O-isopropyl ethylthiocarbamate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Justification for type of information:

QSAR prediction:US EPA accepted QSAR method for chemicals properties assessment.

Qualifier:

according to guideline

Guideline:

other: QSAR model

Principles of method if other than guideline:

ECOSAR Program(v1.00)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

other: QSAR model

Details on test organisms:

not applicable. QSAR model

Test type:

other: QSAR model

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 d

Test temperature:

not applicable. QSAR model

pH:

not applicable. QSAR model

Dissolved oxygen:

not applicable. QSAR model

Salinity:

not applicable. QSAR model

Nominal and measured concentrations:

not applicable. QSAR model

Details on test conditions:

SMILES : O(C(=NCC)S)C(C)C
CHEM : Carbamothioic acid, ethyl-, O-(1-methylethyl) ester
CAS Number: 141-98-0
MOL FOR: C6 H13 N1 O1 S1
MOL WT : 147.24
Log Kow: 3.32 (KowWin estimate)
Wat Sol: 114.4 mg/L (WskowWin estimate)

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

4.529 mg/L

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

not specified

Duration:

30 d

Dose descriptor:

NOEC

Effect conc.:

2.156 mg/L

Nominal / measured:

not specified

Conc. based on:

not specified

Basis for effect:

not specified

Remarks on result:

other: NOEC cited as a ChV value

Details on results:

Green Algae, 96-hr EC50 =4.529 mg/L (ppm)
Green Algae, 30-day, NOEC cited as a ChV value = 2.156 mg/L(ppm)

Overview of QSARs estimations onaquatic toxicity of O-isopropyl ethylthiocarbamate (IPETC ) Green algae

Method	Results	Remarks	Reference
QSAR estimate	Green Algae, 96-hr EC50 =4.529 mg/L (ppm) Green Algae, 30-day, NOEC cited as a ChV value = 2.156 mg/L(ppm)	Reliable with restrictions, QSAR estimated data	ECOSAR Program (v1.00)

 

Green Algae, 96-hr EC50 =4.529 mg/L (ppm)

Green Algae, 30-day, NOEC cited as a ChV value = 2.156 mg/L(ppm)

 

Validity criteria fulfilled:

yes

Remarks:

method for chemicals properties assessment.

Conclusions:

Green Algae, 96-hr EC50 = 4.529 mg/L (ppm)
Green Algae, 30-day, NOEC cited as a ChV value = 2.156 mg/L(ppm)

Executive summary:

The ECOSAR QSAR model predicts that 30-day, NOEC cited as a ChV value would to be 2.156 mg/L (ppm) Green Algae.

The ECOSAR QSAR model predicts that 96-hr EC50 value would to be 4.529 mg/L (ppm) for Green Algae.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

1980

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Propan-2-ol (Isopropyl alcohol) is both reagents used in the manufacture of IPETC/O-isopropyl ethylthiocarbamate . Therefore, Propan-2-ol (Isopropyl alcohol) need to be considered in the assessment of IPETC/O-isopropyl ethylthiocarbamate .

Qualifier:

no guideline followed

Principles of method if other than guideline:

The concentration of the algal suspension is measured turbidimetrically and expressed by the extinction of the primary light of the monochromatic radiation at 578 nm for a layer of 10 mm thickness. The concentration at which the inhibitory action of the test material begins is present in that dilution from a series of dilutions of the test material having, at the end of the test period, a mean extinction value that is ≥ 3% below the mean value of the extinction value for non-toxic dilutions of the test cultures.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Before preparing the test cultures neutralize the test material solution having a known content in sterile double-distilled water to be tested by using the minimum volume of acid or alkaline solution.
From this test material solution, prepare dilutions with varying volume ratios using sterile double-distilled water. These dilutions each contain 1 part v/v of test material solution in 2E0 to 2E14 parts v/v mixture. When preparing the two parallel dilution series in 300-ml Erlenmeyer flasks proceed as follows: the first flask of each dilution series contains 80 ml of test material solution at the start. Starting from this flask, prepare subsequent dilutions using a constant dilution ratio of 40 ml preliminary test material dilution + 40 ml double-distilled water. So each flask will first contain 40 ml liquid.
Then, complete each flask from the dilution series to be inoculated to the rated value of 50 ml by adding 5 ml each of stock solution I and 5 ml each of the algal suspension of the preliminary culture having a known adjusted extinction value.

Test organisms (species):

Scenedesmus quadricauda

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

7 d

Hardness:

not reported

Test temperature:

27ºC

pH:

not reported

Dissolved oxygen:

not reported

Salinity:

freshwater

Nominal and measured concentrations:

2E0 to 2E14 parts v/v mixtures

Details on test conditions:

Following inoculation, the extinction value of the monochromatic radiation at 578 nm for a 10-mm layer of the algal suspension of the test cultures will correspond to the extinction value of the Formazin standard suspension TE/F/578 nm = 20.

While shaking the contents, transfer from each flask of the inoculated dilution series 10 ml into three Kapsenberg culture tubes (18 x 180 mm), from each flask of the non-inoculated dilution series into one Kapsenberg tube each and stopper culture tubes with metal caps. Keep the filled culture tubes from the dilution series on a white surface protected against daylight and exposed to constant lighting by luminescent warm white tubes at 60 cm distance from each other, at 27ºC and a relative humidity of 50% for 7 days and shake once each day.

Measure the extinction of the monochromatic radiation at 578 mm in a 10-mm layer of the cell suspension from each test culture.

Nutrient solution 1 (for stock and preliminary cultures)
Dissolve in double-distilled water:
496 mg sodium nitrate, NaNO3
39 mg dipotassium hydrogen phosphate, K2HPO4 anhydrous
75 mg magnesium sulphate, MgSO4.7 H2O
36 mg calcium chloride, CaCl2.2 H2O
40 mg sodium metasilicate, Na2SiO3
58 mg sodium carbonate Na2CO3, anhydrous
3 mg citric acid C6H8O7.H2O
3 mg iron (III) citrate C6H5FeO7.5 H2O
10 mg disodium salt of ethylene diamine tetracetic acid, C10H14N2Na2O8.2 H2O

Add 10 ml of the trace elements operating solution, complete to 1 litre with double-distilled water and adjust pH to 7.0 using the minimum of Na2CO3 solution.

Stock solution I (for test cultures)
Dissolve in double-distilled water:
248 mg sodium nitrate, NaNO3
19.5 mg disodium hydrogen phosphate, K2HPO4, anhydrous
750 mg magnesium sulphate, MgSO4.7 H2O
360 mg calcium chloride, CaCl2.2 H2O
30 mg iron (III) citrate C6H5FeO7.5 H2O.

Add 10 ml of the trace elements operating solution, complete to 1 liter with double -distilled water and adjust pH to 7.0 using the minimum of Na2CO3 solution.

Stock solution II (trace elements)
Dissolve in double-distilled water:
2.86 g boric acid, H3BO3
1.81 g manganese (II) chloride, MnCl2 . 4 H2O
220 mg zinc sulphate, ZnSO4.7 H2O
80 mg copper (II) sulphate, CuSO4.5 H2O
24 mg sodium molybdate, Na2MoO4.2 H2O
40 mg cobalt (II) chloride, CoCl2.6 H2O

Complete solution with double distilled water to 1 liter in a volumetric flask.

Operating solution of trace elements
Complete 4 ml of stock solution II with double-distilled water to 100 ml in a volumetric flask.

Reference substance (positive control):

no

Duration:

7 d

Dose descriptor:

other: Toxicity threshold

Effect conc.:

1 800 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Toxicity threshold concentration = 1800 mg/l.

Details on results:

For evalution of the toxicological findings at the end of the test period, the mean value (A) of the extinction is calculated for all test cultures that are free from both toxic influence and stimulation of growth except for those having extinction values outside a standard deviation of <3% and also, the mean value (B) of the extinction for those test cultures having the lowest toxic test material concentration within the dilution series.

For mathematical evaluation, (a) (highest non-toxic test material concentration) is plotted against (A) and (b) (lowest toxic test material concentration) against (B) as coordinates. After having entered (A - 3%), the test material concentration at which the inhibitory action (c) begins may be obtained from the regression line between (a;A) and (b;B) if a negative deviation of the mean extinction by a 3% difference against the mean extinction value of all test cultures having a non-toxic and non-stimulating test material concentration is used as an indicator of the beginning of inhibitory action.

Validity criteria fulfilled:

not specified

Conclusions:

A 7 d Toxicity threshold concentration of 1800 mg/l has been determined for growth rate effects to Scenedesmus quadricauda of the test substance.
Propan-2-ol (Isopropyl alcohol) is both reagents used in the manufacture of Reaction mass of O-isopropyl ethylthiocarbamate and n-butanol and propan-2-ol. Therefore, Propan-2-ol (Isopropyl alcohol) need to be considered in the assessment of IPETC/ O-isopropyl ethylthiocarbamate .

Executive summary:

A 7 d Toxicity threshold concentration of 1800 mg/l has been determined for growth rate effects to Scenedesmus quadricauda of the test substance.Propan-2-ol (Isopropyl alcohol) is both reagents used in the manufacture of IPETC/ O-isopropyl ethylthiocarbamateand.Therefore, Propan-2-ol (Isopropyl alcohol) need to be considered in the assessment of IPETC/O-isopropyl ethylthiocarbamate .

Description of key information

The ECOSAR QSAR model predicts that 30-day, NOEC cited as a ChV value would to be 2.156 mg/L (ppm) Green Algae.
The ECOSAR QSAR model predicts that 96-hr EC50 value would to be 4.529 mg/L (ppm) for Green Algae.

Key value for chemical safety assessment

EC50 for freshwater algae:

4.529 mg/L

EC50 for marine water algae:

2.156 mg/L

EC10 or NOEC for freshwater algae:

0.453 mg/L

EC10 or NOEC for marine water algae:

0.216 mg/L

Additional information

The ECOSAR QSAR model predicts that 30-day, NOEC cited as a ChV value would to be 2.156 mg/L (ppm) Green Algae.

The ECOSAR QSAR model predicts that 96-hr EC50 value would to be 4.529 mg/L (ppm) for Green Algae.

 

A 7 d Toxicity threshold concentration of 1800 mg/l has been determined for growth rate effects to Scenedesmus quadricauda of the test substance.Propan-2-ol (Isopropyl alcohol) is both reagents used in the manufacture of IPETC/O-isopropyl ethylthiocarbamate. Therefore, Propan-2-ol (Isopropyl alcohol) need to be considered in the assessment of IPETC/O-isopropyl ethylthiocarbamate.

 

The available data for saltwater algae and cyanobacteria are limited and to obtaine the value for PNECs for saltwaters is taken account a assesment factor 10 to extrapolate to LC50 following the “Guidance on Information Requirement and Chemical Safety Assessment R.10: Characterisation of dose [concentration]- response for environment”and “Table R.10-5 Assessment factors proposed for deriving PNEC water for saltwater for different data sets”, to account for the possibility that greater taxonomic diversity in the marine environment makes it likely that some marine taxa may be more sensitive than the most sensitive freshwater taxa