Reaction mass of dioctyl hydrogen phosphate and octyl dihydrogen phosphate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2007-02-19 to 2007-05-29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study according to OECD guideline

Justification for type of information:

See attached justification document

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

The T° for the main study lay in a range of 24.3°C to 26.3°C and therefore higher than stated in the guidelines.As no mortality occured during the test, this deviation was stated as uncritical

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

yes

Remarks:

The T° for the main study lay in a range of 24.3°C to 26.3°C and therefore higher than stated in the guidelines.As no mortality occured during the test, this deviation was stated as uncritical

GLP compliance:

yes (incl. QA statement)

Remarks:

2007-01-12

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

Preparation of the test solution:

Pre-test: A stock solution containing 1000 mg/L test item was prepared. This solution was used to prepare the test solutions: Date: Feb. 19-23, 2007 Replicates one vessel containing 3 L test solution and 3 Fish. Control: one vessel, containing 3L dilution water and 3 fish.

Main study: A stock solution containing 700 mg/L test item was prepared. This solution was used to prepare the test solutions: Date: May. 21-25, 2007 Replicates one vessel containing 7 L test solution and 7 Fish. Control: one vessel, containing 7L dilution water and 7 fish.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Danio Rerio
- Strain: Hamilton- Buchanan
- Source: Weiler's pet's best, Turmstr. 6, 67433 Neustatd
- Age at study initiation (mean and range, SD): sexually immature young fish
- Length at study initiation (length definition, mean, range and SD): 2 ± 1 cm
- Weight at study initiation (mean and range, SD): Not reported
- Feeding during test: No

ACCLIMATION
- Acclimation period: 14 days
- Acclimation conditions : same as test
- Type and amount of food: warmwater fishfood and daphnia 1-2% of bodyweight per day
- Feeding frequency: 3 times a day
- Health during acclimation (any mortality observed): No data

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

1.08 mmol/L

Test temperature:

24.3 °C to 26.3°C measured (In old solution) at 0h, 24h, 48h, 72h, and 96h

pH:

7.6 to 8.3 measured at 0h, 24h, 48h, 72h, and 96h

Dissolved oxygen:

Stay above 6.8 mg/L (range 6.8-8.1 for control, range 7.1-9.0 for exposed)

Salinity:

Not applicable

Nominal and measured concentrations:

The measured concentration after 96h was 100% and 99% of the nominal concentration and the start concentration, respectively.
(See table measured concentration)

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass aquaria,
- Material, size, headspace, fill volume: size = 10 L fill volume = 7 L
- Aeration: accomplish with glass tube, frequency of bubble 1/s
- Type of flow-through (e.g. peristaltic or proportional diluter): Not applicable (static test)
- Renewal rate of test solution: Not applicable (static test)
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): Not applicable

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Good quality drinking water is used
- Total organic carbon: <1.0mg/L
- Particulate matter: No data
- Metals: No data
- Pesticides: No data
- Chlorine free tap-water: Tap water
- Alkalinity: No data
- Ca/mg ratio: No data
- Conductivity: 229µS/cm
- Intervals of water quality measurement: once a year

OTHER TEST CONDITIONS
- Adjustment of pH: No data
- Photoperiod: 12h-12h
- Light intensity: No data

EFFECT PARAMETERS MEASURED: Observations were made every 24h , measuring pH and dissolved oxygen concentration of the old and the new test solution in each vessel, and documenting mortalities or abnormal behaviour.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: not applicable (Limit test)
- Range finding study: Yes
- Test concentrations: 10 mg/L and 100 mg/L
- Results used to determine the conditions for the definitive study: For each concentration, no fish died or showed any signs of morbidity at the end of the range finding test. The pH and the oxygen value were in the range specified by guidelines

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: None
- Observations on body length and weight: No data reported
- Other biological observations: No
- Mortality of control: No
- Other adverse effects control: No
- Abnormal responses: No
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No
- Effect concentrations exceeding solubility of substance in test medium: No

Sublethal observations / clinical signs:

Mortalities

 

Nominal Concentration in mg/L	Total of fish used	Dead fish
		24h		48h		72h		96h
		New	Cum.	New	Cum.	New	Cum.	New	Cum.
0	7	0	0	0	0	0	0	0	0
100	7	0	0	0	0	0	0	0	0

 

 

 

pH and O₂values

 

Nominal Concentration in mg/L	pH					O2in mg/L
	0h	24h	48h	72h	96h	0h	24h	48h	72h	96h
0	8.3	7.7	7.7	7.8	7.8	8.1	6.8	6.9	7.1	7.0
100	7.6	7.7	7.7	7.8	7.7	9.0	7.1	7.1	7.4	7.3

 

 

 

Temperature

 

0h	24h	48h	72h	96h
24.3	24.6	26.3	25.9	25.6

 

 

 

Measured concentrations

 

Nominal Concentration in mg/L	Measured concentrations in mg/L		% recovery after 96h	% of nominal concentration
	0h	96h		0h	96h
0	<LOQ	<LOQ
100	101.9	100.5	99	102	100

 

Validity criteria fulfilled:

yes

Conclusions:

The validity criteria were met.
The analytical determinations of the test item showed very good correlation between nominal and measured concentrations and very good recovery rates. Therefore, the test item can be stated as "stable under the test conditions" and the determination of the results was based on the nominal concentrations.
The result of the test can be considered valid

Executive summary:

One reliable key study is available on freshwater fish (Danio rerio) for the potassium salt of the Isobutyl Acid Phosphate. The reaction mass IBAP and its potassium salt have high water solubility and their behavior in water and biological systems is dominated by their ionization. The main assumption is that the potassium cation is not significant in respect of the toxicological effect on aquatic organisms which are expected to be related to the IBAP. In experimental dilute aqueous conditions at environmental pH (5-9), the salt will be completely dissociated and will not behave differently to the parent acid, at identical concentration of the particular speciated form present.

In a 96h acute toxicity study in accordance with OECD Guideline 203 and under GLP, Danio rerio, were exposed to Potassium isobutylphosphate at a nominal concentration of 100 mg/L (limit test) under static conditions at 23 +/- 1°C. The mortality was observed daily and the pH, the concentration of dissolved oxygen and the concentrations of the test item were measured at the beginning and the end of the test. The analysis of the test item concentration was performed on phosphate using a validated photometer method.

No mortality was observed in the treated groups and the validity criteria's were fulfilled. The 96h LC₅₀was determined above 100 mg/L and the 96h NOEC above or equal 100 mg/L.The results on effects are expressed in nominal concentration of test item because the analytical measurement based on phosphate show that it was stable among the study (99% recovery after 96h).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L