3-methylbutyl butyrate

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:

2015-08-26 to 2015-08-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

2004

GLP compliance:

yes (incl. QA statement)

Remarks:

dated 2013-11-05

Analytical monitoring:

yes

Details on sampling:

Concentrations: All concentration levels and the control were analytically verified via SPME-GC-FID at the start (0 and 24 hours) and at the end of the exposure (24 and 48 hours)

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution (100 mg of the test item in 1L ISO test water) was prepared and stirred at approximately 1100 rpm for 3 hours
- Controls:ISO test water without test item

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS
- Strain/clone: Clone 5
- Source: Institute for Water, Soil and Air quality (WaBoLu) in Berlin, Germany
- Feeding during test: No
- Food type: A mix of unicellular algae (e.g., Pseudokirchneriella subcapitata)
- Frequency: At least 5 times per week
- Culture medium: Modified Elendt M4 medium according to Elendt (1990)

ACCLIMATION
- Age at study initation: 2 - 24 hours
- Acclimation period: At least 2 hours in ISO test water
- Acclimation conditions (same as test or not): Same as test

Test type:

semi-static

Water media type:

other: ISO test water according to OECD 202

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

Renewal of test item after 24 hours

Hardness:

262 - 267 mg CaCO3/L start of exposure intervals

Test temperature:

20.3 - 20.5 °C start of exposure intervals

pH:

7.66 - 8.18 start of exposure intervals
7.14 - 7.89 end of exposure intervals

Dissolved oxygen:

8.54 - 8.77 mg/L start of exposure intervals
4.74 - 8.43 mg/L end of exposure intervals

Conductivity:

657 - 672 µS/cm start of exposure intervals

Nominal and measured concentrations:

Nominal concentrations: 0 (control), 6.25, 12.5, 25.0, 50.0, 100 mg/L
Measured concentrations: 0 (control), 3.88, 7.90, 16.3, 35.0, 74.6 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass flasks
- Type: closed
- Material, size, headspace, fill volume: approx. 130 mL test volume without headspace
- Aeration: none
- Renewal rate of test solution (frequency/flow rate): one time after 24 hours each
- 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: ISO test water according to OECD 202 (2004)
- Conductivity: 672 µS/cm (0 hours), 657 µS/cm (24 hours)
- Culture medium different from test medium: yes (culture medium: Elendt M4; test medium: ISO test water)

OTHER TEST CONDITIONS
- Adjustment of pH: none
- Photoperiod: 16/8 hours light/dark cycle
- Light intensity: Diffuse light (max. 1340 lx)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
- Number of immobile daphnids after 24 hours and 48 hours

RANGE-FINDING STUDY
- Test concentrations: 1.00, 10.0 and 100 mg/L
- Results used to determine the conditions for the definitive study: Considering 100% immobilisation of the daphnids at 100 mg/L and 0% immobile daphnids below this value, more test concentrations between 10 and 100 mg/L were used, namely 6.25, 12.5, 25, 50 and 100 mg/L

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

48 h

Dose descriptor:

EC10

Effect conc.:

7.36 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence interval: 6.85 - 7.55 mg/L

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

8.12 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% confidence limits: 7.99 - 8.26 mg/L

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

16.3 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

3.88 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

The EC50 value of 2.00 mg/L of the reference item potassium dichromate after 24 hours was within the prescibed concentration range of 0.6 - 2.4 mg/L of quality criteria according to AQS P 9/2 (2000) for daphnids cultured in M4 medium. The EC50 value was also within the recommended range of 0.6 - 2.1 mg/L according to OECD 202 (2004).

Table 1: Results after 24 and 48 hours exposure

Nominal concentration (mg/L)	Geometric mean measured concentration (mg/L)	Immobilisation (%)		Temperature (°C) after 24 hours	Dissolved oxygen concentration (mg/L) after 48 hours (arithmetic mean)	pH value after 48 hours (arithmetic mean)
		24 hours	48 hours
0 (control)	0 (control)	0	0	20.5	8.00	7.85
6.25	3.88	0	0	-	8.19	7.87
12.5	7.90	10	35	-	7.96	7.82
25.0	16.3	70	100	-	6.58	7.58
50.0	35.0	40	100	-	7.16	7.65
100	74.6	100	100	-	-	-

 

Validity criteria fulfilled:

yes

Conclusions:

An Acute Immobilisation Test with Daphnia magna was carried out according to OECD 202 and under GLP conditions to determine the effect values (e.g., EC50) of the test substance after 24 and 48 hours exposure. After 48 hours exposure, an EC50 value of 8.12 mg/L (geometric mean measured) was calculated.

Description of key information

EC50: 8.12 mg/L (geometric mean measured).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

8.12 mg/L

Additional information

The toxicity of Isoamyl butyrate on Daphnia magna was determined in a reliable GLP study according to OECD 202. Individual of D. magna were exposed to 0 (control), 6.25, 12.5, 25.0, 50.0, 100 mg/L of the test substance, equivalent to geometric mean measured concentrations of 0 (control), 3.88, 7.90, 16.3, 35.0, 74.6 mg/L for 48 hours. Concentrations were analytical verified via SPME-GC-FID. After 48 hours exposure, an EC50 value of 8.12 mg/L (geometric mean measured) was estimated.