N-acetylsulphanilyl chloride

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:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard OECD test guideline.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The stock solution 50 mg/l was prepared by dissolving test chemical in reconstituted water. The solution was kept in ultrasonic bath for 20 min. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with reconstituted test water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: Straus
- Source: Own breeding at University of Chemistry and Technology, Prague
- Age at study initiation (mean and range, SD): The animals used for the test shall be less than 24 h old and should not be first brood progeny
- Feeding during test: No feeding

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

± 1 hr

Test temperature:

20±1°C

pH:

without adjustment
sample at concentration:
10 mg/l: pH = 7.5 (at the start of test) changed to 7.8 (at the end of the test)
18 mg/l: pH = 7.4 (at the start of test) changed to 7.6 (at the end of the test)
32 mg/l: pH = 7.1 (at the start of test) changed to 7.5 (at the end of the test)
58 mg/l: pH = 6.6 (at the start of test) changed to 7.4 (at the end of the test)
100 mg/l: pH = 5.2 (at the start of test) changed to 7.1 (at the end of the test)

control: pH = 7.7 changed to pH 7.9 during the test

Dissolved oxygen:

higher than 8.2 mg/L at the end of test both in the control and the sample

Nominal and measured concentrations:

Nominal test chemical concentration used for the study were 0, 10, 18, 32, 58 and 100 mg/l, respectively.

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml glass vessel
- fill volume: 25 ml
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
Natural water (surface or ground water), reconstituted water or dechlorinated tap water are acceptable as culturing and dilution water if D. magna survives in it for the duration of the culturing, acclimation and testing without showing signs of stress. Waters in the range pH 6 to pH 9, with hardness between 140 mg/l and 275 mg/l (as CaCO3) are recommended.
As an example, the preparation of dilution water meeting the requirements is described below.
Dissolve known quantities of reagents in water. The dilution water prepared shall have a pH of 7.8 ± 0.5, a hardness of (225 ± 50) mg/l (expressed as CaCO3), a molar Ca + Mg ratio close to 4 + 1 and a dissolved oxygen concentration above 7 mg/l.

Prepare the solutions specified below:
- Calcium chloride solution: Dissolve 117.6 g of calcium chloride dihydrate (CaCl2.2H2O) in water (4.2) and make up to 1 l with water (4.2).
- Magnesium sulfate solution: Dissolve 49.3 g of magnesium sulfate heptahydrate (MgSO4.7H2O) in water (4.2) and make up to 1 l with water (4.2).
- Sodium bicarbonate solution: Dissolve 25.9 g of sodium bicarbonate (NaHCO3) in water (4.2) and make up to 1 l with water (4.2).
- Potassium chloride solution: Dissolve 2.3 g of potassium chloride (KCI) in water (4.2) and make up to 1 l with water (4.2).

Mixing
Mix 2.5 ml of each of the four solutions and make up to 1 l with water.
The dilution water shall be aerated until the dissolved oxygen concentration has reached saturation and the pH has stabilized. If necessary, adjust the pH to 7.8 ± 0.5 by adding sodium hydroxide (NaOH) solution or hydrochloric acid (HCI). The dilution water prepared in this way shall not be further aerated before use.

- Sodium hydroxide solution, e.g. [NaOH] : 1 mol/l.
- Hydrochloric acid, e.g. [HCl] : 1 mol/l.

Reference substance:
Dissolve 600 mg of potassium dichromate (K2Cr2O7) in water and make up to 1 l with water (4.2).

OTHER TEST CONDITIONS
- Adjustment of pH: no adjustment done
- Photoperiod: Darkness

CALCULATION:
EC50 was calculated using non linear regression by the software Prism 4.0

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

48.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CI: 36.1-65.5 mg/l

Results with reference substance (positive control):

- Results with reference substance valid
- EC50: 0.73 mg/L (24 hours)

In control solution containing reconstituted water without the test chemical, no daphnids were immobilized at the end of the test.

Result of the definitive test:

Sample no.	Sample Information	Conc. (mg/l)	I%	48 hr EC50
				mg/l	95% C. I. (mg/l)
Control	Reconstituted water	0	0
Test chemical	Test chemical	10.0 18.0 32.0 58.0 100.0	15.0 20.0 40.0 60.0 65.0	48.6	36.1 to 65.5

Validity criteria fulfilled:

yes

Conclusions:

Based on the mobility of the test organism Daphnia magna due to the exposure of test chemical, the 48hr EC50 value was determined to be 48.6 mg/l (95 % C. I. - 36.1-65.5 mg/l) (nominal concentration).

Executive summary:

An acute immobilisation test was conducted for 48 hrs for assessing the effect of test chemical on aquatic invertebrates. The test was performed following the principles of the OECD guideline No. 202 “Daphnia sp.,Acute Immobilization Test”. Daphnia magna was used as a test organism for the study. The stock solution 50 mg/l was prepared by dissolving test chemical in reconstituted water. The solution was kept in ultrasonic bath for 20 min. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with reconstituted test water.Test chemical concentrations were not verified analytically. Nominal test chemical concentrations used for the study were 0, 10, 18, 32, 58 and 100 mg/l, respectively. Study was performed using 5 organisms per vessel/replicates in a static fresh water system. Daphnids were exposed to test chemical in 50 ml glass vessel in a volume of 25 ml of liquid solution containing both the chemical and media. Control solution vessel containing reconstituted water without the test chemical was also setup during the study. The beakers were placed in a room at a temperature of 20±1°C. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. EC50 was calculated using non linear regression by the software Prism 4. In the control vessel containing reconstituted water without the test chemical, no daphnids were immobilized at the end of the test. The 24 hr EC50 value of the reference substance was determined to be 0.73 mg/l. The dissolved oxygen concentration at the end of the test both in the control and test vessels was evaluated to be ≥ 3 mg/l (i.e, reported as > 8.2 mg/l), indicating that the validity criteria has been fulfilled. On the basis of the mobility of the test organism Daphnia magna due to the exposure of test chemical, the 48hr median effect concentration (EC50) value was determined to be 48.6 mg/l (95 % C. I. - 36.1 to 65.5 mg/l) (nominal concentration). Thus, test chemical was considered as toxic to aquatic invertebrates. Since the test chemical is readily biodegradable in water, test chemical was considered as non-toxic to aquatic invertebrates at environmental relevant concentrations and hence, considered to be 'not classified' as per the CLP classification criteria.

Description of key information

An acute immobilisation test was conducted for 48 hrs for assessing the effect of test chemical on aquatic invertebrates (Experimental study report, 2018). The test was performed following the principles of the OECD guideline No. 202 “Daphnia sp.,Acute Immobilization Test”. Daphnia magna was used as a test organism for the study. The stock solution 50 mg/l was prepared by dissolving test chemical in reconstituted water. The solution was kept in ultrasonic bath for 20 min. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with reconstituted test water.Test chemical concentrations were not verified analytically. Nominal test chemical concentrations used for the study were 0, 10, 18, 32, 58 and 100 mg/l, respectively. Study was performed using 5 organisms per vessel/replicates in a static fresh water system. Daphnids were exposed to test chemical in 50 ml glass vessel in a volume of 25 ml of liquid solution containing both the chemical and media. Control solution vessel containing reconstituted water without the test chemical was also setup during the study. The beakers were placed in a room at a temperature of 20±1°C. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. EC50 was calculated using non linear regression by the software Prism 4. In the control vessel containing reconstituted water without the test chemical, no daphnids were immobilized at the end of the test. The 24 hr EC50 value of the reference substance was determined to be 0.73 mg/l. The dissolved oxygen concentration at the end of the test both in the control and test vessels was evaluated to be ≥ 3 mg/l (i.e, reported as > 8.2 mg/l), indicating that the validity criteria has been fulfilled. On the basis of the mobility of the test organism Daphnia magna due to the exposure of test chemical, the 48hr median effect concentration (EC50) value was determined to be 48.6 mg/l (95 % C. I. - 36.1 to 65.5 mg/l) (nominal concentration). Thus, test chemical was considered as toxic to aquatic invertebrates. Since the test chemical is readily biodegradable in water, test chemical was considered as non-toxic to aquatic invertebrates at environmental relevant concentrations and hence, considered to be 'not classified' as per the CLP classification criteria.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

48.6 mg/L

Additional information

Experimental study & predicted data of the target chemical and supporting weight of evidence study of its structurally similar read across substance were reviewed for the short term toxicity to aquatic invertebrates end point which are summarized as below:

 

In an experimental key study from study report (2018),an acute immobilisation test was conducted for 48 hrs for assessing the effect of test chemical on aquatic invertebrates. The test was performed following the principles of the OECD guideline No. 202 “Daphnia sp.,Acute Immobilization Test”. Daphnia magna was used as a test organism for the study. The stock solution 50 mg/l was prepared by dissolving test chemical in reconstituted water. The solution was kept in ultrasonic bath for 20 min. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with reconstituted test water. Test chemical concentrations were not verified analytically. Nominal test chemical concentrations used for the study were 0, 10, 18, 32, 58 and 100 mg/l, respectively. Study was performed using 5 organisms per vessel/replicates in a static fresh water system. Daphnids were exposed to test chemical in 50 ml glass vessel in a volume of 25 ml of liquid solution containing both the chemical and media. Control solution vessel containing reconstituted water without the test chemical was also setup during the study. The beakers were placed in a room at a temperature of 20±1°C. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. EC50 was calculated using non-linear regression by the software Prism 4. In the control vessel containing reconstituted water without the test chemical, no daphnids were immobilized at the end of the test. The 24 hr EC50 value of the reference substance was determined to be 0.73 mg/l. The dissolved oxygen concentration at the end of the test both in the control and test vessels was evaluated to be ≥ 3 mg/l (i.e, reported as > 8.2 mg/l), indicating that the validity criteria has been fulfilled. On the basis of the mobility of the test organism Daphnia magna due to the exposure of test chemical, the 48hr median effect concentration (EC50) value was determined to be 48.6 mg/l (95 % C. I. - 36.1 to 65.5 mg/l) (nominal concentration). Thus, test chemical was considered as toxic to aquatic invertebrates. Since the test chemical is readily biodegradable in water, test chemical was considered as non-toxic to aquatic invertebrates at environmental relevant concentrations and hence, considered to be 'not classified' as per the CLP classification criteria.

 

In a prediction done using EPI Suite ECOSAR version 1.11, theshort-term toxicity of the test chemical to aquatic invertebrates was predicted. On the basis of effect of test chemical observed in a static system on the mobility of the test organism during the 48 hr exposure duration, the lethal effect concentration (LC50) for the test chemical was estimated to be 99.133 mg/l. Thus, based on the LC50 value, test chemical can be considered as toxic to aquatic invertebrates. Since the test chemical is readily biodegradable in water, test chemical was considered as non-toxic and hence, considered to be 'not classified' as per the CLP classification criteria.

 

For the test chemical from authoritative database (2020), an acute immobilisation test was conducted for 48 hrs for assessing the effect of test chemical. The test was performed following the principles of the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). The study was performed under static conditions using Daphnia magna (Water flea) as a test organism. On the basis of the toxic effect of the test chemical on mobility of the test organism Daphnia magna, the 48 hr median effect concentration (EC50) value was determined to be 72 mg/l (nominal conc.). Thus, test chemical was considered as toxic to aquatic invertebrates. Since the test chemical is readily biodegradable in water, test chemical was considered as non-toxic to aquatic invertebrates at environmental relevant concentrations and hence, considered to be 'not classified' as per the CLP classification criteria.

 

On the basis of the above results, it can be concluded that the test chemical was considered as toxic to aquatic invertebrates. Since the test chemical is readily biodegradable in water, test chemical was considered as non-toxic to aquatic invertebrates at environmental relevant concentrations and hence, considered to be 'not classified' as per the CLP classification criteria.