3,4-dicyanoaniline

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

Data is from computational model developed by USEPA

Qualifier:

according to guideline

Guideline:

other: Modeling database

Principles of method if other than guideline:

Estimation of 96 hr EC50 value of test chemical by modelling Database - ECOSAR v.1.11. The ECOSAR Class Program is a computerized version of the ECOSAR analysis procedures as currently practiced by the Office of Pollution Prevention and Toxics (OPPT).  It has been developed within the regulatory constraints of the Toxic Substances Control Act (TSCA).  It is a pragmatic approach to SAR. The structure-activity relationships (SARs) presented in this program are used to predict the aquatic toxicity of chemicals based on their similarity of structure to chemicals for which the aquatic toxicity has been previously measured.  Most SAR calculations in the ECOSAR Class Program are based upon the octanol/water partition coefficient (Kow).  Various surfactant SAR calculations are based upon the average length of carbon chains or the number of ethoxylate units.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material : 4-aminobenzene-1,2-dicarbonitrile
- Common name : 3,4-dicyanoaniline
- Molecular formula : C8H5N3
- Molecular weight : 143.148 g/mol
- Smiles notation : N#Cc1c(C#N)ccc(N)c1
- InChl : 1S/C8H5N3/c9-4-6-1-2-8(11)3-7(6)5-10/h1-3H,11H2
- Substance type : Organic
- Physical state : Solid

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

other: Green algae

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Nominal and measured concentrations:

Estimated data

Reference substance (positive control):

not specified

Key result

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

382.32 mg/L

Nominal / measured:

estimated

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Neutral Organics SAR (Baseline Toxicity)

Details on results:

After the exposure of 96hrs, the EC50 was 382.320 mg/l.

Validity criteria fulfilled:

not specified

Conclusions:

The estimated EC50 values for aquatic green algae after 96 hours was 382.320 mg/l on the basis of growth rate.

Executive summary:

Based on the prediction done using the EPI Suite ECOSAR version 1.10, the short term toxicity on green algae was predicted for test substance 4-aminobenzene-1,2-dicarbonitrile    (CAS:56765 -79 -8). On the basis of effects observed in a static freshwater system, the effect concentration EC50 value for the substance 4-aminobenzene-1,2-dicarbonitrile is estimated to be 382.320 mg/l for green algae for 96 hrs of duration. Based on this value, it can be concluded that the test chemical 4-aminobenzene-1,2-dicarbonitrile can be considered as non-toxic to green algae at environmentally relevant concentrations and can be considered not-classified as per the CLP classification criteria.

Description of key information

Based on the prediction done using theEPI Suite ECOSAR version 1.10, the short term toxicity on green algae was predicted for test substance 4-aminobenzene-1,2-dicarbonitrile    (CAS:56765 -79 -8). On the basis of effects observed in a static freshwater system, the effect concentration EC50 value for the substance 4-aminobenzene-1,2-dicarbonitrile is estimated to be 382.320 mg/l for green algae for 96 hrs of duration. Based on this value, it can be concluded that the test chemical 4-aminobenzene-1,2-dicarbonitrile can be considered as non-toxic to green algae at environmentally relevant concentrations and can be considered not-classified as per the CLP classification criteria.

Key value for chemical safety assessment

EC50 for freshwater algae:

382.32 mg/L

Additional information

Based on the various prediction data for the target chemical and experimental data for the read across chemical study have been reviewed to determine the toxic nature of 4-aminobenzene-1,2-dicarbonitrile (Cas no: 56765-79-8) on the growth of aquatic algae. The studies are as mentioned below:

The first predicted study for the target chemical used based on the prediction done using the EPI Suite ECOSAR version 1.10, the short term toxicity on green algae was predicted for test substance 4-aminobenzene-1,2-dicarbonitrile    (CAS:56765 -79 -8). On the basis of effects observed in a static freshwater system, the effect concentration EC50 value for the substance 4-aminobenzene -1,2-dicarbonitrile is estimated to be 382.320 mg/l for green algae for 96 hrs of duration. Based on this value, it can be concluded that the test chemical 4-aminobenzene-1,2-dicarbonitrile can be considered as non-toxic to green algae at environmentally relevant concentrations and can be considered not-classified as per the CLP classification criteria.

 

First predicted study supported by the another weight of evidence study based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the six closest read across substances, toxicity on Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) was predicted for 4-aminobenzene-1,2-dicarbonitrile (56765-79-8). Based on the growth rate inhibition of test organism the EC50 value was estimated to be 104.422 mg/l when 4-aminobenzene-1,2-dicarbonitrile exposed to Pseudokirchneriella subcapitata for 72 hrs. Based on this value it can be concluded that the substance 4-aminobenzene-1,2-dicarbonitrile is considered to be not toxic to aquatic algal environment as per the criteria mentioned in CLP regulation.   

 

Further it is supported by another structurally similar read across 3-Aminophenol (CAS: 591-27-5) from the authoritative database also suggests that the toxicity test result shows that the chemical was nontoxic. Short term toxicity to green algae study was carried out for 72 hrs.The study was based on the effects of the test compound 3 -aminophenol (CAS no. 591 -27 -5) on green algae in a static fresh water system. Based on effect on growth rate of the test organism green algae, the 72 hr EC50 and NOEC value was determined to be 160 and 25 mg/l, and on the basis of biomass and area under the growth curve, the 72 hr EC50 and NOEC value was determined to be 62 and 25 mg/l, respectively. Thus, based on the EC50 value (160 mg/l), it can be concluded that the substance 3 -aminophenol can be considered as non-toxic to aquatic organisms and thus can be considered to be not classified as per the CLP classification criteria.

 

Similarly in the fourth weight of evidence study for the read across chemical 1,2-Dicyanobenzene (91-15-6) which was structurally as well as functionally similar to the target chemical from authoritative database j-check, 2017 study has been conducted. Study was conducted to check the nature of chemical when green algae test organisms comes in contact with the chemical 1,2-Dicyanobenzene. Test was performed in the static system for the total exposure of 48 hrs of exposure. Based on the growth rate inhibition of green algae due to the exposure of chemical 1,2-Dicyanobenzene for 72hrs , the EC50 and NOEC was 140 mg/l 32 mg/l. And on the basis of areas under the growth curves the EC50 and NOEC was 68 mg/l and 32 mg/l. Based on the EC50 (140 mg/l), it can be concluded that the chemical 1,2-Dicyanobenzene was nontoxic and can be consider to be not classified as per the CLP classification criteria.

 

Thus based on the predicted data for the target chemical and experimental studies for the read across chemical obtain from various sources (J-check, 2017) toxicity on aquatic algae was studied due to the exposure of 4-aminobenzene-1,2-dicarbonitrile (Cas no: 56765-79-8), and it was concluded that the chemical 4-aminobenzene-1,2-dicarbonitrile was consider as nontoxic and can be consider to be not classified as toxic to algal and cyanobacterial growth as per CLP classification criteria.