Dodecylbenzenesulphonic acid

Toxicity to reproduction

Administrative data

Endpoint:

fertility, other

Remarks:

based on test type

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Dodecylbenzenesulphonic acid

EC Number:

248-289-4

EC Name:

Dodecylbenzenesulphonic acid

Cas Number:

27176-87-0

Molecular formula:

C18H30O3S

IUPAC Name:

Dodecylbenzenesulfonic acid

Details on test material:

- Code number in testing facility: K-2698- Lot No.: 080108C105- Receipt date: January 14, 2008- Amount of Receipt: 3 kg- Appearance : brown liquid- Purity : 99.5 MIN %- Storage Conditions : Room temperature [archive No.: KIT-401(80)]- Expired date : January 8, 2010

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

1) Test animals- Supplier: Orient Bio Co. Ltd. 143-1, Sangdaewon-dong, Jungwon-ku, Sungnam, Gyunggi-do, 462-120 Korea- Age at study initiation: 7-week-old animals for male and female
- No. of animals at receipt: 57 for male and female
- Body weights at study initiation: 212.5–243.8 g for males and 147.6 -168.6 g for females
- Age at the first day of treatment: 8 weeks for male and female
- Body weight range at the first day of treatment: 274.2∼311.1 g for males and 175.7∼213.4 g for females
- All animals were visually examined on acquisition. Only the animals remained in good physical condition during the 6-day acclimatization in the animal room were selected for the test.
2) Environmental condition
- Temperature 23 +/- 3 deg C, relative humidity of 50 +/- 10%; ventilation of 10 to 20 times/hours; light/dark cycle 12 h/12 h
- All animals used in this study were cared for in accordance with the principles outlined in the "Guide for the Care and Use of Laboratory Animals", a NIH publication.
3) Monitoring- Room temperature was generally in the range 20-26 deg C, relative humidity was generally in the range 40-60%. No significant deviations, which can affect the experiment, were observed.
4) Housing and identification of animals- Equal or less than five for the quarantine and acclimatization
- Equal or less than two for the pre-mating, treatment and recovery period5) Diet, water and bedding material
- Pelleted maintenance diet and tap water ad libitum; no contaminants (analysed)

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: distilled water

Details on mating procedure:

- Premating exposure period for males and females: 2 weeks

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The test article of the highest dose group was mixed with water for injection, and the low dose group's test article was prepared by dilution of that of the highest dose group. The test article solutions were prepared once a day before completion of the analytical method validation, and after completion the test article was formulated over once a week.

Duration of treatment / exposure:

From 2 weeks before mating to the end of -the mating period for male (at least 28 days)From 2 weeks before mating to day 4 of lactation including the mating and gestation periods for female- Post exposure period: 15 days in both sexes

Frequency of treatment:

Once daily

Doses / concentrations

Remarks:

Doses / Concentrations:
nominal conc. 0, 100, 200, and 400 mg/kg bw/day (Dosing volume 10mL/kg/day)
Basis:
nominal conc.

No. of animals per sex per dose:

10 males and females for 100 and 200 mg/kg bw/day and 16 males and females for 400 mg/kg bw/day (10 was for test group and 6 was for recovery group), 16 males and females for vehicle control (10 was for test group and 6 was for recovery group)

Control animals:

yes

Details on study design:

Treatment- Dose levels determined in a pilot toxicity study of dodecylbenzenesulfonic acid in rats- Constant dosage volume of 10 mL/kg bw/day: calculated with Path/Tox system according to the basis of recently measured body weight.- Dosing of both sexes was begun at 2 weeks prior to mating. Dosing was continued in both sexes during the mating period. Males were dosed after the mating period at least until the minimum total dosing period of 28 days had been completed. Daily dosing of the parental females was continued throughout pregnancy and at least up to day 4 post-partum.

Examinations

Parental animals: Observations and examinations:

- Mating: The day verified by sperm in a vaginal rinse was designated as day 0 of pregnancy. Based on the results, following indices were calculated. Mating index = (No. of animals with successful copulation / No. of mated animals) × 100 Fertility index = (No. of impregnating animals / No. of animals with successful copulation) × 100 Pregnancy index = (No. of pregnant animals / No. of animals with successful copulation) × 100
- Observation on gestation and parturition: Abortion, premature delivery and dystocia or prolonged parturition were observed.
- Observation on parturition date: Gestation length, delivery index, litter size, sex ratio, external anomalies of live pups were observed.
- Observation during the lactation period: Nursing behaviours of dams and viability of pups were observed. Following data were obtained from these observations. Pregnancy periodDelivery index: No. of dams with live newborns/ No. of pregnant damsx100Newborn survival index:Newborn mortality index:Viability index: No of live pups on day 4 of lactation/ No of neonates at birthx100Body weight in all survival animals on 0 and 4 days afterbirth.

Postmortem examinations (parental animals):

- Gross findings: At scheduled termination, all live animals were anaesthetized by isoflurane inhalation, blood samples taken and then terminated by exsanguinating the abdominal aorta. Complete gross post mortem examinations were performed on all animals.
- Organ weights: Absolute organ weights were measured and their relative organ weights (organ-to-body weight ratios) were calculated from the terminal body weight for the following organs of selected six animals when they were sacrificed. (Brain, pituitary gland, adrenal gland,spleen, kidneys, heart, thymus, lungs and thyroid (with parathyroid)). However, the following organs were weighed in all animals except the non-pregnant.(liver, salivary gland, testis, epididymis, seminal vesicle, prostate, ovary, uterus).
- Histopathological examination: Histopathological examination was performed on the following tissues from animals in the vehicle control and 64 mg/kg bw/day groups. abnormal lesion, skin (included mammary gland in females), urinary bladder, pancreas, mesenteric lymph node, stomach, duodenum, jejunum, ileum, cecum, colon, rectum, kidneys, adrenal glands,mandibular lymph node, thyroid (included parathyroid), aorta, thymus, heart, lungs, tongue, trachea, esophagus, sciatic nerve, skeletal muscle, sternum, femur, eye with optic nerve, haderian gland, brain, pituitary gland, spinal cord (thoracic) and nasal cavity. Additional examination was conducted in spleen, femur and sternum of the 4 and 16 mg/kg bw/day groups, since treatment-related findings were observed in these organs. Neutral buffered 10% formalin was used for fixation and preservation, except testis, epididymides and eyeballs. Bouin’s fixative was used for testis and epididymides and Davidson’s solution for eye ball. Lungs and urinary bladder were inflated with fixative prior to immersion in fixative. And then organs were embedded in paraffin, sectioned, stained with hematoxylin and eosin (H&E), and examined microscopically.

Statistics:

- Body weights, food consumption, organ weights, and clinical pathology : means the standard deviation of each mean. - Bartlett's test : analyzing for homogeneity of variance- Dunnett's t test : analyzing for the significance of inter-group differences- Analysis of Variance : analyzing for homogeneous data- Kruskal-Wallis test : analyzing for Heterogeneous data- Dunn's Rank Sum test : analyzing for the significance of inter-group differences between the control and treated groups- F test : analyzing the data of recovery groups for homogeneity of variance- Dunnett's t test : analyzing for homogeneous data- Dunn's Rank Sum test : analyzing for the significance of inter-group differences- t test : analyzing for Heterogeneous data- Kruskal-Wallis test : analyzing for the significance of inter-group differences between the control and treated group-Statistical analyses were performed by comparing the different dose groups with the vehicle control group using Path/Tox System.- p<0.05 or p<0.01

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Histopathological findings: non-neoplastic:

no effects observed

Reproductive function / performance (P0)

Reproductive performance:

no effects observed

Details on results (P0)

There were no treatment-related changes in precoital time, mating index, fertility index and pregnancy index.Results for F0- Precoital time, fertility and mating data: There were no statistically significant differences compared with the controls.- Gross findings: There were no chemical- related findings in all treatment groups.- Histopathological findings: There were no chemical- related findings in all treatment groups.

Effect levels (P0)

Dose descriptor:

NOAEL

Effect level:

400 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

reproductive performance

Results: F1 generation

Effect levels (F1)

Generation:

F1

Based on:

test mat.

Remarks on result:

not measured/tested

Overall reproductive toxicity

Reproductive effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

There were no treatment-related changes were observed in copulation, fertility and pregnancy indices, gestation length, the number of corpora lutea and implantation, delivery index. Based on these effects, the NOAEL (no-observed-adverse-effect levels) for fertility was 400 mg/kg bw/day.

Executive summary:

Effects on Fertility

In reproductive toxicity study performed according to the reproduction/developmental toxicity screening test [OECD TG 422] conditions and dose were same asrepeated dose toxicity. A distilled water for injection was used as vehicle.

No statistically significant differences were seen in the following parameters examined: gestation length, the number of corpora lutea and implantation, delivery index, precoital time, fertility, mating data and in the histopathological examination. The NOAEL was 400 mg/kg bw/day in both sexes.