Decanoic acid, mixed esters with heptanoic acid, octanoic acid and trimethylolpropane

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:

17 - 19 Jan 2007

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Water Accommodated Fraction (WAF): This WAF was prepared by moderately stirring 100 mg test substance per liter of medium overnight followed by filtration (MILLIPORE AP15 glass fiber filter).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: Straus
- Length at study initiation (length definition, mean, range and SD): < 2mm
- Method of breeding: Parental and young Daphnia were held in 40L glass aquaria.

BREEDING
- Breeding conditions (same as test or not): Reconstituted water (ISO 6341) was the same as test, prepared with distilled water. The medium in the breeding system was continuously aerated in comparison to the test.
- Type and amount of food: 15 g sera micropan (sera GmbH, Heinsberg) homogenized in 1L deionized water
- Feeding frequency: Once a day, except weekends

ACCLIMATION
- Acclimation period: Daphnia, which had been selected in size, were acclimatized to the reconstituted water for 4 hours before introduction into the test media.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test temperature:

20.0 ± 0.5 °C

pH:

control: 7.3 at 0h, 7.7 at 48h
100 mg/l: 7.5 at 0h, 7.7 at 48h

Dissolved oxygen:

control: 6.2 mg/l at 0h, 6.0 mg/l at 48h
100 mg/l: 6.0 mg/l at 0h, 5.9 mg/l at 48h

Nominal and measured concentrations:

nominal: 100 mg/L (WAF)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 100 mL flasks, all-glass, with 50 mL of test medium
- Aeration: no
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water (ISO 6341), prepared with distilled water. The ratio of Ca:Mg ions is 4:1 and of Na:K ions is 10:1.
- Alkalinity: 0.8 mmol/L
- Ca/mg ratio: 4:1
- Culture medium different from test medium: No, but test medium was not aerated as the culture medium.
- Intervals of water quality measurement: Temperature determined in a control flask at the start and at the end of the test. Oxygen and pH were determined in all vessels prior to the addition of Daphnia to the test medium and at the end of the test.

OTHER TEST CONDITIONS
- Photoperiod: 16 h a day, supplied by overhead white fluorescent tubes.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Observations of immobile Daphnia were made after 24 and 48 h of exposure

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EL0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

The test substance show no acute toxicity for daphnids under test conditions.

Table 1: Immobilisation of Daphnia magna after 24 and 48 hours

Nominal concentration (mg/l)	Code	Number of individuals per test vessel	Immobile Daphnia (No./vessel) 24h	Immobile Daphnia (No./vessel) 48h	% immobile Daphnia after 24h of exposure	% immobile Daphnia after 48h of exposure
Control 0	A B C	20 20 20	0 1 0	0 1 0	0 5 0	0 5 0
100	A B	20 20	0 1	1 1	0 5	5 5

 

Description of key information

No relevant studies are available for decanoic acid, mixed esters with heptanoic acid, octanoic acid and trimethylolpropane. A study is available for closely related structural analogue, CAS 11138-60-6.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

There are no relevant studies available for the test substance.

A study investigating the short-term toxicity to aquatic invertebrates of the closely related structural analogue, decanoic acid, ester with 2-ethyl-2-(hydroxymethyl)-1,3-propanediol octanoate (CAS-No. 11138-60-6), is available. This study was conducted with Daphnia magna and according to OECD 202. The results provided an EL 50 (48h) > 100 mg/L (WAF loading rate).

A report justifying the read-across approach is included in IUCLID Chapter 13.