DL-α-(aminomethyl)-p-hydroxybenzylic alcohol hydrochloride

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

31 Jul 2018 to 11 Dec 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

The experimental start date was 10 Aug 2018. Evaluation: The experimental phase could start sooner than originally anticipated. This has no effect on the test results or study interpretation.

GLP compliance:

yes

Specific details on test material used for the study:

Identification: Octopamine hydrochloride
Appearance: White to off white powder (determined by Charles River Den Bosch)
Batch: D151-1710037
Purity/Composition: See Certificate of Analysis
Test item storage: At room temperature protected from light
Stable under storage conditions until: 26 October 2019 (retest date)

Analytical monitoring:

yes

Details on sampling:

Samples for possible analysis were taken from all test concentrations and the control according to the schedule below. Frequency at t=0 h and t=48 h Volume 1.5 mL from the approximate centre of the test vessels Storage Samples were stored in a freezer (≤-15°C) until analysis at the analytical laboratory of the Test Facility. At the end of the exposure period, the replicates were pooled at each concentration before sampling. Additionally, reserve samples of 1.5 mL were taken for possible analysis. If not used, these samples were stored in a freezer (≤-15°C) for a maximum of three months after delivery of the draft report, pending on the decision of the sponsor for additional analysis.

Vehicle:

yes

Remarks:

test medium

Details on test solutions:

The batch of Octopamine hydrochloride tested was a white to off-white powder with a purity of 99.8% and completely soluble in test medium at the concentrations tested. No correction was made for the purity/composition of the test item. Preparation of test solutions started with the highest concentration of 100 mg/L applying a 15-16 minute period of magnetic stirring to accelerate dissolution of the test item in test medium. Lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. All test solutions were clear and colorless at the end of the preparation procedure. Any residual volumes were discarded.

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna (Crustacea, Cladocera) (Straus, 1820), at least third generation, obtained by a cyclical parthenogenesis under specified breeding conditions.
Source: In-house laboratory culture with a known history.
Reason for selection: This system has been selected as an internationally accepted invertebrate species.
Validity of batch: Daphnids originated from a healthy stock, 2nd to 5th brood, showing no signs of stress such as mortality >20%1, presence of males, ephippia or discoloured animals and there was no delay in the production of the first brood.
Characteristics: Daphnia, less than 24 hours old, from parental daphnids of more than two weeks old.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

CaCO3: 180 mg/L

Test temperature:

between 21 and 22°C

pH:

pH between 6 and 9

Dissolved oxygen:

oxygen: ≥3 mg/L at the end of the test

Nominal and measured concentrations:

Nominal concentrations: 4.6, 10, 22, 46 and 100 mg/L

The measured concentrations were at 100-107% relative to the nominal concentrations at the start of the test, and decreased to 17-90% of the nominal concentrations at the end of the test, whereby a stronger concentration decrease was observed for decreasing test concentrations. Based on these results, the average exposure concentrations were calculated to be 1.9, 7.9, 20, 43 and 95 mg/L at nominally 4.6, 10, 22, 46 and 100 mg/L, respectively.

Details on test conditions:

Test Procedure and Conditions
Test duration: 48 hours
Test type: Static
Test vessels: 60 mL, all-glass.
Number of daphnids: 20 per concentration
Loading: 5 per vessel containing 50 mL of test solution.
Test medium: The following salts (analytical grade) were added to tap water purified by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands): CaCl2.2H2O 211.5 mg/L MgSO4.7H2O 88.8 mg/L NaHCO3 46.7 mg/L KCl 4.2 mg/L The hardness of test medium expressed as CaCO3: 180 mg/L with a pH between 6 and 9.
Light: A daily photoperiod of 16 hours. Feeding No feeding Aeration No aeration of the test solutions was applied. Introduction of daphnids 43 minutes after preparation of the test solutions.

Measurements and Recordings
Immobility (including mortality): At 24 hours and at 48 hours. pH and dissolved oxygen At the beginning and at the end of the test, for all concentrations and the control.
Temperature of medium: Continuously in a temperature control vessel, beginning at the start of the test.

Combined Limit/Range-Finding Test
The project started with a combined limit/range-finding test. Twenty daphnids per concentration (four replicates, 5 daphnids per vessel) were exposed to a control and a concentration of 100 mg/L. Test procedure and conditions were similar to those applied in the final test with the following exceptions:
-Ten daphnids per concentration (in duplicate, 5 per vessel) were exposed to nominally 0.10, 1.0 and 10 mg/L in the combined range-finding test.
-Dissolved oxygen concentrations and pH were only measured in the control and the highest test concentration.

Final Test
Test Concentrations
Octopamine hydrochloride: 4.6, 10, 22, 46 and 100 mg/L.
Control: Test medium without test item or other additives.

Reference substance (positive control):

yes

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

ca. 35 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Combined Limit/Range-Finding Test
No biologically relevant immobility was observed in the control and the three lowest test concentrations throughout the test. At the highest test concentration, 20 and 90% of exposed daphnids were observed to be immobile after 24 and 48 hours of exposure, respectively. Based on these results, samples taken from nominally 1.0 and 100 mg/L were analysed. The measured concentrations at the start of the test were 1.1 and 104 mg/L, respectively. During the exposure period, the concentrations remained stable, i.e. were at 92-96% relative to the initial concentrations at the end of the test. All test conditions were maintained within the limits prescribed by the study plan.

Final Test
Measured Test Item Concentrations
Samples taken from all test concentrations were analysed. The measured concentrations were at 100-107% relative to the nominal concentrations at the start of the test, and decreased to 17-90% of the nominal concentrations at the end of the test, whereby a stronger concentration decrease was observed for decreasing test concentrations. Based on these results, the average exposure concentrations were calculated and used to express effect parameters.

Immobility
After 24 hours of exposure, no immobility was observed in the control and the fours lowest test concentrations, while at the highest test concentration, 25% of exposed daphnids were observed to be immobile. At the end of the test, a dose-related increase of immobility was observed at average concentrations of 20 mg/L and higher, reaching 95% immobility at the highest test concentration. The responses recorded in this test allowed for reliable determination of an EC50 and were in agreement with what was expected based on the results of the combined limit/range-finding test.

Experimental Conditions
These test conditions remained within the limits prescribed by the study plan (pH: 6-9, not varying by more than 1.5 units; oxygen: ≥3 mg/L at the end of the test). The temperature continuously measured in a temperature control vessel varied between 21 and 22°C during the test, and complied with the requirements as laid down in the study plan (18-22°C, constant within ±1°C).

Results with reference substance (positive control):

Potassium dichromate inhibited growth rate and yield of this fresh water algae species at nominal concentrations of 0.18 mg/L and higher. The EC50 for growth rate inhibition (72h-ERC50) was 0.90 mg/L with a 95% confidence interval ranging from 0.88 to 0.93 mg/L. The historical ranges for growth rate inhibition lie between 0.82 and 2.3 mg/L. Hence, the 72h-ERC50 for the algal culture tested corresponds with this range. The EC50 for yield inhibition (72h-EYC50) was 0.30 mg/L with a 95% confidence interval ranging from 0.29 to 0.31 mg/L. The historical ranges for yield inhibition lie between 0.43 and 1.1 mg/L.

Reported statistics and error estimates:

The 48h-EC50-value was calculated from the probits of the percentages of affected daphnids and the logarithms of the corresponding test item concentrations (average) using the maximum likelihood estimation method. The 24h-EC50-value could not be determined because the observed effects were below 50%. ToxRat Professional v 3.2.1 (ToxRat Solutions® GmbH, Germany) was used to perform the analysis.

Validity criteria fulfilled:

yes

Conclusions:

In conclusion, the 48h-EC50 for Daphnia magna exposed to Octopamine hydrochloride was 35 mg/L based on average exposure concentrations (95% confidence interval between 27 and 46 mg/L).

Executive summary:

The objective of the study was to evaluate Octopamine hydrochloride for its ability to generate acute toxic effects on the mobility of Daphnia magna during an exposure period of 48 hours and, if possible, to determine the EC50 at 24 and 48 hours of exposure. The study procedures described in this report were based on the OECD guideline No. 202, 2004.  The batch of Octopamine hydrochloride tested was a white to off-white powder with a purity of 99.8% and completely soluble in test medium at the concentrations tested. A final test was performed based on the results of a preceding combined limit/range-finding test. Twenty daphnids per group (5 per replicate, quadruplicate) were exposed to an untreated control and to nominally 4.6, 10, 22, 46 and 100 mg/L. The total exposure period was 48 hours and samples for analytical confirmation of exposure concentrations were taken at the start and at the end of the test. The measured concentrations were at 100-107% relative to the nominal concentrations at the start of the test, and decreased to 17-90% of the nominal concentrations at the end of the test, whereby a stronger concentration decrease was observed for decreasing test concentrations. Based on these results, the average exposure concentrations were calculated to be 1.9, 7.9, 20, 43 and 95 mg/L at nominally 4.6, 10, 22, 46 and 100 mg/L, respectively. The average concentrations were subsequently used to express effect parameters. At the end of the test, a dose-related increase of immobility was observed at average concentrations of 20 mg/L and higher, reaching 95% immobility at the highest test concentration. The study met the acceptability criteria prescribed by the study plan and was considered valid. In conclusion, the 48h-EC50 for Daphnia magna exposed to Octopamine hydrochloride was 35 mg/L based on average exposure concentrations (95% confidence interval between 27 and 46 mg/L).

Description of key information

The 48h-EC50 for Daphnia magna exposed to Octopamine hydrochloride was 35 mg/L based on average exposure concentrations (95% confidence interval between 27 and 46 mg/L).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

35 mg/L