Butyllithium

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

1997-06-10 to 1997-07-17

Reliability:

1 (reliable without restriction)

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1310-95-2

IUPAC Name:

1310-95-2

Constituent 2

Reference substance name:

Lithium hydroxide

EC Number:

215-183-4

EC Name:

Lithium hydroxide

Cas Number:

1310-65-2

IUPAC Name:

lithium hydroxide

Details on test material:

- Name of test material (as cited in study report): Lithium Hydroxide;
- Physical state: solid;
- Analytical purity: 55.2 %;
- Lot/batch No.: Chg. 19704472
- Expiration date of the lot/batch: May 2017
- Stability under test conditions: stable at ambient conditions;
- Storage condition of test material: room temperature at about 20 degree C; in the dark

Sampling and analysis

Analytical monitoring:

yes

Test organisms

Test organisms (species):

Daphnia magna

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

NA

Test conditions

Hardness:

250.0 mg/L as CaCO3

Test temperature:

20 degree C

pH:

without pH-adjustment: 8.9 at 4.6 mg/L to 11.2 at 100 mg/L;
with pH-adjustment: 7.9 to 8.1 at all concentrations;

Dissolved oxygen:

without pH-adjustment: 8.5 - 8.9 mg/L;
with pH-adjustment: 8.4 - 8.8 mg/L;

Salinity:

NA

Nominal and measured concentrations:

nominal: 4.6; 10; 21; 46; 100 mg/L;
measured: 19.64; 43.90; 99.20 mg/L (with pH adjustment); 9.58; 19.86; 44.80 (without pH adjustment);

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

29.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

without pH-adjustment

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 25.4 to 34.0 mg/L

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

19.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

without pH-adjustment

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 15.1 to 24.1 mg/L

Effect concentrations 3

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

76.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

with pH-adjustment

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 63.6 to 92.8 mg/L

Effect concentrations 4

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

34.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

with pH-adjustment

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 29.6 to 39.7 mg/L

Effect concentrations 5

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

79 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

without pH adjustment

Basis for effect:

mobility

Remarks on result:

other: calculated for butyllithium

Effect concentrations 6

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

51 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

without pH-adjustment

Basis for effect:

mobility

Remarks on result:

other: calculated for butyllithium

Effect concentrations 7

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

205 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

with pH-adjustment

Basis for effect:

mobility

Remarks on result:

other: calculated for butyllithium

Effect concentrations 8

Duration:

48

Dose descriptor:

EC50

Effect conc.:

91.7 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

with pH-adjustment

Basis for effect:

mobility

Remarks on result:

other: calculated for butyllithium

Details on results:

In the test media the test substance concentrations were constant during the test period of 48 hours. Therefore, all reported biological results are related to the nominal concentrations of the test substance.
During the test period, the dissolved oxygen concentrations in the test media were at least 8.3 mg/L or higher. The pH-value in the freshly prepared test media without pH-adjustment ranged from pH 8.9 at the test concentration of 4.6 mg/L to pH 11.2 at 100 mg/L. At the end of the test period the pH-values had decreased to pH 8.0 - 8.7. The pH-value in the test media with pH-adjustment ranged from pH 7.9 to 8.1.

Test media without pH-adjustment:
In the control and in the test media without pH-adjustment up to and including the test concentration of nominal 10 mg test substance/L no immobility or mortality of the test animals or other signs of intoxication were determined during the test period of 48 hours.
The 24-hour EC 50 of the test substance was calculated to be 29.4 mg test substance/L with 95 % confidence limits from 25.4 to 34.0 mg/L. The 24-hour EC 0 was 10 mg test substance/L, the 24-hour EC 100 amounted to 46 mg test substance/L.
After 48 hours of exposure the toxicity of the test substance to Daphnia magna had further increased. The 48-hour EC 50 was calculated to be 19.1 mg test substance/L with 95 % confidence limits from 15.1 to 24.1 mg/L. The 24-hour EC 0 and also the 48-hour NOEC (highest concentration tested without toxic effects after 48 hours) of Lithium Hydroxide was 10 mg test substance/L, since no significant immobilization rate and no other signs of intoxication were observed at the test animals up to and including this test concentration. The 48-hour EC 100 amounted to 46 mg test substance/L.

Test media with pH-adjustment:
In the test media with pH-adjustment the toxic effect of the test substance (Note: The test substance in the experimental part with pH-adjustment is LiCl instead of LiOH due to the pH-adjustment by means of HCl. The toxic effects are caused with high possibility by the Lithium-ion) was slightly lower compared to the effects without pH-adjustment. Thus a part of the toxic effect of Lithium Hydroxide was obviously caused due to the strong basic pH.
The 24-hour EC 50 of the test substance (see above) after pH-adjustment to approximately pH 8 was calculated to be 76.8 mg/L with 95 % confidence limits from 63.6 to 92.8 mg/L. The 24-hour EC 0 was 21 mg/L, the 24-hour EC 100 amounted to > 100 mg/L.
The 48-hour EC 50 was calculated to be 34.3 mg/L with 95 % confidence limits from 29.6 to 39.7 mg/L. The 48-hour EC 0 and also the 48-hour NOEC (highest concentration tested without toxic effects after 48 hours) of the test substance after the pH-adjustment was 21 mg/L. The 48-hour EC 100 amounted to 46 mg/L.
In the test media with pH-adjustment no remarkable observations were made concerning the appearance of the test substance in the test media.
In the test media without pH-adjustment a small precipitate was observed at the test concentrations of 21 and 46 mg/L at the bottom of the testbeakers at the observations after 24 and 48 hours. At 100 mg/L the freshly prepared test media were turbid, and the precipitate was observed after 24 and 48 hours at the bottom and also at the medium surface. However, as the good recoveries of the analytical results demonstrate this was not the test substance which precipitated. Thus, it was possibly a precipitate out of the test water caused by the high pH-values.

Any other information on results incl. tables

Information on results incl. tables see attached document.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Lithium hydroxide (purity 55.2 %) was tested for short term aquatic toxicity in Daphnia in an 48-hour static test according to EU Method C.2 and OECD Guideline 202. Without pH-adjustment the 48 hour EC 50-value was 19.1 mg/L. With pH-adjustment the 48-hour EC 50-value 34.3 mg/L. Therefore, the 48 hr EC 50 value is in the range of > 10 to <= 100 mg/L.

Executive summary:

n-Butyl lithium is pyrophoric and reacts violently with water / air humidity to form butane and lithium hydroxide and butane is practically insoluble in water and readily volatilizes. Thus, a study on the short-term toxicity to aquatic invertebrates with n-buthyllithium as such is scientifically not justified. Instead, lithium hydroxide was tested for short-term toxicity to daphnia. The acute toxicity of the test substance Lithium Hydroxide (purity 55.2 %) to Daphnia magna was determined in a 48-hour static test according to the EU method Annex Part C.2 and the OECD Guideline 202. The nominal concentrations tested were 4.6, 10, 21, 46 and 100 mg test substance/L, and in parallel a control. At one series of test media the pH was adjusted to approximately pH 8 by HCl, at the other series not. This allowed to differentiate if a toxic effect is caused due to a pH-effect of the test substance with a strong basic pH, or if it is a real toxic effect of Lithium hydroxide. The test substance in the experimental part with pH-adjustment is LiCl instead of LiOH due to the pH-adjustment by means of HCl. The toxic effects are caused with high probability by the Lithium-ion. The analytical determined test substance concentrations in the analysed test media varied in the range from 93.5 % to 103.2 % of the nominal values. In the test media the test substance concentrations were constant during the test period of 48 hours. Therefore, all reported biological results are related to the nominal concentrations of the test substance. The 48 hour EC50 of the test substance was determined to be 19.1 mg/L without pH-adjustment and 34.3 mg/L with pH-adjustment. Based on the data, the 48 hour EC50 calculated for buthyllithium is 51 mg/L without pH-adjustment and 91.7 mg/L with pH-adjustment.