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

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

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 203 (Fish, Acute Toxicity 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% aqueous solution of lactic acid.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: measured at 24 (fresh solutions) and 48 hours (spent solutions)
- Sampling method: separation of 250 ml from the bulk of the solution
- Sample storage conditions before analysis: NA

Test solutions

Details on test solutions:

Dilutions with water of a stock solution of 1000 mg/L (test material in water).

Test organisms

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

The organism used was the fresh-water fish species Brachydanio rerio from the commer- cial hatchery M.B. Ruysbroek B.V.(Noordvliet 159,Maassluis). The average total length and weight (± standard deviation) were 2.l ±0.17 cm and 0.07 ± 0.018 g respectively.

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 d

Post exposure observation period:

None

Test conditions

Hardness:

220 mg CaCO3 L-1

Test temperature:

ca. 24.5 degrees C

pH:

Dependent on lactic acid concentration. pH of medium 8.0. pH of highest test concentration 3.25

Dissolved oxygen:

≥ 7.3 mg L-1

Salinity:

Dutch Standard Water (the test medium) is a fresh reconstituted water.

Nominal and measured concentrations:

Nominal lactic acid 0, 80 144, 256 mg/L; actual 0-5, 45-60, 105-110, 180-210 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 2000 mL glass beakers, 1500 mL medium
- Aeration: only before adding fish
- Renewal rate of test solution (frequency/flow rate): once a day
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.7g / 1500 mL


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: DSWL
- Total organic carbon: 2 mg/L
- Metals: Na 1.26 mmol/L, K 0.23 mmol/L, Ca 1.41mmol/L , Mg 0.71 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) : mortality


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Justification for using less concentrations than requested by guideline: expected effect concentration significantly higher than C&L limit.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

180 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 2

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

320 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 3

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

195 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Details on results:

No relevant details

Results with reference substance (positive control):

NA

Any other information on results incl. tables

Sublethal observations / clinical signs:

Results are based on nominal concentrations.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Lactic acid LC50 to D. rerio = 195 mg/L

Executive summary:

The acute toxicity of the test substance, a solution of about 80% L(+) lactic acid, to the fresh-water fish species Brachydanio rerio was determined as described in the OECD Guideline no. 203 (ref. 1) and accotding to the OECD principles of Good Laboratory Prac- tice (ref. 2).

The test was carried out as a semi-static test with daily replacement of the test solutions and with 10 fishes for each concentration. The exposure duration was 96 houirs. The nominal concentrations tested were 100,180,320,560 and 1000 mg.H.

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 70% and 77% of the nominal concentrations just after dosing (average 74%). To test the stability the concentrations of L(+) lactic acid were also analysed just before renewal and were between 56% and 82% of the nominal concen- tration (average 70%).

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

48hLC50(mortality) 96hLC50(mortality) 96h LC100 (mortality) 96hNOEC(mortality =96hLCO) 96h NOEC (condition)

: 320 : 320 :560 :320 :320

mg.H mg.!'1 mg.H mg.1'1*) mg.1'1

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