Bismuth chloride oxide

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 May 2010 - 22 May 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Samples from control and the test item concentration were taken at the start end the end of the exposure period and analysed to determine the actual test item concentrations in comparison to the nominally applied concentrations.
Before analysis, the samples were stored in a refrigerator in polyethylene bottles.

Vehicle:

no

Details on test solutions:

A stock solution (water-accommodated fraction, WAF) at a loading rate of nominal 137 mg test item/L (=100 mg Bi/L) was prepared by dissolving 137.4 mg of the test item in 1004 mL of test medium. This stock solution was agitated for seven days by using a horizontal laboratory shaker at ambient temperature in the dark. The shaker was set to a frequency of 100 rpm to keep the test item in permanent suspension according to OECD guideline. After that, the stock solution was filtered (glass fibre filter, pore size 0.4 µm). The filtrate was used to prepare the desired test item concentrations.

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

common name: green algae (SAG 61.81)
breeder: Georg-August-Universität Göttingen

To adjust the algae to the test conditions a pre-culture was inoculated by an agar stock culture and incubated under test conditions:
pH-value of the algal medium: 5.9
Amount of liquid stock culture per pre-culture vessel: 100 mL
Pre-culture vessels: 300 mL Erlenmeyer flasks
Number of replicates: 2
Light: light/dark (24/0 h); fluorescent tubes of universal white type
Light intensity: 60 – 120 µE/m2 * s
Shaker: 100 ± 5 oscillations/min
Temperature in the test room: 21 - 24°C, controlled at ± 2°C

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22.3-24.0 °C

pH:

5.9-6.1

Nominal and measured concentrations:

nominal added concentrations: control, 1, 3, 10, 30 and 100% of water-accommodated fraction (100 mg Bi/L), corresponding to measured dissolved Bi concentrations of <0.003, <0.003, <0.003, 0.006, 0.02 and 0.046 mg Bi/L (calculated as geometric mean of measured concentrations at start and end of exposure).

Details on test conditions:

-Age of the pre-culture: 4 days
-Number of cells per mL in the pre-culture before inoculating the test solution: 277 x 10^4
-Number of cells per mL test solution at the beginning of the test: 0.5 x 10^4
-Number of replicates per test item concentration: 3
-Number of replicates in the control: 6
-Number of replicates for stability check (limit concentration without algae): 2
-Light cycle: 24/0 hours light/dark
-Types of light: fluorescent tubes of universal white type (Osram Lumilux 58W/865)
-Light intensity: mean value of six measurements: 94.6 µE/m2s (required 60 to 120 µE*m2s1 equivalent to 4440 – 8880 lx)
-Shaker: 100 ± 5 oscillations/min; the test vessels were placed randomly on the shaker
-Counting of algae: daily
-Effect parameter: yield and growth rate

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 137 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: EC50 > 100 mg Bi/L

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 137 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: NOEC >= 100 mg Bi/L

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 137 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: EC50 > 100 mg Bi/L

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 137 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: NOEC >= 100 mg Bi/L

Details on results:

Effect parameter, EC50 and NOEC for yield and growth rate, values based on mean measured dissolved Bismut concentrations are all higher than 0.046 mg Bi/L.

Results with reference substance (positive control):

results of the reference test performed in january 2010: 72h-EC50 for growth rate is 0.85 mg/L. Based on an international ring test (ISO 2004) mentioned in OECD guideline 201, the 72h-EC50 value for potassium dichromate obtained from different laboratories should be 1.19 mg/L with a standard deviation of 0.27 mg/L. The experimentally obtained value of 0.85 mg/L is within the historical range of the results of the testing laboratory (mean EC50 value = 1.15 +- 0.42 mg/L) and within the upper (2.54 mg/L) and lower (0.44 mg/L) warning limit. The warning limits were calculated as two standard deviations from the historical mean of the EC50. Furthermore, the EC50 value is within the refined range of 1.10 +- 0.48 mg/L, recommended based on an international ring test (pattard et al. 2009). Therefore, the results of this reference test are acceptable and the test conditions are reliable.

Reported statistics and error estimates:

The data were evaluated for homogeneity of variances by Levene's Test, and by Williams' test to calculate whether there were significant differences between the growth of algae in the controls and the algae exposed to the test item concentrations.

Treatment [% of WAF]	%Inhibition of Yield (72 h)	Significant difference from control (p≤0.05)	%Inhibition of Growth Rate (72 h)	Significant difference from control (p≤0.05)
Control	0.0	No	0.0	No
1	-13.5	No	-2.3	No
3	-12	No	-2	No
10	-10.6	No	-1.7	No
30	4.4	No	0.8	No
100	2.0	No	0.4	No

Validity criteria fulfilled:

yes

Conclusions:

GLP0 test according to OECD 201 guideline. The 72h-EC50 for growth rate and biomass yield of Pseudokirchneriella subcapitata are both > 137 mg/L bismuth subnitrate (100 mg Bi/L).

Executive summary:

A GLP test conducted according to OECD 201 guideline. The 72h-EC50 for growth rate and biomass yield of Pseudokirchneriella subcapitata are both > 137 mg/L bismuth subnitrate (> 100 mg Bi/L).

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Please refer to the analogue justification provided in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 137 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: EC50 > 100 mg Bi/L

Remarks:

Source: 6.1.5-1

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 137 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: NOEC >= 100 mg Bi/L

Remarks:

Source: 6.1.5-1

Description of key information

ErC 50 (72 h) > 137 mg/L, corresponding to 100 mg Bi/L (nominal, P. subcapitata, OECD 201); read across from bismuth hydroxide nitrate oxide (CAS 1304-85-4)

NOErC (72 h) ≥ 137 mg/L, corresponding to 100 mg Bi/L (nominal, P. subcapitata, OECD 201); read across from bismuth hydroxide nitrate oxide (CAS 1304-85-4)

Additional information

No data were available on the short term toxicity of bismuth chloride oxide (CAS 7787-59-9) on algae and therefore a read across was conducted to reliable data of the source substance bismuth hydroxide nitrate oxide (CAS 1304-85-4). A detailed read across justification is provided in section 13 of the IUCLID dossier.

The available study with the read across substance bismuth hydroxide nitrate oxide, was conducted according to OECD guideline 201 and GLP (Ref.: 6.1.5-1). Pseudokirchneriella subcapitata was used as the test organism in a static test system. The green algae was exposed to 1, 3, 10, 30 and 100% of the stock solution with a nominal loading rate of 137 mg test item/L (corresponding to 100 mg Bi/L) for 72 h. An analytical monitoring via ICP-OES was performed at the test start and end, in order to verify the concentrations in all test item concentrations and in the control. No toxic effects on growth rate or biomass were recorded in the study resulting in ErC 50 (72 h) > 137 mg/L and NOErC (72 h) ≥ 137 mg test item/L (nominal), corresponding to > 100 mg Bi/L.