Reaction mass of 2- (palmitoylamino)ethyl acrylate and 2-(stearoylamino)ethyl acrylate

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

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

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source (i.e. manufacturer or supplier) and lot/batch number of test material:Provided by Sponsor, Lot number 91112Y
- Purity.: 92.4%


STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material:
The test sample was stored in a desiccator under the dark conditions at room temperature.
- Stability and homogeneity of the test material in the vehicle/solvent under test conditions (e.g. in the exposure medium) and during storage: stability


TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing (e.g. warming, grinding):
The test sample(271mg, i.e.250mgas the test item) ， the synthetic sewage(8mL) ，
purified water(117mL) ， and the activated sludge(125mL) were added to each test vessel The test sample was accurately weighed with an electronic analytical balance.

Analytical monitoring:

yes

Details on sampling:

Dissolved oxygen concentration in the test solution was measured with dissolved oxygen analyzer. After 3 hours of exposure， the measurement bottle was filled with the test solution promptly and softly with attention to avoid foaming. Afterwards， the concentration of dissolved oxygen(DO) in the test solution was measured continuously for 10 minutes while stirring. The test solutions(blank control) were measured in 3 replicates at the beginning and the end of the exposure，individually.

Vehicle:

no

Details on test solutions:

The test solutions were prepared by the following procedures. The pH of the test solutions [ b) reference mixture and c) blank control] was measured and confirmed to be within 7.5+0.5. (measured value ：7.4) . The pH of the test solutions[ a) test mixture] was not measured
because the test item was not dissolved in the test solutions.
a) Test mixture ( 3 replicates)
The test sample(271mg， i.e.250mgas the test item) ， the synthetic sewage(8mL) ，
purified water(117mL) ， and the activated sludge(125mL) were added to each test vessel
The test sample was accurately weighed with an electronic analytical balance.
b) Reference mixture ( 1 replicate/exposure level)
The stock solution of 3， 5-dichlorophenol[1， 2， 4， and 8mL， see Section 13.1c) l， the synthetic sewage(8mL) ， purified water(the volume subtracting the additive volume of the
stock solution of 3， 5-dichlorophenol from 117mL) ， and the activated sludge(125mL) were
added to each test vessel.
c) Blank control ( 6 replicates)
The synthetic sewage(8mL) ， purified water(117mL) ， and the activated sludge ( 125 mL) were added to each test vessel.

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

Inoculum: Activated sludge was obtained from an aeration tank of a sewage treatment plant treating predominantly domestic sewage in Kurume-shi， Fukuoka， Japan.

Concentration of suspended solid: 3030mg/L

The activated sludge(3L) was fed with the synthetc sewage[150mL]
and cultivated for 20 hours at 20+2℃ under aerobic conditions in order to acclimate the test
temperature， The activated sludge was then used. performed.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Test temperature:

20±2℃

Details on test conditions:

Aeration rate: 0.5-1 L/min
Volume of test solution :250mL

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Basis for effect:

inhibition of total respiration

Results with reference substance (positive control):

3h-EC50=10mg/L

Validity criteria fulfilled:

yes

Conclusions:

3h-EC50 inhibition of respiration of the test item >1000mg/L (nominal concentration).

Executive summary:

The 3 hr- inhibition of respiration of test item  to the activated sludge was obtained from an aeration tank of a sewage treatment plant treating predominantly domestic sewage was studied under static conditions.  Test species were exposed to  blank control, reference control, and test chemical at nominal concentration of 1000mg/L for 3 hr. 

Oxygen consumption were observed at test termination, with average percentage inhibition of respiration is 1% for 3 replicates . And EC50 of reference item is 10mg/L(2-25mg/L). The CV of 6 blank control is 4.2%(<30%). The 3– hour EC₅₀ was >1000mg a.i./L.  

This study is satisfies the guideline requirements.

LC₅₀: > 1000 mg /L                           

Description of key information

3h-EC50 inhibition of respiration >1000mg/L (nominal concentration) (OECD209,GLP)

 

Key value for chemical safety assessment

EC50 for microorganisms:

1 000 mg/L