Octanoic acid, compound with dicyclohexylamine (1:1)

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

not specified

GLP compliance:

not specified

Analytical monitoring:

yes

Vehicle:

not specified

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

not specified

Limit test:

no

Total exposure duration:

48 h

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

8 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Validity criteria fulfilled:

yes

Conclusions:

An 48-hour EC50 immobilization value of 8 mg/L was found for the crustacea Daphnia magna (water flea).

Executive summary:

An 48-hour EC50 immobilization value of 8 mg/L was found for the crustacea Daphnia magna (water flea).

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 Nov -17 Nov 1989

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)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: stock solution (10 g/100 mL) was prepared while using ultrasound, aliquots were pipetted into test vessel and filled up with standard dilution water
- Controls: 1

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water-flea
- Source: in-house culture
- Feeding during test: none

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

14 °dH (80 mg Ca and 12.2 mg Mg/L)

Test temperature:

20.5 - 21.0 °C (room temperature)

pH:

4.7 - 8.1, this is out of the recommended range of 6 - 9

Dissolved oxygen:

76 - 85 %

Nominal and measured concentrations:

nominal: 10, 30, 100, 300, 1000, 3000, 10000 mg/L

Details on test conditions:

TEST SYSTEM
- Material, size, headspace, fill volume of test vessel: glass beakers, covered with glass plates
- No. of organisms per vessel: 20
- No. of vessels per concentration: 1
- No. of vessels per control: 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: deion. water with 294 mg CaCl2 * 2 H2O, 123 mg MgSO4 * 7 H2O, 63 mg NaHCO3, 5.5 mg KCl

OTHER TEST CONDITIONS
- Photoperiod: 16 h

EFFECT PARAMETERS MEASURED: immobility after 48 h

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

300 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

550 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: at concentrations of 1000, 3000 and 10000 mg/L all daphnids were unable to swim. At 100 mg/L, 5 % were unable to swim

Table 1: Immobilisation of daphnids [%] after 48 h

Nominal test concentration [mg a.s./L]	Immobilisation [%]
0 (control)	0
10	0
30	0
100	5
300	0
1000	100
3000	100
10000	100

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of Octanoic acid to Daphnia magna was determined using a screening method similar to OECD Guideline 202. The number of daphnids per concentration were 20 and the substance concentration was not followed by chemical analysis. The product was tested in a concentration range of 10 to 10000 mg active matter /l (nominal). The incubation period was 48 hours under static conditions (the test-solutions were not renewed). Following results were obtained:
EC0 : 300 mg active matter /l
EC50 : 550 mg active matter! l
EC100 : 1000 mg active matter / l

Executive summary:

The acute toxicity of Octanoic acid to Daphnia magna was determined using a screening method similar to OECD Guideline 202. The number of daphnids per concentration were 20 and the substance concentration was not followed by chemical analysis. The product was tested in a concentration range of 10 to 10000 mg active matter /l (nominal). The incubation period was 48 hours under static conditions (the test-solutions were not renewed). Following results were obtained:

EC0 : 300 mg active matter /l

EC50 : 550 mg active matter! l

EC100 : 1000 mg active matter / l

Description of key information

DCHA:

An 48-hour EC50 immobilization value of 8 mg/L was found for the crustacea Daphnia magna (water flea).

Octanoic acid:

The acute toxicity of Octanoic acid to Daphnia magna was determined using a screening method similar to OECD Guideline 202.

Following results were obtained:

EC0 : 300 mg active matter /l

EC50 : 550 mg active matter! l

EC100 : 1000 mg active matter / l

Since the substance to be registered is Octanoic acid, compound with dicyclohexylamine (1:1) which will dissociate to 1 mol octanoic acid and 1 mol dicyclohexylamine, the lowest EC50 of 8 mg/l for dicyclohexylamine is used for calculating the EC50 for the entire substance considering the molar mass of 325.5 g/mol (55.7% dicyclohexylamine).

Therefore the EC50 for freshwater invertebrates for Octanoic acid, compound with dicyclohexylamine (1:1) is 14.4 mg/ml.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

14.4 mg/L

Additional information

Read Across justification:

In aqueous systems Octanoic acid, compound with dicyclohexylamine (1:1) is hydrolytically very unstable so that in aqueous solution a rapid decomposition to the educts can be observed. The substance will rapidly dissociate to octanoic acid and dicyclohexylamine. Therefore Octanoic acid, compound with dicyclohexylamine (1:1) is not stable at “standard” testing conditions representative for human and environmental exposure. Hence, it is fully justified to apply the read-across methodology by use of the respective data from the breakdown/decomposition products to describe the (eco)toxicological behaviour of the substance to be registered.