4,4'-carbonimidoylbis[N,N-diethylaniline] monohydrochloride

Endpoint summary

Description of key information

Short-term toxicity to fish:

Based on nominal concentrations, experimental median lethal Concentrations [LC-50 (96 h)] for CAS No. 6358-36-7 on Zebra fish (Danio rerio) was found to be 0.625 mg/L.

Short term toxicity to aquatic invertebrates:

The median effective concentration (EC50) for the test substance,4,4'-carbonimidoylbis[N,N-diethylaniline] monohydrochloride, in Daphnia magna was determined to be 0.016 mg/L on the basis of mobiity inhibition effects in a 48 hour study.

Toxicity to aquatic algae and cyanobacteria

The median effective concentration (EC50) for the test substance, 4,4'-carbonimidoylbis[N,N-diethylaniline] monohydrochloride, in Desmodesmus subspicatus was determined to be 0.13 mg/L on the basis of effects on growth rate in a 72 hour study.

Toxicity to microorganisms:

The 48 hrs aquatic toxicity was predicted to assess toxic effects of the test compound 4,4'-carbonimidoylbis(N,N-diethylaniline) monohydrochloride i.e C.I. Basic Yellow 37 (CAS no. 6358 -36 -7) using OECD QSAR toolbox ver.3.4. The study was based on the effects of the test compound on micro organism species Tetrahymena pyriformis in a static fresh water system. The predicted data suggests the effect concentration (EC50) for the test compound 4,4'-carbonimidoylbis(N,N-diethylaniline) monohydrochloride (C.I. Basic Yellow 37) (CAS no. 6358 -3 -7) was estimated to be 48.77 mg/l on the basis of growth inhibition. Thus, based on the effect, it can be concluded that the test chemical 4,4'-carbonimidoylbis(N,N-diethylaniline) monohydrochloride (C.I. Basic Yellow 37)may have toxic effect to micro organism for acute exposure.

Additional information

Short-term toxicity to fish:

Fish Acute Toxicity test according to OECD Guideline 203 was conducted for 4,4'-carbonimidoylbis[N,Ndiethylaniline] monohydrochloride. The nominal concentration selected for the experiment were 0.625mg/L,1.25mg/L,2.5mg/L,5mg/L,10mg/L and test fish were exposed to these concentration for 96 hours. The lethal concentrations LC50 was found to be 0.625 mg/L.

LC50 (96 hours) Experimental = 0.625 mg/L

LC100 (96 hours) (lowest loading at which 100% mortality was observed) = 1.25 mg/L

Thus considering the above value, it can be concluded that 4,4'-carbonimidoylbis[N,Ndiethylaniline] monohydrochloride exhibits toxicity to fish in the acute 1 classification category. Also since long term toxicity data is not available and the substance is inherently biodegradable (near to not readily biodegradable), the final classification for fish is considered to be Aquatic Acute 1 as well as Chronic category 1 as per CLP criteria.

Short term toxicity to aquatic invertebrates:

Experimental key and supporting Short term toxicity to aquatic invertebrates endpoint was reviewed for the substance 4,4'-carbonimidoylbis(N,N-diethylaniline) monohydrochloride (CAS no 6358-36-7) and structurally related substance (CAS 548 -62 -9) which are as follows:

In key study, Determination of the inhibition of the mobility of daphnids was carried out with the substance 4,4'-carbonimidoylbis(N,N-diethylaniline) monohydrochloride according to OECD Guideline 202. The test substance was tested at the concentrations0, 0.01, 0.02, 0.04, 0.08, 0.16 and 0.32 mg/L. Effects on immobilisation were observed for 48 hours. The median effective concentration (EC50) for the test substance,4,4'-carbonimidoylbis[N,N-diethylaniline] monohydrochloride, in Daphnia magna was determined to be 0.016 mg/L for immobilisation effects. This value indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified as Aquatic acute category 1 as per the CLP criteria.

In supporting study, Acute Immobilisation test inDaphnia magnawas performed in compliance with the OECD Guidelines for Testing of Chemicals, Section 2, No. 202, "Daphnia Sp., Acute Immobilisation Test" . Thestructurally related substance

N-(4-{bis[4-(dimethylamino)phenyl]methylene}cyclohexa-2,5-dien-1-ylidene)-N-methylmethanaminium chloride was tested for acute toxic effects on the swimming capabilities ofDaphnia magnaemploying a static test procedure. In the main study, six groups of daphnids, each comprising 5 daphnids per replicate, were exposed to the test article at concentration levels of 0.025 mg, 0.05 mg, 0.1 mg, 0.2 mg, 0.4 mg and 0.8 mg/L. Observations were made for immobilisation at 24 hours and 48 hours of treatment. A concurrent blank control was also run simultaneously.Potassium Dichromatewas employed as a positive control and tested at the concentration of   0.4 mg, 0.63 mg and 1 mg/L. The animals were observed for immobility after 24 hours and 48 hours of exposure. Those daphnids which were unable to swim within 15 seconds after gentle agitation of the test container were considered to be immobile. The rates of immobilisation observed at 24 hours were 0%, 0%, 0%, 10%, 25% and 75% at the test concentrations of 0.025 mg, 0.05 mg, 0.1 mg, 0.2 mg, 0.4 mg and 0.8 mg/L respectively. The rates of immobilisation observed at 48 hours were 0%, 0%, 10%, 25%, 55% and 85% at the test concentrations of 0.025 mg, 0.05 mg, 0.1 mg, 0.2 mg, 0.4 mg and 0.8 mg/L respectively. The Positive control, Potassium Dichromate induced immobilisation in 20%, 50% and 80% of the exposed daphnids at 24 hours and 25%, 65% and 100% immobilization at 48 hours at the concentrations of 0.4 mg, 0.63 mg and 1 mg/L respectively. No immobilisation was observed in blank control group.The acute immobilisation EC50 value of N-(4-{bis[4-(dimethylamino)phenyl]methylene}cyclohexa-2,5-dien-1-ylidene)-N-methylmethanaminium chloridetoDaphniamagnaat 24 hour exposure period was found to be 0.53 mg/L with fiducial limits between 0.41 to 0.69 mg/L at 95% confidence level. The acute immobilisation EC50 value of N-(4-{bis[4-(dimethylamino)phenyl]methylene}cyclohexa-2,5-dien-1-ylidene)-N-methylmethanaminium chloride toDaphniamagnaat 48 hour exposure period was found to be 0.35 mg/L with fiducial limits between 0.24 to 0.50 mg/L at 95% confidence level. On the basis of EC50 value obtained it can be concluded that the substance N-(4-{bis[4-(dimethylamino)phenyl]methylene}cyclohexa-2,5-dien-1-ylidene)-N-methylmethanaminium chloride is toxic to the aquatic environment and can be considered as "Aquatic Acute 1" as per CLP regulation.

Thus considering the key study value, it can be concluded that 4,4'-carbonimidoylbis[N,Ndiethylaniline] monohydrochloride exhibits toxicity to aquatic invertebrate (Daphni magna) in the acute 1 classification category. Also since long term toxicity data is not available and the substance is inherently biodegradable (near to not readily biodegradable), the final classification for aquatic invertebrate is considered to be Aquatic Acute 1 as well as Chronic category 1 as per CLP criteria.

Toxicity to aquatic algae and cyanobacteria

Experimetal studies for the target chemical 4,4’-carbonimidoylbis(N, N-diethylaniline) monohydrochloride (CAS No.6358-36-7) were reviewed for the toxicity to aquatic algae and cyanobacteria end point, which are summarized as below:

 

In key study, Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance4,4'-carbonimidoylbis[N,N-diethylaniline] monohydrochlorideaccording to OECD Guideline 201. The test substance was dissolved in DMSO/ OECD growth medium and tested at the concentrations 0, 3, 6, 12, 24 and 50 mg/L. Effects on the growth rate of the organism were studied. The median effective concentration (EC50) for the test substance,4,4'-carbonimidoylbis[N,N-diethylaniline] monohydrochloride, in Desmodesmus subspicatus was determined to be 0.13 mg/L.

In supporting study, The effect of test item 4,4'-carbonimidoylbis[N,N-diethylaniline] monohydrochloride, CAS No. 6358-36-7 was studied on the growth of fresh water green alga Chlorella vulgaris. The study was conducted following OECD guideline 201- Alga, growth inhibition test. The test concentration chosen for the study were 0.5 mg/L1 mg/L,2 mg/L,4 mg/L,8 mg/L,16 mg/L. The test concentrations were prepared using stock solution of the test item using mineral media. The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of the test item. EC50 calculated graphically through probit analysis was observed to be 1.925 mg/L

Thus considering the key study value, it can be concluded that 4,4'-carbonimidoylbis[N,Ndiethylaniline] monohydrochloride exhibits toxicity to aquatic algae in the acute 1 classification category. Also since long term toxicity data is not available and the substance is inherently biodegradable (near to not readily biodegradable), the final classification for aquatic algae and cynobacteria is considered to be Aquatic Acute 1 as well as Chronic category 1 as per CLP criteria.

Toxicity to microorganisms:

Three studies including predicted data and experimental results of toxicity to micro organism for the target chemical 4,4'-carbonimidoylbis(N,N-diethylaniline) monohydrochloride i.e C.I. Basic Yellow 37 (CAS no. 6358-36-7) with relevant read across chemicals which is close to target using log Kow as primary descriptor were reviewed to summarize the following information:

 

First summary indicate the 48 hrs aquatic toxicity was predicted to assess toxic effects of the test compound 4,4'-carbonimidoylbis(N,N-diethylaniline) monohydrochloride i.e C.I. Basic Yellow 37 (CAS no. 6358 -36 -7) using OECD QSAR toolbox ver.3.4. The study was based on the effects of the test compound on micro organism species Tetrahymena pyriformis in a static fresh water system. The predicted data suggests the effect concentration (EC50) for the test compound 4,4'-carbonimidoylbis(N,N-diethylaniline) monohydrochloride (C.I. Basic Yellow 37) (CAS no. 6358 -3 -7) was estimated to be 48.77 mg/l on the basis of growth inhibition. Thus, based on the effect, it can be concluded that the test chemical 4,4'-carbonimidoylbis(N,N-diethylaniline) monohydrochloride (C.I. Basic Yellow 37) may have toxic effect to micro organism for acute exposure.

Whereas experimental result (Water Pollution Research Journal of Canada Vol. 26, No. 3, pg 361-431, 1991) for read across chemical N,N-dimethylaniline (CAS no. 121-69-7) indicate Effective concentration (EC50) value of N,N-dimethylaniline to Photobacterium phosphoreum was found to be 13.6 mg/L (ppm) in a 30 min Microtox test based on the effect of reduction in light emission.

And another experimental result for read across N,N-diethylaniline (Cas no. 91-66-7) indicate The 50 percent growth impairment concentration (IGC 50) of N,N-diethylaniline in the micro-organism Tetrahymena pyriformis during a 48 hr study was reported as 0.67mg/L. (Toxicology methods, 7, 289-309.; 1997)

Based on the above all available results, it can be concluded that the test substance 4,4'-carbonimidoylbis(N,N-diethylaniline) hydrochloride i.e C.I. Basic Yellow 37 (CAS no. 6358-36-7) may toxic to micro organism for acute exposure.