Thiophanate-methyl

Long-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1989-07-24 to 1989-08-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 211 (Daphnia magna Reproduction Test)

Version / remarks:

October 2012

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.18, 0.56, 1.8, 5.6 and 18.0 mg/L
- Sampling method: samples of fresh media were taken on Day 0 and expired media were taken on Days 2, 4, 7, 9, 11, 14, 16, 18 and 21 from each test and solvent control vessel (replicates pooled). Test item concentration in the samples was determined by high performance liquid chromatography, using an external standard technique.

Vehicle:

yes

Remarks:

1 % Tween 80 in dimethylformamide

Details on test solutions:

Standard stock solutions were prepared in 1 % Tween 80 in dimethyl-formamide at concentrations of approximately 1.8, 5.6, 18.0, 56.0 and 180 g/L. These stock solution were then further diluted with dechlorinated tap water, to give approximate Thiophanate methyl concentrations of 0.18, 0.56, 1.8, 5.6 and 18.0 mg/L, respectively. The stability of the test concentrations were verified by chemical analysis.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Straus
- Age at study initiation: Young daphnids produced overnight were used for testing
- Source: Institute National de Recherche Chimique Appliquée (I.R.CH.A.)
- Feeding during test: yes
- Food type: unicellular algal and fry fish food

ACCLIMATION
At 20 ± 2 °C in glass vessels containing two litres of dechlorinated and aged tap water. Cultures were fed daily with a mixture of fry fish food (Liquifry) and a suspension of mixed algae (predominantly Chlorella spp.). Culture conditions ensure that reproduction is by parthenogenesis.

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

21 d

Hardness:

50 mg/L as CaCO3

Test temperature:

21 ± 1 °C

pH:

7.7 - 7.8

Dissolved oxygen:

8.0 to 8.8 mg/L

Nominal and measured concentrations:

Nominal concentration: 0.18, 0.56, 1.8, 5.6 and 18 mg/L
Concentration found initially: 0.168, 0486, 1.65, 5.24 and 16.3 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass flasks
- Material and fill volume: Glass flasks each containing 400 mL test solution.
- Aeration: none
- Renewal rate of test solution: 3 times per week
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per solvent control (replicates): 4
- Biomass loading rate: 40 mL test solution per organism

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Dechlorinated (with sodium thiosulphate) and aged laboratory tap water

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16h light: 8h dark

EFFECT PARAMETERS MEASURED: Immobilisation and reproduction

Reference substance (positive control):

not specified

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.161 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: Results of the re-evaluation of the study using ToxRat (version 3.2.1)

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

0.273 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: Results of the re-evaluation of the study using ToxRat (version 3.2.1)

Duration:

21 d

Dose descriptor:

other: EC20

Effect conc.:

0.215 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: Results of the re-evaluation of the study using ToxRat (version 3.2.1)

Key result

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

0.19 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: Results of the re-evaluation of the study using ToxRat (version 3.2.1)

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

1.64 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

immobilisation

Remarks on result:

other: Results of the re-evaluation of the study using ToxRat (version 3.2.1)

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

2.77 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

immobilisation

Remarks on result:

other: Results of the re-evaluation of the study using ToxRat (version 3.2.1)

Duration:

21 d

Dose descriptor:

other: EC20

Effect conc.:

1.96 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

immobilisation

Remarks on result:

other: Results of the re-evaluation of the study using ToxRat (version 3.2.1)

Duration:

21 d

Dose descriptor:

EC10

Effect conc.:

1.63 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

immobilisation

Remarks on result:

other: Results of the re-evaluation of the study using ToxRat (version 3.2.1)

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: Results based on initial Daphnia magna toxicity study with Thiophanate-methyl (Handley, 1990, RD-9010) conducted according to the OECD 202 Part II guideline

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

3.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Remarks on result:

other: Results based on initial Daphnia magna toxicity study with Thiophanate-methyl (Handley, 1990, RD-9010) conducted according to the OECD 202 Part II guideline

Duration:

21 d

Dose descriptor:

EC50

Effect conc.:

3.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

immobilisation

Remarks on result:

other: Results based on initial Daphnia magna toxicity study with Thiophanate-methyl (Handley, 1990, RD-9010) conducted according to the OECD 202 Part II guideline

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

0.18 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

immobilisation

Remarks on result:

other: Results based on initial Daphnia magna toxicity study with Thiophanate-methyl (Handley, 1990, RD-9010) conducted according to the OECD 202 Part II guideline

Details on results:

In preparation of the renewal of Thiophanate-methyl according to Annex I of Regulation (EC) No 1107/2009, the validity of the available Daphnia magna toxicity study with Thiophanate-methyl (Handley, 1990, RD-9010) was checked. The study was re-evaluated with the statistic programme ToxRat® Professional (version 3.2.1) in order to see whether the study is still valid and complies with requirements of the current OECD 211 guideline. The nominal test item concentrations were 0.18, 0.56, 1.8, 5.6, and 18 mg/L. All test item treatment groups were analysed. As the measured concentrations differed to more than 20 % from the nominal concentrations, the reported biological results are related to the geometric mean measured concentrations of the test item (0.161, 0.476, 1.64, 5.22, and 16.2 mg/L).

Table 1: Toxicity endpoints for effects on immobility and reproduction of the Daphnia magna study (Handley, 1990) after exposure to Thiophanate-methyl

Parameter	EC10 [mg/L]	EC20 [mg/L]	EC50 [mg/L]	NOEC [mg/L]
0 - 21 d immobility (95 % confidence intervals)	1.63 (1.36 - 1.89)	1.96 (1.67 - 2.24)	2.77 (2.43 - 3.17)	1.64
0 - 21 d reproduction (95 % confidence intervals)	0.190 (0.181 - 0.199)	0.215 (0.205 - 0.225)	0.273 (0.261 - 0.285)	0.161

 

Table 2: Analytical resuts

Nominal test concentration	Mean measured concentration	% of nominal values
Control	-	-
0.18	0.168	93.3
0.56	0.486	86.8
1.8	1.65	91.7
5.6	5.24	93.5
18	16.3	90.6

 

Table 3: Summary of Results for all Endpoints at the End of Exposure Period: Critical effect and threshold concentration as observed at end of experimental time; EC: Effective concentration for xx % reduction; 95 %-CL: 95 % Confidence limits; LOEC: Lowest observed effect concentration; NOEC: No observed effect concentration.

Critical Conc. [mg/L]
Cumulative offspring per introduced parent (21.0 d)
95 % - CL	EC10	0.190
	Lower	0.181
	upper	0.199
95 % - CL	EC20	0.215
	Lower	0.205
	Upper	0.225
95 % - CL	EC50	0.273
	lower	0.261
	upper	0.285
Cumulative offspring per introduced parent LOEC		0.476
NOEC		0.161
Cumulative offspring per survived parent (0 - 21.0 d)
95 % - CL	EC10	0.190
	Lower	0.181
	upper	0.199
95 % - CL	EC20	0.215
	Lower	0.205
	Upper	0.225
95 % - CL	EC50	0.273
	lower	0.261
	upper	0.285
Cumulative offspring per introduced parent LOEC		0.476
NOEC		0.161
Immobility (0 - 21.0 d)
95 % - CL	EC10	1.633
	Lower	1.356
	upper	1.893
95 % - CL	EC20	1.958
	Lower	1.668
	Upper	2.241
95 % - CL	EC50	2.770
	lower	2.427
	upper	3.165
Immobility	LOEC	5.220
	NOEC	1.640

 

Table 4: Offspring per Day and Parent as Dependent on Concentration and Time (Offspring per day and parent in Daphnia magna as dependent on concentration of the test item and time; Mean: arithmetic mean; Std.Dev.: standard deviation; n: number of replicates; CV: coefficient of variation (from Input Offspring))

Treatm. [mg/L]		Control	Solvent	0.161	0.476	1.640	5.220	16.200
0.0 d		0.0	0.0	0.0	0.0	0.0	0.0	0.0
		0.0	0.0	0.0	0.0	0.0	0.0	0.0
		0.0	0.0	0.0	0.0	0.0	0.0	0.0
		0.0	0.0	0.0	0.0	0.0	0.0	0.0
Mean:		0.0	0.0	0.0	0.0	0.0	0.0	0.0
Std.Dev.:		0.00	0.00	0.00	0.00	0.00	0.00	0.00
n:		4	4	4	4	4	4	4
CV:
21.0 d		773.0	733.0	743.0	19.0	0.0	0.0	0.0
		731.0	801.0	754.0	18.0	0.0	0.0	0.0
		770.0	776.0	720.0	20.0	0.0	0.0	0.0
		731.0	689.0	699.0	16.0	0.0	0.0	0.0
Mean:	751.3		749.8	729.0	18.3	0.0	0.0	0.0
Std.Dev.:	23.41		49.28	24.51	1.71	0.00	0.00	0.00
n:	4		4	4	4	4	4	4
CV:	3.1		6.6	3.4	9.4

 

Table 5: Offspring per Day and Beaker as Dependent on Concentration and Time (Offspring per day and beaker in Daphnia magna as dependent on concentration of the test item and time; Mean: arithmetic mean; Std.Dev.: standard deviation; n: number of replicates; CV: coefficient of variation (from Input Offspring))

Treatm. [mg/L]	Control	Solvent	0.161	0.476	1.640		5.220	16.200
0.0 d	0.0	0.0	0.0	0.0	0.0		0.0	0.0
	0.0	0.0	0.0	0.0	0.0		0.0	0.0
	0.0	0.0	0.0	0.0	0.0		0.0	0.0
	0.0	0.0	0.0	0.0	0.0		0.0	0.0
Mean:	0.0	0.0	0.0	0.0	0.0		0.0	0.0
Std.Dev.:	0.00	0.00	0.00	0.00	0.00		0.00	0.00
n:	4	4	4	4	4		4	4
CV:
21.0 d	77.3	73.3	74.3	1.9	0.0		0.0	0.0
	73.1	80.1	75.4	1.8	0.0		0.0	0.0
	77.0	77.6	72.0	2.0	0.0		0.0	0.0
	73.1	68.9	69.9	1.6	0.0		0.0	0.0
Mean:	75.1	75.0	72.9	1.8	0.0		0.0	0.0
Std.Dev.:	2.34	4.93	2.45	0.17	0.00		0.00	0.00
n:	4	4	4	4	4		4	4
CV:	3.1	6.6	3.4	9.4

 

Cumulative Offspring per Introduced Parent (Data)

Table 6: Cumulative Offspring per Introduced Parent as Dependent on Concentration and Time (Cumulative offspring per introduced parent in Daphnia magna as dependent on concentration of the test item and time; Mean: arithmetic mean; Std.Dev.: standard deviation; n: number of replicates; CV: coefficient of variation (calculated from Input Offspring))

Treatm. [mg/L]	Control	Solvent	0.161	0.476	1.640	5.220	16.200
21.0 d	77.3	73.3	74.3	1.9	0.0	0.0	0.0
	73.1	80.1	75.4	1.8	0.0	0.0	0.0
	77.0	77.6	72.0	2.0	0.0	0.0	0.0
	73.1	68.9	69.9	1.6	0.0	0.0	0.0
Mean:	75.1	75.0	72.9	1.8	0.0	0.0	0.0
Std.Dev.:	2.34	4.93	2.45	0.17	0.00	0.00	0.00
n:	4	4	4	4	4	4	4
CV:	3.1	6.6	3.4	9.4

Validity criteria fulfilled:

yes

Conclusions:

The EC10, EC20 and EC50 values for the endpoint immobility were 1.63, 1.96 and 2.77 mg/L, respectively. For the endpoint reproduction, the EC10, EC20 and EC50 values were 0.190, 0.215 and 0.273 mg/L, respectively. The NOEC values for immobility and reproduction were 1.64 and 0.161 mg/L, respectively.

Executive summary:

In preparation of the renewal of Thiophanate-methyl according to Annex I of Regulation (EC) No 1107/2009, the validity of the available Daphnia magna toxicity study with Thiophanate-methyl (Handley, 1990, RD-9010) was checked. The study was conducted according to the OECD 202 Part II guideline. In the study report, the following endpoints were obtained (relative to the performance of the control):

Immobility: Based on nominal concentrations, the 21-day EC50 value for immobility was calculated as 3.1 mg/L. Based on the statistical evaluation, the 21-day No-Observed-Effect Concentration (NOEC) was equal to 0.18 mg/L.

Reproduction: Based on nominal concentrations, the 21-day EC50 value for reproduction was calculated as 3.2 mg/L. Based on the statistical evaluation, the 21-day No-Observed-Effect Concentration (NOEC) was equal to 0.18 mg/L.

The study was re-evaluated with the statistic programme ToxRat® Professional (version 3.2.1) in order to see whether the study is still valid and complies with requirements of the current OECD 211 guideline. The present report provides the re-calculated endpoints as well as the detailed data of the statistical evaluation. The study is considered valid as the following validity criteria were met:

1) the maximum control mortality in females must not exceed 20 % (actual 0 %), and

2) the mean offspring number at day 21 must be at least 60.0 (actual 75.1).

With respect to these criteria, the test is valid.

The nominal test item concentrations were 0.18, 0.56, 1.8, 5.6, and 18 mg/L. All test item treatment groups were analysed. As the measured concentrations differed to more than 20 % from the nominal concentrations, the reported biological results are related to the geometric mean measured concentrations of the test item (0.161, 0.476, 1.64, 5.22, and 16.2 mg/L).

The EC₁₀, EC₂₀ and EC₅₀ values for the endpoint immobility were 1.63, 1.96 and 2.77 mg/L, respectively. For the endpoint reproduction, the EC₁₀, EC₂₀ and EC₅₀ values were 0.190, 0.215 and 0.273 mg/L, respectively. The NOEC values for immobility and reproduction were 1.64 and 0.161 mg/L, respectively.

Description of key information

The EC₁₀, EC₂₀ and EC₅₀ values for the endpoint immobility were 1.63, 1.96 and 2.77 mg/L, respectively. For the endpoint reproduction, the EC₁₀, EC₂₀ and EC₅₀ values were 0.190, 0.215 and 0.273 mg/L, respectively. The NOEC values for immobility and reproduction were 1.64 and 0.161 mg/L, respectively.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.161 mg/L

Additional information

In preparation of the renewal of Thiophanate-methyl according to Annex I of Regulation (EC) No 1107/2009, the validity of the available Daphnia magna toxicity study with Thiophanate-methyl (Handley, 1990, RD-9010) was checked. The study was conducted according to the OECD 202 Part II guideline. In the study report, the following endpoints were obtained (relative to the performance of the control):

Immobility: Based on nominal concentrations, the 21-day EC₅₀ value for immobility was calculated as 3.1 mg/L. Based on the statistical evaluation, the 21-day No-Observed-Effect Concentration (NOEC) was equal to 0.18 mg/L.

Reproduction: Based on nominal concentrations, the 21-day EC₅₀ value for reproduction was calculated as 3.2 mg/L. Based on the statistical evaluation, the 21-day No-Observed-Effect Concentration (NOEC) was equal to 0.18 mg/L.

The study was re-evaluated with the statistic programme ToxRat® Professional (version 3.2.1) in order to see whether the study is still valid and complies with requirements of the current OECD 211 guideline. The present report provides the re-calculated endpoints as well as the detailed data of the statistical evaluation. The study is considered valid as the following validity criteria were met:

1) the maximum control mortality in females must not exceed 20 % (actual 0 %), and

2) the mean offspring number at day 21 must be at least 60.0 (actual 75.1).

With respect to these criteria, the test is valid.

The nominal test item concentrations were 0.18, 0.56, 1.8, 5.6, and 18 mg/L. All test item treatment groups were analysed. As the measured concentrations differed to more than 20 % from the nominal concentrations, the reported biological results are related to the geometric mean measured concentrations of the test item (0.161, 0.476, 1.64, 5.22, and 16.2 mg/L).

The EC₁₀, EC₂₀ and EC₅₀ values for the endpoint immobility were 1.63, 1.96 and 2.77 mg/L, respectively. For the endpoint reproduction, the EC₁₀, EC₂₀ and EC₅₀ values were 0.190, 0.215 and 0.273 mg/L, respectively. The NOEC values for immobility and reproduction were 1.64 and 0.161 mg/L, respectively.