Hyoscine

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006-08-03 to 2006-09-08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The read-across justification is included as attachment to Iuclid section 13.

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

For determination of the test item concentrations, duplicate samples were taken from the freshly prepared test media of all test concentrations and the control at the first treatment period (Day 0), at a treatment period in the second week (Day 7), and at a treatment period in the last week (Day 17).To determine the maintenance of the test item concentrations during the test medium renewal periods, the following stability control samples were taken at the end of two treatment periods (on days 10 and 19):a) from the test media of all test concentrations and the control incubated during the renewal periods under the same conditions as the test itself, however without food particles and test animalsb) from the test media of all test concentrations and the control of the actual test (containing the food particles) by pouring together the contents of the test beakers after the end of the treatment periodAll samples were deep-frozen (at about -20°C) immediately after sampling. Based on pre-experiments (without GLP) for investigation of the storage stability, the test item is stable in the test water under these storage conditions. The concentrations of the test item hyoscine butylbromide were analyzed in the test media samples from the nominal concentrations of 32 and 100 mg/L, determined in the experiment as the NOEC and the LOEC. The test concentrations below the NOEC were not analyzed, because they were not relevant for the interpretation of the biological results.The samples from the start of the renewal periods were analyzed in duplicate. From the samples taken at the end of the renewal periods, one sample without food and one sample containing food were analyzed. From the control samples one of the duplicate samples was analyzed from each of all sampling dates.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)- Method: The test medium of the highest nominal test concentration of 100 mg/L was freshly prepared by dissolving 150 mg of the test item completely in 1500 ml of test water by intensive stirring for 10 minutes. The test medium of the highest test concentration was diluted with test water to prepare the test media of the lower test concentrations. The test media were freshly prepared just before introduction of the daphnids and just prior to each test medium renewal. The actual concentrations of the test item in the test media were analytically determined. The test concentrations were based on the results of a range finding test.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Species: Daphnia magna Straus
- Common name: water flea
- Source: was originally supplied by the University of Sheffield/UK in 1992
- Sex: female
- Age of parental stock (mean and range, SD): 14 days to 4 weeks
- Age at study initiation (mean and range, SD): 24 hours or less
- Feeding during test: yes
- Food type: green algae of the species Scenedesmus subspicatus and fish food suspension
- Amount of food: 0.1 - 0.25 mg TOC/daphnia (The amount was changed within this range depending on the growth stage of water fleas)
- Feeding frequency: three times a week
STOCK ANIMAL
- Each stock animal was maintained separately in a 100 mL glass beaker filled with about 80 mL culture medium and was transferred twice a week to fresh medium. The health of stock animals was frequently checked. No signs of stress were observed and the brood stock was healthy.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

21 d

Hardness:

250 mg/L as CaCO3 (2.5 mmol/L)

Test temperature:

18 - 22°C

pH:

7.2 to 8.0

Dissolved oxygen:

at least 8.0 mg/L

Nominal and measured concentrations:

nominal: 1.0, 3.2, 10, 32 and 100 mg/L measured: 88 to 103% of the nominal value at the start of the test medium renewal periodsmeasured: 90 to 99% of the nominal value at the end of test medium renewal periods

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 ml glass beaker containing 80 mL of test medium
- Renewal rate of test solution (frequency/flow rate): every 48 hours (or 72 hours over week-ends)
- No. of organisms per vessel: 1
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10
- Volume per vessel: 80 ml/vessel
- Biomass loading rate: 10 animals individually at each test concentration and control
TEST MEDIUM / WATER PARAMETERS
- Total hardness (converted to CaCO3): 250 mg/L (2.5 mmol/L)
- Alkalinity: 0.9 mmol/L
- Water: Analytical grade salts and additives will be dissolved in purified water to obtain reconstituted M7 water.
- pH = 7.9
OTHER TEST CONDITIONS
- Photoperiod: 16/8 hour light/dark photo cycle
- Light intensity: 470 to 640 Lux
- Test temperature: 18-22°C continuously monitored
- Initial pH 7.9 +- 0.3
- Test water will be aerated prior to the start of the study until oxygen saturation; during the test the test media will not be aerated
EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- The mortality and visible abnormalities of the test animals and the number of offspring will be recorded at least three times per week. Dead animals and offspring will be removed at the renewal of the test media.The NOEC and, if possible, the LOEC for reproduction rate will be evaluated by appropriate statistical tests (e. g. the multivariate Williams-test) after analysis of variance (ANOVA). If possible, also the EC10 and EC50 for inhibition of the reproduction rate at the end of the test will be calculated, e. g. by appropriate statistical tests as Probit analysis or moving average interpolation.

Reference substance (positive control):

no

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: reproduction and mortality

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: reproduction and mortality

Remarks on result:

other: after 3 d exposure time

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

72 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Number of surviving test animals

Exposure day	Nominal concentration of the test item (mg/L)
	Control	1.0	3.2	10	32	100
0	10	10	10	10	10	10
1	10	10	10	10	10	6
3	10	10	10	10	10	6
5	10	10	10	10	10	0
7	10	10	10	10	10	0
10	10	10	10	10	10	0
12	10	10	10	10	10	0
14	10	10	10	10	10	0
17	10	10	10	10	10	0
19	9	10	10	10	10	0
21	9	10	10	10	10	0
% surviving on day 21	90	100	100	100	100	0

The total number of living young daphnids produced by all adults (cumulative values)

Exposure day	Nominal concentration of the test item (mg/L)
	Control*	1.0	3.2	10	32	100
0	0	0	0	0	0	0
1	0	0	0	0	0	0
3	0	0	0	0	0	0
5	0	0	0	0	0	0
7	0	0	0	0	0	0
10	169	163	174	183	133	0
12	292	426	539	461	390	0
14	366	442	539	519	463	0
17	549	595	636	682	661	0
19	841	993	1036	1022	999	0
21	881	1017	1037	1093	1051	0
% of control based on last exposure day	100.0	115.4	117.7	124.1	119.3	0.0

The number of living offspring produced per surviving adult within 21 days of exposure

Replicate No.	Nominal concentration of the test item (mg/L)
	Control	1.0	3.2	10	32	100
1	98	117	103	102	107	*
2	23**	104	111	115	90	*
3	107	81	104	99	124	*
4	93	111	100	99	117	*
5	99	98	105	134	99	*
6	*	117	97	108	108	*
7	97	122	112	103	107	*
8	108	64	103	102	101	*
9	108	104	107	116	89	*
10	82	99	95	115	109	*
mean	99.0	101.7	103.7	109.3	105.1	-
+-SD	8.9	17.8	5.5	11.0	10.9	-
n	8**	10	10	10	10	0
CV%	9.0	17.5	5.3	10.0	10.4	-
% of control	100.0	102.7	104.7	110.4	106.2	-

CV%: coefficient of variation in % (SD/mean)*100%

*: test animal died during the test period

**: one of the 9 surviving daphnids had offspring only at day 10 and was then obviously no longer fertile. This daphnia was therefore excluded from this calculation

Validity criteria fulfilled:

yes

Conclusions:

A NOEC (21 d) value of 32 mg/L for reproduction was obtained from a study conducted according to OECD 211.

Description of key information

The read-across substance Hyoscine Butylbromide was assessed for its toxicological potential to Daphnia magna in a semi-static reproduction Test over 21 days according to OECD 211. Under this test conditions a NOEC 32 mg/L and a EC50 of 72 mg/L were determined.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

32 mg/L