1-[4-(4-chlorophenoxy)-2-(trifluoromethyl)phenyl]ethanone

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2014-11-04 to 2014-12-04

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Version / remarks:

2010

Deviations:

yes

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)

Version / remarks:

30 May 2008

Deviations:

yes

Principles of method if other than guideline:

Deviations from the test guidelines:
- The start value of oxygen content for measurement of oxygen consumption was lower than 7 mg/L.
- Exceeding the test temperature range of 20 ± 2 °C with 0.1°C.
An influence to the results of this study can be excluded.

GLP compliance:

yes (incl. QA statement)

Remarks:

BASF SE, Experimental Toxicology and Ecology, 67056 Ludwigshafen

Test material

Test material information

Constituent 1

Reference substance name:

1-[4-(4-chlorophenoxy)-2-(trifluoromethyl)phenyl]ethanone

EC Number:

813-142-0

Cas Number:

1417782-28-5

Molecular formula:

C15 H10 Cl F3 O2

IUPAC Name:

1-[4-(4-chlorophenoxy)-2-(trifluoromethyl)phenyl]ethanone

Test material form:

solid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Bbatch No.of test material: L85-76
- Expiration date of the lot/batch: 01. October 2016

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage stability: The stability of the test substance under storage conditions over the test period was guaranteed by the sponsor, and the sponsor holds this responsibility.
- Storage condition of test material: Ambient at room temperature

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: The test substance was added in the required amounts according to the test concentrations directly to the test vessels with about 234 mL deionized water. Aliquots of the reference substance stock solution were dosed to the test vessels and made up with deionized water to a volume of 234 mL. 16 mL synthetic medium were dosed to each test vessel with test substance and reference substance afterwards. To prepare the blank control assays 234 mL of deionized water and 16 mL synthetic medium were mixed.
- Controls: Yes, blank control.

Test organisms

Test organisms (species):

activated sludge, domestic

Details on inoculum:

- Name and location of sewage treatment plant where inoculum was collected: Aeration tank of the wastewater treatment plant of Mannheim, Germany (Collection of test system: 02. December 2014).
- Preparation of inoculum for exposure:
- Pretreatment: After arrival of the activated sludge suspension in the test facility the suspension was sieved with a fine woven mesh (mesh size about 1 mm). This suspension was pre-aerated over night at room temperature. At the next day the sludge suspension was washed once with drinking water and the suspension was adjusted to 3 g/L dw.
- Sludge concentration in the test vessel: 1.5 g/L dw.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test conditions

Test temperature:

21.6 - 22.1 °C

pH:

7.5 - 7.6

Dissolved oxygen:

About 7 mg/L (see exception under "Principles of method it other than guideline")

Nominal and measured concentrations:

Nominal: 62.5, 125, 250, 500 and 1000 mg/L
No measured concentrations.

Details on test conditions:

TEST SYSTEM
- Test vessel (material, size): Glas beakers (nominal volume 1 L)
- Aeration: Yes, with pressured air.
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 6
- No. of vessels per reference substance concentration (replicates): 2
- No. of vessels per abiotic control (replicates): None
- Sludge concentration (weight of dry solids per volume): 1.5 g/L dw

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

OTHER TEST CONDITIONS
- Adjustment of pH: No

EFFECT PARAMETERS MEASURED: Inhibition of oxygen consumption

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

200 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: 95% CL: 117.8 - 325.1

Effect concentrations 2

Duration:

3 h

Dose descriptor:

other: EC20

Effect conc.:

760 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks on result:

other: 95% CL: 505.4 - 1149.7

Effect concentrations 3

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

Effect concentrations 4

Duration:

3 h

Dose descriptor:

other: EC80

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: EC50 was in the range og 2-25 mg/L in 3 hours

Reported statistics and error estimates:

The consumption rates were used for the determination of the ECx by the probit method based on Finney D.J., Probit Analysis; Cambr. Univ. Press, 3rd ed., 1971 with the software TOXRAT Professional 2.10. The effect concentrations were given with an accuracy of 2 significant digits.

Any other information on results incl. tables

The amount of oxygen in the test vessel different from the required amount of >7 mg/L at the start of the oxygen consumption measurements.

Table 1: Start value of oxygen content in the test assays for measurement of oxygen consumption

Test assay	Test concentration [mg/L]	Start value, O2 [mg/L]
TS7	250	~6.9
TS8	250	~6.7
TS9	250	~6.7
TS11	500	~6.5

Applicant's summary and conclusion

Conclusions:

The 3-h EC10 and EC50 for the test substance in the Activated Sludge Respiration Inhibition Test were 200 and >1000 mg/L, respectively.

Executive summary:

The toxicity to microorganisms of the test substance was investigated by determination of the inhibition of oxygen consumption in the Activated Sludge Respiration Inhibition Test according to OECD guideline 209 (2010). Activated sludge from a municipal wastewater treatment plant was exposed to the test substance at concentrations of 62.5, 125, 250, 500 and 1000 mg/L. After 3 hours of exposure EC10 and EC50 values of 200 and >1000 mg/L were determined.