Reaction mass of 3-(difluoromethyl)-1-methyl-N-[(1RS,4SR,9RS)-1,2,3,4-tetrahydro-9-isopropyl-1,4-methanonaphthalen-5-yl]pyrazole-4-carboxamide and of 3-(difluoromethyl)-1-methyl-N-[(1RS,4SR,9SR)-1,2,3,4-tetrahydro-9-isopropyl-1,4-methanonaphthalen-5-yl]pyrazole-4-carboxamide; isopyrazam

Toxicity to other aquatic organisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to other aquatic vertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

05 Jun 2011 to 10 Jun 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Qualifier:

according to guideline

Guideline:

other: Testing Guidelines for Environmental Safety Evaluation of Chemical Pesticides

Version / remarks:

issued by Institute for the Control of Agrochemicals, Ministry of Agriculture (ICAMA), China (2004 d
raft)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

yes

Remarks:

acetone

Aquatic vertebrate type (other than fish):

frog

Test organisms (species):

Xenopus laevis

Limit test:

no

Total exposure duration:

48 h

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

37 µg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Results and Discussion

The median lethal concentration (LC50) was defined as the concentration resulting in 50% mortality of the larvae in the time period specified and was calculated by Moving Average Interpolation and Probit analysis. The NOEC (No Observed Effect Concentration) was defined as the highest tested concentration which did not produce toxic-related mortalities or physical and behavioural abnormalities, when compared to the control organisms, and was determined by visual inspection of the data.

Statistically significant mortalities were observed at nominal concentrations of 25 μg/L and above. Symptoms of toxicity observed included apathy and tumbling during swimming at concentrations of 55 μg/L and above. In the control, solvent control, and the test concentrations up to and including 12 μg/L no significant mortality (not above control response) and no visible abnormalities were observed in the larvae. In the control and at the lowest test concentration of 5.5 μg/L, one larva each was dead after 48 hours (3.3% mortality). These observations were considered as natural mortality since according to the test guidelines a mortality rate up to 10% is tolerated in the controls for the test to be valid.

 

Table 1. Effects of the test substance on the survival of Xenopus larvae 

Nominal concentration (µg/L)	Sum of abnormal and dead larvae / number of dead larvae Type of visible abnormalities (n = 30)
	6 hours	24 hours	48
Dilution water control	0/0	0/0	1/1*
Solvent Control	0/0	0/0	0/0
5.5	0/0	0/0	1/1*
12	0/0	0/0	0/0
25	0/0	1/1	4/4
55	30/0 AP	30/4 AP, TS	30/26 AP, TS
120	30/6	30/30	-/-
LC50 (µg/L)	> 120	71	37
95% confidence interval	Cannot be determined	62 - 82	32 - 43
NOEC (µg/L)	n.d.	n.d.	12
LOEC (µg/L)	n.d.	n.d.	25

-/-: all larvae dead

*: 3.3% mortality (a mortality rate of 10% is tolerated by the test guidelines for the test to be valid)

AP: apathy

TS: tumbling during swimming

 

Validity criteria

The test was considered to be valid, since the mortality in the control and solvent control did not exceed 10%, and the oxygen concentration was always higher than 5.8 mg/L as requested by the test guideline.

Validity criteria fulfilled:

yes

Remarks:

See validity criteria in 'Any other information on results incl. tables'

Conclusions:

In this acute toxicity study in Xenopus larvae, performed in accordance with ICAMA guideline, the 48-h LC50 and NOEC were determined to be 37 µg/L and 12 µg/L, respectively, based on the nominal concentrations.

Executive summary:

The acute toxicity of the test item to larvae of the amphibian species Xenopus laevis was determined in a 48-hour semi-static test with daily test medium renewal according to the ICAMA Testing Guideline for Environmental Safety Evaluation of Chemical Pesticides (Draft, 2004). The study was in compliance with GLP criteria. The organisms were exposed to nominal concentrations of 5.5, 12, 25, 55 and 120 μg/L. Additionally, a control and a solvent control (acetone) group were tested in parallel. At the start of the test 30 larvae were randomly allocated to three replicates of each of the test concentrations and the dilution water and solvent controls. The larvae were transferred to new replicate vessels with freshly prepared test medium every 24 hours. Observations for mortalities and visible abnormalities were made at 6, 24 and 48 hours. The test conditions were: 21° C, pH 7.0 – 7.3, dissolved oxygen concentrations at 8.0 – 8.8 mg/L (no aeration was provided), and 16 hours light and 8 hours dark with 30 minute dawn and dusk transition periods (180 – 480 lux).

Statistically significant mortalities were observed at nominal concentrations of 25 μg/L and above. Symptoms of toxicity observed included apathy and tumbling during swimming at concentrations of 55 μg/L and above. In the control, solvent control, and the test concentrations up to and including 12 μg/L no significant mortality (not above control response) and no visible abnormalities were observed in the larvae. In the control and at the lowest test concentration of 5.5 μg/L, one larva each was dead after 48 hours (3.3% mortality). These observations were considered as natural mortality since according to the test guidelines a mortality rate up to 10% is tolerated in the controls for the test to be valid. Based on the findings, the 48-h LC50 and NOEC were determined to be 37 µg/L and 12 µg/L, respectively, based on the nominal concentrations.

Description of key information

48-h LC50 = 37 μg/L and NOEC = 12 μg/L, Xenopus laevis, ICAMA, Peither 2007

Additional information

One study is available for this endpoint. The acute toxicity of the test item to larvae of the amphibian species Xenopus laevis was determined in a 48-hour semi-static test with daily test medium renewal according to the ICAMA Testing Guideline for Environmental Safety Evaluation of Chemical Pesticides (Draft, 2004). The study was in compliance with GLP criteria. The organisms were exposed to nominal concentrations of 5.5, 12, 25, 55 and 120 μg/L. Additionally, a control and a solvent control (acetone) group were tested in parallel. The larvae were transferred to new replicate vessels with freshly prepared test medium every 24 hours. Observations for mortalities and visible abnormalities were made at 6, 24 and 48 hours. The test conditions were: 21° C, pH 7.0 – 7.3, dissolved oxygen concentrations at 8.0 – 8.8 mg/L (no aeration was provided), and 16 hours light and 8 hours dark with 30 minute dawn and dusk transition periods (180 – 480 lux).

Statistically significant mortalities were observed at nominal concentrations of 25 μg/L and above. Symptoms of toxicity observed included apathy and tumbling during swimming at concentrations of 55 μg/L and above. In the control, solvent control, and the test concentrations up to and including 12 μg/L no significant mortality (not above control response) and no visible abnormalities were observed in the larvae. Based on the findings, the 48-h LC50 and NOEC were determined to be 37 µg/L and 12 µg/L, respectively, based on the nominal concentrations.