Superphosphates

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

no data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: Standard methods for the examination of water and wastewater. 14th ed., American Public Health Association, New York (1975)

Deviations:

not specified

Principles of method if other than guideline:

D. carinata collected from local ponds were acclimated to laboratory conditions for four days. Bioassays were performed according to American Public Health Association. Standard Methods for the Examination of Water and Wastewater. 1975. Experiments were run at 22.7°C and 30.8°C for 72-hours in 500 mL beakers using unchlorinated well water at pH 7.0. Dissolved oxygen was 7.6 ppm and total alkalinity was 150 ppm as CaCO3. Twenty animals were kept per container and six replicates were conducted for each test and control.

GLP compliance:

not specified

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
No data

Analytical monitoring:

no

Details on sampling:

Not applicable

Vehicle:

not specified

Details on test solutions:

No data

Test organisms (species):

other: Daphnia carinata (water flea)

Details on test organisms:

The zooplankton Daphnia carinata, Moina micrura and Cyclops viridis and larvae Chironomus and Dragon fly nymphs were collected from local ponds were acclimated to laboratory conditions for four days.

In addition, worm and molluscs were also collected from local ponds and tested.

Test type:

not specified

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

no data

Hardness:

total alkalinity 150 ppm as CaCO3

Test temperature:

22.7°C and 30.8°C

pH:

7.0

Dissolved oxygen:

7.6 ppm

Salinity:

No data

Nominal and measured concentrations:

No data

Details on test conditions:

Twenty animals per container and six replicates for each test were conducted alongwith controls.
Unchlorinated tubewell water was used (pH 7.0. Dissolved oxygen 7.6 ppm, total alkalinity 150 ppm as CaCO3, ammonia nitrogen 0.08 ppm,
phosphate 0.05 ppm)

Reference substance (positive control):

not specified

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

1 790 mg/L

Basis for effect:

mortality

Remarks on result:

other: Daphnia carinata, 22.7°C

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

1 825 mg/L

Basis for effect:

mortality

Remarks on result:

other: Daphnia carinata, 30.8°C

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

1 650 mg/L

Basis for effect:

mortality

Remarks on result:

other: Moina micrura, 22.7°C

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

1 600 mg/L

Basis for effect:

mortality

Remarks on result:

other: Moina micrura, 30.8°C

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

2 260 mg/L

Basis for effect:

mortality

Remarks on result:

other: Cyclops viridis, 22.7°C

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

2 350 mg/L

Basis for effect:

mortality

Remarks on result:

other: Cyclops viridis, 30.8°C

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

1 520 mg/L

Basis for effect:

mortality

Remarks on result:

other: Chironomus, 22.7°C

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

1 500 mg/L

Basis for effect:

mortality

Remarks on result:

other: Chironomus, 30.8°C

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

1 145 mg/L

Basis for effect:

mortality

Remarks on result:

other: Dragonfly nymph, 22.7°C

Duration:

72 h

Dose descriptor:

LC50

Effect conc.:

1 120 mg/L

Basis for effect:

mortality

Remarks on result:

other: Dragonfly nymph, 30.8°C

Details on results:

Number Daphnia carinata tested = 700.
The lowest LC50 value of all organisms tested was 1120 mg/L for Dragon fly nymph at 30.8°C.

Results with reference substance (positive control):

No data

Reported statistics and error estimates:

No data

Validity criteria fulfilled:

not specified

Conclusions:

The LC50 value to Daphnia carinata after 72-hours of exposure at both 20.7°C and 30.8°C is very high (1790 and 1825 mg/L, respectively).
The lowest LC50 value of all organisms tested was 1120 mg/L for Dragon fly nymph at 30.8°C.

Description of key information

Based on a reliable 72-hours study performed with single superphosphate an EC50 of 1790 mg/L at 20.7°C was determined.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1 790 mg/L

Additional information

In a reliable study performed according to "Standard Methods for the Examination of Water and wastewater (APHA-1975)", Daphnia carinata collected from local ponds were exposed to single superphosphate for 72 hr. Although the recommended exposure time is 48 hr it is not expected to have affected the study as the LC50 values are high. LC50 values after 72 -hours of exposure at both 20.7°C and 30.8°C are 1790 and 1825 mg/L, respectively.