Ricinoleyl monomaleate triglyceride

Toxicity to microorganisms

Administrative data

Endpoint:

activated sludge respiration inhibition testing

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 - 28 October 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study according to international guidelines.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes

Test material

Reference

Name:

Unnamed

Type:

Constituent

Test material form:

liquid: viscous

Details on test material:

Batch: T4649
Expiry date: 23 April 2000
Storage at 10 to 30 dC

Sampling and analysis

Analytical monitoring:

no

Test solutions

Details on test solutions:

Ceraphyl RMT was not soluble in water at concentrations normally used for stock solutions. Therefore, the weighed amounts of substance were directly added to the test medium. The test solutions were subsequently treated with ultra-sonic waves for ten minutes before addition of the inoculum.

Test organisms

Test organisms (species):

activated sludge

Details on inoculum:

Collected from one of the return lines at Burley Menston domestic sewage treatment works (Yorkshire water). The activated sludge had not been adapted or acclimatised to Ceraphyl RMT before exposure.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

3 h

Test conditions

pH:

pH was checked before the start of the test and adjusted to a value between 6 - 8 when it was below 6.

Nominal and measured concentrations:

Nominal: 1.0, 10, 100 and 1000 mg/L

Details on test conditions:

All mixtures tested comprised 16 mL synthetic sewage diluted to 300 mL. Inoculation entailed addition of 200 mL activated sludge.
Before measurements the DO-meter was calibrated at 0 and 100% saturation. At the end of the 3-h incubation, a portion of the first test mixture was transferred to fill a clean 250 mL sample bottle containing a stirrer bar. The dissolved oxygen was measured at 15-minute intervals with the DO-meter under continuous stirring. Respiration rates were subsequently derived from tthe longest linear portion of each valid trace.

Reference substance (positive control):

yes

Remarks:

3,5-dichlorophenol

Results and discussion

Effect concentrations

Effect concentrations 1

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:

respiration rate

Effect concentrations 2

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:

respiration rate

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The control respiration rates used to obtain the mean lay within 15% of each other. The EC50 of the reference inhibitor was between 5 and 30 mg/L, the limits for acceptance of the reference test.

Conclusions:

The test substance has proven to be non-toxic to fresh-water micro-organisms at levels below, at and above its solubility in water.