Chloro(1-methylethyl)magnesium

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:

2012-11-20 to 2013-06-14

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: "The Guidelines for the Testing of Chemicals" State Environmental Protection Administration (SEPA) of China, No.202

Deviations:

no

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Chloro(1-methylethyl)magnesium

EC Number:

213-947-1

EC Name:

Chloro(1-methylethyl)magnesium

Cas Number:

1068-55-9

Molecular formula:

C3H7ClMg

IUPAC Name:

chloro(1-methylethyl)magnesium

Constituent 2

Reference substance name:

Isopropylmagnesium chloride

IUPAC Name:

Isopropylmagnesium chloride

Test material form:

other: 20% in 80% Tetrahydrofuran

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Testconcentration was messeaured at beginning and the end of the test c(48h)/c(0h) = 96.8%

Test solutions

Details on test solutions:

Preparation of stock solution (100 mg/L Mg) and nominal tested concnentrations:

250 µL Isopropyl magnesium chloride ca. 20% in Tetrahydrofuranwas added into a 500 mL beaker (contained 50 mL pure water). 500 mL test water was added and treated with ultrasonic dissolving for 20 min. Thereafter, after filtrated through 0.45 µn filter membrane, 1 mol/L HNO3 was added to adjust the pH value to 7.8 +- 0.1 and it was stirred with a glass rod for 2 min to obtain 100 mg/L test solution of Isopropyl magnesium chloride ca. 20% in Tetrahydrofuran.

Reference soluiton: Deionized water

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna (Straus)
- Source: Shanghai Fisheries university school of life science and technology
- Age at study initiation: 0-24 h (small Daphnia were removed), more than second generation

ACCLIMATION
- Temperature: 20°C
- Culturing avoided from direct sunlight
- Type and amount of food: cultivated algae of the lab, daily
- Health during acclimation (any mortality observed): if no mortality occured during 24 hours Daphnia were used for the test

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Test temperature:

Temperature 20.1°C to 20.6°C at the start of the test
Temperature 19.8°C to 20.7°C at the end of the test

pH:

pH 7.82 to 7.85 at the start of the test
pH 7.81 to 7.85 at the end of the test

Dissolved oxygen:

108.1 to 110.5 mg/L at test start of the test
94.9 mg/L to 97.5 mg/L at test end of the test

Nominal and measured concentrations:

Nominal concentration: 100 mg/L (limited test); it was not necessary to conduct the defiitve test , because Daphnia magna showed no effects during exposition. Nominal concentration is equal to analytical measured concentration of 116,89 mg/L.
The concentrations were measured by the described analytical method.

Details on test conditions:

TEST SYSTEM

- No. of organisms per vessel: five
- No. of vessels per concentration (replicates): four replicates
- No. of vessels per control (replicates): four replicates
- No. of vessels per vehicle control (replicates): four replicates

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
- 11.76 g CaCl2 dissolved in deionized water, diluted to 1 L deionized water
- 2.59 g NaHCO3 dissolved in deionized water, diluted to 1 L deionized water
- 0.23 g KCl issolved in deionized water, diluted to 1 L deionized water
- 25 mL of these solutions were mixed and diluted in 1L deionized water
- after 30 min of aearation ph, dissolved oxygen were measured (after 48h test duration again)

OTHER TEST CONDITIONS
- Photoperiod: 16 h light : 8 h dark
- Adjustment of pH: 1 mol/L HNO3 to adjust the pH value to 7.8 +- 0.1

EFFECT PARAMETER MEASURED:
- Inhibition of Daphnia after 24h and 48h
- EC50 (48h)

TEST CONCENTRATIONS:
Preliminary test:
- nominal concentrations: 1, 10, 100 mg/l + control group (five Daphnia magna pro group)
- Expositiontime: 48 hours
- Pretest results showed that the inhibiton rate to Daphnia was 0 at 100 mg/L (higest tested concentration) - tested concentrations: 1, 10, 100 m/L
- Therefore it was not necessary to conduct the definitve test
- EC50 (48h) was determinded with limited testconcentration of 100 mg/L
- Testconcentration was messeaured at beginning end end of the test c(48h)/c(0h) = 96.8%

Reference substance (positive control):

yes

Remarks:

Potassium dichromat

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

116.89 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

EC50 (24h) = 0.9 mg/L
This 24-hour EC50 value is in accordance with the accepted 0.6 – 2.1 mg/L range for Daphnia magna.

Reported statistics and error estimates:

No calculation was necessary, because under exposition at highest test concentration no effects were observed.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Daphnia magna did not have abnormal behavior/mobility during the test period. The result indicated that the EC50(48h) for Daphnia magna was greater than 100 mg/L (highest observed testconcentration).

Executive summary:

The purpose of this study was to evaluate the influence of the test item isopropyl magnesium chloride on the mobility of Daphnia magna. Young organims were exposed to testwater at a range of test item concetrations for 48 h.

Atomic absorption spectrometry of test solutions was used to generate standard curve. This chromotographic genereated curve enabled to read substance concentration directly at the beginning and the end of test ( c(48h)/c(0h) = 96.8%).

During the pretest the testsolution indicated no effets on Daphnia magna under nominal concentrations of 1, 10 and 100 mg/L isopropyl magnesium chlorid. Therefore it was not necessary to conduct the definitve test. However limit test with 100 mg/L testsolution was carried out for four replicates (five organisms). Each organism was less than 24 h old and more than the second generation. The inhibition of Daphnia magna was recorded after 24 h and 48 h test duration. The result indicated that the EC50(48h) for Daphnia magna was greater than 100 mg/L, which was highest observed nominal testconcentration and and was equivalent to 116,89 mg/L (analytical meassured result). Potassium dichromat was used as positive control. The calculated EC50 (24h) = 0.9 mg/L is in accordance with the accepted 0.6 – 2.1 mg/L range for Daphnia magna.