N-ethyl-o(or p)-toluenesulphonamide

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24th March of 1981 - 26th March of 1981

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

no CoA, no analytics, use of solvent, no reference substance test but all raw data reported and GLP reviewed

Qualifier:

equivalent or similar to guideline

Guideline:

other: Methods for Acute Toxicity Tests With Fish, Macroinvertebrates, and Amphibians (U.S. EPA, 1975)

Version / remarks:

EPA 660/3/75-009

Qualifier:

equivalent or similar to guideline

Guideline:

other: MIC Environmental Assessment Method for conductinng acute toxicity tests with Daphnia Magna (Grueber and Adams, 1980)

GLP compliance:

yes

Specific details on test material used for the study:

The chemicals used in these tests were obtained from R. H .Mills. Santicizer 8 was received in 11 glass bottles in good condition on 3/10/81. The lot number for this chemical is OH-18 (S-8). Chemicals are stored in the Environmental Assessment Group chemical storage cabinet.

Analytical monitoring:

no

Vehicle:

yes

Remarks:

dimethylformamide

Details on test solutions:

The dilution water used in this study was well water from St.Peters, Missouri. For each test concentration, the appropriate amount of the test compound, dissolved in dimethylformamide was pipetted into 1000 ml of dilution water and shaken vigorously for 1 minute. This solution was then divided into three 200 ml aliquots in triplicate beakers to provide appropriate replication. The remaining 400 ml were used for 0-hour DO, pH, alkalinity and hardness determinations. A control, consisting of the same dilution water and conditions but with no test compound was established. Also, a solvent control was employed which consisted of dilution water and the maximum amount of solvent used in the test concentrations. The amount of solvent used in the S-8 solvent controls was 0.5 ml dimethyl formamide/l.

Test organisms (species):

Daphnia magna

Details on test organisms:

The Daphnia magna used in this test were cultured at the MIC aquatic laboratory. The adult Daphnia were fed a trout chow solution daily. Daphnids known to be less than 24 hours old were separated from the adults and used for this test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

Start of the test: 264-282
End of the test: 240 - 306 mg/L

Test temperature:

Start of the test: 23 °C
End of the test: 21 °C

pH:

Start of the test: 7.6
End of the test: 7.9-8

Dissolved oxygen:

Start of the test: 6.9 - 7.6 mg/L
End of the test: 7.6 - 8.4 mg/L

Nominal and measured concentrations:

Nominal concentrations: 0, 62,125, 250, 500, 1000 mg/L

Details on test conditions:

TEST SYSTEM
The static toxicity test was conducted in 250 milliliter(ml) beakers which contained 200 ml of test solution. All test vessels were maintained at room temperature. Test solutions were not aerated during the test. Ten daphnids were randomly assigned to each test vessel within 30 minutes after the compound was added for a total of 30 daphnids per concentration.

TEST MEDIUM / WATER PARAMETERS
Average water quality characteristics of the dilution (well) water .

Characteristic Well Water Measurement
Alkalinity (mg/l CaC03) 303'
Hardness (mg/l CaC03) 297
pH (median) 8.10
Aluminum (mg/l Al ) 0.014
Ammonia-total (mg/l N) 0.35
Ammonia-unionized {mg/1 NH4) 0.001
Antimony (mg/l Sb) 0.006 "
Barium {mg/1 B) <0.035
Beryllium (mg/l Be) 0.001
Cadmium {mg/l Cd) <0.001
Calcium (mg/1 Ca) 67.0
Chloride (mg/l Cl-) 54.5
Chromium (mg/l Cr) <0.009
Cobalt (mg/l Co) 0.002
Copper (mg/l Cu) 0.005
Fluoride (mg/l F-) 1.90
Iron (mg/l Fe) 0.013
Lead (mg/l Pb) 0.01
Magnesium (mg/1 Mg) 2.79
Manganese (mg/l Mn) 0.001
Molybdenum (mg/l Mo ) 0.005

Nickel (mg/1 Ni) 0.025
Phosphorus (mg/1 P) 0.006
Silicon (mg/l Si ) 4.3
Silver (mg/1 Ag) <0.001
Sodium {mg/l Na) 83.2
Sulfate (mg/1 SO-) 175.4
Strontium (mg/1 Sr) 1.30
Tin (mg/1 Sn) 0.006
Titanium (mg/l Ti ) 0.001
Total Organochlorine(ug/l) <0.5
Total Organopho sphorus (ug/l ) <0.05
Vanadium (mg/l V) 0.14
Zinc (mg/l Zn) 0.006

During this test, the dissolved oxygen concentration, pH, alkalinity and hardness, and temperature of test solutions were monitored at the initiation (control and high concentration only) and termination of the toxicity test in the high, middle, low and control test concentrations . DO was measured by the Winkler titration method. The pH as measured with a Beckman pH meter (SOP EEAS-80-SOP-007). The total hardness and alkalinity determinations were conducted according to "Standard Methods for the Examination of Water and Wastewater" (1975).

VEHICLE CONTROL PERFORMED: yes

RANGE-FINDING STUDY
- Test concentrations: 0, 25, 50, 100, 200, 400 mg/L
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

500 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Results met the two validity criterias specified in the OECD (202) guidelines. In the controls, no mortality of Daphnids were seen or immobilization above 10 %. The dissolved oxygen concentrations in the control and test vessels remained above 3 mg/L.

In general, pH values remained within acceptable limits throughout the duration of the expeirment. Starting temperature did seem to be slightly above the recommended range of between 18-22 °C, and water hardness a little higher than recommended for Daphnia Magna as specified in the OECD 202 guidelines. However this did not seem to have any impact on the validity/outcome of the results.

Reported statistics and error estimates:

Test concentrations and corresponding percent mortality data derived from definitive tests were used to calculate the 48-hour median effect concentration (EC50) and 95% confidence intervals. The EC50 value as calculated using a LC50 computer program developed by Stephen et al.,(1978). The EC50 is defined as the calculated nominal concentration of the test compound in dilution water which causes 50% immobi izati on in the test animal populati on at the stated exposure interval .

Concentrations tested and corresponding percent immobilization of Daphnia Magna exposed to Santicizer8

 

Nominal concentration ( mg/L)	Percent immobilization for combined replicates
	24 hours	48 hours
Control	0	0
62	0	0
125	0	0
250	0	0
500	3.3	6.7
1000	26.7	26.7

Validity criteria fulfilled:

yes

Remarks:

See details on results

Conclusions:

The 48h EC50 (immobilisation) value with Daphnia magna is > 1000 mg/I, based on nominal concentrations.

Executive summary:

This study was performed to assess the acute toxicity of the substance to Daphnia magna. The study closely follows methods and guidelines described in the MIC Environmental Assessment Method for Conducting Acute Toxicity Tests with Daphnia magna (Grueber &Adams, 1980), and Methods for Acute Toxicity Tests with Fish, Macroinvertebrates and Amphibians (U.S. EPA, 660/3 -75 -009, 1975). During a 48 hour static toxicity test, a group of 30 Daphnia Magna (less than 24 hours old) per concentration (3x 10) were exposed to the substance, Santicizer 8, dispersed in test water via the use of DMF. Nominal concentrations of 62, 125, 250, 500 and 1000 mg/L were used. The incidence of immobilisation was recorded for each test group and control groups at 24 hours and at 48 hours. No effects were observed in the controls and the concentrations ≤250 mg/L. The 48h EC50 is reported to be >1000 mg/L at both 24 and 48 hours. All results are expressed in terms of the nominal concentrations.

Description of key information

This study was performed to assess the acute toxicity of the substance to Daphnia magna. The study closely follows methods and guidelines described in the MIC Environmental Assessment Method for Conducting Acute Toxicity Tests with Daphnia magna (Grueber &Adams, 1980), and Methods for Acute Toxicity Tests with Fish, Macroinvertebrates and Amphibians (U.S. EPA, 660/3 -75 -009, 1975). During a 48 hour static toxicity test, a group of 30 Daphnia Magna (less than 24 hours old) per concentration (3x 10) were exposed to the substance, Santicizer 8, dispersed in test water via the use of DMF. Nominal concentrations of 62, 125, 250, 500 and 1000 mg/L were used. The incidence of immobilisation was recorded for each test group and control groups at 24 hours and at 48 hours. No effects were observed in the controls and the concentrations≤250 mg/L. The 48h EC50 is reported to be >1000 mg/L at both 24 and 48 hours. All results are expressed in terms of the nominal concentrations.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

1 000 mg/L

Additional information

The EC50 is a > value, (EC50> 1000 mg/L)