Ester reaction products of 1,4-Benzenedicarboxylic acid with C11-14 iso-alcohols, C13-rich

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Reliability rating was 1 because study was carried out using OECD 209 test guideline and was performed under GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Test material

Test material information

Constituent 1

Constituent 2

Reference substance name:

MCP 1440

IUPAC Name:

MCP 1440

Details on test material:

- Name of test material (as cited in study report): MCP 1440
- Physical state: Liquid
- Analytical purity: 100%

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:

Activated sludge was collected from municipal wastewater treatment plant that handles predominantly domestic waste.
Suspended solids in the collected activated sludge sample was determined. The collected activated sludge was diluted as need to provide 8 liters of activated sludge inoculum with a nominal suspended solid conc of 4 gm/L. pH of the activated sludge was maintained between pH 6-8. Inoculum was not acclimated or adapted to the test substance before start of study.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

3 h

Test conditions

pH:

pH 6-8

Nominal and measured concentrations:

Test material evaluated at 1, 10, 100 and 1000 mg/L nominal concentration.
Positive control, 3,5-DCP was evaluated at 5, 15 and 45 mg/L concentrations.

Reference substance (positive control):

yes

Remarks:

3,5-DCP

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

3 h

Dose descriptor:

other: EL50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

nominal loading

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Effect concentrations 2

Duration:

3 h

Dose descriptor:

other: NOEL

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

nominal loading

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Results with reference substance (positive control):

In order for the test to be valid, ghd OECD 209 guidelines require that the EC50 for positive control (3,5-DCP) be in the range of 5 to 30 mg/L. In this test, 3,5-DCP was found to have an EC50 of 6 mg/L which satisfies the guideline requirement.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The test substance did not inhibit the respiration of activated sludge microorganisms. The 3 hr EL50 value was determined to be >1000 mg/L . The 3 hr NOEL was estimated to be >1000 mg/L. Overall, these results indicate that the test substance was not toxic to aquatic microorganism or bacteria in activated sludge inoculum.

Executive summary:

The test substance did not inhibit the respiration of activated sludge microorganisms. The 3 hr EL50 value was determined to be >1000 mg/L (nominal). The 3 hr NOEL was estimated to be >1000 mg/L (nominal). Overall, these results indicate that the test substance was not toxic to aquatic microorganism or bacteria in activated sludge inoculum.