Santicizer 2148

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1990-01-26 to 1990-01-30

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OTS 797.1400 (Fish Acute Toxicity Test)

Deviations:

not specified

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Monsanto, 4355206

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature
- Solubility and stability of the test substance in the solvent/vehicle: Not specified

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: Diluter stock solution (20 mg/ml) was prepared by dissolved 5.000g of XP-2563 in 250 mls of dimethylformamide (DMF).
- Final nominal concentrations: 0.13; 0.25; 0.50; 1.0 and 2.0 mg/L.

Analytical monitoring:

yes

Details on sampling:

~100 ml of water was collected from each replicate control and test concentration from mid aquaria level using a glass pipet. 10ml of diluter stock were collected at 0- and 96-hour. The samples were held at room temperature prior to shipping them to the study sponsor, who reported them seperately.

Test solutions of XP-2563 were collected by ABC personnel at ABC Labortories at 0- and 96-hours. 10 ml of methylene chloride were added to each sample. A litre sample of control water and a 10 ml sample of diluter stock were also collected. All samples were shipped to Monsanto Company for analysis.

Vehicle:

yes

Remarks:

Dimethylformamide

Details on test solutions:

Diluter stock solution (20 mg/ml) was prepared by dissolving 5.000g of XP-2563 in 50 mLs of Dimethylformamide (DMF).
Nominal concentration regime of XP-2563: 0; solvent control (0.1 ml DMF) 0.13; 0.25; 0.50; 1.0; 2.0 mg/L

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: Fathead minnow
- Source: Aquiatic BioSystems inc.
- Age at study initiation (mean and range, SD):
- Maintenance of the brood fish: Maintained in well water, fed newly hatched brine shrimp or commercial fish food daily.
- Mean weight: 0.49 (±0.15) g
- Mean length: 32 (±3) mm

ACCLIMATION
- Acclimation period: 72 hours
- Acclimation conditions (same as test or not): Same as test
- Type and amount of food during acclimation: Held without food

FEEDING DURING TEST
Maintained in well water, fed newly hatched brine shrimp or commercial fish food daily.

Test type:

flow-through

Water media type:

other: Soft blended water (mixture of reverse osmosis and well water)

Limit test:

no

Total exposure duration:

96 h

Hardness:

42-44 mg/l (as CaCO3)

Test temperature:

21-22°C

pH:

7.8-8.2

Dissolved oxygen:

8.1-8.4 mg/l representing 95 and 100% saturation at 21 and 22°C respectively

Conductivity:

100-110 μMhos/cm

Nominal and measured concentrations:

Nominal: 0; solvent control; 0.13; 0.25; 0.50; 1.0; 2.0 mg/l
Mean measured: 0; solvent control; 0.13; 0.21; 0.46; 1.1; 1.8 mg/l

Details on test conditions:

TEST SYSTEM
Proportional diluter system described by Mount and Brungs and a hamilton model 420 syringe dispenser were used for intermittent introduction of XP-2563 test solutions and diluent water into each test chamber. 5 concentrations of test material, solvent control, and soft blended dilution water control comprised the test desig. Each concentration and control was replicated twice with 10 fish per vessel.

The diluter delivered 0.5 liter of test solution or control water to the test vessels at an average rate of 8.1x per hour, which would result in 97 liters of water flowing through the 15 L replicate aquaria per day and yield 6.4 replacement volumes flowing through each replicate chamber each day. The test aquaria were immersed in a water bath held at 22°C.

- Biomass loading rate: 0.051 g/l/day

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Soft blended water (mixture of reverse osmosis and well water)
- Total organic carbon: <1 mg/l
- Suspended solids 0.0 mg/l
- Alkalinity: 52-56 mg/l (as CaCO3)
- Intervals of water quality measurement: Hardness, Alkalinity, pH, and Conductivity measured on day of test initiation and termination, total organic carbon and suspended solids screened monthly, all other measurements quarterly.


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :

TEST CONCENTRATIONS
- Range finding study : Static 96-jour range-finding test conducted to find the concentration range to use in the definitive test. Concentrations uised: 1.1, 10, adn 100 mg/l. No abnormal effects were noted in any test chamber during the test. The 10 and 100 mg/l chambers had droplets of oily precipitate on the surface throughout the test. It was agreed the definitive flow-through test would be run at a nominal high concentration of 2.0 mg/l, near the water solubility limit of the test material
- Test concentrations (Definitive): 0.13; 0.25; 0.50; 1.0; 2.0 mg/l.

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 1.8 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Key result

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

0.46 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

From the data collected during this study, the 24-, 48-, 72-, and 96-hour LC50 values were all >1.8 mg/l or greater than the water solubility limits of the test material. The slope of the 96-hour dose-response line could not be calculated since no mortalitiy occured. The mixing cell and 1.8 mg/l solutions were slightly cloudy throughout the test period. Behavioral/sublethal effects noted during the study included fish on bottom of test aquaria and quiescence (3 on bottom/quiescent at 1.0 mg/l, 5 at 2.0 mg/l). These effects were noted at 24 hours but not at any time thereafterwards. Given these behavioral/subletbal effects at the test concentrations of 1.1 and 1. 8 mg/l a no-effect concentration of XP-2563 toxicity to fathead minnow was determined to be 0.46 mg/l. This conclusion is supported by the lack of mortality or bebavioral/sublethal effects at the teat concentrations of 0.13 , 0.21 and 0.46 mg/l.

Sublethal observations / clinical signs:

Table 4. The LC50 values for the 96-hour flow-through toxicity study of XP-2563 with Fathead Minnow (pimephales promelas)

Exposure period (hours	LC50*
24	>1.8 mg/l
48	>1.8 mg/l
72	>1.8 mg/l
96	>1.8 mg/l

* = Since no mortality occurred an LC50 value couldn’t be calculated. The LC50 was shown to be greater than the water solubility limits of the test material.

 

Table 5. Mortality and Behavioural observations during the acute flow-through toxicity test of XP-2563 with Fathead Minnow (Pimephales promelas)

Nominal test concentration mg/l (ppm)	No. placed in test	24-hour		48-hour		72-hour		96-hour
		Mort.	Obs.	Cum. Mort.	Obs.	Cum. Mort.	Obs.	Cum. Mort.	Obs.
Control	20	0	20 N	0	20 N	0	20 N	0	20 N
Solvent Control	20	0	20 N	0	20 N	0	20 N	0	20 N
0.13	20	0	20 N	0	20 N	0	20 N	0	20 N
0.25	20	0	20 N	0	20 N	0	20 N	0	20 N
0.50	20	0	20 N	0	20 N	0	20 N	0	20 N
1.0	20	0	3 OB/Q; 17N	0	20 N	0	20 N	0	20 N
2.0	20	0	15N; 5 OB/Q	0	20 N	0	20 N	0	20 N

Key to Observations: N = Normal; OB = On bottom of test chamber; Q = Quiescent

Conclusions:

From the data collected during this study, the 24-, 48-, 72- and 96-hour LC50 values were all >1.8 mg/1 or greater than the water solubility limits of the test material (Table 4). The slope of the 96-hour dose-response line could not be calculated since no mortality occurred. The mixing cell and 1.8 mg/l solutions were slightly cloudy throughout the teat period. The maximum amount of solvent allowed in a flow-through test was used. The mixing cell solution was stirred during the test is an attempt to get as much of the compound into solution as possible. The MSDS reported the water solubility of XP-2563 as 1-3 mg/l at 25°C. Behavioural/sublethal effects noted during the study included fish on bottom of test aquaria and quiescence. These effects were noted at 24 hours but not at any time thereafter. Given these behavioural/sublethal effects at the test concentrations of 1.1 and 1.8 mg/l a no-effect concentration of Xl'-2563 toxicity to fathead minnow was determined to be 0.46 mg/1. This conclusion is supported by the lack of mortality or behavioural/sublethal effects at the teat concentrations of 0.13, 0.21 and 0.46 mg/l.

Executive summary:

A 96-hour flow-through toxicity study of XP-2563 to fathead minnow (Pimpheles promelas) was conducted for Monsanto Company from January 26, 1990 to January 30, 1990. 20 fish per test concentration plus solvent control and soft blended water control (10 fish per replicate chamber) were used in a nominal dosing regime of 0.13, 0.25, 0.50, 1.0, and 2.0 mg/l. Analytical measurements of XP-2563 were made by the study sponsor from samples collected by ABC personnel at 0- and 96-hours. The mean measured test concentrations were 0.13, 0.21, 0.46, 1.1, and 1.8 mg/l. Water chemistry measurements of dissolved oxygen, pH, and temperature were consistent throughout the term of the experiment and were within protocol specifications.

 

From the data collected during this study, a 96-hour LC50 was calculated to be >1.8 mg/l based on the measured concentrations of XP-2563. The test showed that the LC50 was greater than the water solubility limits of the test material. The water solubility was reported in the MSDS to be 1-3 mg/l at 25°C. The mixing cell solution and level 5 (2 mg/l nominal values) were both slightly cloudy throughout the test. The mixing cell solution was stirred and the maximum amount of solvent allowed in a flow-through test was used in this test. Sublethal/behavioural responses (eg, quiescence and fish on the bottom of the test chambers) were noted among the fish in the 1.1 and 1.8 mg/l test levels. As determined by this study, a 96-hour no-effect concentration of XP2563 toxicity to fathead minnow was 0.46 mg/l based on a lack of sublethal responses at this concentration.

Description of key information

96-hour no-effect concentration of XP2563 in fathead minnow was 0.46 mg/L, based on a lack of sublethal responses at this concentration.

96-hour LC₅₀ was calculated to be >1.8 mg/L, based on the measured concentrations of XP-2563.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1.8 mg/L

Additional information

A 96-hour flow-through toxicity study of XP-2563 to fathead minnow (Pimpheles promelas) was conducted (Analytical Bio-chemistry Laboratories, Inc., 1990a). 20 fish per test concentration plus solvent control and soft blended water control (10 fish per replicate chamber) were used in a nominal dosing regime of 0.13, 0.25, 0.50, 1.0, and 2.0 mg/l. Analytical measurements of XP-2563 were made by the study sponsor from samples collected by ABC personnel at 0- and 96-hours. The mean measured test concentrations were 0.13, 0.21, 0.46, 1.1, and 1.8 mg/l. Water chemistry measurements of dissolved oxygen, pH, and temperature were consistent throughout the term of the experiment and were within protocol specifications.

 

From the data collected during this study, a 96-hour LC50 was calculated to be >1.8 mg/l based on the measured concentrations of XP-2563. The test showed that the LC50 was greater than the water solubility limits of the test material. The water solubility was reported in the MSDS to be 1-3 mg/l at 25°C. The mixing cell solution and level 5 (2 mg/l nominal values) were both slightly cloudy throughout the test. The mixing cell solution was stirred and the maximum amount of solvent allowed in a flow-through test was used in this test. Sublethal/behavioural responses (eg, quiescence and fish on the bottom of the test chambers) were noted among the fish in the 1.1 and 1.8 mg/l test levels. As determined by this study, a 96-hour no-effect concentration of XP2563 toxicity to fathead minnow was 0.46 mg/l based on a lack of sublethal responses at this concentration.