Disodium piperazine-1,4-diethanesulphonate

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:

23 Oct 2017 to 21 Jan 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:

None of the deviations were considered to have impacted the overall integrity of the study or the interpretation of the study results and conclusions.

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Test item information
Appearance: White powder
Test item storage: At room temperature
Stable under storage conditions until: 30 November 2018 (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: 2.0 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 2.0 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 1,4 piperazinediethanesulfonic acid disodium salt tested was a white powder of high purity 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. No other treatment than vigorous shaking was needed to completely dissolve 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. Due to the observed degree of adsorption during the analytical method development, all glass ware employed in this study was silanized prior to use. 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 brood, showing no signs of stress such as mortality >20%, presence of males, ephippia or discoloured animals and there was no delay in the production of the first brood.
Characteristics: For the test selection of young daphnids with an age of < 24 hours, from parental daphnids of more than two weeks old.

Breeding
Start of each batch: With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 5 litres of medium in an all-glass culture vessel.
Maximum age of the cultures: 4 weeks
Renewal of the cultures: After 7 days of cultivation half of the medium twice a week.
Temperature of medium: 18-22°C
Feeding: Daily, a suspension of fresh water algae.
Medium: M7, as prescribed by Dr. Elendt-Schneider (Elendt, B.-P., 1990: Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus. Protoplasma 154, 25-33)

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

The hardness: 180 mg/L expressed as CaCO3

Test temperature:

The temperature continuously measured in a temperature control vessel varied between 19 and 20°C during the test, and complied with the requirements as laid down in the study plan (18-22°C, constant within 2°C).

pH:

pH: 7.7 ± 0.3.

Dissolved oxygen:

The oxygen concentration at the end of the test was ≥3 mg/L in control and test vessels.

Nominal and measured concentrations:

Nominal concentration: 100 mg/L
Measured concentrations: 24 and 48 hour EC50 > 75

Details on test conditions:

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%, presence of males, ephippia or discoloured animals and there was no delay in the production of the first brood.
Characteristics: For the test selection of young daphnids with an age of < 24 hours, from parental daphnids of more than two
weeks old.

Breeding
Start of each batch: With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 5 litres of medium in an all-glass culture vessel.
Maximum age of the cultures: 4 weeks
Renewal of the cultures: After 7 days of cultivation half of the medium twice a week.
Temperature of medium: 18-22°C
Feeding: Daily, a suspension of fresh water algae.
Medium: M7, as prescribed by Dr. Elendt-Schneider (Elendt, B.-P., 1990: Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus. Protoplasma 154, 25-33).

pH: 6-9
oxygen: >/= 3 mg/L
The temperature continuously measured in a temperature control vessel varied between 19 and 20°C during the test, and complied with the requirements as laid down in the study plan (18-22°C, constant within 2°C).

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 75 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Details on results:

Combined Limit/Range-Finding Test
No significant immobility was observed at any of the test concentrations during the test period. However, more than 10% of daphnids in the control showed signs of stress, i.e. were trapped at the surface of the medium.
It was thus decided to perform a limit test to verify that the test item is not toxic to daphnids.
Samples taken from nominally 100 mg/L were analysed. The actual concentration was 65 mg/L at the start of the test, which remained stable throughout the test, i.e. was at 101% of the initial concentration at the end of the test

Final Test
Measured Concentrations
Samples taken from nominally 100 mg/L were analysed. The actual concentration was 75 mg/L at the start of the test, which remained stable throughout the test, i.e. was at 92% of the initial concentration at the end of the test
Based on these results, the measured concentrations were used to determine the effect parameters.

Immobility
No immobility was recorded in the control or the limit concentration.

Reported statistics and error estimates:

No EC50 could be calculated because the test item proved to be non-toxic (EC50 > maximum soluble concentration tested).
ToxRat Professional v 3.2.1 (ToxRat Solutions® GmbH, Germany) was used to perform the analyses.

Validity criteria fulfilled:

yes

Conclusions:

In conclusion, the 48h-EC50 for Daphnia magna exposed to 1,4 piperazinediethanesulfonic acid disodium salt was beyond the range tested, i.e. exceeded a measured concentration of 75 mg/L being considered to be the maximum concentration soluble in test medium at a loading rate of 100 mg/L.

Executive summary:

The objective of the study was to evaluate 1,4 piperazinediethanesulfonic acid disodium salt 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 The batch of 1,4 piperazinediethanesulfonic acid disodium salt tested was a white powder of high purity and completely soluble in test medium at the concentrations tested.  To prevent adsorption, all glass ware employed in this study was silanized prior to use.

A limit 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 nominal 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.  No immobility was recorded in the control or the limit concentration. Samples taken from nominally 100 mg/L were analysed. The actual concentration was 75 mg/L at the start of the test, which remained stable throughout the test, i.e. was at 92% of the initial concentration at the end of the test. Based on these results, the measured concentrations were used to determine the effect parameters.  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 1,4 piperazinediethanesulfonic acid disodium salt was beyond the range tested, i.e. exceeded a measured concentration of 75 mg/L being considered to be the maximum concentration soluble in test medium at a loading rate of 100 mg/L.

 

Additional information

In conclusion, the 48h-EC50 for Daphnia magna exposed to 1,4 piperazinediethanesulfonic acid disodium salt was beyond the range tested, i.e. exceeded a measured concentration of 75 mg/L being considered to be the maximum concentration soluble in test medium at a loading rate of 100 mg/L.