Tetrachloro-μ-hydroxy(μ-methacrylato-O:O')dichromium

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
In aqueous media, the target substance complexation reaction products of Tetrachloro-μ-hydroxy(μ-methacrylato-O:O')dichromium, isopropylalcohol and water (CAS 15096-41-0) dissociates into the three compounds methacrylic acid (CAS 79-41-4), chromium trichloride (CAS 10025-73-7) and propan-2-ol (CAS 67-63-0). Hence, methacrylic acid, chromium trichloride and propan-2-ol will be present regardless whether the target substance itself or methacrylic acid, chromium trichloride and propan-2-ol, respectively, were used as test material. Moreover, dissociation of the target substance (CAS 15096-41-0) is to be expected in aquatic environmental systems, which allows the read across between the target substance (CAS 15096-41-0) and the source substance chromium trichloride (CAS 10025-73-7).

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
The purity of the source substance which was used in the most reliable test with fish (reference 6.1.1-3) is unknown. The target substance complexation reaction products of Tetrachloro-μ-hydroxy(μ-methacrylato-O:O')dichromium, isopropylalcohol and water (CAS 15096-41-0), has a purity of 100 % (w/w).

3. ANALOGUE APPROACH JUSTIFICATION
Experimental data i.e. acute toxicity studies with fish were available for source substance. The source substance was tested in an study similar to OECD Guideline 203. This study revealed an 96-h LC50 of 11.2 mg/L (nominal) . The information given on chromium trichloride (CAS 10025-73-7) is considered to be sufficient to cover the required endpoint information for the target substance complexation reaction products of Tetrachloro-μ-hydroxy(μ-methacrylato-O:O')dichromium, isopropylalcohol and water (CAS 15096-41-0).

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

11.2 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

chromium

Basis for effect:

mortality (fish)

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
In aqueous media, the target substance complexation reaction products of Tetrachloro-μ-hydroxy(μ-methacrylato-O:O')dichromium, isopropylalcohol and water (CAS 15096-41-0) dissociates into the three compounds methacrylic acid (CAS 79-41-4), chromium trichloride (CAS 10025-73-7) and propan-2-ol (CAS 67-63-0). Hence, methacrylic acid, chromium trichloride and propan-2-ol will be present regardless whether the target substance itself or methacrylic acid, chromium trichloride and propan-2-ol, respectively, were used as test material. Moreover, dissociation of the target substance (CAS 15096-41-0) is to be expected in aquatic environmental systems, which allows the read across between the target substance (CAS 15096-41-0) and the source substance propan-2-ol (CAS 67-63-0).

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
The purity of the source substance which was used in the most reliable test with fish (reference 6.1.1-5) is unknown. The target substance complexation reaction products of Tetrachloro-μ-hydroxy(μ-methacrylato-O:O')dichromium, isopropylalcohol and water (CAS 15096-41-0), has a purity of 100 % (w/w).

3. ANALOGUE APPROACH JUSTIFICATION
Experimental data i.e. acute toxicity studies with fish were available for source substance propan-2-ol (CAS 67-63-0). The source substance was tested in an study similar to OECD to Guideline 203. This study revealed an 96-h LC50 of 10000 mg/L (measured, not specified). The information given on propan-2-ol is considered to be sufficient to cover the required endpoint information for the target substance complexation reaction products of Tetrachloro-μ-hydroxy(μ-methacrylato-O:O')dichromium, isopropylalcohol and water (CAS 15096-41-0).

Reason / purpose for cross-reference:

read-across source

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

10 000 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

9 640 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
In aqueous media, the target substance complexation reaction products of Tetrachloro-μ-hydroxy(μ-methacrylato-O:O')dichromium, isopropylalcohol and water (CAS 15096-41-0) dissociates into the three compounds methacrylic acid (CAS 79-41-4), chromium trichloride (CAS 10025-73-7) and propan-2-ol (CAS 67-63-0). Hence, methacrylic acid, chromium trichloride and propan-2-ol will be present regardless whether the target substance itself or methacrylic acid, chromium trichloride and propan-2-ol, respectively, were used as test material. Moreover, dissociation of the target substance (CAS 15096-41-0) is to be expected in aquatic environmental systems, which allows the read across between the target substance (CAS 15096-41-0) and the source substance methacrylic acid (CAS 79-41-4).

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
The source substance which was used in the most reliable test with fish (reference 6.1.1-1), had a analytical purity of 99.72 %. The target substance, Tetrachloro-μ-hydroxy(μ-methacrylato-O:O')dichromium, isopropylalcohol and water (CAS 15096-41-0), has a purity of 100 % (w/w). Thus, the purity of the test materials is comparable.

3. ANALOGUE APPROACH JUSTIFICATION
Experimental data i.e. acute toxicity studies with fish were available for methacrylic acid. The source substance was tested in an study according to Guideline US EPA OTS 797.1400. This study revealed an effect level of LC50 = 85 mg/L (measured, not specified). The information given on source substance is considered to be sufficient to cover the required endpoint information for the target substance complexation reaction products of Tetrachloro-μ-hydroxy(μ-methacrylato-O:O')dichromium, isopropylalcohol and water (CAS 15096-41-0).

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

833 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Description of key information

In an acute toxicity test similar to OECD Guideline 203 with chromium trichloride (CAS 79-41-4), the 96-h LC50 was determined to be 11.2 mg/L (nominal). This value has been chosen in a worst case approach out of available data for the structural analogues Methacrylic acid (CAS 79-41-4), Chromium trichloride (CAS 10025-73-7) and Propan-2-ol (CAS 67-63-0).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

11.2 mg/L

Additional information

No data on toxicity to fish was availbale for the substance itself. In aqueous media, the substance dissociates into the three compounds methacrylic acid (CAS 79-41-4), chromium trichloride (CAS 10025-73-7) and propan-2-ol  (CAS 67-63-0). Thus, dissociation of the target substance (CAS 15096 -41 -0) is to be expected in aquatic environmental systems. Therefore, a read across between the target substance (CAS 15096-41-0) and the source substances methacrylate (CAS 79-41-4), chromium trichloride (CAS 10025-73-7) and propan-2-ol (CAS 67-63-0) was conducted. The available studies were assesseed in a weight of evidence approach.

 

Data were available of a valid acute toxicity test with the structural analogue methacrylate (CAS 79-41-4) according to the guideline US EPA OTS 797.1400, twenty fish (Oncorhynchus mykiss) per concentration plus a dilution water control were used in a flow-through system with a duplicate nominal dosing regimen of 6.5, 13, 25, 50 and 100 mg/L. Fish were temperature acclimated in the absence of food for 72 hours before initiation of the test. Test temperature, dissolved oxygen and pH was measured at all test concentrations at 0, 48 and 96 hours. Samples for analytical measurements of the test item concentration were taken at 0 and 96 hrs. The measured test item concentrations were: 6.2, 12, 23, 46, and 97 mg/L. During the test, the hardness of the test media was 47 - 48 mg CaCO3/l, the temperature between 11 and 12 °C, the pH between 5.3 and 7.8 and the dissolved oxygen concentration in the range of 8.2 - 9.4 mg/L. In result, the 96-h NOEC and EC50 of the test item was determined to be 12 and 85 mg/L (based on measured concentrations), respectively. This value was chosen as key parameter for the risk assessment.

 

In a valid acute toxicity test with Scophthalmus maximus according to the OSPAR Protocols on Methods for the Testing of Chemicals Used in the Offshore Oil Industry, 1995, in a semi-static test system was investigated. Test temperature, dissolved oxygen and pH were measured at all test concentrations at 0, 48 and 96 hours. Samples for analytical measurements of the test item concentration were taken at 0 and 96 hrs. During the test, the temperature between 13 and 17 °C, the pH 8 were maintained. In result, the 96-h EC50 of the test item was determined to be 833 mg/L (based on measured concentrations), respectively. (reference 6.1.1-1).

 

In a study similar to OECD Guideline 203, the effects of pre-treatment of rainbow trouts by different concentrations of polychorinated biphenyls on the acute toxicity to six different contaminants (mercury(II), chromium(III), cyanides, nitrates, nitirite, and chlorides) was investigated. Acute toxicity to these contaminants was tested using a control group of rainbow trouts (no pre-treatment towards PCBs) a low level group (PCB concentration of 0.46 µg/g tissue) and a high level group (PCB concentration of 3.40 µg/g tissue). The results found for the control groups exposed to chromium(III) was a LC50 (96h) of 11.2 mg Cr/L. Results with animals from the low level and high level group were 9.0 and 7.05 mg Cr/L respectively. The result for the control group is considered representative for acute toxicity towards the structural analogue chromium trichloride (CAS 10025-73-7) and can be converted to LC50 (96h) of 57.4 mg/L as chromium trichloride hexahydrate (reference 6.1.1-3).

 

In an acute toxicity test with the structural analogue propan-2-ol (CAS 67-63-0) similar to OECD Guideline 203 with 4 fish (Pimephales promelas) per concentration of the test item (concentration levels not reported, 2 vessels per concentration, 2 animals per vessel) were exposed in a flow-through system over a period of 96.0 h. Additionally, a negative control (2 replicates) was performed. For the test solutions Lake Superior water was was used as dilution water. Its alkalinity was determined to be 42.2 mg/L Calcium Carbonate. The test temperature was 25 ± 1°C, the pH = 7.5 and the dissolved oxygen concentration greater than 60% of saturation. Mortality was recorded in two test runs after 1, 3, 6, 12, 24, 48, 72, and 96 hours. In result, the 96-h LC50 for the first test was determined to be 10000 mg/L, for the second test 9640 mg/L (reference 6.1.1 5).

 

Conclusion

Based on a worst case approach, the 96-h LC50 for the target substance is considered to be 11.2 mg/L as determined for chromium(III) (reference 6.1.1-3).