and ("d" and ( not "e") )  )  and ("f" and ( not "g") )  )  and "h" )  and "i" )  and ("j" and "k" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Cyclo conjugated system AND Cycloketone AND Fused unsaturated carbocycles AND Quinoid compounds by Organic Functional groups

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as Fused unsaturated carbocycles AND Overlapping groups AND Quinoid compounds by Organic Functional groups (nested)

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Carbonyl, olefinic attach [-C(=O)-] AND Ketone in a ring, olefinic aromatic attach AND Miscellaneous sulfide (=S) or oxide (=O) AND Olefinic carbon [=CH- or =C<] by Organic functional groups (US EPA)

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Michael addition AND Michael addition >> Polarised Alkenes-Michael addition AND Michael addition >> Polarised Alkenes-Michael addition >> Alpha, beta- unsaturated ketones by DNA binding by OECD

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Michael addition >> P450 Mediated Activation of Heterocyclic Ring Systems OR Michael addition >> P450 Mediated Activation of Heterocyclic Ring Systems >> Furans OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Alkyl phenols OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Arenes OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Hydroquinones OR Michael addition >> P450 Mediated Activation to Quinones and Quinone-type Chemicals >> Polycyclic (PAHs) and heterocyclic (HACs) aromatic hydrocarbons-Michael addition OR Michael addition >> Polarised Alkenes-Michael addition >> Alpha, beta- unsaturated amides OR Michael addition >> Quinones and Quinone-type Chemicals OR Michael addition >> Quinones and Quinone-type Chemicals >> Quinone-imines OR Michael addition >> Quinones and Quinone-type Chemicals >> Quinones OR No alert found OR Schiff base formers OR Schiff base formers >> Direct Acting Schiff Base Formers OR Schiff base formers >> Direct Acting Schiff Base Formers >> Alpha-beta-dicarbonyl OR SN1 OR SN1 >> Carbenium Ion Formation OR SN1 >> Carbenium Ion Formation >> Alpha halo ethers (including alpha halo thioethers) OR SN1 >> Carbenium Ion Formation >> Polycyclic (PAHs) and heterocyclic (HACs) aromatic hydrocarbons-SN1 OR SN1 >> Iminium Ion Formation OR SN1 >> Iminium Ion Formation >> Aliphatic tertiary amines OR SN1 >> Nitrenium Ion formation OR SN1 >> Nitrenium Ion formation >> Aromatic nitro OR SN1 >> Nitrenium Ion formation >> Primary aromatic amine OR SN1 >> Nitrenium Ion formation >> Secondary aromatic amine OR SN1 >> Nitrenium Ion formation >> Tertiary aromatic amine OR SN2 OR SN2 >> Direct Acting Epoxides and related OR SN2 >> Direct Acting Epoxides and related >> Aziridines OR SN2 >> Episulfonium Ion Formation OR SN2 >> Episulfonium Ion Formation >> Mustards OR SN2 >> SN2 at an sp3 Carbon atom OR SN2 >> SN2 at an sp3 Carbon atom >> Aliphatic halides by DNA binding by OECD

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Moderately reactive (GSH) AND Moderately reactive (GSH) >> Substituted 1-Alken-3-ones (MA) by Protein binding potency

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Highly reactive (GSH) OR Highly reactive (GSH) >> 3-Alken-2-ones (MA) OR Highly reactive (GSH) >> Miscellaneous alpha-halogenated ketones (SN2) OR Not possible to classify according to these rules (GSH) OR Slightly reactive (GSH) OR Slightly reactive (GSH) >> alpha-fluoro ketones (SN2) by Protein binding potency

Domain logical expression index: "h"

Similarity boundary:Target: O=C1C=CC=C2C=C3C=CC=CC3=CC=C12
Threshold=30%,
Dice(Atom centered fragments)
Atom type; Count H attached; Hybridization

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Does NOT Biodegrade Fast by Biodeg probability (Biowin 2) ONLY

Domain logical expression index: "j"

Parametric boundary:The target chemical should have a value of log Kow which is >= 1.82

Domain logical expression index: "k"

Parametric boundary:The target chemical should have a value of log Kow which is <= 3.51

Interpretation of results:

Category 5 based on GHS criteria

Conclusions:

LD50 was estimated to be 2125 mg/kg bw when rats were orally exposed with 1H-dibenzo[a,d][7]annulen-1-one.

Executive summary:

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute oral toxicity was estimated for 1H-dibenzo[a,d][7]annulen-1-one. The LD50 was estimated to be 2125 mg/kg bw when rats were orally exposed with 1H-dibenzo[a,d][7]annulen-1-one.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 125 mg/kg bw

Quality of whole database:

Data is from Klimisch 2 and from OECD QSAR toolbox

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Acute oral toxicity:

In different studies, 1H-dibenzo[a,d][7]annulen-1-one has been investigated for acute oral toxicity to a greater or lesser extent. Often are the studies based on in vivo experiments and estimated data in rodents, i.e. most commonly in mice and rats for 1H-dibenzo[a,d][7]annulen-1-one along with the study available on structurally similar read across substance5,12-dihydroquino[2,3-b]acridine-7,14-dione (CAS no 1047-16-1). The predicted data using the OECD QSAR toolbox has also been compared with the experimental studies.

In a prediction done by SSS (2017) using the OECD QSAR toolbox with log kow as the primary descriptor, the acute oral toxicity was estimated for 1H-dibenzo[a,d][7]annulen-1-one. The LD50 was estimated to be 2125 mg/kg bw when rats were orally exposed with 1H-dibenzo[a,d][7]annulen-1-one.

In another experimental study conducted by Eastman Kodak Company (OTS0533577, Acc. No. 002237, LAB. No . 76-177,1977) on structurally similar read across substance 5,12-dihydroquino[2,3-b]acridine-7,14-dione (CAS no 1047-16-1), mice and rat were treated with 5,12-dihydroquino[2,3-b]acridine-7,14-dione in the concentration of 3200 mg/kg/day orally. No effect on survival of treated mice and rat were observed at 3200 mg/kg bw. Therefore, LD50 was considered to be > 3200 mg/kg/day when mice and rat were treated with 5,12-dihydroquino[2,3-b]acridine-7,14-dione orally.

Also it si further supported by experimental study conducted by Dunc:an et al (E. 1. du Pont de Nemourl and Company, Acc. No. 002237, report No 18-66) on structurally similar read across substance 5,12-dihydroquino[2,3-b]acridine-7,14-dione (CAS no 1047-16-1), CD male rats were treated with 5,12-dihydroquino[2,3-b]acridine-7,14-dione in the concentration of 11000 and 1700 mg/kg/day orally. No effect on survival of treated of rats were observed at 17000 mg/kg bw. Severe diarrhea and Weight loss was observed in treated rats. Therefore, LD50 was considered to be > 17000 mg/kg/day when CD male rats were treated with 5,12-dihydroquino[2,3-b]acridine-7,14-dione orally.

Thus, based on the above predictions and studies on 1H-dibenzo[a,d][7]annulen-1-one and its read across substances, it can be concluded that LD50 value is greater than 2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 1H-dibenzo[a,d][7]annulen-1-one can be Not classified for acute oral toxicity.

Justification for classification or non-classification

Based on the above predictions and studies on 1H-dibenzo[a,d][7]annulen-1-one and its read across substances, it can be concluded that LD50 value is greater than 2000 mg/kg bw. Thus, comparing this value with the criteria of CLP regulation, 1H-dibenzo[a,d][7]annulen-1-one can be Not classified for acute oral toxicity.