Reaction mass of chromium (+ 3) hydroxide sulfate and sodium sulfate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1988-07-18 - 1988-08-12 (experimental phase)

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Remarks:

The study was conducted under GLP in accordance with a recognised guideline and the validity criteria were fulfilled. However, the report omits some details of the characterisation of the test substance and of the test procedure.

Qualifier:

equivalent or similar to guideline

Guideline:

ISO 7346-1 (Determination of the Acute Lethal Toxicity of Substances to a Freshwater Fish [Brachydanio rerio Hamilton-Buchanan (Teleostei, Cyprinidae)] - Part 2: Semi-static method)

Version / remarks:

The report cites a method of the German Umweltbundesamt (UBA), Berlin of May 1984: "Letale Wirkung beim Zebrabarrbling - Brachydanio rerio - LC0, LC50, LC100; 48 - 96 Stunden

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 4526, 6400, 9051 and 10000 mg/L and control
- Sampling method: Samples of the fresh (0h) and expired (24h) media of each renewal period were taken from the test vessels of each tretament to determine concentrations of total and dissolved Cr. Samples were taken from the control vessel at the same times and analysed for total Cr only. Samples were taken 4 h after the second pH adjustment of the test media.
- Sample storage conditions before analysis: Samples were analysed directly after sampling.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test substance was diluted with dlílution water to receive the test media of the nominal test concentrations. Freshly prepared test media were neutralised in two steps, with the addition of an unspecified alkali to raise the initial pH. A second adjustment to pH 7.0 +/- 0.2 followed 2 h after the first.
- Controls: Water control containing dilution water only.
- Other relevant information: The absence of mortality or other observed effects on the test organisms implies that the neutralisation and pH-stabilisation steps were completed before introducing the fish to the test media, however this is not documented in the report.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: zebrafish
- Species: Brachydanio rerio Hamilton-Buchanan.
- Source: commercial supplier 'West Aquarium', Bad Lauterberg, Germany.
- Age at study initiation: about 14 to 17 weeks.
- Length at study termination (range): 2.5 to 3.2 cm in the control, 2.5 to 3.5 cm in all treatments.
- Wet weight at termination (mean): 0.23 g per fish in the control, 0.22 g per fish in all treatments.
- Feeding during test: not stated.


ACCLIMATION
- Acclimation period: ca. 3 to 6 weeks.
- Acclimation conditions (same as test or not): According to relevant test facility SOP.
- Health during acclimation (any mortality observed): no medication or mortalities prior to test initiation.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

Not stated.

Test temperature:

21.2 to 23.9 °C

pH:

0 mg 'Chromosal B'/L (control): pH 6.8 in all fresh media, pH 6.3 to 6.7 in expired media
4526 mg 'Chromosal B'/L: pH 2.8 to 3.6 in fresh media before neutralisation, pH 6.9 to 7.1 in fresh media after neutralisation, pH 5.9 to 7.1 in expired media
6400 mg 'Chromosal B'/L: pH 2.9 to 3.7 in fresh media before netralisation, pH 6.8 to 7.1 in fresh media after neutralisation, pH 5.8 to 6.4 in expired media
9051 mg 'Chromosal B'/L: pH 2.9 to 3.4 in fresh media before netralisation, pH 6.9 to 7.2 in fresh media after neutralisation, pH 5.8 to 7.2 in expired media
10000 mg 'Chromosal B'/L: pH 2.9 to 3.3 in fresh media before netralisation, pH 6.9 to 7.2 in fresh media after neutralisation, pH 5.6 to 6.3 in expired media

Dissolved oxygen:

8.9 to 9.6 mg O2/L in fresh media (all treatments)
7.7 to 8.6 mg O2/L in expired media (all treatments)

Salinity:

Not relevant.

Nominal and measured concentrations:

nominal: 4526, 6400, 9051 and 10000 mg/L
arthmetic mean measured: 0.0075, 0.23, 0.72 and 3.21 mg Cr/L (dissolved chromium)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): aquaria
- Material, size, fill volume: 300 x 135 x 200 mm, 5L medium.
- Aeration: yes
- Renewal rate of test solution (frequency): every 24h
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): one
- No. of vessels per control (replicates): one
- Biomass loading rate: 0.39 to 0.51 g wet weight/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: not stated
- Culture medium different from test medium: no
- Intervals of water quality measurement: 0 h (fresh), 24 h (expired & fresh), 48 h (expired & fresh), 72 h (expired & fresh) and 96 h (expired)


OTHER TEST CONDITIONS
- Adjustment of pH: The test media containing the test substance, initially pH 2.8 to 3.6, were adjusted twice to pH 7.0 +/- 0.2 before taking analytical samples and also before exposure of fish. The identity of reagent used for pH adjustment is not stated.
- Photoperiod: not stated.
- Light intensity: not stated.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mortality and sub-lethal effects after 2, 24, 48, 72 and 96 h of test duration.


TEST CONCENTRATIONS
- Spacing factor for test concentrations: variable, x 1.4 to x 1.1.
- Justification for using less concentrations than requested by guideline: not relevant: all concentrations exceded solubility limit and all concentratiions resulted in 0% mortality.
- Range finding study
- Test concentrations: Analysis results are given for two tests that preceded the definitive study: concentration range for test I: 4525, 6400, 9051 and 10000 mg/L, concentration range for test II: 1600, 2262, 3200 and 4526 mg/L.
- Results used to determine the conditions for the definitive study: not stated.

Reference substance (positive control):

no

Remarks:

Not required.

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

'Chromosal B'

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

>= 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

'Chromosal B'

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

>= 10 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

'Chromosal B'

Basis for effect:

other:

Remarks:

appearance and behaviour

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 3.21 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr. (dissolved fraction)

Remarks:

chromium

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

>= 3.21 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

>= 3.21 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr. (dissolved fraction)

Remarks:

chromium

Basis for effect:

other:

Remarks:

appearance and behaviour

Details on results:

- Behavioural abnormalities: None observed.
- Observations on body length and weight: No evidence of treatment-related effects, relative to the control, following exposure to the test substance.
- Other biological observations: No evidence of adverse sub-lethal effects in the control or the test substance treatments.
- Mortality of control: 0% after 96 h.
- Other adverse effects control: None.
- Abnormal responses: None.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: Implied by filtration of analysis samples to distinguish between total and dissolved Cr, but observations not stated in report.
- Effect concentrations exceeding solubility of substance in test medium: Yes: nominal 'Chromosal B' concentrations exceed solubility limit.

Results with reference substance (positive control):

Not applicable.

Reported statistics and error estimates:

Due to the lack of effects all results could be determined directly from the raw data.

Sublethal observations / clinical signs:

Analytical Results

Table 1. Measured concentrations of total and dissolved Cr

Nominal concentration [mg/L]	Measured total Cr [mg/L]		Measured dissolved Cr [mg/L]		Arithmetic mean measured concentration [mg Cr/L]
	0h fresh	24h expired	0h fresh	24h expired
Control	0.003	0.022	n.d.	n.d.	0
4526	823	801	0.010	0.005	0.0075
6400	1131	1143	0.36	0.093	0.23
9051	1658	1654	1.19	0.25	0.72
10000	1859	1854	4.96	1.46	3.21

n.d. = not determinable

Biological Results

 Table 2. Mortality and sublethal effects

Nominal concentration [mg/L]	Arithmetic mean measured concentration [mg Cr/L]	Mortality after 96 hours [%]	Sublethal effects*
Control	0	0	0
4526	0.0075	0	0
6400	0.23	0	0
9051	0.72	0	0
10000	3.21	0	0

* Based on observations on appearance and behaviour of the test fish after 2, 24, 48, 72 and 96h of exposure

Examined catalogue of visible effects on the appearance and behaviour of the test fish 

1. normal swimming behaviour 

2. shooting, uncontrolled swimming movements 

3. gasping for air; irregular respiratory movements

4. accelerated breathing 

5. abnormal swimming position

6. lethargic swimming behaviour 

7. increased aggressiveness 

8. jumping movements 

9. uncontrolled bumping against the aquarium wall 

10. substance accumulates in the skin tissue of the test fish 

11. motionless, uncontrolled swimming movements when touched

Validity criteria fulfilled:

yes

Remarks:

Control mortality <10%, dissolved oxygen concentration >60%.

Conclusions:

The study was conducted under GLP according to a method of the German Umweltbundesamt (UBA), Berlin of May 1984, which is in the relevant parts equivalent to ISO 7346-1 on the registered substance, without deviations which may have an impact on the validity of the study. Thus, the results were obtained via a scientifically reasonable method and the obtained results can be considered as reliable to assess the short-term toxicity of the test substance towards fish.
In a semi-static test the freshwater fish Danio rerio was exposed to the test substance at the concentrations of nominal 4526, 6400, 9051 and 10000 mg/L and a control for a period of 96 hours under defined conditions. Using AAS detection arithmetic mean measured concentrations of 0.0075, 0.23, 0.72 and 3.21 mg Cr/L (dissolved chromium) were determined. Based on the obtained results no effects were observed on the test fish up to the highest concentration tested and the 96h LC50 for Danio rerio was determined to be > 10000 mg test substance/L, corresponding to > 3.21 mg Cr/L based on the arithmetic mean measured concentration of dissolved Chromium. Based on the absence of any effect on the appearance and the behaviour of the test fish, the 96h NOEC was determined to be ≥ 10000 mg test substance/L, corresponding to ≥ 3.21 mg Cr/L based on the arithmetic mean measured concentration of dissolved Chromium.

Executive summary:

The acute toxicity of the registered substance to fish was studied according to ISO 7346 -1 under GLP with the zebrafish (Danio rerio) exposed to nominal concentrations of 4526, 6400, 9051 and 10000 mg/L for 96 hours under semi-static conditions, with renewal of pH-adjusted media at 24-h intervals. A water control was tested in parallel and the pH, temperature as well as the content of dissolved oxygen was measured in all fresh and expired test media. For the test item concentrations as well as for the control 1 replicate with 10 test fish was prepared. As effect parameters the mortality as well as the appearance and the behaviour of the test fish was observed after 2, 24, 48, 72 and 96 hours of exposure. Using AAS detection the concentrations of dissolved Chromium were determined in fresh and expired test media of all treatments and the control and arithmetic mean measured concentrations of 0, 0.0075, 0.23, 0.72 and 3.21 mg Cr/L were determined.

Based on the obtained results, the following results were determined:

 

LC50 (96) > 10000 mg/L (nominal)

LC0 (96h) ≥ 10000 mg/L (nominal)

NOEC (96h) ≥ 10000 mg/L (nominal)

 

LC50 (96) > 3.21 mg Cr/L (arithmetic mean measured)

LC0 (96h) ≥ 3.21 mg Cr/L (arithmetic mean measured)

NOEC (96h) ≥ 3.21 mg Cr/L (arithmetic mean measured)

Description of key information

Key_Short-term toxicity to fish: LC₅₀(96h) > 10000 mg/L (nominal) and > 3.21 mg Cr/L (arithmetic mean measured) for Danio rerio (semi-static daily renewal, freshwater, Method of the German Umweltbundesamt (UBA), Berlin of May 1984, quivalent to ISO 7346-1, GLP)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Remarks:

based on dissolved chromium

Effect concentration:

> 3.21 mg/L

Additional information

The acute toxicity of the registered substance to fish was studied under GLP with the zebrafish (Danio rerio) exposed to nominal concentrations of 4526, 6400, 9051 and 10000 mg/L for 96 hours under semi-static conditions, with renewal of pH-adjusted media at 24-h intervals. A water control was tested in parallel and the pH, temperature as well as the content of dissolved oxygen was measured in all fresh and expired test media. For the test item concentrations as well as for the control 1 replicate with 10 test fish was prepared. As effect parameters the mortality as well as the appearance and the behaviour of the test fish were observed after 2, 24, 48, 72 and 96 hours of exposure. Using AAS detection the concentrations of dissolved Chromium were measured in fresh and expired test media of all treatments and the control and arithmetic mean measured concentrations of 0, 0.0075, 0.23, 0.72 and 3.21 mg Cr/L were determined.

Based on the obtained results, the following results were determined:

 

LC50 (96) > 10000 mg/L (nominal)

LC0 (96h) ≥ 10000 mg/L (nominal)

NOEC (96h) ≥ 10000 mg/L (nominal)

 

LC50 (96) > 3.21 mg Cr/L (arithmetic mean measured)

LC0 (96h) ≥ 3.21 mg Cr/L (arithmetic mean measured)

NOEC (96h) ≥ 3.21 mg Cr/L (arithmetic mean measured)