Fatty acids, coco, iso-Bu esters

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

06 - 27 Sept 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP-Guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: OECD 202 of 1984 and additional suggestions for OECD 202 part 2 of 1993

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Two stock solutions with nominal concentrations of 1 and 100 mg/L M4 medium; 16 h to 7 d magnetic stirring; suspensions were filtered via glas fibre filter (pre-treated with NaOH)

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: in-house culture, originally obtained from BGA Berlin, May 1994
- Feeding during test: yes
- Food type: Scenedesmus subspicatus
- Amount: 0-7 d old animals: 2.5*10E6 cells/daphnid/d; >7d old animals: 5.0*10E6 cells/daphnid/d
- Frequency: daily

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Post exposure observation period:

not relevant

Test temperature:

21.6 - 23.2°C

pH:

7.7 - 8.2

Dissolved oxygen:

84 - 100% saturation (90-100% in control; 84-97% in 1 mg/L; 86-98% in 100 mg/L)

Nominal and measured concentrations:

nominal: 0, 1 and 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL Erlenmeyer flask
- Type: closed with watchglass
- Material, size, headspace, fill volume: 50 mL test solution
- Renewal rate of test solution (frequency/flow rate): every 2 to 3 days
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light, 8 hours dark
- Light intensity: 300 Lux

EFFECT PARAMETERS MEASURED: number of offspring per daphnid

Reference substance (positive control):

no

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: filtered test solution

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

other: filtered test solution

Basis for effect:

reproduction

Details on results:

- Mortality of parent animals: 0%
- No. of offspring produced per day per female: 4.3 daphnids/day in the control; 4.1 daphnids/day in 1 mg/L TS and 4.0 daphnids/day in 100 mg/L test substance
- Time to first brood release or time to hatch: 7 days after test begin in the control

Table 1: Reproduction and mortality after 21 days:

Concentration (mg/L)	Average reproduction (offspring/daphnid/day)	Mortality (%)
0	4.3	0
1	4.1	0
100	4.0	0

Reference 2

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

06 Oct - 28 Oct 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study with restrictions. Insoluble test substance was visible during the test.

Qualifier:

according to guideline

Guideline:

other: OECD 202, adopted 04 Apr 1984

Qualifier:

according to guideline

Guideline:

other: DIN method proposal, adopted 22 Nov 1990

Qualifier:

according to guideline

Guideline:

other: method proposal for OECD 202, part 2, adopted Jun 1993

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Stock solutions of the test substance were produced in M4 medium at nominal concentrations of 1 and 100 mg/L. The stock solutions were continuously stirred for at least 16 h and up to 5 days. These suspensions were carefully filtrated through a NaOH pretreated glass fibre filter. The aqueous phases saturated with test substance were then used in the test without further dilution.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: Straus 1820
- Source: Laboratory breed at TTB-Ökologie, Henkel KGaA, received from BGA Berlin May 1994
- Food type: Scenedesmus subspicatus
- Amount: age 0 - 7 days: 2.5E06 cells/daphnid, age > 7 days: 5.0E06 cells/daphnid
- Frequency: daily

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

no data

Test temperature:

20.9 - 22.1 °C

pH:

7.8 - 8.3

Dissolved oxygen:

90 - 100% saturation

Nominal and measured concentrations:

Nominal: 0, 1 and 100 mg/L
Measured at 0, 24, 48 and 72 h: < 0.01 mg/L (LOQ)

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flask
- Type (delete if not applicable): closed (covered with watchglass)
- Material, size, fill volume: glass, 100 mL, 50 mL
- Renewal rate of test solution (frequency/flow rate): every 2 - 3 days
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: M4-medium according to guideline (no information about the water used)

OTHER TEST CONDITIONS
- Photoperiod: 16 h light/8 h darkness
- Light intensity: approx. 300 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Reproduction rate, mortality and other toxic effects

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 100
- Range finding study
- Test concentrations: nominal 100 mg/L
- Results used to determine the conditions for the definitive study: no negative effects were observed at 100 mg/L

Duration:

21 d

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

other: reproduction and mortality

Remarks on result:

other: measured concentration < 0.01 mg/L

Duration:

21 d

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

other: reproduction and mortality

Remarks on result:

other: measured concentration < 0.01 mg/L

Details on results:

- Mortality of control: No mortality was observed in the control
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: The stock solution at 100 mg/L was turbid.
- Effect concentrations exceeding solubility of substance in test medium: yes

No negative effects were observed in the range of water solubility of the test substance.

Table: Reproduction and mortality of D. magna exposed to the test substance for 21 days. The reproduction rate is given per surviving parent animal counted from the first appearance of neonates in the control (9 days after test start).

Concentration (mg/L)	Average Reproduction Rate (Neonates/daphnid*day)	Mortality (%)
0	5.8	0
1	5.8	0
100	7.0	10

Reference 3

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The target substance FATTY ACIDS, COCO, ISO-BU ESTERS (CAS 91697-43-7) and the source substance FATTY ACIDS, C16-18, ISOBUTYL ESTERS (CAS 85865-69-6) are both Short Chain Alcohol Esters (SCAE C2-C8) composed by a fatty acid (C16-C18) and a C4 alcohol (isobutanol).
The source and the target substance show therefore the same reactive groups and a similar composition. A read-across to the source is therefore justified.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Both target and source substances are fatty acid esters produced by chemical reaction of an alcohol (isobutanol) with organic acids (e. g. stearic acid) in the presence of an acid catalyst. The esterification reaction is started by a transfer of a proton from the acid catalyst to the acid to form an alkyloxonium ion. The carboxylic acid is protonated on its carbonyl oxygen followed by a nucleophilic addition of a molecule of the alcohol to a carbonyl carbon of acid. An intermediate product is formed. This intermediate product loses a water molecule and proton to give an ester. Monoesters are the final product of esterification.

3. ANALOGUE APPROACH JUSTIFICATION
Since both target and source substances are fatty acid esters produced by chemical reaction of an alcohol (isobutanol) with an organic acid and therefore share similar/overlapping structural features and functional groups, it is justified to use a read across approach. The source substance has been registered already and its long term toxicity to aquatic invertebrates has been investigated using a grouping of substance and read across approach. It has been concluded that no toxicological long-term effects on aquatic invertebrates are expected up to the limit of water solubility for of Fatty acids, C16-18, isobutyl esters (CAS No. 85865-69-6).
The same behaviour is predicted for the target substance FATTY ACIDS, COCO, ISO-BU ESTERS (CAS 91697-43-7) .

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Conclusions:

No toxicological long-term effects on aquatic invertebrates are expected up to the limit of water solubility for of Fatty acids, C16-18, isobutyl esters (CAS No. 85865-69-6)

Executive summary:

Since both target and source substances are fatty acid esters produced by chemical reaction of an alcohol (isobutanol) with an organic acid and therefore share similar/overlapping structural features and functional groups, it is justified to use a read across approach. The source substance has been registered already and its long term toxicity to aquatic invertebrates has been investigated using a grouping of substance and read across approach. It has been concluded that no toxicological long-term effects on aquatic invertebrates are expected up to the limit of water solubility for of Fatty acids, C16-18, isobutyl esters (CAS No. 85865-69-6).

The same behaviour is predicted for the target substance FATTY ACIDS, COCO, ISO-BU ESTERS (CAS 91697-43-7) .

Description of key information

No effects up to the limit of water solubility for Daphnia magna (OECD 202 part 2)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

.