(3S-cis)-3,6-dimethyl-1,4-dioxane-2,5-dione

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Recent GLP study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

L-(+)-lactic acid

EC Number:

201-196-2

EC Name:

L-(+)-lactic acid

Cas Number:

79-33-4

IUPAC Name:

2-hydroxypropanoic acid

Details on test material:

80% lactic acid, batch no ZO 3456

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Samples taken at t=0 and at end of exposure period (48 h for all concentrations except highest (24 h) since all organisms had died)
- Sampling method: 250 ml in glass bottles
- Sample storage conditions before analysis: None

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

The organism used was the fresh-water crustacean Daphnia magna, cultured in the labora- tory under standard conditons, according to the principles of NPR 6503 (ref. 3). The animals were less than 24 h old at the teginning of the test.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

None

Test conditions

Hardness:

220 mg/L CaCO3

Test temperature:

19.9 degrees C

pH:

Variable, depending on concentration of lactic acid. Control pH 8.2

Dissolved oxygen:

≥7.9 mg/L

Nominal and measured concentrations:

Nominal test material 0, 32, 56, 180, 320, 560 mg/L; nominal active substance 0, 26, 144, 448 mg/L; actual active substance <5, 15, 60-110, 340-350 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 150 mL glass beakers, open
- Renewal rate of test solution (frequency/flow rate): None
- No. of organisms per vessel:5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dutch Standard Water (reconstituted water), prepared from Linschoten ground water
- Total organic carbon: 2 mg/L
- Metals: Na 1.26 mmol/L, K 0.23 mmol/L, Ca 1.41 mmol/L, Mg 0.78 mmol/L.
- Chlorine: 2.81 mmol/L,


OTHER TEST CONDITIONS
- Adjustment of pH: NA
- Photoperiod: 16 h light, 8 h dark


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobilization


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

180 mg/L

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

250 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Effect concentrations 3

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

130 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Any other information on results incl. tables

Results are based on nominal concentrations.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 48 h EC50 (immobilization) of lactic acid to Daphnia magna is 130 mg/L

Executive summary:

The acute toxicity of the test substance, a solution of about 80% L(+) lactic acid, to the fresh-water crustacean Daphnia magna was determined as described in the OECD Guideline no. 202 (ref. 1) and according to the OECD principles of Good Laboratory Practice (ref. 2).

The test was carried out with 4 x 5 daphnias (quadruplicate test solutions) for each concen- tration, and the test solutions were not replaced. The exposure duration was 48 houre. The nominal concentrations tested were 32,56,100,180,320 and 560 mg.H.

At the start of the test the test substance appeared to be completely dissolved at all concentrations tested (visually assessed).

The actual concentrations of L(+) lactic acid were determined enzymatically with a Boehringer test kit. They were between 42% and 76% of the nominal concentrations just after dosing (average 59%). To test the stability, the concentrations of L(+) lactic acid were also analysed at the end of the test and were between 58% and 78% of the nominal concen- tration (average 71%).

The results of the test were (in nominal concentrations):

24h EC50 (mobility) 48h EC50 (mobility) 48h EC100 (mobility) 48h NOEC (mobility = 48h ECO) 48h NOEC (condition)

:240mg.l-1 :240mg.!'1 :320mg.H :180mg.H :180mg.H

The concentrations quoted in this report to the test substance (a solution of about 80% L(+) lactic acid) as supplied by sponsor.