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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
screening for reproductive / developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Justification for type of information:
Results are based on octanethiol which is a shorter alkyl chain version of octadecylmercaptan. As the thiol/mercaptan group is the active functional group then any toxic effects will specifically be due to the terminal thiol/mercaptan group. The alkyl chain just affects the water solubility and does not play a significant biochemical role or toxicological role. That is why the C8 thiol is a very good analogue for the longer chain thiol/mercaptan.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Report date:
2000

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
GLP compliance:
not specified
Limit test:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Octane-1-thiol
EC Number:
203-918-1
EC Name:
Octane-1-thiol
Cas Number:
111-88-6
Molecular formula:
C8H18S
IUPAC Name:
octane-1-thiol

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
Rearing automatically controlled at a temperature of 22 ± 2 ° C., relative humidity of 55 ± 15%, ventilation at about 12 times / hour, lighting 12 hours / day (7: 00-19: 00) I used.

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
olive oil
Details on exposure:
Daily exposure for 35 days total.
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
35 days
Frequency of treatment:
Daily
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day (actual dose received)
Dose / conc.:
10 mg/kg bw/day (actual dose received)
Dose / conc.:
50 mg/kg bw/day (actual dose received)
Dose / conc.:
250 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
12 females per dose level
Control animals:
yes, concurrent vehicle
Details on study design:
For the administration period, the males were taken for a total of 35 days before the mating and for the mating period up to the day before the autopsy, the females were for 14 days before the mating, the mating period, the gestation period and the 4 days after the birth via the parturition. Females who did not mate and females that did not deliver were taken until the day before necropsy. At the time of administration, it was administered by gavage once a day using the teflon stomach probe, in the morning. The volume of solution administered was 2 mL / kg, and it was calculated based on the body weight measured on the nearest day.
Positive control:
None

Examinations

Parental animals: Observations and examinations:
Observations made at 0, 3, 7, 14, 21, 28 and 34 days test duration for males
Observations made at 0, 3, 7, 14 prior to mating; 0, 7, 14, 20 gestation period and 0, 4 days lactation period for females
Oestrous cyclicity (parental animals):
3.98 up to 4.36 from 0 to 250mg/kg bw dosing.
Sperm parameters (parental animals):
No effects observed.
Litter observations:
No change due to the test substance was observed in the examination of neonates in any of the number of births, the number of babies born, sex ratio, birth rate, 4 day survival rate of neonates, external table, general condition, weight and autopsy.
Postmortem examinations (parental animals):
In the 250 mg / kg group, a significant lower value of the gestation period extension and delivery rate was observed. In addition, no change was observed in the test substance administered group for the number of corpus luteums, the number of implantation, the implantation rate and the birth rate. In addition, abnormalities in labor condition and nursing behavior were not observed.
No abnormality was found in any of the 10 and 50 mg / kg groups.
Postmortem examinations (offspring):
No change due to the test substance was observed in the examination of neonates in any of the number of births, the number of babies born, sex ratio, birth rate, 4 day survival rate of neonates, external table, general condition, weight and autopsy.

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:
no effects observed
Dermal irritation (if dermal study):
not specified
Mortality:
mortality observed, non-treatment-related
Description (incidence):
1 death but not attributed to administration.
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not specified
Haematological findings:
not specified
Clinical biochemistry findings:
not specified
Urinalysis findings:
not specified
Behaviour (functional findings):
not specified
Immunological findings:
not specified
Organ weight findings including organ / body weight ratios:
no effects observed
Histopathological findings: non-neoplastic:
not specified
Histopathological findings: neoplastic:
not specified

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:
no effects observed
Reproductive function: sperm measures:
not specified
Reproductive performance:
no effects observed

Effect levels (P0)

open allclose all
Key result
Dose descriptor:
NOAEL
Effect level:
>= 250 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male
Basis for effect level:
clinical signs
mortality
body weight and weight gain
organ weights and organ / body weight ratios
gross pathology
reproductive function (oestrous cycle)
reproductive performance
Key result
Dose descriptor:
NOAEL
Effect level:
>= 250 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
female
Basis for effect level:
clinical signs
gross pathology
reproductive function (oestrous cycle)
reproductive performance

Results: P1 (second parental generation)

General toxicity (P1)

Clinical signs:
no effects observed
Dermal irritation (if dermal study):
not specified
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not specified
Haematological findings:
not specified
Clinical biochemistry findings:
not specified
Urinalysis findings:
not specified
Behaviour (functional findings):
not specified
Immunological findings:
not specified
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Neuropathological findings:
not specified
Histopathological findings: non-neoplastic:
not specified
Histopathological findings: neoplastic:
not specified

Reproductive function / performance (P1)

Reproductive function: oestrous cycle:
not specified
Reproductive function: sperm measures:
not specified
Reproductive performance:
not specified

Results: F1 generation

General toxicity (F1)

Clinical signs:
not specified
Dermal irritation (if dermal study):
not specified
Mortality / viability:
not specified
Body weight and weight changes:
not specified
Food consumption and compound intake (if feeding study):
not specified
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not specified
Haematological findings:
not specified
Clinical biochemistry findings:
not specified
Urinalysis findings:
not specified
Sexual maturation:
not specified
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Histopathological findings:
not specified

Developmental neurotoxicity (F1)

Behaviour (functional findings):
not specified

Developmental immunotoxicity (F1)

Developmental immunotoxicity:
not specified

Effect levels (F1)

Key result
Dose descriptor:
NOAEL
Generation:
F1
Effect level:
>= 250 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
viability
clinical signs
mortality
body weight and weight gain
gross pathology

Overall reproductive toxicity

Key result
Reproductive effects observed:
no
Lowest effective dose / conc.:
250 mg/kg bw/day (actual dose received)
Treatment related:
no

Any other information on results incl. tables

The result of 250mg/kg bw for reproductive toxicity is based on interpretation of the paper. The result of a slight increase in gestation cycle and decrease in the pup viabiliy ratio are within the statistical parameters of the test background parameters so the quoted 50 mg/kg bw value for NOAEL is considered too harsh compared to the statistics of the test results.

Applicant's summary and conclusion

Conclusions:
The NOAEL on reproductive and developmental toxicity was 250 mg / kg / day in male parent animals, 250 mg / kg / day for female parent animals and 250 mg / kg / day in pediatric animals.