2-Hydroxypropyl-β-cyclodextrine ethers

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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

.beta.-Cyclodextrin, 2-hydroxypropyl cycloheptaamylose

IUPAC Name:

.beta.-Cyclodextrin, 2-hydroxypropyl cycloheptaamylose

Constituent 2

Reference substance name:

-

EC Number:

420-920-1

EC Name:

-

Cas Number:

128446-35-5

Molecular formula:

Hill formula: (C42H70-nO35)(C3H7O)n; n(mittel)=5,25

IUPAC Name:

5,10,15,25-tetrakis(hydroxymethyl)-40,44,47,49-tetrakis(2-hydroxypropoxy)-20,30,35-tris[(2-hydroxypropoxy)methyl]-2,4,7,9,12,14,17,19,22,24,27,29,32,34-tetradecaoxaoctacyclo[31.2.2.2³,⁶.2⁸,¹¹.2¹³,¹⁶.2¹⁸,²¹.2²³,²⁶.2²⁸,³¹]nonatetracontane-36,37,38,39,41,42,43,45,46,48-decol

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): hydroxypropylated .beta.-cyclodextrin
- Physical state: White powder
- Analytical purity: >95%
- Lot/batch No.: 74B008
- Expiration date of the lot/batch: 31 December 2002
- Stability in water: At least 96 h
- Stability under storage conditions: Stable
- Storage condition of test material: At room temperature in the dark

Sampling and analysis

Analytical monitoring:

no

Test organisms

Test organisms (species):

activated sludge

Details on inoculum:

- Laboratory culture: the accumulated biological mass produced in the treatment of waste water by the growth of bacteria and other micro-organisms in the presence of dissolved oxygen.
- Method of cultivation: no data
- Preparation of inoculum for exposure: sludge was coarsely sieved, washed and diluted with tap-water. After dilution a small amount of the
sludge was weighed and dried at ca. 105°C to determine the amount of suspended solids (3.7g/l of sludge, as used for the test). Before use the pH was checked.
- Pretreatment: The batch of sludge was used on subsequent days (maximum four days), therefore 50 ml of synthetic sewage feed was added to each litre of activated sludge at the end of each working day. The sludge was kept aerated at test temperature until use.
- Initial biomass concentration: no data

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

30 min

Test conditions

Hardness:

no data available

Test temperature:

19°C

pH:

7

Dissolved oxygen:

no data available

Salinity:

no data available

Nominal and measured concentrations:

3.2, 10, 32 and 100 mg/l (nominal)

Reference substance (positive control):

yes

Remarks:

one at the start and one at the end

Results and discussion

Effect concentrations

Duration:

30 min

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

inhibition of total respiration

Remarks:

respiration rate

Details on results:

The EC50 of 3,5-dichlorophenol was 15 mg/I (regression line:Y = 71.01 X -33.25, Y =·% inhibition of respiration and X = log concentration (mg/I)).

Since all criteria for acceptability of the test were met, this study was considered to be valid.

Results with reference substance (positive control):

The mean respiration rate of control 1 and 2 was 38 mg O2/I/hr.The difference between the controls was 0%.
The mean respiration rate of control 2 and 3 was 41 mg O2/I/hr. The difference between the controls was 14.6%.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In conclusion, under the conditions of this present test, hydroxypropylated .beta.-cyclodextrin was not toxic to waste water (activated sludge) bacteria at a concentration of 100 mg/l.

Executive summary:

The influence of hydroxypropylated .beta.-cyclodextrinon the respiration rate of activated sludge was investigated after a contact time of 30 minutes.

The study procedure was based on OECD Guideline No. 209, adopted April 4, 1984 and EEC Directive 67/548 amended November 18, 1987 (87/302), Part C, Publication No. L133, adopted May 30, 1988.

Hydroxypropylated .beta.-cyclodextrinis white powder that was easily soluble in milli-Q water. A stock solution was prepared in milli-Q water at a concentration of 0.5 g/l. The pH of the clear stock solution was 7.6. A concentration of 100 mg/I, corresponding with 100 ml of the 0.5 g/l stock solution in 500 ml final volume, was tested in duplicate.

No significant inhibition in respiration rate of the sludge was recorded at 100 mg hydroxypropylated .beta.-cyclodextrinper litre. The duplicate measurement confirmed the result of the first measurement. Values of -7% and -5% inhibition were recorded (negative values indicate stimulation in respiration rate of the sludge). Hence, the EC50 for hydroxypropylated .beta.-cyclodextrinexceeded 100 mg/l and no further testing was necessary.

The respiration rates of the controls were within 15% of each other. The EC50 of the reference substance, 3,5 -dichlorophenol, was 15 mg/l. Therefore, the test was considered to be valid.

In conclusion, under the conditions of this present test,hydroxypropylated .beta.-cyclodextrinwas not toxic to waste water (activated sludge) bacteria at a concentration of 100 mg/l.