Ethyl 4-[[(methylphenylamino)methylene]amino]benzoate

Toxicity to microorganisms

Link to relevant study record(s)

Reference

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From October 05, 2016 to November 09, 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test (Carbon and Ammonium Oxidation))

GLP compliance:

yes

Test organisms (species):

activated sludge

Details on inoculum:

- Source of inoculum/activated sludge: James Wastewater Treatment Plant-Abbotsford BC.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Nominal and measured concentrations:

Nominal concentrations: 0 and 1000 mg/L

Details on test conditions:

- Aeration: Clean, filtered, oil-free air was provided at ~1.0 L/min
- No. of vessels per concentration (replicates): three
- No. of vessels per negative control (replicates): three
- Sludge concentration: 2.1 g suspended solids/L

Reference substance (positive control):

yes

Remarks:

3,5-Dichlorophenol (CAS NO.: 591-35-5)

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: aerobic respiration rate

Results with reference substance (positive control):

The 3-h EC50 of thr reference substance (3,5-Dichlorophenol) was 16.1 mg/L.

The oxygen uptake rate of the controls was 22.5 mg O₂/h/g dry weight of suspended solids (SS). The coefficient of variation (%CV) of the controls was 11.0%.

 

Table 1. EC50 and 95% Confidence Intervals for Reference Item Test

3-h EC50 (mg/L)	95% Confidence Intervals	± 2SD of Previous Mean
16.1	N/A-20.8	5.5-20.7

Table 2. Inhibition of Aerobic Respiration Rate by Test Item Eversorb EP4

Sample ID	Nominal Test Item Concentration (mg/L)	Slope	Aerobic Respiration Rate (R, mg O2/L·h)	Inhibitory Effect on Respiration Rate (%)
Control #1, Rep A	0	0.7000	42.0	N/A
Control #1, Rep B	0	0.6873	41.2	N/A
Control #1, Rep C	0	0.8533	51.2	N/A
1000 mg/L, Rep A	1000	0.8339	50.0	-5.9
1000 mg/L, Rep B	1000	0.8255	49.5	-4.9
1000 mg/L, Rep C	1000	0.8255	49.5	-4.9
Control #2, Rep A	0	0.8286	49.7	N/A
Control #2, Rep B	0	0.8667	52.0	N/A
Control #2, Rep C	0	N/A	N/A	N/A

Validity criteria fulfilled:

yes

Conclusions:

According to OECD 209 test method, the 3-h EC50 of the test substance was greater than 1000 mg/L.

Executive summary:

This test using the procedures outlined in the Maxxam Study Plan for TOX1613 which is based on the SOP for the OECD 209 (BBY2SOP-00019) and OECD 209 (OECD, 2010). The results of this OECD 209 test for Eversorb EP4 show that all validity criteria were met. The 3-h EC50 of the test substance was greater than 1000 mg/L.

 

Description of key information

The 3-h EC₅₀ of Eversorb EP4 was greater than 1000 mg/L (OECD TG 209).

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L

Additional information

For controls at the end of the test, the oxygen uptake rate was greater than or equal to 20 mg O₂/h/g dry weight of suspended solids (SS) and the coefficient of variation (%CV) of the control was less than or equal to 30%. The 3-h EC50 of the reference item (3, 5-Dichlorophenol) was within 2 standard deviations of the previous EC50 values. All test validity criteria were met.Based on the nominal concentrations of Eversorb EP4, the 3-h EC50 for respiration inhibition was greater than 1000 mg/L.