Registration Dossier

Diss Factsheets

Administrative data

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:
other: The study was conducted according to the O.E.C.D. test guideline 209 with GLP compliance.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report date:
2010

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
2,3-epoxypropyl neodecanoate
EC Number:
247-979-2
EC Name:
2,3-epoxypropyl neodecanoate
Cas Number:
26761-45-5
Molecular formula:
C13H24O3
IUPAC Name:
Oxiran-2-ylmethyl 2-ethyl-2,5-dimethylhexanoate
Constituent 2
Reference substance name:
Neodecanoic acid, oxiranylmethyl ester
IUPAC Name:
Neodecanoic acid, oxiranylmethyl ester
Test material form:
other: Colorless liquid at room temperature.
Details on test material:
As per IUCLID5 Sections 1.1. 1.2. 1.4. and 4.1. for 2,3-epoxypropyl neodecanoate, REACH Registration: 01-2119431597-33-0000.
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
As per IUCLID5 Sections 1.1. 1.2. 1.4. and 4.1. for 2,3-epoxypropyl neodecanoate, REACH Registration: 01-2119431597-33-0000.

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
A stock solution was prepared by adding. 1.0 g test substance to 1000 mI of deionized water and homogenizing for approximately 18 hours. After homogenization, 16 mL of synthetic sewage feed and 200 mL of microbial inoculum (activated sludge) were added to the appropriate amount of test substance stock solution and brought to 500 mL volume with deionized water.

Test organisms

Test organisms (species):
activated sludge of a predominantly domestic sewage
Details on inoculum:
A sample of activated sludge was obtained from the Brazos River Authority in Sugar Land, TX and was aerated during transport and storage. The activated sludge had a pH of 7.6 and temperature of 24° C. The sludge was washed three times, with a settling time of -40 minutes between each wash before use. .


Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h
Post exposure observation period:
None

Test conditions

Hardness:
No data
Test temperature:
24° C
pH:
7.6
Dissolved oxygen:
3.8.mg/L
Salinity:
1 ppt
Nominal and measured concentrations:
1.5, 5, 15, 50, 155 and 500 mg/L nominal.
Details on test conditions:
All test procedures took place in thoroughly cleansed glassware. The analyses (blanks, reference, and test substances) were performed in 300 inL BOD bottles.

Synthetic sewage feed was prepared using 16 g peptone, 11 g meat extract, 3 g urea, 0.7 g sodium chloride, 0.4 g calcium chloride dihydrate, 0.2 g magnesium sulfate heptahydrate, and 2.8 g dipotassium hydrogen phosphate in 1 L of deionized water.

The control, test and reference sample solutions wdre measured for dissolved oxygen content independently in series such that each bottle was measured immediately after the expiration of the three-hour contact time. Dissolved oxygen was measured over a ten-minute time span to determine. the oxygen uptake rate (O.U.R.) using a YSI oxygen meter with an internal O.U.R. program.
Reference substance (positive control):
yes
Remarks:
3,5-dichlorophenol at 2.5 - 125 mg/L.

Results and discussion

Effect concentrations
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
>= 500 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
No inhibition of the sludge respiration rate was observed over the concentration range of 1.5 - 155 mg/L. At 500 mg/L the relative inhibition of the sludge respiration rate was 16.4 %.
Results with reference substance (positive control):
The estimated EC50 value for 3,5-dichlorophenol was 13.5 mg/L. The relative inhibition of the sludge respiration rate was 75% at 25 mg/L and was 96.4% at 125 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The test substance did not inhibit the respiration rate of activated sludge up to a concentration of 500 mg/L. Therefore, the test substance will not have an adverse effect upon the activity of waste water treatment plants.
Executive summary:

The test substance, 2,3-epoxypropyl neodecanoate was accessed for the potential to inhibit the activity of activated sludge in an O.E.C.D. test guideline 209 study. The test substance did not inhibit the respiration rate of activated sludge up to a concentration of 500 mg/L. Therefore, the test substance will not have an adverse effect upon the activity of waste water treatment plants. Neononanoic acid glycidyl ester is also unlikely to inhibity the activity of activated sludge.