Registration Dossier

Administrative data

Key value for chemical safety assessment

Effects on fertility

Description of key information

The potential for reproductive toxicity was examined in a three generation study in rats (two years). Overall, no significant effects were observed at the highest dose tested and the resulting NOAEL for the parental and both offspring generations was the highest dose tested, i.e., 350 mg/kg bw (0.5%).

Link to relevant study records
Reference
Endpoint:
three-generation reproductive toxicity
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well documented peer-reviewed publication.
Justification for type of information:
The test as performed on a commercially available C10-14 LAS (C10-14 Monoalkylbenzene sulfonic acid, sodium salt), which is similar to the substance which is the subject of this dossier, benzenesulfonic acid, C10-13-alkyl derivs., sodium salt. The composition of a typical commercially available C10-14 LAS at the time of the study was as follow: C14 <1%. The great majority of the test substance is in the C10-13 range, which makes it a valid analogue for the dossier substance.
Principles of method if other than guideline:
Na-LAS (chain length distribution C10-14) was fed for 84 days to 4 groups of weanling rats (3 dose levels, plus control), each dose consisting of 50 animals each of both sexes (PO-generation). When the P0 generation was 107-112 days old, 20 females from each dose group were mated with 20 males from the same group and maintained together for 17 days. The first litters of each generation (Fla- and F2a-generation) were sacrificed at 21 days of age. Ten days after the final litter was sacrificed, all females were remated with different males from the same group to obtain the F1b generation. From the Flb-generation, 20 males and females of each group were selected at weaning to continue their respective diets and to be used for further reproduction studies. Reproduction studies on the F1b and F2b generations were started when the rats were 80 to 85 days old, and were continued until the F3b generation was weaned.
GLP compliance:
no
Limit test:
no
Species:
rat
Strain:
other: Charles River
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source:
- Age at study initiation: (P) weanling; (F1) 21 days
- Weight at study initiation: (P) Males: average 59.4-59.9 g; Females: average 57.0-57.3 g; (F1) Males: group weight 183.5-214.2 g; Females: group weight 157.8-193.2 g
- Housing: individual wire bottom cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 76 +/- 3
- Humidity (%): 50 +/- 5
- Photoperiod (hrs dark / hrs light): 12/12 hrs

:
Route of administration:
oral: feed
Vehicle:
other: LAS was administered in feed (Purina Laboratory Meal) - no documentation of dilution prior to addition to meal
Details on mating procedure:
premating exposure period 84 days
Analytical verification of doses or concentrations:
no
Duration of treatment / exposure:
2 years ( 3 generations)
Frequency of treatment:
continuous in feed
Details on study schedule:
- F1 parental animals not mated until 80-85 days old
- Selection of parents from F1 generation when pups were 21 days of age.
- Age at mating of the mated animals in the study: 107-112 days old
Remarks:
Doses / Concentrations:
0.02, 0.1, 0.5% (14, 70, 350 mg/kg bw d)
Basis:
actual ingested
No. of animals per sex per dose:
50 males and 50 females per group.
Control animals:
yes, concurrent no treatment
Litter observations:
Deformities and number of pups, average body weights, feed consumption, feed efficiency.
Postmortem examinations (parental animals):
Necropsy, body weight, organ to body weight ratios, routine hematology and histology.
Postmortem examinations (offspring):
Necropsy, body weight, organ to body weight ratios, routine hematology and histology.
Reproductive indices:
fertility, gestation, parturition, neonatal viability, lactation, and post-weaning growth
Clinical signs:
no effects observed
Body weight and weight changes:
no effects observed
Description (incidence and severity):
no effects to body weight were noted in the initial twelve weeks
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
no effects to body weight were noted in the initial twelve weeks
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Other effects:
no effects observed
Description (incidence and severity):
Test substance intake: no effects to average food consumption were noted in the initial twelve weeks
Reproductive function: oestrous cycle:
no effects observed
Reproductive function: sperm measures:
no effects observed
Reproductive performance:
no effects observed
No mortality or clinical signs were observed in parental animals. A statistically significant decrease in liver weights was noted in male rats at the low and mid dose levels at the 8 month sacrifice. As the decreased liver weight was within normal range, was not seen at the highest dose level, nor was seen at the 15 and 24 month sacrifices, it was not considered biologically significant. Body weight gains and organ to body weight ratios were normal. Gross examination revealed no abnormalities attributable to the test substance. General reproduction including fertility, gestation, parturition, neonatal viability, lactation, and post-weaning growth were normal for all test groups and did not vary from controls.
Dose descriptor:
NOAEL
Effect level:
350 mg/kg bw/day
Sex:
male/female
Basis for effect level:
other: 0.5%
Clinical signs:
not specified
Mortality / viability:
no mortality observed
Body weight and weight changes:
no effects observed
Sexual maturation:
not specified
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings:
no effects observed
Rats sacrificed at weaning were normal with respect to growth, organ to body weight ratios, gross pathology, and histology, and did not vary from controls. There were a number of statistically significant hematologic values, though these differences were small and did not indicate a trend or pattern.
Dose descriptor:
NOAEL
Generation:
F1
Effect level:
350 mg/kg bw/day
Sex:
male/female
Basis for effect level:
other: 0.5%
Dose descriptor:
NOAEL
Generation:
F2
Effect level:
350 mg/kg bw/day
Sex:
male/female
Basis for effect level:
other: 0.5%
Reproductive effects observed:
not specified
Conclusions:
No significant effects on reproduction were observed at the highest concentration tested.
Executive summary:

Na-LAS was fed for 84 days to 4 groups of weanling rats for two years (three generations). No significant effects were observed at the highest dose tested and the resulting NOAEL for the parental and both offspring generations was 350 mg/kg bw (0.5%)

Effect on fertility: via oral route
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
350 mg/kg bw/day
Study duration:
chronic
Species:
rat
Quality of whole database:
Key study meets/exceeds OECD 416
Effect on fertility: via inhalation route
Endpoint conclusion:
no study available
Effect on fertility: via dermal route
Endpoint conclusion:
no study available
Additional information
This key study examined the effects of exposure to LAS on reproductive toxicity. LAS was given in the feed at doses of 0.02, 0.1, and 0.5% (14, 70, and 350 mg/kg bw d) for 84 days to four groups of weanling rats and evaluated for two years (three generations). Each dose consisting of 50 animals each of both sexes (P0-generation). When the P0-generation was 107-112 days old, 20 females from each dose group were mated with 20 males from the same group and maintained together for 17 days. The first litters of each generation (Fla- and F2a-generation) were sacrificed at 21 days of age. Ten days after the final litter was sacrificed, all females were remated with different males from the same group to obtain the F1b-generation. From the Flb-generation, 20 males and females of each group were selected at weaning to continue their respective diets and to be used for further reproduction studies. Reproduction studies on the F1band F2b-generations were started when the rats were 80 to 85 days old, and were continued until the F3b-generation was weaned. All rats sacrificed at weaning were normal with respect to growth, organ to body weight ratios, gross pathology, and histology, and did not vary from controls. There were a number of statistically significant hematologic values, though these differences were small and did not indicate a trend or pattern. Overall, no significant effects were observed at the highest dose tested and the resulting NOAEL for the parental and both offspring generations was the highest dose tested, i.e., 350 mg/kg bw (0.5%).

Effects on developmental toxicity

Description of key information

Two reliable prenatal developmental toxicity studies equivalent to or exceeding OECD 416 (rat and mouse) are available to evaluate the potential developmental effects of LAS. The derived NOAELs for developmental effects (2 or 300 mg/kg bw/d) were either the same or higher than the NOAELs for maternal toxicity.

Link to relevant study records

Referenceopen allclose all

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented publication/study report which meets basic scientific principles.
Qualifier:
no guideline followed
Principles of method if other than guideline:
After overnight mating, the rats were randomly allocated to five groups which included one control group and four different treatment groups. LAS was prepared daily as a series of graded aqueous solutions. Animals in all groups were dosed orally at the standard volume of 1.0 mL/100 g. Control animals were dosed in a similar manner with distilled water used as the vehicle. The dams were observed daily for signs of toxicity and weighed on days 1, 3, 6, 10, 14, 17 and 20 of pregnancy. On day 20, the rats were killed by CO2 euthanasia. Their ovaries and uterine contents were examined immediately for number of copora lutea, number of viable young, number of resorption sites, litter weight, and fetal abnormalities.
GLP compliance:
no
Limit test:
no
Species:
rat
Strain:
other: Charles River CD strain
Route of administration:
other: oral in distilled water
Vehicle:
not specified
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
day 6 to day 15 of pregnancy
Frequency of treatment:
daily
Duration of test:
20 days
No. of animals per sex per dose:
no data
Control animals:
yes, concurrent no treatment
Details on maternal toxic effects:
Maternal toxic effects:yes

Details on maternal toxic effects:
Parent animals were observed daily. Change in bodyweight was not affected by treatment at 0.2, 2.0, and 300 mg/kg, but treatment at 600 mg/kg was associated with retarded weight gain and a transient diarrhea following initiation of treatment. The pregnancy rate was comparable at all dosages.
Dose descriptor:
NOAEL
Effect level:
300 other: mg/kg
Based on:
test mat.
Basis for effect level:
other: maternal toxicity
Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
Embryonic and fetal development were assessed by the incidence of major malformations. The incidence of minor visceral anomalies was unaffected by treatment at any dosage. The distribution of skeletal variants were not statistically significant with the exception of a marginal retardation of sternebral ossification at 600 mg/kg.
Dose descriptor:
NOAEL
Effect level:
300 other: mg/L
Based on:
test mat.
Basis for effect level:
other: teratogenicity
Abnormalities:
not specified
Developmental effects observed:
not specified

Pregnancy/litter data: The litter parameters assessed included litter size, fetal loss and litter weight.  These parameters were not significantly affected by any dosage.  Mean pup weights were statistically higher at 0.2, 2.0 and 300 mg/kg.

Conclusions:
NOAEL = 300 mg/kg for both maternal and teratogenicity
Executive summary:

Female rats were given LAS orally in distilled water from gestation days 6 to 15 during pregnancy. Some effects such as decreased weight gain and transient diarrhea occurred at the highest dose. Pregnancy rates were comparable at all doses. Litter parameters were not significantly affected at any dose. No significant differences were observed in visceral anomalies or skeletal variants, with the exception of a marginal retardation of sternabral ossification at the highest dose.

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well documented peer-reviewed journal article by researchers at GLP contract testing laboratory.
Principles of method if other than guideline:
Twenty female mice were administered 0.2, 2.0, 300 or 600 mg/kg bw of LAS by gavage at days 6-15 of gestation. All animals were sacrificed on day 17 of pregnancy.
GLP compliance:
yes
Remarks:
not stated, but likely GLP
Limit test:
no
Species:
mouse
Strain:
CD-1
Details on test animals and environmental conditions:
Mice were held in plastic containers at standard environmental conditions (20 =/- 1 degrees C, 50 =/- 5% relative humidity) and free access to drinking water and food (Spratt's Laboratory Diet No. 1).
Route of administration:
oral: gavage
Vehicle:
not specified
Details on exposure:
Dosing commenced on day 6 after confirmation of mating by detection of the vaginal plug. Exposure continued until day 15 of gestation.
Analytical verification of doses or concentrations:
not specified
Details on mating procedure:
Male and female mice were housed five per cage in opaque plastic cages until natural mating occurred.
Duration of treatment / exposure:
days 6 - 15 of pregnancy
Frequency of treatment:
daily
Duration of test:
sacrifice at day 17 of pregnancy
No. of animals per sex per dose:
20 female mice per dose
Control animals:
yes, concurrent no treatment
Details on study design:
Two doses were chosen to form the basis for safety evaluation (0.2 and 2.0 mg/kg/day) because the likely maximum human intake of detergent from ordinary kitchen use has been estimated at 0.14 mg/kg/day, thus providing factors of 1-2 times the human exposure level. Two further doses were also investigated (300 and 600 mg/kg/day) based on previous toxicity data suggesting that these would impair maternal economy and result in obvious adverse effects.
Maternal examinations:
All animals were observed daily for signs of adverse reactions and were weighed regularly throughout gestation. All animals that died, and survivors at termination, were dissected and examined for macroscopic changes.
Ovaries and uterine content:
Ovaries were examined and the number of corpora lutea counted.
Details on maternal toxic effects:
Maternal toxic effects:yes

Details on maternal toxic effects:
Among parent animals treatment at 300 and 600 mg/kg bw d was associated with increased mortality (35% and 90% respectively). At 300 mg/kg bw d weight gain was retarded only during the first four days. No assessment could be made at 600 mg/kg bw d, due to the high mortality rate. Necropsy revealed a ubiquitous occurrence of tympanites, sometimes associated with gastritis. Pregnancy rate was essentially comparable for all groups.
Dose descriptor:
NOAEL
Effect level:
2 mg/kg bw/day
Basis for effect level:
other: maternal toxicity
Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
At doses with no maternal toxicity, no differences were observed among the dose group and the control group with respect to number of litters, viable young, litter weight, foetal weight, embryonic deaths, implantations and post implantation embryonic loss. At these doses the incidences of major malformations and minor abnormalities were not affected. At doses with maternal toxicity there was an increased foetal loss and reduced litter size due almost entirely to total litter loss, which was considered to be a secondary effect due to the maternal toxicity. The incidences of major malformations was not affected; minor skeletal or visceral anomalies were increased at 300 mg/kg.
Dose descriptor:
NOAEL
Effect level:
300 mg/kg bw/day
Basis for effect level:
other: teratogenicity
Abnormalities:
not specified
Developmental effects observed:
not specified

The maternal NOAEL of 2 mg/kg bw d is considered very conservative because the range (2-300 mg/kg bw d) was too wide, especially considering the repeated dose toxicity studies (section 7.5.1) which give much higher NOAEL values.

Conclusions:
Maternal NOAEL = 2 mg/kg bw/day; Teratogenicity NOAEL = 300 mg/kg bw/day
Executive summary:

Pregnant female mice were exposed to LAS via gavage on days 6 -15 of gestation. Increased mortality was observed at the two highest doses (300 and 600 mg/kg bw/day). These doses also exhibited retarded weight gain and adverse signs in the necropsy. Pregnancy was comparable, however, for all groups. At doses without maternal toxicity, no differences were observed in any parameters. Because of the very wide range between the 2 mg/kg and 300 mg/kg doses, the maternal NOAEL of 2 mg/kg bw/day must be considered very conservative. The NOAEL for teratogenicity was 300 mg/kg bw/day.

Effect on developmental toxicity: via oral route
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
300 mg/kg bw/day
Study duration:
chronic
Species:
rat
Quality of whole database:
Two reliable prenatal developmental toxicity studies available (rat and mouse) from well-documented reports. There is no reliable data on the rabbit.
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

Two key studies examined the potential developmental toxicity of LAS. In the first study (Palmer and Lovell 1971), female rats were given LAS orally in distilled water from gestation days 6 to 15 during pregnancy. Doses were 0.2, 2.0, 300 and 600 mg/kg. Some effects such as decreased weight gain and transient diarrhea occurred at the highest dose. Based on these effects, the maternal LOAEL is 600 mg/kg bw/d and the maternal NOAEL is 300 mg/kg bw/d. Pregnancy rates were comparable at all doses. The litter parameters assessed included litter size, fetal loss and litter weight. These parameters were not significantly affected by any dosage. Mean pup weights were statistically higher at 0.2, 2.0 and 300 mg/kg. No significant differences were observed in visceral anomalies or skeletal variants, with the exception of a marginal retardation of sternabral ossification at the highest dose. Based on these marginal effects the developmental LOAEL is considered to be 600 mg/kg bw/d and the developmental NOAEL is 300 mg/kg bw/d.

In the second study done in the same laboratory (Palmer et al. 1974), pregnant female mice were exposed to LAS via gavage on days 6 -15 of gestation. Two doses were chosen to form the basis for safety evaluation (0.2 and 2.0 mg/kg/day) because the likely maximum human intake of detergent from ordinary kitchen use has been estimated at 0.14 mg/kg/day, thus providing factors of 1-10 times the human exposure level. Two further doses were also investigated (300 and 600 mg/kg/day) based on previous toxicity data suggesting that these would impair maternal survival and result in obvious adverse effects. Increased mortality (35 and 90%, respectively) was observed at these two highest doses. These doses also exhibited retarded weight gain and adverse signs in the necropsy. Based on these effects, the maternal LOAEL is 300 mg/kg and the maternal NOAEL is 2 mg/kg. Because of the very wide range between the 2 mg/kg and 300 mg/kg doses, the maternal NOAEL of 2 mg/kg bw/day must be considered very conservative. At the 300 mg/kg dose, the incidence of total liter loss was 20%; this was attributed to the high maternal toxicity observed at this dose. Among the nine animals with viable young, mean litter parameters, including litter size andfoetalloss, and incidence of major malformations were not statistically different from controls. Minor anomalies, including gross or visceral and skeletal anomalies, were increased. At the 600 mg/kg dose, there were no live births. Based on these data, the developmental NOAEL was 300 mg/kg bw/day and the developmental LOAEL was 600 mg/kg bw/day.

An available prenatal developmental study on the rabbit is not considered reliable (KR = 3) because the doses tested are inadequate to determine a reliable NOEL. The study is included for completeness.

Justification for classification or non-classification

Based on the absence of reproductive or developmental adverse effects at doses that were not also maternally toxic, LAS is not expected to be a reproductive or developmental toxicant.