Dodecanoic acid, 1-methyl-2-sulfoethyl ester, sodium salt (1:1)

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Link to relevant study records

Reference

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)

GLP compliance:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: RCC Ltd, Switzerland
- Age at study initiation: 11 weeks
- Weight at study initiation: Males: 291-333 g; Females: 172-207 g;
- Food and water: ad libitum

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
A standard dose volume of 10 mL/kg body weight with a daily adjustment to the actual body weight was used. Control animals were dosed with the vehicle alone (Milli-Q-water).

Details on mating procedure:

Females were housed with sexually mature males (1:1) in special automatic mating cages i.e. with synchronized timing to initiate the nightly mating period, until evidence of copulation was observed. This system reduced the variation in the copulation times of the different females. The females were removed and housed individually if:
a) The daily vaginal smear was sperm positive, or b) A copulation plug was observed. The day of mating was designated day 0 post coitum.

If a female did not mate during the 14-day pairing period, this female was paired with a male of the same group which had already mated successfully. If mating was not recorded during this additional pairing period of a maximum of 14 days, the female was sacrificed and, if indicated, the reproductive organs examined histopathologically in order to ascertain the reason for the infertility.

Duration of treatment / exposure:

Males were treated over a 15-day pre-pairing period and during the pairing period up to one day before necropsy. Females were treated throughout the pre-pairing, pairing, gestation and lactation period up to weaning on day 21 post partum.

Frequency of treatment:

Daily

Remarks:

Doses / Concentrations:
0, 100, 300, 1000 mg/kg/day
Basis:
nominal conc.

No. of animals per sex per dose:

12 males and 12 females per dose group

Control animals:

yes, concurrent vehicle

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Once daily

DETAILED CLINICAL OBSERVATIONS: Yes


BODY WEIGHT: Yes daily


FOOD CONSUMPTION:
Males - weekly during pre-pairing and after pairing periods.

Females - pre-pairing period days 1-8 and 8-15; gestation days 0-7, 7-14 and 14-21 post coitum, and lactation days 1-7 and 7-14 post partum (since pups begin to consume maternal feed on or about lactation day 14, food consumption was not recorded after this day).
No food consumption was recorded during the pairing period.

Oestrous cyclicity (parental animals):

Duration of cycle was recorded

Sperm parameters (parental animals):

not reported

Litter observations:

Litters were examined for litter size, live births, still births and any gross anomalies.
Sex ratio of the pups were recorded on days 0/1, 4 and 21 post partum. Pups were weighed individually on days 0 (if possible, without identification), 1, 4, 7, 14 and 21 post partum.

Postmortem examinations (parental animals):

The testes and epididymides of all parental males were weighed as pairs

HISTOPATHOLOGY
Slides of all organs and tissues collected at terminal sacrifice from the animals of the control and high-dose groups were examined. The same applied to the female, which was terminated in extremis. Special emphasis was made on the stages of spermatogenesis and histopathology of interstitial cell structure.
If test item-related morphologic changes were detected in organs of any high-dose animal, those same organs from the mid- and low-dose group were examined to establish a no-effect level, if possible.
Histological examination of ovaries was carried out on any females that did not give birth. In addition, microscopic examination of the reproductive organs of all infertile males was made, if necessary.

Statistics:

Dunnett test, Steel-test, Fisher's exact test

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:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Reproductive function: oestrous cycle:

no effects observed

Reproductive performance:

no effects observed

Key result

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day

Sex:

male/female

Basis for effect level:

clinical signs

body weight and weight gain

food consumption and compound intake

organ weights and organ / body weight ratios

gross pathology

histopathology: non-neoplastic

reproductive function (oestrous cycle)

reproductive performance

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings:

no effects observed

CLINICAL SIGNS (OFFSPRING)


BODY WEIGHT (OFFSPRING)


SEXUAL MATURATION (OFFSPRING)


ORGAN WEIGHTS (OFFSPRING)


GROSS PATHOLOGY (OFFSPRING)


HISTOPATHOLOGY (OFFSPRING)


OTHER FINDINGS (OFFSPRING)

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

1 000 mg/kg bw/day

Sex:

male/female

Basis for effect level:

clinical signs

mortality

body weight and weight gain

organ weights and organ / body weight ratios

gross pathology

histopathology: non-neoplastic

Reproductive effects observed:

not specified

General tolerability:  All animals survived until scheduled necropsy, except one female at 1000 mg/kg, which died, possibly due to a dosing error.

Food consumption and bodyweight:  In males at 300 and 1000 mg/kg, mean food consumption was slightly reduced. Additionally, mean body weights were reduced from the pairing period until the end of the study, whereas no clear dose-dependency was noted. Mean body weight gain was slightly reduced and recovered in the after pairing period at 300 mg/kg but not at 1000 mg/kg.

In females at 1000 mg/kg, mean food consumption was slightly reduced during the treatment period. At 300 mg/kg mean food consumption was only reduced during the second week of the lactation period. As a result, a slight transient reduction of mean body weight gain was noted in the lactation period at both dose levels. Mean body weights were similar in all groups at the end of the study.

Reproductive Data:  The fertility rate was 100% in all groups. At all dose-levels, there were no treatment-related effects on estrous cycle, precoital time, mean duration of gestation, number of corpora lutea and implantations, post-implantation loss, pup survival or litter size from birth through to scheduled sacrifice on day 21 post partum.

Organ Weights:  No significant deviations in mean organ weight of testes and epididymides were recorded which could be attributed to the treatment with the test item, since lower mean absolute weights of epididymides were considered to be in relation with lower body weights and no test item-related histopathological findings were present.

Macroscopical Findings and Histopathological Examinations:  No test item-related histopathologic findings were observed in the reproductive organs of either sex from the parental generation. In particular, the assessment of the integrity of the spermatogenetic cycle did not provide any evidence of impaired spermatogenesis.

Litter Data:  No abnormal findings were noted for pups at first litter check or during the lactation period. Sex ratios at first litter check and on day 21 post partum were unaffected by treatment with the test item.

Mean pup weights on day 1 post partum and mean pup weight development during the lactation period were unaffected by treatment with the test item.

Conclusions:

In a study performed to OECD 421 on SCI, the NOAEL was 1000 mg/kg body weight/day.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

Klimisch 1 GLP Study

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

A waiver has been requested for the multi-generation toxicity.

In the reproduction / developmental screening test performed to OECD 421, SCI had no adverse effect on sexual function and fertility at dose levels up to 1000 mg/kg/day (the limit dose for reproductive toxicity studies). Furthermore, a sub chronic study (90 d oral) and a sub-acute toxicity data (28 d dermal study) confirms the structurally related chemicals SI and SLI show no evidence of systemic toxicity (despite the dermal test site being occluded) in doses of 246mg/kg/bw/day and in excess of 2000 mg/kg/d, with gross and histopathology confirming no adverse affect on sexual organs (seminal vesicles, testes, prostate, uterus/cervix, ovaries, fallopian tubes). Furthermore, the repeat dose dermal toxicity NOAEL is at least 2000 mg/kg/ bw/day (7.5.2).

Justification for selection of Effect on fertility via oral route:
Only study available

Effects on developmental toxicity

Description of key information

In a study performed to OECD 414, the NOEL (No Observed Effect Level) for maternal and fetal organisms of SLI was considered to be 1000 mg/kg body weight/day.

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2008-01-07 till 2008-04-23

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: RCC Ltd., Füllinsdorf / Switzerland
- Age at study initiation: 11 weeks
- Weight at study initiation: 187 to 237 g
- Fasting period before study: no data
- Housing: Individually in Makrolon type-3 cages with wire mesh tops and sterilized standard softwood bedding
- Diet (e.g. ad libitum): Pelleted standard Kliba Nafag 3433 rat/mouse maintenance diet, ad libidum
- Water (e.g. ad libitum): Community tap-water from Füllinsdorf, ad libidum
- Acclimation period: 7 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3 °C
- Humidity (%): 30 - 70%
- Air changes (per hr): 10 - 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
For groups 2 and 3: every second week
For group 4: daily.

DIET PREPARATION:
not applicable (administration by gavage)


VEHICLE
- Concentration in vehicle: no data
- dose volume applied: 10 mL/kg
- Amount of vehicle (if gavage): 10 mL/kg
- Purity: Milli-Q-water

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

For groups 1, 2 and 3:
The formulations mixed for the first two weeks of the study were sampled to confirm achieved concentration and homogeneity. One ml samples were taken in triplicate from the top, middle and bottom of the treated formulation during stirring. Five 1 mL samples were taken from the vehicle control group. After dosing on day 1 of each preparation, the residual formulation were stored frozen. From the formulations mixed on each subsequent occasion, five 1 mL samples were taken from the middle of each formulation during stirring and from the vehicle control. These samples were used to confirm achieved concentration only.
For group 4:
The formulation mixed for the first day of treatment was sampled to confirm achieved concentration and homogeneity. One ml samples were taken in triplicate from the top, middle and bottom of the formulation during stirring. Thereafter every two weeks samples were taken to confirm achieved concentration. Five 1 mL samples were taken from the middle of the formulation during stirring on each occasion.

All formulation samples (for all groups) despatched to the Principal Investigator were transferred to an amber glass vial and frozen (-20 ± 5 °C) pending analysis by Liquid Chromatography/Mass Spectrometry (LC/MS).

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1/1
- Length of cohabitation: until evidence of copulation was observed
- Further matings after two unsuccessful attempts: no data
- Verification of same strain and source of both sexes: no (these male rats were in the possession of RCC)
- Proof of pregnancy: vaginal plug or sperm in vaginal smear, referred to as day 0 of pregnancy
- Any other deviations from standard protocol: no

Duration of treatment / exposure:

from day 6 post-coitum to day 20 post-coitum

Frequency of treatment:

Daily

Duration of test:

20 days (day 21: females sacrificed and fetuses removed by Caesarean section)

No. of animals per sex per dose:

22 females per dose

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The dose levels were selected based on a previous Reproduction/Developmental Toxicity Screening Test in the Han Wistar Rat, RCC Study Number B57982, using dose levels of 100, 300, and 1000 mg/kg/day, which showed no adverse effects on reproduction.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily


DETAILED CLINICAL OBSERVATIONS: No data


BODY WEIGHT: Yes
- Time schedule for examinations: daily from day 0 until day 21 post coitum


FOOD CONSUMPTION: Yes
- Time schedule: recorded at 3-day intervals: days 0-3, 3-6, 6-9, 9-12, 12-15, 15-18 and 18-21 post coitum.


POST-MORTEM EXAMINATIONS: Yes (gross macroscopic examination)
- Sacrifice on gestation day 21 post coitum
- Organs examined: all internal organs with emphasis to on the uterus, uterine contents, position of fetuses in the uterus and the number of corpora lutea

Ovaries and uterine content:

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

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: Yes: half per litter

Statistics:

- Means and standard deviations of various data
- The Dunnett-test (many to one t-test) based on a pooled variance estimate, applied if the variables could be assumed to follow a normal distribution for the comparison of the treated groups and the control groups for each sex.
- The Steel-test (many-one rank test), applied instead of the Dunnett-test when the data could not be assumed to follow a normal distribution.
- Fisher's exact-test, applied if the variables could be dichotomized without loss of information.

Indices:

No data

Historical control data:

Yes

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
General Tolerability - All females survived until the scheduled necropsy. No signs of discomfort or clinical symptoms from the treatment with the test item were observed.
Food Consumption and Body Weights - Mean food consumption, mean body weight and corrected body weight gain (corrected for the gravid uterus weight) were not affected by treatment with the test item in any dose group.
Reproduction Data - Post-implantation losses and the mean number of fetuses per dam were not affected by treatment with the test item at any dose level.
Macroscopical Findings - No macroscopical findings were noted during necropsy of the females.

Key result

Dose descriptor:

NOEL

Effect level:

1 000 mg/kg bw/day

Basis for effect level:

other: maternal toxicity

Key result

Dose descriptor:

NOEL

Effect level:

1 000 mg/kg bw/day

Basis for effect level:

other: developmental toxicity

Fetal body weight changes:

no effects observed

Description (incidence and severity):

No test item-related effects on fetal body weights were noted.

Changes in sex ratio:

no effects observed

Description (incidence and severity):

No test item-related effects on fetal sex ratios were noted in any dose group.

External malformations:

no effects observed

Description (incidence and severity):

During the external examination of the fetuses, no test item-related abnormal findings were noted.

Skeletal malformations:

no effects observed

Description (incidence and severity):

No abnormalities, which were considered to be test item-related, were noted during examination of fetal skeletons and cartilages.

Visceral malformations:

no effects observed

Description (incidence and severity):

No test item-related abnormalities were noted during the visceral examination of fetuses.

Key result

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day

Sex:

female

Basis for effect level:

changes in sex ratio

fetal/pup body weight changes

external malformations

skeletal malformations

visceral malformations

Key result

Abnormalities:

no effects observed

Key result

Developmental effects observed:

no

Maternal Toxicity:

General Tolerability

All females survived until the scheduled necropsy. No signs of discomfort or clinical symptoms from the treatment with the test item were observed.

Food Consumption and Body Weights

Mean food consumption, mean body weight and corrected body weight gain (corrected for the gravid uterus weight) were not affected by treatment with the test item in any dose group.

Reproduction Data

Post-implantation losses and the mean number of fetuses per dam were not affected by treatment with the test item at any dose level.

Macroscopical Findings

No macroscopical findings were noted during necropsy of the females.

Embryotoxic/teratogenic effects:

External Examination

During the external examination of the fetuses, no test item-related abnormal findings were noted.

Sex Ratios

No test item-related effects on fetal sex ratios were noted in any dose group.

Body Weights

No test item-related effects on fetal body weights were noted.

Visceral Examination

No test item-related abnormalities were noted during the visceral examination of fetuses.

Skeletal and Cartilage Examination

No abnormalities, which were considered to be test item-related, were noted during examination of fetal skeletons and cartilages.

Conclusions:

Based on the above mentioned results, the NOEL (No Observed Effect Level) for maternal and fetal organisms was considered to be 1000 mg/kg body weight/day.
Under the conditions described for this study, MILLED SLI (76) did not reveal teratogenic potential up to and including 1000 mg/kg body weight/day.

Executive summary:

Females were treated with MILLED SLI (76) to detect effects on the pregnant rat and development of the embryo and fetus.

Four groups of females were treated by gavage once daily (from day 6 post coitum to day 20 post coitum) at dose levels of 0 mg/kg body weight/day (control group), 100 mg/kg body weight/day, 300 mg/kg body weight/day and 1000 mg/kg body weight/day. A standard dose volume of 10 mL/kg body weight with a daily adjustment to the actual body weight was used. Control animals were dosed with the vehicle alone (Milli-Q-Water).

All females survived until the scheduled necropsy. No signs of discomfort or clinical symptoms from the treatment with the test item were observed. Mean food consumption, mean body weight and corrected body weight gain (corrected for the gravid uterus weight) were not affected by treatment with the test item in any dose group. Post-implantation losses and the mean number of fetuses per dam were not affected by treatment with the test item at any dose level. No macroscopical findings were noted during necropsy of the females.

No test item-related abnormal findings were noted during the external examination of the fetuses. No test item-related effects on fetal sex ratios were noted in any dose group. No test item-related effects on fetal body weights were noted. No test item-related abnormalities were noted during the visceral examination of fetuses. No abnormalities, which were considered to be test item-related, were noted during examination of fetal skeletons and cartilages.

Based on the above mentioned results, the NOEL (No Observed Effect Level) for maternal and fetal organisms was considered to be 1000 mg/kg body weight/day.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

Klimisch 1 GLP Study

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

Justification for selection of Effect on developmental toxicity: via oral route:
only study available

Justification for classification or non-classification

The results of the reproduction/developmental screening test and a pre natal developmental test found that SLI had no adverse effect on development of the offspring, at dose levels up to 1000 mg/kg bw/day.

As such, SLMI has not been classified as a reproductive toxicant.