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Ecotoxicological information

Toxicity to microorganisms

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Administrative data

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
A preliminary non-GLP test was run to determine test substance concentration at the beginning and end of the exposure period. The definitive study was terminated based on the results of the preliminary test (the test substance was not detectable after the minimum exposure period and the mean concentration could not be determined).

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009

Materials and methods

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

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Purity: 99.9%

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
activated sludge

Results and discussion

Effect concentrationsopen allclose all
Duration:
30 min
Dose descriptor:
other: Not detected at end of 30-minute exposure.
Effect conc.:
0.4 other: mg C/L
Conc. based on:
other: Average of three replicates of the test substance after bubbling with air. The total carbon in the water blank contained 0.4 mg C/L.
Duration:
0 min
Effect conc.:
3.1 other: mg C/L
Conc. based on:
other: The average concentration of the test substance at time zero was 6.5% of the expected concentration. The total carbon in the water blank contained 0.4 mg C/L.
Conc. based on:
other: Testing of this test substance using the Activated Sludge Respiration Inhibition OECD 209 method is not technically feasible given the inability to detect the test substance in the test system after the minimum exposure period.

Applicant's summary and conclusion

Conclusions:
Testing of this test substance using the Activated Sludge Respiration Inhibition OECD 209 method is not technically feasible given the inability to detect the test substance in the test system after the minimum exposure period.
Executive summary:

A test substance working solution (48 mg C/L) was prepared and the solution was sealed and mixed at room temperature for a minimum of 10 minutes. Three subsample aliquots from the working solution of the test substance were analyzed. The remaining test substance working solution was bubbled with air at a flow rate between 0.5 to 1 L/min for 30 minutes and three replicate aliquots were immediately dispensed for analysis. The average concentration of the test substance at time zero was 3.10 mg C/L, 6.5% of the expected concentration. Three replicates of the test substance after bubbling with air showed an average of 0.4 mg C/L after 30 minutes. The total carbon in the water blank contained 0.4 mg C/L. These results show that the test substance concentration after the 30 minute exposure period in the test vessel was equivalent to the water blank. Therefore, testing of this test substance using the Activated Sludge Respiration Inhibition OECD 209 method is not technically feasible given the inability to detect the test substance in the test system after the minimum exposure period.