Decanoic acid, monoester with glycerol

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:

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

Adequacy of study:

key study

Justification for type of information:

Please refer to Analogue Justification provided in section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

218.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Remarks on result:

other: Read across from CAS 85536-07-8

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

102.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Read across from CAS 85536-07-8

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

136.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Remarks on result:

other: Read across from CAS 85536-07-8

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 Aug - 24 Aug 2012

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Qualifier:

according to guideline

Guideline:

other: OECD Guidance Document No. 23 on Aquatic Toxicity of Difficult Substances and Mixtures, OECD 2000

GLP compliance:

yes (incl. QA statement)

Remarks:

LUBW Landesanstalt für Umwelt, Messungen und Naturschutz Baden-Württemberg, Karlsruhe, Germany

Analytical monitoring:

yes

Details on sampling:

- Analysis was performed in additional test vessels without Daphnia to avoid disturbance of the measurement by the organisms itself or excrements. At the start (0 h) and at the end (48 h) of the experimental phase samples (4 mL) were taken and filtered for DOC analysis with a 0.45 µm CA membrane filter (Whatman FP 30/0.45 (im). First the filter was washed with 100 mL bi-distilled water and with about 15 mL sample. For TOC the samples were measured without filtration.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Due to the sparingly soluble properties of the test item, the study was performed with WAFs ("water accommodated fraction") prepared with Daphnia medium similar to M4 described in OECD 202. The test item was weighted on a piece of polyethylene foil (rinsed with ethanol and H2O bidest. before) which was transferred together with the test item into a defined volume of Daphnia medium into a 1000 mL beaker. The suspension was stirred for 48 hours at 21 - 22 °C in the dark. For stirring a magnetic stirrer with a 2 cm stir bar was used. After stirring was stopped, the suspension was allowed to float and sediment for a period of 1 hour. After stopping the stirring the WAFs with higher loading rates were slightly turbid. After one hour sedimentation and flotation period no particles could be observed in suspension which could affect the organisms physically. The test solution was taken from the middle of the suspension in the beaker using a glass tube and transferred into the test vessels.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: German Federal Environmental Agency, Marienfelde, Department IV 2.4; current breeding is held at Hydrotox GmbH since February 2007
- Age at study initiation (mean and range, SD): 30 min - 21 h 30 min (gathered by separating the adults from the young animals twice within a period of 21 h 40 min)
- Method of breeding: Twice a week the animals are placed into fresh Elendt-Medium M4 (according to OECD 202). They are kept at approximately 10 animals / 200 mL. Daily, they are fed with a suspension of the algae Desmodesmus subspicatus in order to keep the C-content in the incubation beakers at 0.1 mg C per Daphnia and day. The C-content oft the algal suspension is measured photometrically taking a correlation between measured TOC and photometrical chlorophyll determination as basis. The Daphnia are held at 20 ± 2 °C with a light / dark cycle of 16 / 8 h.
- Feeding during test: none

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

20.9 - 21.6 °C

pH:

7.69 - 8.01

Dissolved oxygen:

7.9 - 9.2 mg O2/L

Nominal and measured concentrations:

Nominal: control, 5.8, 12.8, 28.2, 62.0, 136.4, and 300 mg/L (WAF, nominal)
Mean measured concentrations were 3.0, 15.6, 29.8 and 140.7 mg/L at nominal loading rates of 5.8, 28.2, 62 and 300 mg/L, respectively.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 50 mL glass beakers filled with 20 mL test solution
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per chemical analysis: 2

TEST MEDIUM / WATER PARAMETERS
- Culture medium different from test medium: no; similar to M4-medium accordig to OECD 202

OTHER TEST CONDITIONS
- Photoperiod: 16 h light, 8 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): After 24h and 48h, the swimming capability of Daphnia magna was determined.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2.2

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

218.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

102.6 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

136.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

mobility

Details on results:

- 100% immobilization was reported at the highest nominal loading rate of 300 mg/L, whereas no immobilization was observed at any other test concentration.
- A correlation between measured loading rates and nominal loading rates for the 62 mg/L and 300 mg/L treatment groups was made. The parameters of the curve allow calculating the measured EC50 concentration.

Results with reference substance (positive control):

EC50 (<24h) = 2.88 mg/L (95% CL: 2.55 - 3.97 mg/L).
EC50 (<48h) = 1.58 mg/L (95% CL: 1.42 - 1.73 mg/L).

Results of the accompanying analysis:

The analytical results show that only 40.2 - 61.7% of the nominal TOC concentration was found in the test solutions. That means that the test item is not completely dispersible. During the 48 hours test course almost no decrease of TOC/DOC concentration was measured. Only marginal differences between 0 h and 48 h measurements occurred. In addition, only slightly higher TOC concentrations were measured compared to the DOC concentrations. TOC content of the test item was determined with 64.3%. From this the recovery rates and the measured test item concentration in the test solution were calculated.

Table: Results from the TOC/DOC analysis of the test item concentration

	A	C	D	E
Nominal loading rate [mg/L]	300	62	28.2	5.8
DOC measured 0h [mg/L]	85.2	16.6	7.9	1.7
DOC measured 48h [mg/L]	85.2	15.1	9.3	2.2
TOC measured 0h [mg/L]	89.4	16.1	10.8	2.3
TOC measured 48h [mg/L]	91.6	22.2	9.2	1.5
TOC expected [64.3% mg/L]	192.9	39.9	18.1	3.7
Recovery 0h [%]	46.3	40.4	59.6	61.7
Recovery 48h [%]	47.5	55.7	50.7	40.2
Measured loading rate 0h [mg/L]	139.0	25.0	16.8	3.6
Measured loading rate 48h [mg/L]	142.5	34.5	14.3	2.3
Measured loading rate 0-48h [mg/L]	140.7	29.8	15.6	3.0

Table: Results of the Daphnia test

	A	B	C	D	E	F	Control
Loading Rate [mg/L]	300	136.4	62.0	28.2	12.8	5.8	0
Immobile Daphnia 24h	30%	0%	0%	0%	0%	0%	0%
Immobile Daphnia 48h	100%	0%	0%	0%	0%	0%	0%

Table: Results of the Daphnia test in detail (0 h - 48 h)

Concentration test item [mg/L]	Volume test solution [mL]	[h]	Number of immobile Daphnia / number Daphnia introduced				Immobile Daphnia total	Introduced Daphnia total	Daphnia immobile [%]
			1	2	3	4
300	20	24	1/5	1/5	2/5	2/5	6	20	30
		48	5/5	5/5	5/5	5/5	20	20	100
136.4	20	24	0/5	0/5	0/5	0/5	0	20	0
		48	0/5	0/5	0/5	0/5	0	20	0
62.0	20	24	0/5	0/5	0/5	0/5	0	20	0
		48	0/5	0/5	0/5	0/5	0	20	0
28.2	20	24	0/5	0/5	0/5	0/5	0	20	0
		48	0/5	0/5	0/5	0/5	0	20	0
12.8	20	24	0/5	0/5	0/5	0/5	0	20	0
		48	0/5	0/5	0/5	0/5	0	20	0
5.8	20	24	0/5	0/5	0/5	0/5	0	20	0
		48	0/5	0/5	0/5	0/5	0	20	0
Control		24	0/5	0/5	0/5	0/5	0	20	0
		48	0/5	0/5	0/5	0/5	0	20	0

Additional information

Since no studies investigating the short-term toxicity of Esterification product of glycerol and C8-C12 (even numbered) fatty acids (no CAS) to aquatic invertebrates are available, in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5, a read-across to the structurally related source substance Glycerides, C8-10 mono- and di- (CAS 85536-07-8) was conducted. The source substance is representative to evaluate the short-term toxicity of the target substance to aquatic invertebrates.

The target substance Esterification product of glycerol and C8-C12 (even numbered) fatty acids” (no CAS) is a UVCB substance characterized by the alcohol component glycerol which is esterified with C8, 10 and 12 fatty acids.

The source substance C8-10 mono- and di- (CAS 85536-07-8) is a UVCB substance characterized by the alcohol component glycerol which is esterified by C8 and 10 fatty acids.

This read-across is justified in detail within the analogue justification in IUCLID section 13. In this case of read-across, the best suited (highest degree of structural similarity, nearest physico-chemical properties) read-across substance was used for the assessment.

The study with the source substance Glycerides, C8-10 mono- and di- (CAS 85536-07-8) was performed according to OECD 202. The test was performed under GLP conditions. Daphnia magna were exposed to five different loading rates (5.8, 12.8, 28.2, 62.0, 136.4, and 300 mg test material/L; WAF, nominal) over a period of 48 h in a static freshwater system.

Due to the low water solubility of the test material, WAFs ("water accommodated fraction") prepared with test medium were used to prepare the five test material loading rates.

After 24 and 48 h, the mobility of Daphnia magna was assessed. The EL50 (48 h) was determined to be 102.6 mg/L. Immobility was only observed in the highest loading rate, not in the loading rates below or in the control group.

Based on the structurally related read-across substance (in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5) which is characterized by a similar ecotoxicological profile and comparable structure, it can be concluded that a similar toxicity range to aquatic invertebrates can be expected for the target substance Esterification product of glycerol and C8-C12 (even numbered) fatty acids (no CAS).