2-(octylthio)ethanol

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: According to secondary source listed below, the study was conducted with methods similar to OECD guidelines.

Data source

Reference

Reference 1

Reference Type:

secondary source

Title:

Prevention, Pesticides and Toxic Substances Reregistration Eligibility Decision (RED) Hydroxyethyl Octyl Sulfide

Author:

U.S. EPA

Year:

1995

Bibliographic source:

EPA 738-R-96-001

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

1992

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Ethanol, 2-(octylthio)-

IUPAC Name:

Ethanol, 2-(octylthio)-

Constituent 2

Reference substance name:

2-(octylthio)ethanol

EC Number:

222-598-4

EC Name:

2-(octylthio)ethanol

Cas Number:

3547-33-9

Molecular formula:

C10H22OS

IUPAC Name:

2-(octylsulfanyl)ethan-1-ol

Constituent 3

Reference substance name:

Hydroxyethyl octyl sulfide

IUPAC Name:

Hydroxyethyl octyl sulfide

Details on test material:

- Name of test material (as cited in study report): Hydroxyethyl octyl sulfide
- Substance type: Active
- Physical state: Liquid
- Analytical purity: 96.5 %

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

No data

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

not specified

Details on exposure:

No data

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

No data

Duration of treatment / exposure:

Days 6-15 of gestation

Frequency of treatment:

Daily

Duration of test:

No data

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 100, 300 or 1000 mg/kg/day
Basis:

No. of animals per sex per dose:

24

Control animals:

yes, concurrent no treatment

Details on study design:

No data

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes


BODY WEIGHT: Yes


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes

Ovaries and uterine content:

Cesarean parameters were examined, but no details were provided in the study.
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Other: number of pre and post implantation losses

Fetal examinations:

- External examinations: Yes
- Soft tissue examinations: Yes
- Skeletal examinations: Yes

Statistics:

No data

Indices:

No data

Historical control data:

No data

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
Not applicable

Effect levels (maternal animals)

1

Dose descriptor:

NOEL

Effect level:

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

Basis for effect level:

other: maternal toxicity

2

Dose descriptor:

NOEL

Effect level:

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

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
No treatment related incidences on external/visceral or skelet abnormalities except for a minor variant of 14th vestigial rib in the high dose group.

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Based on the results of the oral gavage study, the maternal NOEL was 1000 mg/kg/day (a LOEL was not established); the NOEL for developmental toxicity was 300 mg/kg/day and the LOEL was 1000 mg/kg/day.

Executive summary:

In a developmental toxicity study conducted with methods similar to OECD 414 guidelines, Sprague-Dawley Crl:CD BR rats(24/group) were orally administered technical hydroxyethyl octyl sulfide (96.5%) at 0, 100, 300 or 1000 mg/kg bw/day during days 6 through 15 of gestation. No maternal toxicity was reported. The slight decrease in food consumption seen during gestation days 9-11 in dams treated at 1000 mg/kg/day was not considered to be toxicologically significant due to the size of the standard deviations, range of food consumed, and because there were no corresponding decreases in either mean body weight or weight gain. Dosing had no effect on any of the cesarean parameters measured (e.g. mean numbers of corpora lutea, implantations, live fetuses; pre- and post-implantation losses). Therefore, for maternal toxicity, the NOEL was 1000 mg/kg bw/day; a LOEL was not established.

No treatment-related fetal external or fetal soft tissue abnormalities were seen at any dose level. Minor treatment-related skeletal variations were limited to an increase, both in the number and percent of fetuses, as well as litters with 14th vestigial ribs at 1000 mg/kg bw/day when compared to controls. No treatment-related skeletal malformations were seen. Based on these results, the NOEL for developmental toxicity was 300 mg/kg bw/day and the LOEL was 1000 mg/kg bw/day. The LOEL was based on increased incidence of skeletal variations.