N,N-dimethylhydrazine

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

06 September 2010 - 29 October 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Compliant to GLP and testing guideine; adequate coherence between data, comments and conclusions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

N,N-dimethylhydrazine

EC Number:

200-316-0

EC Name:

N,N-dimethylhydrazine

Cas Number:

57-14-7

Molecular formula:

C2H8N2

IUPAC Name:

1,1-dimethylhydrazine

Details on test material:

- Name of test material (as cited in study report): UDMH (Unsymmetrical Dimethylhydrazine)
- Physical state: liquid
- Analytical purity: 99.4%
- Impurities (identity and concentrations): water 0.2%, amines 0.4%, methanol <0.01%, chlorides 0.0022%, iron < 0.00006%, mechanical impurities < 0.0001%
- Purity test date: 10 september 2008
- Lot/batch No.: 1
- Expiration date of the lot/batch: 23 january 2012
- Storage conditions of test material: at room temperature.

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all, before and after each renewal
- Sampling method: aliquot (approximately 10 mL)
- Sample storage conditions before analysis: analyzed <1h after sampling

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no, soluble

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain: Daphnia magna Straus
- Source: internal breeding lab
- Age at study initiation: 6 to 24 hours old
- Size at initiation: pass through 800 µm sieve and remain on 560 µm sieve
- Method of breeding: from parthenogenetically reproducing brood female population (20°C, light/dark cycle 16/8 hours, ISO freshwater Medium)
- Feeding during test: no

ACCLIMATION: no data

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

no

Test conditions

Test temperature:

20-21°C

pH:

7.7 to 8.5: dose-dependent alcalinisation by test item, from 80 mg/L

Dissolved oxygen:

100%

Nominal and measured concentrations:

Theoretical: 0, 10, 20, 40, 80 and 160 mg/L
Nominal (based on weighed amounts for preparations, average T=0 and T=24h after renewal): 0, 11.3, 22.6, 45.3, 90.5 and 181.0 mg/L
Measured (average T=0 and T=24h after renewal):

Details on test conditions:

TEST SYSTEM
- Renewal rate of test solution (frequency/flow rate): 1x/24h
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: demineralized water added with Calcium chloride, Magnesium sulphate, Sodium hydrogenocarbonate, Potassium chloride

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: dark always
- Light intensity: NA

EFFECT PARAMETERS MEASURED: mobility 24, 48h

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

28.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 25.3-32.1 mg/L

Results with reference substance (positive control):

September 8th, 2010: EC50= 0.99 mg/L; september 22nd, 2010: EC50= 1.03 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

For UDMH, EC50 in daphnids was 28.7 mg/L over 48h.

Executive summary:

UDMH was tested in semi-static conditions for acute toxicity toward Daphnia magna. The EC50 over 48h was 28.7 mg/L, based on the average initial nominal concentrations (as measured concentrations were within +-20% of nominal values).