Reaction products of 7-hydroxy-3,7-dimethyloctanal and methyl 2-aminobenzoate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June - December 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 7346-1 (Determination of the Acute Lethal Toxicity of Substances to a Freshwater Fish [Brachydanio rerio Hamilton-Buchanan (Teleostei, Cyprinidae)] - Part 1: Static Method)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Description: Yellow viscous liquid
Batch: SC00010629
Purity/Composition: UVCB substance

Analytical monitoring:

yes

Details on sampling:

Samples for Total Organic Carbon (TOC) analysis were taken at the start, after 24 hours and at the end of the test.

Vehicle:

no

Details on test solutions:

Information provided by the Sponsor indicated that the test item is a complex mixture (UVCB) composed of constituents with different water solubility. Therefore the test item was prepared as a Water Accommodated Fraction (WAF). Weighing of test substance and preparation of test solutions was performed under dimmed light. No correction was made for the purity/composition of the test substance.
All test solutions were prepared separately. Various loading rates of the test substance were added to test medium and magnetically stirred for one day. The resulting aqueous mixtures were left to stabilize for 1-1.5 hours where after the clear and colourless WAFs were taken out by siphoning and used for testing.
WAFs were prepared at loading rates of 10, 18, 32, 56 and 100 mg/l

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Species: Carp (Cyprinus carpio)
Source: Zodiac, proefacc, ''De Haar Vissen'', Wageningen University and Research Centre, The Netherlands
Mean length: 2.2± 0.2 cm
Mean weight: 0.28± 0.07g
Characteristics: F1 from single parent-pair in UV-treated water

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

Not applicable

Hardness:

180 mg CaCO3/L

Test temperature:

21.1 - 21.9 oC

pH:

7.4-8.0

Dissolved oxygen:

6.0 - 9.0 mg/L

Salinity:

Not applicable

Nominal and measured concentrations:

A correction was made for the measured amount of TOC in the control. The initial concentrations in samples taken from the WAFs prepared at loading rates of 10, 18, 32, 56 and 100 mg/l were calculated to be 8.2, 14, 24, 40 and 66 mg/l. These concentrations remained stable during the exposure period (96-98% of initial at the end of the test).

Details on test conditions:

The test was conducted over 96 hours with static test conditions. Test vessels were 9.5 litre glass vessels containing 8 litres of test solution. The test medium was adjusted ISO medium with a hardness of 180 mg CaCO3/L and a pH of 7.7 ±0.3. Each test concentration contained 7 fish. The photoperiod during testing was 16 hours light to 8 hours dark. Fish were not fed during the test period.

Reference substance (positive control):

yes

Remarks:

pentachlorophenol

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

75 mg/L

Nominal / measured:

nominal

Conc. based on:

dissolved

Basis for effect:

mortality (fish)

Details on results:

The initial concentrations in samples taken from the WAFs prepared at 10, 18, 32, 56 and 100 mg/l were calculated to be 8.2, 14, 24, 40 and 66 mg/l. These concentrations remained stable during the exposure period (96-98% of initial at the end of the test).
After 96 hours of exposure all fish exposed to the highest test concentration had died. No mortality or clinical effects were observed at any of the lower test concentrations during the test period. The responses recorded in this test allowed for reliable determination of an LL50.

Results with reference substance (positive control):

Under the conditions of the present test PCP induced no lethal effects in carp at 0.10 mg/l. The 96h-LC50 for carp exposed to PCP was 0.24 mg/l. This effect was already reached within 48 hours of exposure. This falls in the range of sensitivities generally observed for carp.

Reported statistics and error estimates:

The 72 and 96h-LL50-values were calculated from the probits of the percentages of dead fish and the logarithms of the corresponding test substance loading rates using linear maximum likelihood regression. No confidence intervals could be given as the calculations were based on two concentrations.
ToxRat Professional v 2.10.05 (ToxRat Solutions® GmbH, Germany) was used to perform the analyses.

Sublethal observations / clinical signs:

Table 1: Fish mortality results with Aurantiol Pure

Loading rate Aurantiol Pure (mg/L)	Initial number of fish	Cumulative mortality					Total mortality (%)
		2.5h	24h	48h	72h	96h
Control	7	0	0	0	0	0	0
10	7	0	0	0	0	0	0
18	7	0	0	0	0	0	0
32	7	0	0	0	0	0	0
56	7	0	0	0	0	0	0
100	7	0	0	0	4	7	100

Table 2: Measured TOC during final test

Time of sampling (hours)	Loading rate (mg/L)	Measured organic carbon (mg/L)	Calculated Conc. Aurantiol Pure (mg/L)	Relative loading rate (%)	Relative to initial (%)
0	0	0.01796
	10	5.603	8.2	82
	18	9.822	14	80
	32	16.43	24	75
	56	27.33	40	72
	100	45.09	66	66
24	0	0.02897
	10	5.533	8.1	81	99
	18	9.670	14	79	98
	32	16.41	24	75	100
	56	27.04	40	71	99
	100	44.59	65	65	99
96	0	0
	10	5.449	8.0	80	98
	18	9.560	14	78	98
	32	15.72	23	72	96
	56	26.44	39	69	97
	100	44.39	65	65	98

Validity criteria fulfilled:

yes

Conclusions:

Given that toxicity cannot be attributed to a single component or a mixture of components but to the test item as a whole, the effect parameters were based on nominal loading rates. The study met the acceptability criteria prescribed by the protocol and was considered valid. The 96h-LL50 was 75 mg/L.

Executive summary:

A study was conducted to determine the toxicity of Aurantiol Pure to Carp (Cyprinus carpio) according to OECD Guidenline 203. Information provided by the Sponsor indicated that the test item is a complex mixture (UVCB) composed of constituents with different water solubility. Therefore the test item was prepared as a Water Accommodated Fraction (WAF). Weighing of test substance and preparation of test solutions was performed under dimmed light.

A final test was performed based on the results of a preceding range-finding test. All test solutions were prepared separately. Various loading rates of the test substance were added to test medium and magnetically stirred for one day. The resulting aqueous mixtures were left to stabilize for 1-1.5 hours where after the clear and colourless WAFs were taken out by siphoning and used for testing. Seven fish per test group were exposed to a control and to WAFs prepared at loading rates of 10, 18, 32, 56 and 100 mg/l. The total exposure period was 96 hours and samples for Total Organic Carbon (TOC) analysis were taken at the start, after 24 hours and at the end of the test.

The concentration of the test substance in the aquatic samples was calculated using the TOC content of pure test substance (i.e. 68.20%). A correction was made for the measured amount of TOC in the control. The initial concentrations in samples taken from the WAFs prepared at loading rates of 10, 18, 32, 56 and 100 mg/l were calculated to be 8.2, 14, 24, 40 and 66 mg/l. These concentrations remained stable during the exposure period (96-98% of initial at the end of the test).

Given that toxicity cannot be attributed to a single component or a mixture of components but to the test item as a whole, the effect parameters were based on nominal loading rates. The study met the acceptability criteria prescribed by the protocol and was considered valid. The 96h-LL50 was 75 mg/L.

Description of key information

Methyl anthranilate is being used as an assessment entity for the purposes of the environmental risk assessment of the registered UVCB substance. The rationale for using this substance is provided in the "Assessment Entities" endpoint. The acute toxicity of methyl anthranilate in a static system against the fry of four species of fish has been tested. The lowest 96h LC50 value of 9.12 mg/L has been chosen for derivation of PNECaquatic for this assessment entity.

Additional information

For the purpose of classification and labelling, data on the whole substance is considered. A study was conducted to determine the toxicity of Aurantiol Pure to Carp (Cyprinus carpio) according to OECD Guidenline 203. Since the substance is a complex mixture (UVCB) composed of constituents with different water solubility, the test item was prepared as a Water Accommodated Fraction (WAF). Weighing of test substance and preparation of test solutions was performed under dimmed light. A final test was performed based on the results of a preceding range-finding test. All test solutions were prepared separately. Various loading rates of the test substance were added to test medium and magnetically stirred for one day. The resulting aqueous mixtures were left to stabilize for 1-1.5 hours where after the clear and colourless WAFs were taken out by siphoning and used for testing. Seven fish per test group were exposed to a control and to WAFs prepared at loading rates of 10, 18, 32, 56 and 100 mg/l. The total exposure period was 96 hours and samples for Total Organic Carbon (TOC) analysis were taken at the start of the test, after 24 hours and at the end of the test.

The concentration of the test substance in the aquatic samples was calculated using the TOC content of pure test substance (i.e. 68.20%). A correction was made for the measured amount of TOC in the control. The initial concentrations in samples taken from the WAFs prepared at loading rates of 10, 18, 32, 56 and 100 mg/l were calculated to be 8.2, 14, 24, 40 and 66 mg/l . These concentrations remained stable during the exposure period (96-98% of initial at the end of the test).

Given that toxicity cannot be attributed to a single component or a mixture of components but to the test item as a whole, the effect parameters were based on nominal loading rates. The study met the acceptability criteria prescribed by the protocol and was considered valid. The 96h-LL50 was 75 mg/L.