Tetraamminepalladium(2+) dihydroxide

Toxicity to microorganisms

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other: GLP-compliant, guideline study available as an unpublished report. No restrictions, fully adequate for assessment.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Diamminedichloropalladium

EC Number:

238-269-3

EC Name:

Diamminedichloropalladium

Cas Number:

14323-43-4

Molecular formula:

Cl2H6N2Pd

IUPAC Name:

Diamminedichloropalladium

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Diamminedichloropalladium
- Molecular formula (if other than submission substance): C12H6N2Pd
- Molecular weight (if other than submission substance): 211.39 g/mol
- Physical state: Yellow powder
- Analytical purity: >99.5%
- Composition of test material, percentage of components: 50.33% palladium
- Lot/batch No.: 11011
- Expiration date of the lot/batch: 31 October 2012
- Storage condition of test material: Closed dry vessel at room temperature

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

activated sludge of a predominantly domestic sewage

Details on inoculum:

The sludge was taken from the activation basin of the ESN (Stadtentsorgung Neustadt) sewage treatment plant D-67435 NW-Lachen-Speyerdorf and aerated during transport. Upon arrival at the test facility the sludge was filtered, washed with tap water and resuspended in tap water. The activated sludge was aerated until usage and fed daily with 50mL/L synthetic sewage feed.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test conditions

Hardness:

1.08 mmol/L

Test temperature:

Pre-test: 19.1 - 20.8°C
Main study: 19.7 - 20.8°C

pH:

Pre-test: 6.25 - 8.25 at end of test
Main study: 7.6 - 8.0 at end of test

Dissolved oxygen:

Not reported

Salinity:

Not relevant

Nominal and measured concentrations:

Pre-test: Nominal Control, 1, 10, 100 and 100 mg/L
Main study: Nominal Control, 10, 20, 30, 60, 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Beaker
- Material, size, headspace, fill volume: Glass containing 500 mL test solution, nutrient solution and inoculum
- Aeration: purified air through pasteur pipette at 0.75L/min flow rate
- No. of vessels per concentration (replicates): Pre-test: 1 per test item concentration except highest contentration (5 replicates); Main study: 5 per test item concentration
- No. of vessels per control (replicates): Pre-test: 6 Control, 4 positive control; Main study: 6 Control, 4 positive control
- Biomass loading rate: Pre-test: 1.08g suspended solids/L; Main-study: 1.35 g suspended solids/L

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

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : oxygen consumption

TEST CONCENTRATIONS
- Spacing factor for test concentrations:
- Range finding study: yes
- Test concentrations: 0, 10, 100, 1000 mg/L
- Results used to determine the conditions for the definitive study: -4.2% inhibition at 1 mg/L, -0.6% inhibition at 10 mg/L, 81.7% inhibition at 100 mg/L, 100% inhibition at 1000 mg/L

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

29 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Diamminedichloropalladium

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: 95% CL 28 - 30 mg/L

Effect concentrations 2

Duration:

3 h

Dose descriptor:

EC50

Effect conc.:

61 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Diamminedichloropalladium

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Remarks on result:

other: 95% CL 59 - 63 mg/L

Effect concentrations 3

Duration:

3 h

Dose descriptor:

NOEC

Effect conc.:

18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

Diamminedichloropalladium

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 4

Key result

Duration:

3 h

Dose descriptor:

EC10

Effect conc.:

14 590 µg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

3-hour EC50 8.8 mg/L (95% CL 5.0 - 13 mg/L) which lies within the recommended range of 2- 25 mg/L.

Reported statistics and error estimates:

Oxygen consumption was calculated using linear regression.
EC50 was calculated using linear fit on a probability-logarithmic scale using Origin™ software.
NOEC was determined by testing equality of variance using and t-test or WEIR test.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 3-hour EC10 is 29 mg DDP/L (95% CL 28 - 30 mg/L). The 3-hour EC50 is 61 mg DDP/L (95% CL 59 - 63 mg/L). The NOEC is 18 mg DDP/L. This corresponds to 14.6 mg Pd L-1, 30.7 mg Pd L-1 and 9.1 mg Pd L-1, respectively.

Executive summary:

A GLP compliant, OECD guideline study to assess the inhibition of respiration of activated sludge was carried out (LAUS 2012). The study is considered to be suitable for use as the key study for this endpoint.