Hydrazine

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Deviations:

yes

Remarks:

The fluctuation of the temperature during the test was slightly higher than 1°C. This is not regarded to be relevant to the results.

Principles of method if other than guideline:

The method described in the Council Regulation (EC) No 440/2008, Method C.20 'Daphnia magna Reproduction Test" (2008), which equals in all relevant parts to the OECD Test guideline 211 (Daphnia magna Reproduction Test; adopted: Oct. 3, 2008), assesses adverse effects of various concentrations of a test item to a freshwater microcrustacean species within a 21 day exposure period under semi-static conditions.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Routinely the samples are analysed immediately. Only in exceptional cases, they are stored in a refrigerator overnight and protected from light.

- Sampling schedule:
Control :
on day 0, 7 and 14 in the freshly prepared media;
on day 2, 9 and 16 in the old media

Test concentrations :
on day 0, 7 and 14 in the freshly prepared media;
on day 2, 9 and 16 in the old media

Vehicle:

no

Details on test solutions:

A stock solution was prepared to give the desired series of test concentrations. To achieve this 19.4 µL (= 20 mg) of the test item were added to 2 litres of dilution water. The pH was measured.

To produce the different test item concentrations appropriate amounts of the stock solution were diluted with dilution water to a volume of 100 mL per replicate. For each test item concentration and control 10 replicates were prepared. This procedure was repeated three times a week at each water renewal.

Test organisms (species):

Daphnia magna

Details on test organisms:

Name: Daphnia magna STRAUS, parthenogenetic females

Source: Strain of Bundesgesundheitsamt Berlin

Maintenance and Acclimatisation : A population of parthenogenetic females of synchronized age structure

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

21 d

Hardness:

The hardness of the dilution water used ranged from 13.5 – 15.8 °dH (= 241 - 282 mg/L CaCO3) during the test.

Test temperature:

19.9 °C - 21.9 °C

pH:

7.9 - 8.2

Dissolved oxygen:

8.5 - 10.5 mg/L

Nominal and measured concentrations:

The results are expressed in terms of time-weighted means of measured concentrations. Effective concentrations ranged from 78.1 – 170 % of the nominal values in the freshly prepared media and from 17.0 – 110 % of the nominal values in the media after 48 hours, or 72 hours of exposure, respectively.

Details on test conditions:

Test vessels: 150 mL glass beakers holding 1 neonate in 100 mL of test medium
Experimental design: 5 test concentrations plus 1 control, 1 neonate per vessel, 10 replicates per concentration/control, semi-static system (renewal of the test media on Monday, Wednesday and Friday) respectively
Method of initiation: neonates were placed in prepared media
Photoperiod: 16 h light: 8 h dark
Light intensity: 15 - 20 µE x m-2 x s-1
Temperature of incubation unit: 20.0 to 21.0 °C (measured in air)
Aeration: none
Test item concentration/s (nominal): 0.01, 0.032, 0.1, 0.32 and 1 mg/L
Food source and : Desmodesmus subspicatus
feeding rate: day 0-7: 0.1 mg C / Daphnia / day
day 8-21: 0.2 mg C / Daphnia / day
Duration of exposure: 21 days
Criteria of effects: The criterion of adverse effects used in this study was the item-induced inhibitory effect on the parthenogenetic reproduction rate and the mobility behaviour/mortality rate of parent Daphnia, all effects being assessed at least three times a week.

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.01 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

0.031 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.123 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Basis for effect:

mortality

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

0.662 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

act. ingr.

Basis for effect:

mortality

Details on results:

- 1st brood on day 9th
- all parenteral daphnids died at nominal concentrations of 1 mg/L
- test item concentrations were monitored throughout the test duration. As effective concentrations ranged from 78.1 – 170 % of the nominal values in the freshly prepared media and from 17.0 – 110 % of the nominal values in the media after 48 hours, or 72 hours of exposure, respectively, the test evaluation was based on time-weighted means of the measured concentrations.

Validity criteria fulfilled:

yes

Remarks:

The mortality rate in the controls did not exceed 20 % by the end of the test. Living offspring produced per parent Daphnia surviving at the end of the test was > 60 in the controls. The dissolved oxygen concentration remained above 3 mg/L throughout the

Executive summary:

The long-term toxicity of hydrazine towards invertebrates was measured yielding a NOEC(21 d) of 0.010 mg/L having reproduction as most sensitive end point (Currenta, 2010b). The test evaluation was based on time-weighted means of the measured concentrations.

Description of key information

The long-term toxicity of hydrazine towards invertebrates was measured yielding a NOEC(21 d) of 0.010 mg/L having reproduction as most sensitive end point (Currenta, 2010c). The test evaluation was based on time-weighted means of the measured concentrations.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.01 mg/L

Additional information

As hydrazine is known to rapidly degrade in aqueous media, tests were conduced under semi-static conditions refreshing aqueous solutions each Monday, Wednesday and Friday to ensure a constant exposure of the test animals throughout the entire test duration. Furthermore, concentrations were measured on day 0, 7 and 14 in the freshly prepared media; and on day 2, 9 and 16 in the old media by the means of a photometric method to determine the effective exposure concentration. Effective concentrations ranged from 78.1 – 170 % of the nominal values in the freshly prepared media and from 17.0 – 110 % of the nominal values in the media after 48 hours, or 72 hours of exposure, respectively. Therefore, the test evaluation was based on time-weighted means of the measured concentrations.