Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
key study
Study period:
January 30, 2002
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report date:
2002

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
no
GLP compliance:
no
Remarks:
Screening level assay. GLP compliance was not required at the time of the test.

Test material

Constituent 1
Chemical structure
Reference substance name:
1-BUTANESULFONAMIDE, 1,1,2,2,3,3,4,4,4-NONAFLUORO-N-METHYL-
EC Number:
614-396-3
Cas Number:
68298-12-4
Molecular formula:
C5H4F9NO2S
IUPAC Name:
1-BUTANESULFONAMIDE, 1,1,2,2,3,3,4,4,4-NONAFLUORO-N-METHYL-
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: 3M. Lot #3
- Purity: 97.25%
- Physical state: Off white crystalline powder

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Ambient conditions

Sampling and analysis

Analytical monitoring:
no

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Test substance directly weighed into the test vessel.
- Controls: Blank control and reference controls

Test organisms

Test organisms (species):
activated sludge
Details on inoculum:
- Name and location of sewage treatment plant where inoculum was collected: Activated sludge collected on January 28th, 2002 (two days prior to test) from Denton Wastewater Treatment Facility, Denton Maryland.
- Total Suspended Solids: 3633 mg/L
- pH for sludge: 7.8

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h

Test conditions

Test temperature:
20-21°C
Nominal and measured concentrations:
Nominal: Blank control, 10, 100, 1000 mgL; Reference control: 3, 15, 50 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: Exposure was in 500mL erlenmeyer flasks and then solution was tansferred to 300 mL Biochemical Oxygen Demand bottles
- Aeration: 3 hours
- No. of vessels per concentration (replicates): The 10, 100, and 1000 mg/L solutions were tested with 1 replicate.
- No. of vessels per control (replicates): two for blank control
- Nutrients provided for bacteria: synthetic sewage per OECD 209 (peptone 16g, meat extract 11.0 g, urea 3.0 g, NaCl 0.7 g, CaCl2.2H2O 0.4 g, MgSO4.7H2O 0.2 g, K2HPO4 2.8 g (dissolved in 1 L of water).
- Test setup: The test substance was added directly to the test system vessels by direct weight addition. Sludge was aerated until measurement.

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: municipal water

OTHER TEST CONDITIONS:
Details on termination of incubation: After a 3 hour exposure, test solutions were transferred to a 300 mL BOD for measurement.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Respiration inhibition. Dissolved oxygen (DO) concentrations were measured using a YSI Model 50B Dissolved Oxygen Meter. Readings were recorded every 10 seconds for 10 minutes until the DO dropped below 1.0 mg/L.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10x
- Range finding study : No
Reference substance (positive control):
yes
Remarks:
3, 5-dichlorophenoL

Results and discussion

Effect concentrationsopen allclose all
Key result
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks on result:
other:
Remarks:
No inhibition observed at highest concentration tested.
Key result
Duration:
3 h
Dose descriptor:
NOEC
Effect conc.:
1 000 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks on result:
other:
Remarks:
No inhibition observed at highest concentration tested.
Details on results:
- Coefficient of variation of oxygen uptake rate in control replicates: 13%
-Inhibition for 1000 mg/L concentration = -41.5%
Results with reference substance (positive control):
The EC50 for 3,5-dichlorophenol reference group was 28.3 mg/L
- Results with reference substance valid? Yes, within the 5-30 mg/L range considered acceptable for the test.

Any other information on results incl. tables

Table 1. Respiration Rate and Percent Inhibition

Treatment

Respiration Rate (mg O2/L/hour)

Percent inhibition

Control (1)

52.7

NA

Control (2)

46.1

NA

Reference Control (3 mg/L)

50.9

-3.0

Reference Control (15 mg/L)

42.4

14.2

Reference Control (50 mg/L)

8.5

82.8

MeFBSA (10 mg/L)

87.4

-76.9

MeFBSA (100 mg/L)

66.9

-35.4

MeFBSA (1000 mg/L)

66.9

-41.5

*Reference control was 3,5-dichlorophenol

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Remarks:
Control oxygen uptake rate >20 mg O2/gram sludge/hour (No information); coeff. of variation <15% for control replicates (13%); ref substance EC50 in range 5-30 mg/L (28.3 mg/L).
Conclusions:
3 hour EC50>1000 mg/L in activated sludge for respiration inhibition (OECD 209)
3 hour NOEC=1000 mg/L in activated sludge for respiration inhibition (OECD 209)
Executive summary:

The toxicity of MeFBSA to activated sludge was assessed according to the OECD 209 guideline in a screening assay conducted at 10, 100, and 1000 mg/L. The validity criteria were partially met based on acceptable variation among control replicates and a typical level of inhibition with the positive control. The 3-hour EC50 (respiration) of MeFBSA to activated sludge is >1000 mg/L, as no inhibition was observed. The study followed an international standard method and but is not GLP compliant and lacks key details including biomass loading rate. However, the study included a positive control indicating normal susceptibility of sludge. The study is deemed reliable with restrictions and can be utilized to calculate a PNEC for STP.