Mecoprop

Long-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adult fish: sub(lethal) effects

Type of information:

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

Adequacy of study:

supporting study

Justification for type of information:

Please see the read-across justification report in Section 13 of the dossier.

Reason / purpose for cross-reference:

read-across source

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Conclusions:

Under the conditions of this study the overall NOEC was determined to be 50 mg/L for the rainbow trout (nominal concentration).
The threshold level for lethal effects was greater than 100 mg/L, for toxic signs about 100 mg/L and for the growth parameters body weight plus length greater than 50 and smaller than 100 mg/L (nominal concentrations).

Considering the very close structural similarity between the source and target substances (as justified in the read-across report that is attached to section 13 of the dossier), results from the study performed with mecoprop-p can be extrapolated to mecoprop.

Executive summary:

The toxicity of the test material was assessed according to OECD Test Guideline 204 and in compliance with GLP

The test material was tested for its sublethal toxic effects on rainbow trout, 20 fish/test group, in the concentrations 0 (control), l, 10, 50 and 100 mg/L in a flow-through system for a period of 4 weeks, and the following results were obtained:

Mortality:

- In the control group as well as in all groups containing test compound (l, 10, 50 and 100 mg/L) no mortalities occurred.

- The threshold level of lethal effects was greater than 100 mg/L. Highest concentration tested without test material-related mortalities was 100 mg/L.

Toxic signs (symptoms): No marked toxic signs were seen in all test groups. Only in the highest dose group (100 mg/L) a slight discolouration was seen on days 2 and 5 of the study. The threshold level for toxic signs was about 100 mg/L.

The "No Observed Effect Concentration" for toxic signs was 50 mg/L.

Body weight and length: Compared with the control group, at the end of the study, the mean body weight in the test group 100 mg/L was statistically significantly smaller at the p ≤ 0.05 level. The mean body length at the end of the study was statistically significantly smaller in this test group at the p ≤ 0.01 level.

Under the conditions of this study the threshold level for the growth parameters body weight and length was greater than 50 and smaller than 100 mg/L and the no effect concentration for these parameters was 50 mg/L.

Under the conditions of this study the overall NOEC was determined to be 50 mg/L for the rainbow trout (nominal concentration).

The threshold level for lethal effects was greater than 100 mg/L, for toxic signs about 100 mg/L and for the growth parameters body weight plus length greater than 50 and smaller than 100 mg/L (nominal concentrations).

 

Findings from the study conducted with the read-across substance are viewed as representing a 'worst case' scenario bearing in mind it is information on the read-across substance that is driving the environmental classification of the registered substance. Hence relying on information on the read-across substance is viewed as representing a conservative approach to risk assessment of the registered substance.

Reference 2

Endpoint:

fish early-life stage toxicity

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Please see the read-across justification report in Section 13 of the dossier.

Reason / purpose for cross-reference:

read-across source

Key result

Duration:

89 d

Dose descriptor:

NOEC

Effect conc.:

11.2 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: Effects on eggs, larvae and fish

Conclusions:

Under the conditions of the study, the test material had no toxic effects to rainbow trout up to the highest test concentration of mean measured 11.2 mg/L (NOEC 11.2 mg/L).

Considering the very close structural similarity between the source and target substances (as justified in the read-across report that is attached to section 13 of the dossier), results from the study performed with mecoprop-p can be extrapolated to mecoprop.

Executive summary:

The toxicity of the test material was investigated in an early-life stage toxicity test according to the OECD Guideline 210 and in compliance with GLP.

Freshly fertilised eggs of rainbow trout were exposed to test media containing the test material at nominal concentrations of 0.12, 0.38, 1.2, 3.8 and 12 mg/L under flow-through conditions for the test period of 89 days (60 days post hatch). Additionally, a control and a solvent control (DMF) were tested in parallel. 

At the start of the test, 80 eggs each (divided into 4 replicates) were distributed to the test concentrations, control and solvent control. The eggs, larvae and juvenile fish were observed for toxic effects on their development, growth and survival.

The test material concentration in the test medium of nominal 12 mg/L (determined as the overall NOEC) varied in the range from 84 to 111 % of the nominal value during the whole exposure period of 89 days (except on Days 14 and 76, where slightly lower values of 74 and 68 % of nominal were determined). The analytical results demonstrate that the test concentration was sufficiently maintained during the test period of 89 days. The mean measured test material concentration (calculated as the arithmetic mean of all measurements of the test concentration of 12 mg/L) was calculated to be 11.2 mg/L. The NOEC and LOEC were related to the mean measured test material concentrations of the test material.

Hatching rate, development rate of embryos, survival of larvae and juvenile fish, fish body length and fish wet weight and dry weight all resulted in a NOEC of 11.2 mg/L and a LOEC of > 11.2 mg/L.

The NOEC values for each of the test parameters assessed, the overall NOEC of the test material for early life stages of rainbow trout was determined to be the mean measured test concentration of 11.2 mg/L (nominal 12 mg/L), since no toxic effect on the eggs, larvae or fish was observed up to and including this test concentration. The overall LOEC could not be determined due to the absence of toxic effect of the test material up to the highest test concentration (LOEC > 11.2 mg/L).

Under the conditions of the study, the test material had no toxic effects to rainbow trout up to the highest test concentration of mean measured 11.2 mg/L.

 

 

Findings from the study conducted with the read-across substance are viewed as representing a 'worst case' scenario bearing in mind it is information on the read-across substance that is driving the environmental classification of the registered substance. Hence relying on information on the read-across substance is viewed as representing a conservative approach to risk assessment of the registered substance.

Description of key information

Key study: Peither (2015) - Read across (MCPP-P)

Under the conditions of the study, the test material had no toxic effects to rainbow trout up to the highest test concentration of mean measured 11.2 mg/L.

 

Supporting Study: Munk (1993) - - Read across (MCPP-P)

Under the conditions of this study the overall NOEC was determined to be 50 mg/L for the rainbow trout (nominal concentration).

The threshold level for lethal effects was greater than 100 mg/L, for toxic signs about 100 mg/L and for the growth parameters body weight plus length greater than 50 and smaller than 100 mg/L (nominal concentrations).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

NOEC

Effect concentration:

11.2 mg/L

Additional information

Key study: Peither (2015) - Read across (MCPP-P)

The toxicity of the test material was investigated in an early-life stage toxicity test according to the OECD Guideline 210 and in compliance with GLP. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

Freshly fertilised eggs of rainbow trout were exposed to test media containing the test material at nominal concentrations of 0.12, 0.38, 1.2, 3.8 and 12 mg/L under flow-through conditions for the test period of 89 days (60 days post hatch). Additionally, a control and a solvent control (DMF) were tested in parallel. 

At the start of the test, 80 eggs each (divided into 4 replicates) were distributed to the test concentrations, control and solvent control. The eggs, larvae and juvenile fish were observed for toxic effects on their development, growth and survival.

The test material concentration in the test medium of nominal 12 mg/L (determined as the overall NOEC) varied in the range from 84 to 111 % of the nominal value during the whole exposure period of 89 days (except on Days 14 and 76, where slightly lower values of 74 and 68 % of nominal were determined). The analytical results demonstrate that the test concentration was sufficiently maintained during the test period of 89 days. The mean measured test material concentration (calculated as the arithmetic mean of all measurements of the test concentration of 12 mg/L) was calculated to be 11.2 mg/L. The NOEC and LOEC were related to the mean measured test material concentrations of the test material.

Hatching rate, development rate of embryos, survival of larvae and juvenile fish, fish body length and fish wet weight and dry weight all resulted in a NOEC of 11.2 mg/L and a LOEC of > 11.2 mg/L.

The NOEC values for each of the test parameters assessed, the overall NOEC of the test material for early life stages of rainbow trout was determined to be the mean measured test concentration of 11.2 mg/L (nominal 12 mg/L), since no toxic effect on the eggs, larvae or fish was observed up to and including this test concentration. The overall LOEC could not be determined due to the absence of toxic effect of the test material up to the highest test concentration (LOEC > 11.2 mg/L).

Under the conditions of the study, the test material had no toxic effects to rainbow trout up to the highest test concentration of mean measured 11.2 mg/L.

 

Supporting Study: Munk (1993) - - Read across (MCPP-P)

The toxicity of the test material was assessed according to OECD Test Guideline 204 and in compliance with GLP. The study was awarded a reliability score of 2 in accordance with the criteria set forth by Klimisch et al. (1997).

The test material was tested for its sublethal toxic effects on rainbow trout, 20 fish/test group, in the concentrations 0 (control), l, 10, 50 and 100 mg/L in a flow-through system for a period of 4 weeks, and the following results were obtained:

Mortality:

- In the control group as well as in all groups containing test compound (l, 10, 50 and 100 mg/L) no mortalities occurred.

- The threshold level of lethal effects was greater than 100 mg/L. Highest concentration tested without test material-related mortalities was 100 mg/L.

Toxic signs (symptoms): No marked toxic signs were seen in all test groups. Only in the highest dose group (100 mg/L) a slight discolouration was seen on days 2 and 5 of the study. The threshold level for toxic signs was about 100 mg/L.

The "No Observed Effect Concentration" for toxic signs was 50 mg/L.

Body weight and length: Compared with the control group, at the end of the study, the mean body weight in the test group 100 mg/L was statistically significantly smaller at the p≤0.05 level. The mean body length at the end of the study was statistically significantly smaller in this test group at the p≤0.01 level.

Under the conditions of this study the threshold level for the growth parameters body weight and length was greater than 50 and smaller than 100 mg/L and the no effect concentration for these parameters was 50 mg/L.

Under the conditions of this study the overall NOEC was determined to be 50 mg/L for the rainbow trout (nominal concentration).

The threshold level for lethal effects was greater than 100 mg/L, for toxic signs about 100 mg/L and for the growth parameters body weight plus length greater than 50 and smaller than 100 mg/L (nominal concentrations).

 

 

Considering the very close structural similarity between the source and target substances (as justified in the read-across report that is attached to section 13 of the dossier), results from the study performed with mecoprop-p can be extrapolated to mecoprop.

 

Findings from studies conducted with the read-across substance are viewed as representing a 'worst case' scenario bearing in mind it is information on the read-across substance that is driving the environmental classification of the registered substance. Hence relying on information on the read-across substance is viewed as representing a conservative approach to risk assessment of the registered substance.