Dimethyl octadecylphosphonate

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

Water accomodated fraction (WAF) procedure was applied to prepare the test solutions due to the poor solubility of the test item

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Dimethyl octadecylphosphonate

EC Number:

246-904-0

EC Name:

Dimethyl octadecylphosphonate

Cas Number:

25371-54-4

Molecular formula:

C20H43O3P

IUPAC Name:

dimethyl octadecylphosphonate

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Test Item Identification: DURAPHOS 100
Batch: F14E002
Purity: 91.1% dimethyl octadecylphosphonate (DMOP)
Description: White powder
Storage conditions: room tempearure and protected from humidity

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

Each test solution was prepared by stirring the test item in M4 reconstituted water at the appropriate loading rate between 20 and 24 hours . After filtration through a filter of porosity 0.45 µm, the water soluble fraction (WSF) was collected and used as the test solution.
Range Finding Test: Nominal Loading Rates of 1 and 10 mg/L.
Limit Test: Nominal Loading Rate of 100 mg/L

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain:STRAUS-clone 5
- Source: CIT
- Age at study initiation: 6-24 hours old (first instar daphnids)
- Method of breeding: produced from parthenogenically reproducing brood female population.
- Feeding during test: animals were not fed during the test


ACCLIMATION
- Acclimation period: acclimitisation from birth
- Acclimation conditions (same as test or not):animals were held in water of the same quality and conditions as test water
- Type and amount of food:culture animals were fed with a diet of between 0.1 and 0.2 mg of carbon per Daphnia, in
the form of the algal strain Scenedesmus subspicatus which was cultured at CIT.
- Feeding frequency: daily

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

303 and 346 mg/L as CaCO3

Test temperature:

19.8 °C to 21.6°C

pH:

7.88 to 8.44 (variation within 1 unit for each test solution)

Dissolved oxygen:

8.4 to 8.8 mg/l (> 3 mg/l)

Salinity:

N/A

Nominal and measured concentrations:

100 mg/L (nominal concentration, water-accomodated fraction procedure was used to prepare the test solutions)

Details on test conditions:

TEST SYSTEM
- Test solution volume: 50 ml (10 ml per daphnid)
- Aeration: the test vessels were not aerated during the test, however the dilution water was aerated prior to addition of the test item

- Renewal rate of test solution (frequency/flow rate): Not applicable (static test)
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates):4 replicates
- No. of vessels per control (replicates): not applicable (control test was only included in the rangefinding test)
- No. of vessels per vehicle control (replicates): 4 replicates

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M4 reconstituted water was prepared by the test facility using deionized water


OTHER TEST CONDITIONS
- Photoperiod:16/8 hours

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :24 and 48 h

TEST CONCENTRATIONS
- test concentration: 0 and 100 mg/L (limit test)
- range finding study: 1 and 10 mg/L

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: water soluble fractions

Basis for effect:

mobility

Details on results:

Limit Test
There was 0% immobilisation at 0 and 100 mg/L at 24 and 48 h

EL50 (Median Effective Loading rate) :> 100 mg/L.
No Observed Effect Loading rate: ≥ 100 mg/L.

As the test item is poorly soluble in water (estimated solubility < 1 mg/L), the water-accommodated fraction (WAF) procedure was applied to prepare the test solutions. The effect data are therefore presented Loading Rates (Median Effective Loading Rate and No Observed Effect Loading rate).

Rangefinding Test
There was 0% immobilisation at 0 and 10 mg/L at 24 and 48 h

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Not applicable

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EL50 (Median Effective Loading rate) derived from the limit test for dimethyl octadecylphosphonate (DMOP) was > 100 mg/l and the No Observed Effect Loading rate was ≥ 100mg/l. The validity criteria of the test were met (the immobilization in the control was ≤ 10% at the end of the test, the dissolved oxygen concentration remained > 3 mg/L throughout the test and the pH of the control did not vary by more than 1 unit during the test).

Executive summary:

A 48-hour static acute toxicity test with Daphnia magna was performed in a test designed to meet the requirements OECD Test Guideline 202. As the test item, DMOP (91.1%) is poorly soluble in water (estimated solubility < 1 mg/L); the water-accommodated fraction (WAF) procedure was applied to prepare the test solutions. A WAF is an aqueous medium containing only the fraction of test item (present either in true solution or as a stable emulsion) which remains in the aqueous phase after stirring and phase separation. When filtered through appropriate filters, water-soluble fractions (WSFs) are obtained.

In the limit test where 20 daphnids (4 replicates of 5) were exposed to a nominal loading rate of 100 mg/L (the limit test loading rate) for 48 hours while a second group of 20 daphnids (also 4 replicates of 5) was exposed to dilution test water (M4) only (control solution). In the range finding test, two groups of 20 daphnids (4 replicates of 5) were exposed to nominal loading rates of 1 and 10 mg/l for a period of 48 hours. The test solutions (50 ml per replicate of 5 daphnids) remained unchanged for the duration of the test. Immobilisation in the rangefinding and limit test was recorded at 0, 24 and 48 hours.

No immobilisation was observed in any of the test solutions during the rangefinding test or limit test. The EL50 (Median Effective Loading rate) derived from the limit test for DMOP was > 100 mg/l and the No Observed Effect Loading rate was ≥ 100 mg/l. The validity criteria of the test were met (the immobilization in the control was ≤ 10% at the end of the test, the dissolved oxygen concentration remained > 3 mg/l throughout the test and the pH of the control did not vary by more than 1 unit during the test).