O-isobutyl ethylthiocarbamate

Toxicity to aquatic plants other than algae

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic plants other than algae

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 organic chemicals properties assessment.

Qualifier:

according to guideline

Guideline:

other: QSAR

Principles of method if other than guideline:

ECOSAR Program(v1.00)

GLP compliance:

no

Remarks:

not applicable to QSAR models

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

other: QSAR model

Test type:

other: QSAR model

Water media type:

freshwater

Limit test:

no

Total exposure duration:

30 d

Hardness:

not applicable. QSAR model

Test temperature:

not applicable. QSAR model

pH:

not applicable. QSAR model

Dissolved oxygen:

not applicable. QSAR model

Salinity:

not applicable. QSAR model

Details on test conditions:

SMILES : O(C(=NCC)S)CC(C)C
CHEM : Carbamothioic acid, ethyl-, o-(2-methylpropyl) ester
CAS Num: 55860-53-2
MOL FOR: C7 H15 N1 O1 S1
MOL WT : 161.26
Log Kow: 3.81 (KowWin estimate)
Wat Sol: 37.72 mg/L (WskowWin estimate)

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

EC50

Effect conc.:

2.441 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: (Q)SAR prediction

Duration:

30 d

Dose descriptor:

NOEC

Effect conc.:

1.261 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: (Q)SAR prediction

Details on results:

A 96 h LC50 value of 2.441 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group.
The data show the substance to be acutely toxic at concentrations of between 1.261-2.441 mg/L.
This result signifies that the test substance is expected to be moderately toxic.

A NOEC value of 1.261 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group.
This result signifies that the test substance is expected to be moderately toxic.
.

Overview of QSARs estimations onaquatic toxicity of  O-isobutyl ethylthiocarbamate to algae and aquatic plants

 

Method	Results	Remarks	Reference
QSAR estimate	Green Algae, 96-hr EC50 =2.441mg/L (ppm) Green Algae, 30-day, NOEC cited as a ChV value =1.261mg/L(ppm)	Reliable with restrictions, QSAR estimated data	ECOSAR Program (v1.00)

 

Green Algae, 96-hr EC50 = 2.441 mg/L (ppm)

Green Algae, 30-day, NOEC cited as a ChV value = 1.261 mg/L(ppm)

Validity criteria fulfilled:

yes

Remarks:

US EPA accepted QSAR method for organic chemicals properties assessment.

Conclusions:

A 96 h LC50 value of 2.441 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group.
The data show the substance to be acutely toxic at concentrations of between 1.261-2.441 mg/L.
This result signifies that the test substance is expected to be moderately toxic.

A NOEC value of 1.261 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group.
This result signifies that the test substance is expected to be moderately toxic.
.

Executive summary:

A 96 h LC50 value of 2.441 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group.

The data show the  substance  to be acutely toxic at concentrations of between 1.261-2.441 mg/L.

This result signifies that the test substance is  expected to be moderately toxic.

A NOEC value of 1.261 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group.

This result signifies that the test substance is  expected to be moderately toxic.

.

. 

Description of key information

A 96 h LC50 value of 2.441 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group.

The data show the  substance  to be acutely toxic at concentrations of between 1.261-2.441 mg/L.

This result signifies that the test substance is  expected to be moderately toxic.

A NOEC value of 1.261 mg/L has been calculated for the effects of the test substance on the mortality of the Algae group.

This result signifies that the test substance is  expected to be moderately toxic.

Key value for chemical safety assessment

EC50 for freshwater plants:

2.441 mg/L

EC50 for marine water plants:

0.244 mg/L

EC10 or NOEC for freshwater plants:

1.261 mg/L

EC10 or NOEC for marine water plants:

0.126 mg/L

Additional information

The available data for saltwater aquatic plants 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