O-isopropyl ethylthiocarbamate

Toxicity to reproduction

Administrative data

Endpoint:

two-generation reproductive toxicity

Remarks:

based on test type

Type of information:

experimental study

Adequacy of study:

key study

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.

Data source

Reference

Reference Type:

publication

Title:

Multi-generation rat reproduction study with isopropanol

Author:

Bevan, C., Tyler, T.R., Gardiner, T.H., Kapp, R.W., Jr., Andrews, L. and Beyer, B.K.

Year:

1995

Bibliographic source:

B.K. Journal of Applied Toxicology, Vol. 15(2) pp. 117- 123 (1995).

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

Deviations:

no

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

O-isopropyl ethylthiocarbamate

EC Number:

205-517-7

EC Name:

O-isopropyl ethylthiocarbamate

Cas Number:

141-98-0

Molecular formula:

C6H13NOS

IUPAC Name:

N-ethyl(propan-2-yloxy)carbothioamide

Test material form:

liquid

Details on test material:

IPETC is prepared through reacting ethoxycarbonyl isothiocyanate/ Ethyl isothiocyanatoformate (CAS 16182-04-0) with propan-2-ol/ isopropyl alcohol (CAS Number 67-63-0) and Butan-1-ol/ butyl alcohol (CAS Number 71-36-3).

IPETC/O-isopropyl ethylthiocarbamate contains propan-2-ol (CAS number 67-63-0) and Butan-1-ol (CAS number 67-63-0) which are an integral part of the substance.
Propan-2-ol (CAS number 67-63-0) and Butan-1-ol (CAS number 67-63-0) are both reagents used in the manufacture of IPETC/O-isopropyl ethylthiocarbamate. Therefore, Propan-2-ol (CAS number 67-63-0) and Butan-1-ol (CAS number 67-63-0) need to be considered in the assessment of IPETC/O-isopropyl ethylthiocarbamate.

EC Name: propan-2-ol
CAS Number :67-63-0
EC Number:200-661-7
CAS Name: isopropyl alcohol

EC Name: Butan-1-ol
CAS Number : 71-36-3
EC Number: 200-751-6
CAS Name: butyl alcohol

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Inc, Kingston facility, Stone Ridge, New York.
- Age at study initiation: (P) 8 wks; (F1) 8 wks
- Weight at study initiation: (P) Males: 265.5-331.9 g; Females: 175.2-228.4 g; (F1) Males: 265.2-265.4 g; Females: 181.1-181.2 g
- Fasting period before study: None
- Housing: stainless steel and wire mesh cage, individually housed, except during the first week of quarantine, during mating, and during lactation
- Diet (e.g. ad libitum): Purina certified rodent chow ad libitum
- Water (e.g. ad libitum): automatic watering system, ad libitum (Elizabethtown Water Company, Elizabeth, New Jersey)
- Acclimation period: 21 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 to 24.4°C
- Humidity (%): 40 to 70 %
- Air changes (per hr): not reported
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: June 13, 1990 To: April 15, 1992

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Undiluted test material was thoroughly miscible in carrier (RO water) prior to dispensing. Test material dosing solutions were prepared at 6-15 day intervals, in consideration of laboratory scheduling/ Dosing solutions were aliquoted on or prior to the first scheduled day of dosing. Aliquoted dosing solutions were stored in the Compound Preparation Department refrigerator. Unused portions were returned to the Compound Preparation Lab for disposal.

DIET PREPARATION
not administered in diet

VEHICLE
- Justification for use and choice of vehicle (if other than water): vehicle used was water

Details on mating procedure:

- M/F ratio per cage: 1/1
- Length of cohabitation: when pregnant or 7 days had elapsed (then cohabited with a different male)
- Proof of pregnancy: copulatory plug or sperm in vaginal smear referred to as day 0 of pregnancy
- After 7 days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: yes 3 attempts
- After successful mating each pregnant female was caged (how): individually

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Samples of isopropyl alchohol dose solutions in reverse osmosis water were analyzed by Gas Chromatography for concentration verification.

Duration of treatment / exposure:

All P1 and F1 (P2) male and female animals received test or control material daily for at least 10 weeks prior to mating, throughout the mating period, and until the day prior to euthanasia. Additionally, P1 and F1 (P2) females received test or control material during gestation, lactation, and until the day prior to euthanasia, following weaning of their offspring on day 21 postpartum. F1 neonates prior to selection for mating received test or control material beginning on postnatal day 21.

Frequency of treatment:

daily

Details on study schedule:

- F1 parental animals not mated until 11 weeks after selected from the F1 litters.
- Selection of parents from F1 generation when pups were 21 days of age.
- Age at mating of the mated animals in the study: 15 weeks

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
100 mg/kg bw/day
Basis:
actual ingested

Doses / concentrations 2

Remarks:

Doses / Concentrations:
500 mg/kg bw/day
Basis:
actual ingested

Doses / concentrations 3

Remarks:

Doses / Concentrations:
1000 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

30/sex/dose

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: not reported
- Rationale for animal assignment (if not random): random

Positive control:

no

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: morning and afternoon


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: prior to selecton, first day of dosing and weekly thereafter until euthanasia (males) or weekly until post partum day 21 (females)


BODY WEIGHT: Yes
- Time schedule for examinations: prior to selecton, first day of dosing and weekly thereafter until euthanasia (males) or weekly until post partum day 21 (females)

Oestrous cyclicity (parental animals):

not reported

Sperm parameters (parental animals):

not reported

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 8 pups/litter (4/sex/litter as nearly as possible); excess pups were killed and discarded.


PARAMETERS EXAMINED
The following parameters were examined in F1 / F2 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, and physical abnormalities.


GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All surviving animals as soon as possible after the last litters in each generation were produced.
- Maternal animals: All surviving animals after the last litter of each generation was weaned.


GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations.


HISTOPATHOLOGY / ORGAN WEIGHTS
The following organs and tissues were prepared for microscopic examination: liver, kidney, vagina, uterus, ovaries, testes, epididymides, seminal vesicles, prostate, pituitary, liver, and any abnormal tissue

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring not selected as parental animals and all F2 offspring were sacrificed at 21 days of age.
- These animals were subjected to postmortem examinations macroscopic and microscopic examination


GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations

Statistics:

The following parameters were analyzed statistically for significant differences: mean body weights; mean food consumption; mean organ weights; mean relative organ weights

Reproductive indices:

calculated

Offspring viability indices:

calculated

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

no effects observed

Other effects:

no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
Free of any observable abnormalities
1 death in control and 1 death in mid dose group considered to be incidental. 2 deaths in high dose group, cause of death was not determined

BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)
no significant differences

TEST SUBSTANCE INTAKE (PARENTAL ANIMALS)
no significant differences


REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)
no significant differences


ORGAN WEIGHTS (PARENTAL ANIMALS)
Mean absolute and relative liver weights in high dose P1 males were statistically significantly increased compared to controls. In females, relative liver weight was increased in the mid-dose and high-dose groups and relative kidney weight was increased in the high dose group.


GROSS PATHOLOGY (PARENTAL ANIMALS)
no significant effects

HISTOPATHOLOGY (PARENTAL ANIMALS)
no significant effects

Effect levels (P0)

Dose descriptor:

NOAEL

Remarks:

offspring toxicity

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: reduced body weights and increased mortality at 1000 mg/kg bw/day

Remarks on result:

other: Generation: F1/F2 (migrated information)

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

mortality observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings:

no effects observed

Details on results (F1)

VIABILITY (OFFSPRING)
Increased mortality was observed in high-dose F1 offspring compared with controls from postnatal Days 0 to 2. Several F1 weanlings died or were euthanized prior to P2 selection; 1 each in the low- and mid-dose groups, and 18 in the high-dose group.

CLINICAL SIGNS (OFFSPRING)
no significant effects

BODY WEIGHT (OFFSPRING)
High dose F1 male body weights were significantly lower on postnatal days 0 and 1 compared to controls.


GROSS PATHOLOGY (OFFSPRING)
No significant effects

HISTOPATHOLOGY (OFFSPRING)
No significant effects

Effect levels (F1)

1

Dose descriptor:

NOAEL

Remarks:

parental

Generation:

F1

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: increased organ weights at 1000 mg/kg bw/day

2

Dose descriptor:

NOAEL

Remarks:

reproductive

Generation:

F1

Effect level:

1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects observed at highest dose

Overall reproductive toxicity

Reproductive effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

NOAEL-500 mg/kg bw/day. Propan-2-ol (Isopropyl alcohol) as a main constituent of IPETC/ O-isopropyl ethylthiocarbamate and need to be considered in the assessment of IPETC/ O-isopropyl ethylthiocarbamate .