Butyl (dialkyloxy(dibutoxyphosphoryloxy))titanium(trialkyloxy)titanium phosphate

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2007 July 30th to 2008 May 5th

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.20 (Daphnia magna Reproduction Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Sponsor's identification: VERTEC(TM) IA10
Appearance: clear colorless liquid
Batch number: VO502255
Date received: 17 May 2007
Storage conditions: room temperature in the dark.

Analytical monitoring:

yes

Details on sampling:

Water samples were taken from the control and each surviving test group (replicates pooled) for quantitative analysis. Samples of the test preparations were taken on Days 0 (fresh media), 2, 4, 7, 9, 11, 14, 16, 18 (old and fresh media) and 21 (old media). Duplicate samples were taken stored at approximately -20°C for further analysis if necessary.
Information provided by the sponsor indicated that the test material undergoes rapid hydrolysis in water to give titanium dioxide, three simple alcohols (methyl, ethyl and isopropyl) and mono and dibutyl phosphate esters. Given that titanium dioxide is insoluble, for the purpose of ecotoxicity testing it was considered appropriate to expose the test organisms to the hydrolysis products and to assess the toxicity of the test material based on the mono and dibutyl phosphate esters. The t3est concentrations were monitored by analysis of the test samples for the degradants only.
SAMPLE PREPARATION
A volume of test sample was diluted with water to gice a final theoretical concentration of approxymately 0.050 mg/L for the monobutyl ester and 0.30 mg/L for the dibutyl ester.

Vehicle:

no

Details on test solutions:

An amount (500 mg) of test material was dispersed in dechlorinated tap water with the aid of ultrasonication and vigorous shaking for approximately 10 minutes and the volume adjusted to 5 litres to give the 100 mg/L test concentration Aliquots (20, 64, 200 and 640 ml) of the 100 mg/L test concentration were each added separately to dechlorinated tap water and the volume adjusted to2 litres to give the remaining test concentrations of 1.0, 3.2, 10 and 32 mg/L respectively.
Each stock dispersion and prepared concentration was inverted several times to ensure adequate mixing and homogeneity.

Test organisms (species):

Daphnia magna

Details on test organisms:

The test was carried out using 1st instar Daphnia magna derived from in-house laboratory cultures.
Adult daphnids were mantained in polypropylene vessels containing approximately 2 litres of sechlorinated tap water at a temperature of 19 to 20 °C. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods.
Each culture was fed daily with a suspension of algae. Culture conditions ensured that reproduction was by parthenogenesis. Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old. These young were removed from the cultures and used for testing. The diet and diluent water are considered not to contain any contaminat that would affest the integrity or outcome of the study.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

120 - 150 mg/L as CaCO3

Test temperature:

21 °C

pH:

7.4 - 8.8

Dissolved oxygen:

3.5 - 8.9 mg O2/L

Nominal and measured concentrations:

Nominal (selected after a range-finding test): 1.0, 3.2, 10, 32 and 100 mg/L

Details on test conditions:

For each concentration a single daphnid was placed in 100 mL of the test preapration in a50 mL glass flasks which were then covered with a plastic lid to reduce evaporation. For each test and control group ten replicate test vessels were prepared. The flasks were maintained at 20 to 22 °C with a photoperiod of 16 hours light (512 to 532 lux) and 8 hours darkness with 20 minutes dawn and dusk transition periods for 21 days. Test vessels were not aerated. The diluent water was not aerated prior to use.
The control group was maitained under identical conditions.
The test preparations were renewed 3 times per week.
Each daphnid received unicellualr algal culture (Chlorella sp.) daily. Feeding was at a level of approximately 0.1 to 0.2 mg carbon/daphnid/day, dependent on the age and size of the animals.

Reference substance (positive control):

no

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

immobilisation

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

45 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

10 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

3.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other:

Remarks:

Immobilisation and reproduction

Details on results:

Lethal effects on the parental generation (P1)
Immobilisation occured at the highest test concentration of 100 mg/l resulting in 40% immobilized daphnids at day 21. Immobilization also occured at 32 mg/l resulting in 30% immobilized daphnids at day 21.
No immobilization occured at the other concentrations tested.

Sub-lethal effects on the parental generation (P1)
The 10, 32 and 100 mg/L test groups showed a statistically significant difference from the control and the remaining test groups after 21 days in terms of producing fewer numbers of live young per adult.
The lenght of the adult after 21 days showed no statistically significant differences for all dose levels comapred to control.

Effects on the filial generation (F1)
Information on the effects on F1 generation is limited, since, by study design, the young are removed soon after liberation from the brood pouch.
However, an assessment made at each media renewal showed the filial daphnids produced by all test groups were in the same general condition as the young of the control.

Results with reference substance (positive control):

Not applicable

Validity criteria fulfilled:

yes

Conclusions:

EC50 (immobilization) after 21 days: > 100 mg/L
EC50 (reproduction) after 21 days: 45 mg/L with 95% confidence limit of 23-130 mg/L.
21-d LOEC: 10 mg/L
21-d NOEC: 3.2 mg/L

Description of key information

21d NOEC in a Daphnia Magna reproduction test according to OECD 204: 3.2 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

3.2 mg/L