Potassium (E,E)-hexa-2,4-dienoate

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:

20.01.1999 - 30.06.2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Justification for type of information:

Since sorbic acid is the corresponding acid to potassium sorbate, the substance in question, extrapolation of the obtained results is not considered to be restricted.

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Date received: December 14, 1998
Lot No.: ACH5495
Appearance: White crystals
Purity: 99.5%

Analytical monitoring:

yes

Details on sampling:

- Concentrations: the test concentrations were determined at each of the test concentrations. Samples were taken at the beginning of the exposure and before water replacements after day 2, 6, 8, and 14. In additon, samples were collected on day 16 before water replacement.
- Sample storage conditions before analysis: No, samples were analysed directly

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Age at study initiation (mean and range, SD): up to 24 hours
- Method of breeding: under laboratory conditions
- Feeding during test: no


TEST ORGANISM
- Common name: Water flea. Japanese name as mentioned in the report: Ohmijinko
- Source: initially obtained form the National Environmental Research Center, and successively bred at the lab
- Age of parental stock (mean and range, SD): 2-4 weeks
- Feeding during test
- Food type: algae (Chlorella vulgaris)
- Amount: 0.15 mg C per animal
- Frequency: once per day


METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: Parent daphnids were transferred into the freshly prepared test medium by means of a glass pipette. Juveniles remaining in the old test medium were counted.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Remarks on exposure duration:

water replacement one every 48 hours

Hardness:

87 mg/L (as CaCO3)

Test temperature:

20 +/- 1°C

pH:

7.6 - 8.2

Dissolved oxygen:

The dissolved oxygen was 8.1 - 9.4 mg/L which is more than 60% of the saturated dissolved oxygen concentration.

Nominal and measured concentrations:

Nominal concentrations: 0.46, 1.0, 2.2, 4.6, 10, 22 and 46 mg/L
Time weighted mean measured test concentrations (day 0 - 21): 0.343, 0.909, 2.12, 4.76, 10.2, 23.7 and 50.2 mg/L
Since the measured concentrations of the test substance concentrations deviated by more than 20% of the nominal concentration, the results were calculated based on measured values.

Details on test conditions:

TEST SYSTEM
- Test vessel: screw mouth flask
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 100 mL glass flask, 80 mL fill volume
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water of Tsukaba city
- Alkalinity: 46 mg/L
- Ca/mg ratio: 20:8.7 mg/L
- Conductivity: 350 µS/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: periodically. No more details are reported

OTHER TEST CONDITIONS
- Photoperiod: 16 h light/8 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobility/death of parent animals, mean cumulative number of births per animal after 21 days

RANGE-FINDING STUDY
- Results used to determine the conditions for the definitive study: The results of an acute toxicity test were used as a basis for setting the concetrations of the definite test

Reference substance (positive control):

no

Key result

Duration:

21 d

Dose descriptor:

LC50

Effect conc.:

> 50 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks:

of parent animals

Key result

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 50 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

reproduction

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

50 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

other: overall value

Key result

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

> 50 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

other: overall value

Details on results:

- Mortality of parent animals: none
- No. of offspring produced per day per female: 114.3 (mean value of the control)
- Body length and weight of parent animals: The sizes of the parent water fleas in all test concentrations did not differ from the control
- Time to first brood release or time to hatch: The average initial birth date in all test concentrations was between 8.0-8.5 days. The average initial birth date in the control was after 8.3 days.

Reported statistics and error estimates:

The NOEC and the LOEC were calculated by means of the Dunnett test. As no effects were observed up to the highest test concentration, both LC50 and EC 50 were determined to be higher than the highest test concentration of 50 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

The EC50, LC50 and the LOEC were above the highest test concentration of 50 mg/L. The NOEC was determined to be 50 mg/L.

Executive summary:

The effects of sorbic acid on the reproduction of Daphnia magna was tested in a semi-static test. Animals were exposed to seven different test concentrations over a period of 21 days. No effects were observed at the highest test concentration of 50 mg/L, which was statistically determined as the NOEC. Consequently, all other endpoints were determined to be above the highest test concentration.

Description of key information

One long-term daphnia study is available which was conducted with sorbic acid.  Based on effects on reproduction, the long-term NOEC of sorbic acid to Daphnia magna was determined to be above the highest test concentration of 50 mg/L, based on measured values. All other advere effects were above this test concentration as well.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

50 mg/L