O-isobutyl ethylthiocarbamate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

Non-ER binder due to non-cyclic molecular structure. O-isobutyl ethylthiocarbamate (IBETC) have a molecular weight of less than 500, but do not possess a cyclic structure is reported to non-binders to the receptor and therefore O-isobutyl ethylthiocarbamate (IBETC) does not cause reproductive toxicity.

NOAEL for Reproductive Toxicity was 250 mg/kg bw/day (No adverse effects on the highest dose tested) for O-isobutyl ethylthiocarbamate (IBETC)  and does not cause Reproductive Toxicity.

Link to relevant study records

Reference

Reference 1

Endpoint:

two-generation reproductive toxicity

Type of information:

(Q)SAR

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

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: Accepted Estrogen Receptor Binding QSAR method for chemicals properties assessment.. This method is relevant for reproductive toxicity endpoints in fish and mammals.

Qualifier:

according to guideline

Guideline:

other: QSAR Toolbox Version 3.3.5.17

Principles of method if other than guideline:

This grouping method contains simple categories for estrogen receptor (ER) binding. This method is relevant for reproductive toxicity endpoints in fish and mammals.

GLP compliance:

no

Remarks:

not applicable. QSAR model,Estrogen Receptor Binding method, relevant for reproductive toxicity endpoints in fish and mammals.

Limit test:

no

Species:

other: fish (trout) and mammals.

Strain:

other: QSAR model

Sex:

not specified

Route of administration:

other: QSAR model

Vehicle:

other: QSAR model

Details on exposure:

Estrogen receptor (ER) binding is a molecular initiating event much like protein binding that leads to a series of adverse outcomes, which are typically considered reproductive and development hazards. It is an endpoint where several comprehensive databases exist, which has lead to the development of several approaches for using (Q)SARs to predict ER-binding and possible endocrine disruption .

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

Estrogen receptor (ER) binding is a molecular initiating event much like protein binding that leads to a series of adverse outcomes, which are typically considered reproductive and development hazards. It is an endpoint where several comprehensive databases exist, which has lead to the development of several approaches for using (Q)SARs to predict ER-binding and possible endocrine disruption .

Remarks:

Doses / Concentrations:

Basis:
other: QSAR model

Control animals:

not specified

Parental animals: Observations and examinations:

Estrogen receptor (ER) binding is a molecular initiating event much like protein binding that leads to a series of adverse outcomes, which are typically considered reproductive and development hazards. It is an endpoint where several comprehensive databases exist, which has lead to the development of several approaches for using (Q)SARs to predict ER-binding and possible endocrine disruption .

Clinical signs:

no effects observed

Description (incidence and severity):

QSAR model

Body weight and weight changes:

no effects observed

Description (incidence and severity):

QSAR model

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

QSAR model

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

QSAR model

Other effects:

no effects observed

Description (incidence and severity):

Test substance intake: QSAR model

Reproductive function: oestrous cycle:

no effects observed

Description (incidence and severity):

QSAR model

Reproductive function: sperm measures:

no effects observed

Description (incidence and severity):

QSAR model

Reproductive performance:

no effects observed

Description (incidence and severity):

QSAR model

Non-ER binder due to non-cyclic molecular structure. O-isobutyl ethylthiocarbamate (IBETC)  have a molecular weight of less than 500, but do not possess a cyclic structure is reported to non-binders to the receptor and therefore  O-isobutyl ethylthiocarbamate (IBETC)  does not cause reproductive toxicity
1.1. CAS number:55860-53-2
1.2. Other regulatory numbers: Not reported
1.3. Chemical name(s):
carbamothioic acid, ethyl-, o-(2-methylpropyl) ester
o-isobutyl ethylthiocarbamate
o-(2-methylpropyl) ethylcarbamothioate
1.4. Structure codes:
a. SMILES:
CCNC(=S)OCC(C)C
1.5. Profiling results:
-DNA binding by OECD-No alert found
-Est rogen Receptor Binding-Non binder, non cyclic structure
-OECD HPV Chemical Categories-Not categorized
-Protein binding by OECD-No alert found
-Protein binding potency-Not possible to classify according to these rules (GSH)
-Superfragments-No superfragment
-US-EPA New Chemical Categories-Not categorized

Dose descriptor:

other: Relative ERBA (Estrogen Receptor Binding Affinity)

Effect level:

< -3 other: Log RBA(Relative Binding Affinities )

Based on:

other: Estrogen receptor (ER) binding

Sex:

not specified

Basis for effect level:

clinical signs

body weight and weight gain

water consumption and compound intake

organ weights and organ / body weight ratios

gross pathology

histopathology: non-neoplastic

reproductive performance

other: see 'Remark'

Remarks on result:

other: Generation: QSAR model (migrated information)

Clinical signs:

no effects observed

Description (incidence and severity):

QSAR model

Mortality / viability:

no mortality observed

Description (incidence and severity):

QSAR model

Body weight and weight changes:

no effects observed

Description (incidence and severity):

QSAR model

Sexual maturation:

no effects observed

Description (incidence and severity):

QSAR model

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

QSAR model

Gross pathological findings:

no effects observed

Description (incidence and severity):

QSAR model

Histopathological findings:

no effects observed

Description (incidence and severity):

QSAR model

Non-ER binder due to non-cyclic molecular structure. O-isobutyl ethylthiocarbamate (IBETC)  have a molecular weight of less than 500, but do not possess a cyclic structure is reported to non-binders to the receptor and therefore  O-isobutyl ethylthiocarbamate (IBETC)  does not cause reproductive toxicity
1.1. CAS number:55860-53-2
1.2. Other regulatory numbers: Not reported
1.3. Chemical name(s):
carbamothioic acid, ethyl-, o-(2-methylpropyl) ester
o-isobutyl ethylthiocarbamate
o-(2-methylpropyl) ethylcarbamothioate
1.4. Structure codes:
a. SMILES:
CCNC(=S)OCC(C)C
1.5. Profiling results:
-DNA binding by OECD-No alert found
-Est rogen Receptor Binding-Non binder, non cyclic structure
-OECD HPV Chemical Categories-Not categorized
-Protein binding by OECD-No alert found
-Protein binding potency-Not possible to classify according to these rules (GSH)
-Superfragments-No superfragment
-US-EPA New Chemical Categories-Not categorized

Dose descriptor:

other: Relative ERBA (Estrogen Receptor Binding Affinity)

Generation:

F1

Effect level:

< -3 other: Log RBA(Relative Binding Affinities )

Based on:

other: Estrogen receptor (ER) binding

Sex:

not specified

Basis for effect level:

sexual maturation

clinical signs

mortality

body weight and weight gain

clinical biochemistry

organ weights and organ / body weight ratios

gross pathology

histopathology: neoplastic

other:

Remarks on result:

other: Non-ER binder due to non-cyclic molecular structure.

Reproductive effects observed:

not specified

This grouping method contains simple categories for estrogen receptor (ER) binding. This method is relevant for reproductive toxicity endpoints in fish and mammals.

 

Non-binder, impaired OH or NH2 group

Non-binder without OH or NH2 group

Non-binder, non-cyclic structure

Non-binder, MW > 500

Non-binder, non-cyclic structure– chemicals without cycles and MW =<500

Non-ER binder due to non-cyclic molecular structure.

 

Estrogen receptor (ER) binding is a molecular initiating event much like protein binding that leads to a series of adverse outcomes, which are typically considered reproductive and development hazards. It is an endpoint where several comprehensive databases exist, which has lead to the development of several approaches for using (Q)SARs to predict ER-binding and possible endocrine disruption .

Popular among these are the “four phase” assessment that includes Comparative Molecular Field Analysis (CoMFA) and the Common Reactivity Pattern Approach (COREPA)

Since the RE-binding is a receptor mediated event, particular organic functional groups, size and shape are critical to binding potency.

O-isobutyl ethylthiocarbamate (IBETC) have a molecular weightless than 500, but do not possess a cyclic structure is reported to non-binders to the receptor and therefore O-isobutyl ethylthiocarbamate (IBETC) does not cause reproductive toxicity.

Conclusions:

Non-ER binder due to non-cyclic molecular structure. O-isobutyl ethylthiocarbamate (IBETC) have a molecular weight of less than 500, but do not possess a cyclic structure is reported to non-binders to the receptor and therefore O-isobutyl ethylthiocarbamate (IBETC) does not cause reproductive toxicity.

Executive summary:

Non-ER binder due to non-cyclic molecular structure. O-isobutyl ethylthiocarbamate (IBETC)  have a molecular weight of less than 500, but do not possess a cyclic structure is reported to non-binders to the receptor and therefore  O-isobutyl ethylthiocarbamate (IBETC)  does not cause reproductive toxicity

1.1. CAS number:55860-53-2

1.2. Other regulatory numbers: Not reported

1.3. Chemical name(s):

carbamothioic acid, ethyl-, o-(2-methylpropyl) ester

o-isobutyl ethylthiocarbamate

o-(2-methylpropyl) ethylcarbamothioate

1.4. Structure codes:

a. SMILES:

CCNC(=S)OCC(C)C

1.5. Profiling results:

-DNA binding by OECD-No alert found

-Est rogen Receptor Binding-Non binder, non cyclic structure

-OECD HPV Chemical Categories-Not categorized

-Protein binding by OECD-No alert found

-Protein binding potency-Not possible to classify according to these rules (GSH)

-Superfragments-No superfragment

-US-EPA New Chemical Categories-Not categorized

Reference 2

Endpoint:

screening for reproductive / developmental toxicity

Remarks:

other: QSAR model

Type of information:

(Q)SAR

Adequacy of study:

key study

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: Accepted Estrogen Receptor Binding QSAR method for chemicals properties assessment.. This method is relevant for reproductive toxicity endpoints in fish and mammals.

Qualifier:

according to guideline

Guideline:

other: Estrogen Receptor Binding method

Principles of method if other than guideline:

This grouping method contains simple categories for estrogen receptor (ER) binding. This method is relevant for reproductive toxicity endpoints in fish and mammals.

GLP compliance:

no

Remarks:

not applicable. QSAR model

Limit test:

no

Species:

other: fish and mammals.

Strain:

other: QSAR model

Sex:

not specified

Route of administration:

other: QSAR model

Vehicle:

other: QSAR model

Details on exposure:

Estrogen receptor (ER) binding is a molecular initiating event much like protein binding that leads to a series of adverse outcomes, which are typically considered reproductive and development hazards. It is an endpoint where several comprehensive databases exist, which has lead to the development of several approaches for using (Q)SARs to predict ER-binding and possible endocrine disruption .

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

Estrogen receptor (ER) binding is a molecular initiating event much like protein binding that leads to a series of adverse outcomes, which are typically considered reproductive and development hazards. It is an endpoint where several comprehensive databases exist, which has lead to the development of several approaches for using (Q)SARs to predict ER-binding and possible endocrine disruption .

Remarks:

Doses / Concentrations:

Basis:
other: QSAR model

Control animals:

not specified

Parental animals: Observations and examinations:

Estrogen receptor (ER) binding is a molecular initiating event much like protein binding that leads to a series of adverse outcomes, which are typically considered reproductive and development hazards. It is an endpoint where several comprehensive databases exist, which has lead to the development of several approaches for using (Q)SARs to predict ER-binding and possible endocrine disruption .

Clinical signs:

no effects observed

Description (incidence and severity):

QSAR model

Body weight and weight changes:

no effects observed

Description (incidence and severity):

QSAR model

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

QSAR model

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

QSAR model

Other effects:

no effects observed

Description (incidence and severity):

Test substance intake: QSAR model

Reproductive function: oestrous cycle:

no effects observed

Description (incidence and severity):

QSAR model

Reproductive function: sperm measures:

no effects observed

Description (incidence and severity):

QSAR model

Reproductive performance:

no effects observed

Description (incidence and severity):

QSAR model

No binding to Estrogen Receptor Alpha (Log RBA >-3) for the O-isobutyl ethylthiocarbamate (IBETC) and therefore O-isobutyl ethylthiocarbamate (IBETC) does not cause reproductive toxicity.

Dose descriptor:

other: QSAR model

Effect level:

< -3 other: Log RBA(Relative Binding Affinities )

Based on:

other: Estrogen receptor (ER) binding

Sex:

not specified

Basis for effect level:

other: No binding to Estrogen Receptor Alpha (Log RBA >-3) for the Isopropyl Ethyl Thionocarbamate (IPETC) (CAS# 141-98-0 ) and respectively Reaction mass of O-isopropyl ethylthiocarbamate (98%) and n-butanol (1%) and propan-2-ol (1%)

Remarks on result:

other: Generation: QSAR model (migrated information)

Clinical signs:

no effects observed

Description (incidence and severity):

QSAR model

Mortality / viability:

no mortality observed

Description (incidence and severity):

QSAR model

Body weight and weight changes:

no effects observed

Description (incidence and severity):

QSAR model

Sexual maturation:

no effects observed

Description (incidence and severity):

QSAR model

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

QSAR model

Gross pathological findings:

no effects observed

Description (incidence and severity):

QSAR model

Histopathological findings:

no effects observed

Description (incidence and severity):

QSAR model

No binding to Estrogen Receptor Alpha (Log RBA >-3) for the O-isobutyl ethylthiocarbamate (IBETC) and therefore O-isobutyl ethylthiocarbamate (IBETC) does not cause reproductive toxicity.

Dose descriptor:

other: Relative ERBA (Estrogen Receptor Binding Affinity)

Generation:

F1

Effect level:

< -3 other: Log RBA(Relative Binding Affinities )

Based on:

other: Estrogen receptor (ER) binding

Sex:

not specified

Basis for effect level:

clinical signs

mortality

body weight and weight gain

organ weights and organ / body weight ratios

gross pathology

histopathology: non-neoplastic

other: No binding to Estrogen Receptor Alpha (Log RBA >-3) for the O-isobutyl ethylthiocarbamate (IBETC) and therefore O-isobutyl ethylthiocarbamate (IBETC) does not cause reproductive toxicity.

Remarks on result:

other: No binding to Estrogen Receptor Alpha (Log RBA >-3) for the O-isobutyl ethylthiocarbamate (IBETC)

Reproductive effects observed:

not specified

No binding to Estrogen Receptor Alpha (Log RBA >-3) for the O-isobutyl ethylthiocarbamate (IBETC) and therefore   O-isobutyl ethylthiocarbamate (IBETC)  does not cause reproductive toxicity.

Conclusions:

No binding to Estrogen Receptor Alpha (Log RBA >-3) for the O-isobutyl ethylthiocarbamate (IBETC) and therefore O-isobutyl ethylthiocarbamate (IBETC) does not cause reproductive toxicity.

Reference 3

Endpoint:

two-generation reproductive toxicity

Type of information:

(Q)SAR

Adequacy of study:

key study

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:Accepted DART QSAR method for chemicals properties assessment.. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals.

Qualifier:

according to guideline

Guideline:

other: QSAR Toolbox Version 3.3.5.17

Principles of method if other than guideline:

This grouping method contains simple categories for Developmental and Reproductive toxicity. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals.

GLP compliance:

no

Remarks:

not applicable. QSAR model

Limit test:

no

Species:

rat

Strain:

other: QSAR model

Sex:

not specified

Route of administration:

other: QSAR model

Vehicle:

other: QSAR model

Details on exposure:

This grouping method contains simple categories for Developmental and Reproductive toxicity. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals. The database include a set of 716 chemicals (664 positive, 16 negative, and 36 with insufficient data) that have been evaluated for their DART potential. These chemicals were grouped into 25 different categories, and 129 sub-categories, based on defined receptor binding and chemical properties, and when known, their MOA. Data is separated into two types of endpoints: developmental and reproductive toxicity. Detailed information for the effect associated with observed data is available in the metadata information of the database.

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

This grouping method contains simple categories for Developmental and Reproductive toxicity. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals. The database include a set of 716 chemicals (664 positive, 16 negative, and 36 with insufficient data) that have been evaluated for their DART potential. These chemicals were grouped into 25 different categories, and 129 sub-categories, based on defined receptor binding and chemical properties, and when known, their MOA. Data is separated into two types of endpoints: developmental and reproductive toxicity. Detailed information for the effect associated with observed data is available in the metadata information of the database.

Remarks:

Doses / Concentrations:

Basis:
other: QSAR model

Control animals:

not specified

Parental animals: Observations and examinations:

This grouping method contains simple categories for Developmental and Reproductive toxicity. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals. The database include a set of 716 chemicals (664 positive, 16 negative, and 36 with insufficient data) that have been evaluated for their DART potential. These chemicals were grouped into 25 different categories, and 129 sub-categories, based on defined receptor binding and chemical properties, and when known, their MOA. Data is separated into two types of endpoints: developmental and reproductive toxicity. Detailed information for the effect associated with observed data is available in the metadata information of the database.

Clinical signs:

no effects observed

Description (incidence and severity):

QSAR model

Body weight and weight changes:

no effects observed

Description (incidence and severity):

QSAR model

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

QSAR model

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

QSAR model

Other effects:

no effects observed

Description (incidence and severity):

Test substance intake: QSAR model

Reproductive function: oestrous cycle:

no effects observed

Description (incidence and severity):

QSAR model

Reproductive function: sperm measures:

no effects observed

Description (incidence and severity):

QSAR model

Reproductive performance:

no effects observed

Description (incidence and severity):

QSAR model

Maternal toxic effects:yes
Details on maternal toxic effects:
No adverse effects on the highest dose tested according the DART QSAR method for chemicals properties assessment..
This grouping method contains simple categories for Developmental and Reproductive toxicity. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals. The database include a set of 716 chemicals (664 positive, 16 negative, and 36 with insufficient data) that have been evaluated for their DART potential.

Dose descriptor:

NOAEL

Effect level:

250 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

not specified

Basis for effect level:

other: Reproductive toxicity

Remarks on result:

other: No adverse effects on the highest dose tested according the DART QSAR method for chemicals properties assessment.. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals.

Clinical signs:

no effects observed

Description (incidence and severity):

QSAR model

Mortality / viability:

no mortality observed

Description (incidence and severity):

QSAR model

Body weight and weight changes:

no effects observed

Description (incidence and severity):

QSAR model

Sexual maturation:

no effects observed

Description (incidence and severity):

QSAR model

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

QSAR model

Gross pathological findings:

no effects observed

Description (incidence and severity):

QSAR model

Histopathological findings:

no effects observed

Description (incidence and severity):

QSAR model

NOAEL for Reproductive Toxicity was 250 mg/kg bw/day (No adverse effects on the highest dose tested) for O-isobutyl ethylthiocarbamate (IBETC) and does not cause Reproductive Toxicity.

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

250 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

not specified

Basis for effect level:

clinical signs

mortality

body weight and weight gain

organ weights and organ / body weight ratios

gross pathology

histopathology: non-neoplastic

other: No adverse effects on the highest dose tested according the DART QSAR method for chemicals properties assessment.. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals.

Remarks on result:

other: NOAEL for Reproductive Toxicity was 250 mg/kg bw/day (No adverse effects on the highest dose tested) for O-isobutyl ethylthiocarbamate (IBETC) and does not cause Reproductive Toxicity.

Reproductive effects observed:

not specified

Profiling results:

DNA binding by OECD: No alert found

Est rogen Receptor Binding :Non binder, non cyclic structure

OECD HPV Chemical Categories \;Not categorized

Developmental & Reproductive Toxicity (DART): Not known precedent reproductive and developmental toxic potential (DART scheme v.1.0)

Conclusions:

NOAEL for Reproductive Toxicity was 250 mg/kg bw/day (No adverse effects on the highest dose tested) for O-isobutyl ethylthiocarbamate (IBETC) and does not cause Reproductive Toxicity.
Developmental & Reproductive Toxicity (DART): Not known precedent reproductive and developmental toxic potential (DART scheme v.1.0)

Executive summary:

Profiling results:

DNA binding by OECD: No alert found

Est rogen Receptor Binding :Non binder, non cyclic structure

OECD HPV Chemical Categories \;Not categorized

Developmental & Reproductive Toxicity (DART): Not known precedent reproductive and developmental toxic potential (DART scheme v.1.0)

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

250 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

NOAEL for Reproductive Toxicity was 250 mg/kg bw/day (No adverse effects on the highest dose tested) for O-isobutyl ethylthiocarbamate (IBETC) and does not cause Reproductive Toxicity.

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Effects on developmental toxicity

Description of key information

NOAEL for developmental toxicity was 250 mg/kg bw/day (No adverse effects on the highest dose tested) for O-isobutyl ethylthiocarbamate (IBETC)  and does not cause developmental toxicity.

Developmental & Reproductive Toxicity (DART): Not known precedent reproductive and developmental toxic potential (DART scheme v.1.0)

NOAEL for maternal toxicity of zinc bis(diethyldithiocarbamate) was 125 mg/kg bw/day (Based on clinical signs of toxicity and mortality at the next dose level) and  the NOAEL for developmental toxicity was 250 mg/kg bw/day (No adverse effects on the highest dose tested).

Dithiocarbamates are related compounds to Thionocarbamate.

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

(Q)SAR

Adequacy of study:

key study

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:Accepted DART QSAR method for chemicals properties assessment.. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals.

Qualifier:

according to guideline

Guideline:

other: QSAR Toolbox Version 3.3.5.17

Principles of method if other than guideline:

This grouping method contains simple categories for Developmental and Reproductive toxicity. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals.

GLP compliance:

no

Remarks:

not applicable DART QSAR method for chemicals properties assessment..

Limit test:

no

Species:

rat

Strain:

other: QSAR model

Route of administration:

other: QSAR model

Vehicle:

other: QSAR model

Details on exposure:

This grouping method contains simple categories for Developmental and Reproductive toxicity. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals. The database include a set of 716 chemicals (664 positive, 16 negative, and 36 with insufficient data) that have been evaluated for their DART potential. These chemicals were grouped into 25 different categories, and 129 sub-categories, based on defined receptor binding and chemical properties, and when known, their MOA. Data is separated into two types of endpoints: developmental and reproductive toxicity. Detailed information for the effect associated with observed data is available in the metadata information of the database.

Analytical verification of doses or concentrations:

no

Details on mating procedure:

QSAR model

Duration of treatment / exposure:

QSAR model

Frequency of treatment:

QSAR model

Duration of test:

QSAR model

Control animals:

other: QSAR model

Maternal examinations:

This grouping method contains simple categories for Developmental and Reproductive toxicity. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals. The database include a set of 716 chemicals (664 positive, 16 negative, and 36 with insufficient data) that have been evaluated for their DART potential. These chemicals were grouped into 25 different categories, and 129 sub-categories, based on defined receptor binding and chemical properties, and when known, their MOA. Data is separated into two types of endpoints: developmental and reproductive toxicity. Detailed information for the effect associated with observed data is available in the metadata information of the database.

Fetal examinations:

This grouping method contains simple categories for Developmental and Reproductive toxicity. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals. The database include a set of 716 chemicals (664 positive, 16 negative, and 36 with insufficient data) that have been evaluated for their DART potential. These chemicals were grouped into 25 different categories, and 129 sub-categories, based on defined receptor binding and chemical properties, and when known, their MOA. Data is separated into two types of endpoints: developmental and reproductive toxicity. Detailed information for the effect associated with observed data is available in the metadata information of the database.

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
No adverse effects on the highest dose tested according the DART QSAR method for chemicals properties assessment..
This grouping method contains simple categories for Developmental and Reproductive toxicity. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals. The database include a set of 716 chemicals (664 positive, 16 negative, and 36 with insufficient data) that have been evaluated for their DART potential.

Dose descriptor:

NOAEL

Effect level:

250 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Fetal body weight changes:

no effects observed

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Basis for effect level:

other:

Remarks on result:

other: No adverse effects on the highest dose tested according the DART QSAR method for chemicals properties assessment.. This method is relevant for Developmental and Reproductive toxicity endpoints in mammals.

Abnormalities:

not specified

Developmental effects observed:

not specified

See attached QSAR study report

Conclusions:

NOAEL for developmental toxicity was 250 mg/kg bw/day (No adverse effects on the highest dose tested) for O-isobutyl ethylthiocarbamate (IBETC) and does not cause developmental toxicity.
Developmental & Reproductive Toxicity (DART): Not known precedent reproductive and developmental toxic potential (DART scheme v.1.0)

Executive summary:

Profiling results:

DNA binding by OECD: No alert found

Est rogen Receptor Binding :Non binder, non cyclic structure

OECD HPV Chemical Categories \;Not categorized

Developmental & Reproductive Toxicity (DART): Not known precedent reproductive and developmental toxic potential (DART scheme v.1.0)

Reference 2

Endpoint:

developmental toxicity

Type of information:

other: published data

Adequacy of study:

weight of evidence

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:

Dithiocarbamates are related compounds to Thionocarbamate.

Qualifier:

no guideline followed

Principles of method if other than guideline:

The test substance was administered at dose levels of 31.25, 64.2, 125 and 250 mg/kg bw/day as suspension in olive oil to groups of pregnant Wistar rats (21-23 animals/group) during days 7 to 15 of gestation. On gestation day 20, 14 rats from the control and high dose groups and 15 rats from the other test groups were opened under anesthesia to inspect the uterus, number of corpora lutea, number of inplants, sex ratio and number of live and dead fetuses. The other rats from each group were allowed to give natural birth, and post-natal development of the pups was examined. The assessed parameters were number of pups, mortality rate, outward abnormalities, skeletal and soft tissue abnormalities and body weight, as well as ear auricle extension, tooth bud collapse or emergence, fur emergence, eyelid opening and timing for testes descent and vagina opening. Pups were allowed to wean and the observation continued till age 10 weeks, after which animals were sacrificed and gross pathological and organ weight examinations were performed.

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS- Source: Japan- Age at study initiation: females 12 weeks, males 14 weeks- Housing: singly in aluminum pregnancy cages (Natsume Seisakusho)- Diet: solid feed pellets (Oriental Yeast Co., MF), ad libitum- Water: tap water, ad libitumENVIRONMENTAL CONDITIONS- Temperature (°C): 25±1- Humidity (%): 55±5- Air changes (per hr): 15- Photoperiod (hrs dark / hrs light):

Route of administration:

oral: gavage

Vehicle:

olive oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: using an ultrasonic disintegrator (360W, 5 minutes) as a 20% suspension fluid in olive oil (The Japanese Pharmacopoeia).

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

- Impregnation procedure: cohoused- M/F ratio per cage: 2 / 5- Length of cohabitation: overnight- Verification of same strain and source of both sexes: yes - Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy

Duration of treatment / exposure:

During days 7-15 of gestation

Frequency of treatment:

Once daily

Duration of test:

Until gestation day 20 or natural labor; naturally born pups were observed until age of 10 weeks

No. of animals per sex per dose:

21-23 females/dose

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: based on the dose-range finding study

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes - Time schedule: dailyBODY WEIGHT: Yes - Time schedule for examinations: dailyFOOD CONSUMPTION : Yes / No / No data- Time schedule for examinations: dailyOTHER: spleen weights of pregnant dams were examined

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes Examinations included:- Gravid uterus weight: No- Number of corpora lutea: Yes - Number of implantations: Yes - Number of early resorptions: Yes - Number of late resorptions: Yes - Other: sex ratio

Fetal examinations:

- External examinations: Yes: [all per litter ]- Soft tissue examinations: Yes: [ca. 1/3 per litter ] - Skeletal examinations: Yes: [ca. 2/3 per litter ] - Head examinations: No

Statistics:

x2 test (death rate of dams), the t test (dam body weight, feed intake volume, number of corpora lutea, implant number and spleen weight, fetus number and weight, and the newborn number, body weight, and weight of important organs), and the rank sum test (fetus death rate, frequency of malformations, number of bone variations, delivery rate, suckling rate, and survival rate of newborns)

Details on maternal toxic effects:

Maternal toxic effects:yesDetails on maternal toxic effects:The 31.25 and 62.5mg/kg groups showed the same body weight increases as the control group, and no abnormalities in the normal state were seen, nor were there any examples of deaths. In the 125mg/kg group, while no change in the average weight trend was seen, minor cases of diarrhea were observed in 5 rats out of 22 rats from the 6th day after start of administration (gestation day 12) through the 8th day (gestation day 14). In the 250 mg/kg group, minor suppression of body weight increase was seen from the 2nd day after start of administration (gestation day 8), and in all cases piloerection, diarrhea, bleeding around the eyes, and debilitation were observed, with 7 rats out of 21 dying between gestation day 9 and day 13. The pregnant rats that avoided death continued to show minor suppression of body weight increase even after administration was ended.A drop in feed intake volume was seen for the control group and for each of the ZDEC groups on the 2nd day after the start of administration (gestation day 8). The feed intake volume during the gestation period for the groups at 125 mg/kg and lower showed no major difference when compared with the control group. In the 250 mg/kg group, the feed intake volume was lower than the control group from the 2nd day after start of administration (gestation day 8) through the 6th day (gestation day 12). From the 7th day of administration, however, it showed generally the same trend as the control group.

Dose descriptor:

NOAEL

Effect level:

125 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOAEL

Effect level:

62.5 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOAEL

Effect level:

250 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effectsDetails on embryotoxic / teratogenic effects:No significant differences were found in the number of corpora lutea, implantations sites, implantation rates, live and dead fetuses, sex ratio and fetus weights between the controls and the test groups. In the external abnormality test, no abnormal fetuses were observed in the control group, and in the ZDEC groups of 125 mg/kg or less. In the 250 mg/kg group, one case of a fetus with a cleft palate was found. However, this occurrence rate was 0.6%, and was not a significant difference when compared with the control group. In the internal organs test, no abnormal fetuses were observed among the surviving fetuses. Abnormalities thought to be skeletal malformations were not observed in the control group and in the ZDEC groups of 125 mg/kg or less. In the 250 mg/kg group, one case of a fetus with a cleft palate was found (0.8%). However, this occurrence frequency of skeletal malformation fetuses was low, and was not a significant difference when compared with the control group.Abnormalities that could be considered skeletal deformations were observed in all groups, including the control group. Cervical ribs were observed in 1.5 to 8.9% of all groups. Fetuses with shortened or split cervical arches were observed in 1.7% of the 62.5 mg/kg group and 4.2% of the 250 mg/kg group. Deformations (vestigial conditions, dual sphere conditions) of the thoracic centra were observed in 3.0 to 11.0% of all groups, split thoracic centra was observed in 2.7% of the control group, 1.6% of the 31.25 mg/kg group, 0.7% of the 62.5 mg/kg group, and 2.2% of the 250 mg/kg group. Fetuses with sternebrae abnormalities (deformation, splitting, fusion, deficiency) included 64.0% of the control group, 59.7% of the 31.25 mg/kg group, 63.6% of the 62.5 mg/kg group, 64.1% of the 125 mg/kg group, and 81.4% of the 250 mg/kg group. Lumbar ribs were observed in 31.1 to 58.5% of all groups, including the control group. Shortened pubic bones were observed in 0.8% of the 31.25 mg/kg group. Nevertheless, the occurrence rates for these skeletal deformations did not show significant differences between the control group and the ZDEC dosage groups.For the ossification state, the bone number for the metacarpal bone, metatarsal bone, and sacro-cardal vertebrae was determined. In every case, there was no significant difference in bone number between the target group and the ZDEC dosage groups.No significant differences in body weight were observed between the test groups and control groups up till the age of 10 weeks, when the study was terminated. For the ear auricle extension, tooth bud collapse or emergence, fur emergence, eyelid opening, and timing for testes descent and vagina opening of newborn pups, each measurement period showed no significant difference between the control group and the ZDEC dosage groups.

Dose descriptor:

NOAEL

Effect level:

250 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: developmental toxicity

Abnormalities:

not specified

Developmental effects observed:

not specified

Conclusions:

In the present study, the NOAEL for maternal toxicity of zinc bis(diethyldithiocarbamate) was 125 mg/kg bw/day (Based on clinical signs of toxicity and mortality at the next dose level) and the NOAEL for developmental toxicity was 250 mg/kg bw/day (No adverse effects on the highest dose tested).
Dithiocarbamates are related compounds to Thionocarbamate.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

250 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

NOAEL for developmental toxicity was 250 mg/kg bw/day (No adverse effects on the highest dose tested) for O-isobutyl ethylthiocarbamate (IBETC) and does not cause developmental toxicity.
Developmental & Reproductive Toxicity (DART): Not known precedent reproductive and developmental toxic potential (DART scheme v.1.0)

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the hazard assessment of O-isobutyl ethylthiocarbamate (IBETC) in section 2.1 and 2.2. in IUCLID 6., available data for the substance and following the “Guidance on Information Requirement and Chemical Safety Assessment R.8. Characterisation of dose [concentration]- response for human health” andaccording to the criteria described in Directive 67/548 and in the CLP Regulation:

 

Directive 67/548	Toxicity to reproduction/development Repr. Cat. 1; R61 May cause harm to the unborn child. Repr. Cat. 2; R61 May cause harm to the unborn child. Repr. Cat. 3; R63 Possible risk of harm to the unborn child. Toxicity to reproduction/fertility  Repr. Cat. 1; R60 May impair fertility. Repr. Cat. 2; R60 May impair fertility. Repr. Cat. 3; R62 Possible risk of impaired fertility
CLP	Reproductive toxicity Repr. 1A Repr. 1B Repr. 2 H360: May damage fertility or the unborn child <state specific effect if known > <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. H361: Suspected of damaging fertility or the unborn child <state specific effect if known>

 

 

It is concluded that the O-isobutyl ethylthiocarbamate (IBETC) does not meet the criteria to be classified for human health hazards for Reproductive toxicity.