4,4'-Methylene-bis-(3-chloro-2,6-diethylaniline)

Endpoint summary

Description of key information

Acute fish toxicity:  

 

The study was performed in 1987 as GLP-test following EU-testing method C.1 using Poecilia reticulata (Guppy) as test species. The test was performed under semi-static conditions with nominal test item concentrations of 0.01, 0.1, 1.0 and 5.0 mg/L in the range-finding test and 1.0 mg/L in the main study. Due to the very low solubility of the test item, DMSO was added as auxiliary agent to prepare the stock solutions. It was not possible to dissolve the test item at a concentration of 1 mg/L completely, therefore a suspension was tested. There were no effects on fish throughout the main study at this nominal concentration, therefore, the LC50 was determined to be above the water solubility of 0.02 mg/L.  

  

Long-term fish toxicity: 

 

Long-term toxicity on fish was waived. The test item was found to be non-toxic at the solubility limit in the three acute aquatic toxicity studies on fish, Daphnia and algae; due to the poor water solubility, high log Pow and the lack of biodegradability, we propose to conduct a long-term toxicity study on an aquatic species; however as none of the three tested species showed effects in the acute tests and could be identified as the most sensitive organism, for animal welfare reasons we suggest to perform a reproduction test over 21 days on Daphnia magna.  

  

Acute daphnia toxicity: 

 

The study was performed in 1987 as GLP-test following EU-testing method C.2 using Daphnia magna as test species. The test was performed under static conditions with nominal test item concentrations of 0.01 and 0.1 mg/L in the main study. Due to the very low solubility of the test item, methanol was added as auxiliary agent to prepare the stock solutions. There were no effects on Daphnia observed throughout the main study at 0.1 mg/L nominal concentration, therefore, the EC50 was determined to be above the water solubility of 0.02 mg/L.  

  

Long-term Daphnia toxicity: 

 

The test item was found to be non-toxic at the solubility limit in the three acute aquatic toxicity studies on fish, Daphnia and algae; due to the poor water solubility, high log Pow and the lack of biodegradability, we propose to conduct a long-term toxicity study on an aquatic species; however as none of the three tested species showed effects in the acute tests, for animal welfare reasons we suggest to perform a reproduction test over 21 days on Daphnia magna.  

  

Toxicity to aquatic algae (growth inhibition):  

 

The study was performed in 1996 as GLP-test following EU-testing method C.3 on the green algae species Selenastrum capricornutum. The test was performed under static conditions as limit test with a nominal test item concentration of 10.0 mg/L in the main study. Due to the low solubility, the test item was dissolved in an auxiliary solvent, 10% Tween 80 dimethylformamide mixture to give a preliminary stock solution of 100 mg/ml. The loss of concentration of test item over the test period was 26%, therefore 74% of the nominal concentration was found at the end of the study. Statistically significant inhibition of growth (21 %) was found in the test cultures, when compared to the biomass of the solvent control using the student’s t-test. Bartlett’s test for homogeneity confirms the difference was not due to replicate variation. However, since the percentage inhibition was less than 25% and the concentration of the test dispersion is well in excess of the water solubility of the test substance (2.5 x 10 Exp.-5 g/L), this is not considered to be biologically significant.  

 

The EbC50 and ErC50 were determined to be > 1 mg/L (measured concentration of filtered algal media). If the results are expressed as mean measured concentration of the test dispersion, the ErC50 and EbC50 were both > 7.4 mg/L.  

     

Toxicity to microorganisms (activated sludge):  

 

The study was performed in 1996 as GLP-test following OECD-testing method 209 using a mixed population of activated sewage sludge micro- organisms. Due to the low solubility, the test item was dissolved in an auxiliary solvent, 10% Tween 80 dimethylformamide mixture. The test was performed under static conditions with a nominal test item concentration of 10 mg/L, which was the highest test concentration in the test medium at which a stable dispersion could be formed with the solvent. Therefore. it was regarded as impossible to test at higher concentrations of P5367 in the test medium. The IC50 was determined to be above the maximum tested concentration of 10 mg/L. 

 

The EC50 (respiration inhibition) value for P5367 with activated sewage sludge has been determined as > 10 mg/L for the 3-hour contact time.