[No public or meaningful name is available]

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

18 May - 20 May 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

For the read-across justification see section 13.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Remarks:

according to the Japanese GLP Standard

Specific details on test material used for the study:

PHYSICO-CHEMICAL PROPERTIES
- Melting point: 48 °C
- Boiling point: 225 °C
- Vapour pressure: 1 mmHg (at 121 °C)
- Water solubility: 4.81 mg/L (at 25 °C)
- log Pow: 4.2

Analytical monitoring:

yes

Details on sampling:

- Concentrations: control, nominal concentration: 0.95, 1.71, 3.09, 5.56, 10.0 and 18.0 mg/L
- Sampling method: test solution was directly sampled from each vessel at study initiation and after 24 hours exposure. Water was changed after 24 hours.
- Sample storage conditions before analysis: analysis was conducted immediately after sampling, no storage

Vehicle:

yes

Details on test solutions:

- Method: test substance was diluted in dilution water with dispersant
- Controls: dilution water with/without vehicle
- Chemical name of vehicle (dispersant): HCO-50
- Concentration of vehicle in test medium (final test solution(s) including control(s)): 100 mg/L
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no precipitate was observed

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: breed in-house (origin: Incorporated Administrative Agency, National Institute for Environmental Studies, Tsukuba, Japan)
- Age at study initiation (mean and range, SD): max 24 hours
- Feeding during test: no

ACCLIMATION
- Acclimation period for parental animals: 16 days
- Acclimation conditions (same as test or not): similar to test condition (animals per unit volume: acclimation condition: 20 - 50 animals/L, test condition: 5 animals/100 mL)
- Type and amount of food: Chlorella vulgaris, 0.1 - 0.2 mgC (organic carbon content)/day
- Health during acclimation (any mortality observed): mortality was low and no presence of males and ephippia

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

hardness of the diluted water was 25.3mg/L(CaCO3 conversion)

Test temperature:

20+/-1ºC

pH:

6.7-7.2

Dissolved oxygen:

7.6 - 8.9 mg/L (> 60 % of saturated oxygen in all testing containers)

Nominal and measured concentrations:

nominal concentration: 0.95, 1.71, 3.09, 5.56, 10.0 and 18.0 mg/L
measured concentration (geometric mean): <0.8, 1.5, 2.6, 5.6, 10.8 and 19.9 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL beaker
- Material, fill volume: glass, 100 mL
- Renewal rate of test solution (frequency): once in 24 hours
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dilution water was M4 medium

OTHER TEST CONDITIONS
- Photoperiod: 16 : 8 hours day-night regime

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

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.8
- Range finding study: performed
- Results used to determine the conditions for the definitive study: EC50 for 48 hours: 13.4 mg/L (nominal concentration), test system: static was not suitable for this substance (the testing substance concentration was significantly decreased in all concentration classes; quantifying the test substance concentration was not possible.)

Reference substance (positive control):

yes

Remarks:

potassium dichromate (reagent grade)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

3.6 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: other: 2.6 - 5.6 mg/L

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

1.5 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Mortality of control: not observed

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- EC50 for 48 hours: 0.60 mg/L

Reported statistics and error estimates:

Binominal test and probit test

Table 1: Measured concentration of lauric acid

Nominal Concentration (mg/L)	Measured Concentration (mg/L)			Percent of Nominal
	0 Hour new	24 Hour Old	Geometric Mean	0 Hour new	24 Hour old
Control	< 0.8	< 0.8	-	-	-
Dispersant Control	< 0.8	< 0.8	-	-	-
0.95	0.8	< 0.8	< 0.8	84.2	-
1.71	2.0	1.1	1.5	117	64.3
3.09	3.3	2.0	2.6	107	64.7
5.56	6.3	4.9	5.6	113	88.1
10.0	11.6	10.1	10.8	116	101
18.0	21.0	18.8	19.9	117	104

new: freshly prepared test solution

old: test solutions after 24 hours exposure period

Table 2: Immobility of Daphnia magna

Measured Concentration (mg/L)	Cumulative Number of Dead or Immobilized Daphnia (Percent Mortality or Immobility)
	24 Hour	48 Hour
Control	0 (0)	0 (0)
Dispersant Control	0 (0)	0 (0)
< 0.8	0 (0)	0 (0)
1.5	0 (0)	0 (0)
2.6	1 (5)	1 (5)
5.6	15 (75)	20 (100)
10.8	15 (75)	20 (100)
19.9	13 (65)	20 (100)

Validity criteria fulfilled:

yes

Conclusions:

Lauric acid shows toxic effects to aquatic invertebrates at 3.6 mg/L.
Thus Reaction mass of stearic acid and stearic anhydride does not has to be classified.

Description of key information

Lauric acid shows toxic effects to aquatic invertebrates at 3.6 mg/L.
Thus Reaction mass of stearic acid and stearic anhydride does not has to be classified.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

3.6 mg/L