1-nitroguanidine

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: ASTM Designation E 729-80 (ASTM, 1980)

GLP compliance:

not specified

Specific details on test material used for the study:

Test substance supplier U.S Naval Ordnance Station
Lot No 985-1
Essay 99.998%

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Ceriodaphnia dubia

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

2 698 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Remarks:

nitroguanidine

Basis for effect:

mortality

Remarks on result:

other: 95% fiducial limits = 2276 - 3298 mg/l

Validity criteria fulfilled:

not specified

Conclusions:

Based on the results of this study, Nitroguanidine appears to present little hazard to Ceriodaphnia dubia.

Executive summary:

The 48h acute toxicity of nitroguanidine to Ceriodaphnia dubia was studied under static renewal conditions. Daphnids were exposed to nitroguanidine at mean measured concentrations of 0, 500, 920, 730, 1440, 2540, and 4020 mg/L.

The LC₅₀(48h) for nitroguanidine was 2698 mg/L (mean measured concentration).

Based on the results of this study, nitroguanidine appears to present little hazard to Ceriodaphnia dubia.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1985

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: Am. Soc. Test. Mat. 1980. Standard practice for conducting acute toxicity tests with fishes, macroinvertebrates, and amphibians. E 729-80.

Deviations:

not specified

GLP compliance:

not specified

Specific details on test material used for the study:

Test substance supplier: Aldrich Chemicla Co
Water content: 25%

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 2 838 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: nitroguanidine solution

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

24.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

photolyzed nitroguanidine

Basis for effect:

mobility

Remarks on result:

other: photolyzed nitroguanidine solution

Table 1: Acute toxicity of nitroguanidine to Daphnia magna

Species	Length of exposure (h)	Mean measured concentration^a (mg/l)	Percent immobilization
Daphnia magna	48	2838	16.7
		1485	0
		< 1.49	0

^athe high, low and control nitroguanidine concentrations are listed

Table 2: The Effect of photolyzation on the acute toxicity of nitroguanidine to Daphnia magna

Species	End point	Toxicant concentration (mg/l)			Relative Toxicity Ratio, photol. NGu/ NGu
		NGu		Photolyzed NGu^a
Daphnia magna	EC50(48h)	> 2838	Aged photolyzed NGu^b:	24.6 (21.1-28.7) 35.0 (26.2-38.5)	> 115 > 81

^aConcentration reported as NGu (mg/l) prior to photolyzation. No mortality was observed in the photolyzed well water control tanks

^bTest used the same photolyzed NGu solution as the first test after it was stored for 3 days at room temperature

Validity criteria fulfilled:

not specified

Conclusions:

Nitroguanidine appears to present little hazard to Daphnia magna.
Photolysis increased the acute toxicity by a factor from over 115, and aging of photolyzed nitroguanidine for 72 hours had little effect on its toxicity.

Executive summary:

The 48 h acute toxicity of nitroguanidine to Daphnia magna was studied under static conditions. Daphnids were exposed to nitroguanidine at two concentrations (nitroguanidine saturation concentration at the test temperature and 50 % of saturation) and to photolyzed nitroguanidine at least at four test concentrations so that an LC₅₀ or EC₅₀ could be adequately defined.

The EC₅₀(48h) for nitroguanidine was > 2838 mg/L (mean measured concentration).

 

The EC₅₀(48h) for photolyzed nitroguanidine was 24.6 mg/L (mean measured concentration).

Based on the results of this study, nitroguanidine appears to present little hazard to Daphnia magna. Photolysis increased the acute toxicity by a factor from over 115, and aging of photolyzed Nitroguanidine for 72 hours had little effect on its toxicity.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2-4 May 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

not specified

Analytical monitoring:

no

Details on sampling:

Not applicable

Vehicle:

no

Details on test solutions:

- The final test medium contained 25 mL/L of each of the following 4 stock solutions:
* CaCl2 x 2 H2O, 11.76 g/L
* MgSO4 x 7 H2O, 4.93 g/L
* NaHCO3, 2.59 g/L
* KCl, 0.23 g/L

- Sum of Mg and Ca ions: 2.5 mmol/L
- Ca:Mg ratio = 4:1
- Na:K ratio = 10:1
- Alkalinity: 0.8 mmol/L

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain: Daphnia magna (Straus, 1820)
- Source: breeding in laboratory
- Breeding: * Parental and young Daphnia were held in 250 l glass aquaria at 20 +/- 2 °C
* Illumination 16h/d
* Medium: reconstituted water (ISO 6341 (3)); prepared with distilled water (conductivity < 1.5 µS/cm)
* Feed: 15 g sera micropan homogenized in 1 L deionized water
* Frequency of feeding: once daily, except weekends
* Measurements: temperature, pH, conductivity, oxygen concentration and hardness of water were determined once weekly
* Control of sensitivity: periodically conducted reference test with potassium dichromate
- Size: < 2 mm


ACCLIMATION
- Acclimation period: 4 h before introduction into the test media
- Acclimation conditions: same as test

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

no data

Test temperature:

20 +/- 0.5 °C (temperature-controlled water bath)

pH:

7.5 - 8.0

Dissolved oxygen:

6.6 - 7.0 mg/L

Salinity:

no data

Nominal and measured concentrations:

- 100, 200 400, 800, 1600 and 3000 mg/L
- no analytical verification of test concentrations

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL flasks, all-glass, with 50 mL of test medium
- Aeration: no
- Test medium: reconstituted water (ISO 6341 (5); see also "details on test solution")
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 3


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water (ISO 6341 (5); see also "details on test solution")
- Alkalinity: 0.8 mmol/L
- Ca/mg ratio: 4/1
- Conductivity: < 1.5 µS/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: at the start and at the end of the test
- Handling: * Prior to the test, a batch of reconstituted water was aerated vigorously over a period of 2 h
* Final test concentrations were prepared with this aerated water by dilution of stock solutions of the test substance
* 2 h before the test, vessels were filled with the formulated media to allow equilibration of pH, oxygen and temperature


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h/d
- Illumination: overhead white fluorescent tubes


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Mobility


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2 of 100, 200, 400, 800, 1600 mg/L and additionally 3000 mg/L were chosen
- Range finding study:
- Test concentrations (nominal): 0, 1, 10, 100 mg/L
- Exposure time: 24 and 48 h
- 2 x 20 individuals per test concentration, 3 blank controls were conducted
- Results used to determine the conditions for the definitive study: immobility

Reference substance (positive control):

no

Remarks:

Control of sensitivity: periodically conducted reference test with potassium dichromate during breeding

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 3 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

80% active ingredient, 20% water

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 3 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

80% active ingredient, 20% water

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

>= 3 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

80% active ingredient, 20% water

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 1 600 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

80% active ingredient, 20% water

Basis for effect:

mobility

Details on results:

- After 24 h no significant effects (< 10 % of total of 40 individuals) were observed at all test concentrations and in the blank controls
- After 48 h of incubation the following percentage of immobilization of the total of 40 individuals was observed : 3000 mg/L (10%); no significant effects were observed at all other test concentrations and in the blank control; immobilization at 48 h was not increased as compared to the effects after 24 h

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

No statistics reported

Table 1: Definitive test: Immobilization of Daphnia magna after 24 and 48 h of exposure to the test material

Nominal Concentration (mg/L)	Code	Number of individuals per test vessel	Immobile Daphnia (No./vessel) 24 h	Immobile Daphnia (No./vessel) 48 h	% immobile Daphnia after 24 h of exposure	% immobile Daphnia after 48 h of exposure
Control          0.0	A B C	20 20 20	0 0 0	0 0 1	0 0 0	0 0 5
100	A B	20 20	0 0	0 0	0 0	0 0
200	A B	20 20	0 0	0 0	0 0	0 0
400	A B	20 20	0 0	0 1	0 0	0 5
800	A B	20 20	0 0	0 0	0 0	0 0
1600	A B	20 20	0 0	0 0	0 0	0 0
3000	A B	20 20	0 0	3 1	0 0	15 5

 

Validity criteria fulfilled:

yes

Remarks:

The test is considered valid if < 10% of the Daphnia in the control have been immobilized or trapped at the surface of the water. The dissolved oxygen conc. at the end of the test should not be < 60 % of the air saturation value at the temp. used.

Conclusions:

Based on the immobilization data the nominal median effect concentration (EC50) of nitroguanidine (moistened) to Daphnia magna for 24 and 48 h was estimated to be > 3000 mg/L, respectively.
The experimentally determined no-effect concentration (NOEC, EC0) was > 3000 and > 1600 mg/L after an exposure of 24 and 48 h, respectively.
100 % immobility (EC100) was not observed.
Therefore, it can be concluded that nitroguanidin is practically non-toxic towards Daphnia magna under the conditions of this test.

Executive summary:

The 48 h acute toxicity of nitroguanidine to Daphnia magna was studied under static conditions.  Daphnids were exposed to nitroguanidine at 0 (control), 100, 200 400, 800, 1600 and 3000 mg/L (nominal) for 48 h. Immobilization was observed after 24 h and at test termination (48 h). 

The 24- and 48-hour EC₅₀was > 3000 mg/L. The experimentally determined no-effect concentration (NOEC, EC0) was ≥ 3000 and ≥ 1600 mg/L after an exposure of 24 and 48 h, respectively. 100 % immobility (EC₁₀₀) was not observed.  

This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

REMARK:

These results refer to nitroguanidine (moistened) which has a water content of 20 %. For the reason of comparability and registration purposes the results of this study have to be converted to nitroguanidine (dry).

Therefore, the 24- and 48-hour EC₅₀ nitroguanidine (dry) was > 2400 mg/L. The experimentally determined no-effect concentration (NOEC, EC0) was ≥ 2400 and ≥ 1280 mg/L after an exposure of 24 and 48 h, respectively.

Description of key information

Häner & Henzen, 2000, van der Schalie, 1985, and Burton et al., 1993 studied the 48 h acute toxicity of nitroguanidine to aquatic invertebrates. Daphnids were exposed to nitroguanidine at concentrations up to 4020 mg/L. In addition, van der Schalie determined the effects of photolyzed nitroguanidine on Dahnia magna at least at four concentrations. The lowest EC₅₀(48 h) value in all tests was determined to be > 2400 mg/L. Therefore, it can be concluded that nitroguanidine presents only negligible hazard to D. magna and Ceriodaphnia dubia. In contrast, the EC₅₀(48 h) for photolyzed nitroguanidine being 24.6 mg/L (see van der Schalie, 1985) is much lower. Therefore, photolyzed nitroguanidine poses a potential hazard towards aquatic invertebrates.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

24.6 mg/L

Additional information

Häner & Henzen, 2000, studied the 48 h acute toxicity of nitroguanidine to Daphnia magna according to OECD 202 under static conditions. Daphnids were exposed to Nitroguanidine at 0 (control), 100, 200 400, 800, 1600 and

3000 mg/L (nominal) for 48 h. Immobilization was observed after 24 hr and at test termination (48 h). The 24- and 48-hour EC₅₀ for Daphnia magna was determined to be > 2400 mg/L. The experimentally determined no-effect concentration (NOEC, EC₀) was ≥ 2400 and ≥ 1280 mg/L after an exposure of 24 and 48 h, respectively. 100 % immobility (EC₁₀₀) was not observed.  

 

These results are supported by the results from van der Schalie, 1985, and Burton et al., 1993:

Van der Schalie, 1985, studied the 48 h acute toxicity of nitroguanidine to D. magna under static conditions (Guideline: Am. Soc. Test. Mat. 1980. Standard practice for conducting acute toxicity tests with fishes, macroinvertebrates, and amphibians. E 729-80). Daphnids were exposed to nitroguanidine at two concentrations (nitroguanidine saturation concentration at the test temperature (2838 mg/L) and 50 % of saturation (1485 mg/L)) and to photolyzed nitroguanidine at least at four test concentrations so that an LC₅₀ or EC₅₀ could be adequately defined.

Burton et al., 1993 studied the 48 h acute toxicity of nitroguanidine to Ceriodaphnia dubia under static renewal conditions (Guideline: ASTM Designation E 729-80 (ASTM, 1980)). Daphnids were exposed to nitroguanidine at mean measured concentrations of 0, 500, 920, 730, 1440, 2540, and 4020 mg/L.

Van der Schalie, 1985, and Burton et al., 1993, determined the EC₅₀(48h) for nitroguanidine to be > 2838 mg/L (mean measured concentration) and the LC₅₀(48h) for nitroguanidine to be 2698 mg/L (mean measured concentration), respectively. 

 

Moreover, van der Schalie conducted experiments with photolyzed nitroguanidine. The EC₅₀(48h) for photolyzed nitroguanidine was 24.6 mg/L (mean measured concentration). Photolysis increased the acute toxicity by a factor from over 115.

 

Based on these results, nitroguanidine appears to present little hazard to Daphnia magna and Ceriodaphnia dubia.

Table 1: Study synopsis

Guideline Test Type	Species	Effect Concentration	Reference	Reliability
OECD 202	Daphnia magna	Nitroguanidine moistened(20 % H2O): EC50(24h) mg/L > 3000 EC50(48h) mg/L > 3000 NOEC (24h) ≥ 3000 NOEC (48h) ≥ 1600    results converted to Nitroguanidine dry: EC50(24h) mg/L > 2400 EC50(48h) mg/L > 2400 NOEC (24h) = 2400 NOEC (48h) = 1280	Häner, A.; Henzen, F.; BMG; 2000	Reliable without restrictions > key study
Am. Soc. Test. Mat. 1980. Standard practice for conducting acute toxicity tests with fishes, macroinvertebrates, and amphibians.E 729-80.	Daphnia magna	Nitroguanidine: EC50(48h) mg/L > 2838   Photolyzed Nitroguanidine: EC50(48h) mg/L = 24.6	Schalie, W.H. van der; U.S.Army Medical Bioengineering Research and Development Laboratory; 1985	Reliable with restrictions
ASTM Designation E 729-80 (ASTM, 1980)	Ceriodaphnia dubia	Nitroguanidine: LC50(48h) mg/L = 2698	Burton, D.T.; Turley, S.D.; Peters, G.T.; University of Maryland System, Wye Research and Education Center, Queenstown, MD, U.S.A.	Reliable with restrictions