Benzenesulfonic acid, C10-13-alkyl derivs., sodium salts

Endpoint summary

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Effects on fertility

Description of key information

Fertility studies and developmental toxicity studies were conducted with the read-across source substance C10-14 LAS as well as with the target substance C10-13 LAS. Overall, results from these studies indicate no adverse effect on the fertility of the parenteral animals and development of the offspring. The read-across target substance C10-14 LAS has very similar composition to the sponsored substance C10-13 LAS (slight differences in C10 and C14 content).

The target and source substances present a similar potency of toxicological behaviour with respect to acute oral toxicity, with LD50 being 1080 mg/kg bw for the target substance and 900 mg/kg bw for the source substance. With respect to repeated dose endpoint, for the studies available on the source and target substances, the doses at which effects were observed were similar (after consideration of exposure route and dose spacing) as were the observed effects. 

The reproductive toxicity study of the source substance (C10-14 LAS) in rats across three generations was conducted according to the accepted scientific principles (Buehler et al., 1971). Rats were divided into 4 groups and administered 0 (control), 0.02, 0.1 and 0.5% (corresponding to 14, 70 and 350 mg/kg bw/day, respectively) test substance added to their diets. Administration of the test substance to male and female rats by diet for three generations resulted in a NOAEL of 350 mg/kg bw/day for P0, F1, F2 and F3 generations, based on absence of marked effects on general reproduction parameters, growth, body weight, organ weight, body weight to organ weight ratio, haematology and histopathology parameters at the highest dose. This reproductive toxicity study is acceptable and satisfies accepted scientific principles.

Link to relevant study records

Reference

Endpoint:

three-generation reproductive toxicity

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: read-across from a study predating current guidelines and GLP, but adequate for assessment.

Justification for type of information:

The reproductive toxicity study of C10-13 LAS is based on read-across with C10-14 LAS. The read-across justification is presented in the assessment reports section. A cross-reference is made to that record.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

Remarks:

read-across justification

Key result

Dose descriptor:

NOAEL

Remarks:

Systemic toxicity

Effect level:

350 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

other: No effects observed at the highest dose of 350 mg/kg bw/day (0.5% LAS in diet)

Key result

Dose descriptor:

NOAEL

Remarks:

Reproductive toxicity

Effect level:

350 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

other: No effects observed at the highest dose of 350 mg/kg bw/day (0.5% LAS in diet)

Key result

Critical effects observed:

no

Key result

Dose descriptor:

NOAEL

Remarks:

Systemic toxicity

Effect level:

350 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

other: No effects observed at the highest dose of 350 mg/kg bw/day (0.5% LAS in diet)

Key result

Dose descriptor:

NOAEL

Remarks:

Reproductive toxicity

Effect level:

350 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

other: No effects observed at the highest dose of 350 mg/kg bw/day (0.5% LAS in diet)

Key result

Critical effects observed:

no

Key result

Dose descriptor:

NOAEL

Generation:

F1b

Effect level:

350 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

other: No effects observed at the highest dose of 350 mg/kg bw/day (0.5% LAS in diet)

Key result

Critical effects observed:

no

Key result

Dose descriptor:

NOAEL

Generation:

F2b

Effect level:

350 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Remarks on result:

other: No effects observed at the highest dose of 350 mg/kg bw/day (0.5% LAS in diet)

Key result

Critical effects observed:

no

Key result

Reproductive effects observed:

no

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

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Reproductive toxicity 

Study 1 (C10-14 LAS-Na): 

A three-generation reproductive toxicity study was conducted with the read-across substance C10-14 LAS, sodium salt in Charles River rats. The test substance was administered to groups of 50 males and 50 females in the feed at doses of 0, 0.02, 0.1, and 0.5% (0, 14, 70, and 350 mg/kg bw/day) for 84 days and evaluated for three generations (a total of 2 years). 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-generations) were sacrificed at 21 days of age. Ten days after the final litter was sacrificed, all females were re-mated with different males from the same group to obtain the F1b-generation. From the F1b-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. All rats sacrificed at weaning were normal with respect to growth, organ to body weight ratios, gross pathology, and histopathology, 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 up to the highest dose tested. Based on the results, the systemic, reproductive and developmental toxicity NOAEL of 350 mg/kg bw/day for P0, F1, F2 and F3 generations based on the absence of treatment-related effects on general reproduction parameters, growth, body weight, organ weight, body weight to organ weight ratio, haematology and histopathology up to the highest dose (Buehler, 1971).

Effects on developmental toxicity

Description of key information

Furthermore, four reliable prenatal developmental toxicity studies in rat, mouse and rabbit are available to evaluate the potential developmental effects of LAS(Palmer et al., 1971; 1975 a, b, c) These studies performed with the target substance (C10-13 LAS) support the conclusion of no adverse effects of C10-13 LAS on reproductive health.The derived NOAELs for developmental effects (2 mg/kg bw in mice and rabbits studies or 300 mg/kg bw/d in rats) were either the same or higher than the NOAELs for maternal toxicity.The observed fetal toxicity was due to maternal toxicity at high dose levels. Because of the very wide range between the 2 mg/kg bw/day and 300 mg/kg bw/day doses in both the mice and rabbit study, and high maternal toxicity at 300 mg/kg bw/d, the maternal and developmental NOAEL of 2 mg/kg bw/day were considered very conservative. Therefore, based on the entire data set, the maternal and developmental NOAELs were determined to be 300 mg/kg bw/day from the study on rats, WoE study 1.

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The purpose of this study was to evaluate the teratogenic potential of linear alkylbenzene sulphonate (LAS) in rats. Twenty female rats/dose were divided into 5 groups and administered 0 (water), 0.2, 2.0, 300 and 600 mg/kg bw/day of test substance by oral gavage from day 6 to 15 of gestation. Throughout experiment animals were observed daily for signs of malreaction and weighed regularly. After euthanasia on day 20, their uterine content was examined for number of implantations, viable young and embryonic deaths along with ovaries, number of corpora lutea and viable pups. Body weight, incidents of external malformation, visceral and skeletal anomalies were also recorded in pups. Non parametric methods were used for statistical analysis and on the basis of adverse effects, NOAEL value was derived for maternal toxicity and teratogenicity.

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

other: CD rats

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Wilmington, Mass., U.S.A. and St-Aubin-les-Elbeuf, France.
- Housing: Female rats (5 per cage) were housed in opaque plastic cages.
- Diet: Spratt’s Laboratory Diet No. 1, ad libitum.
- Drinking water: ad libitum.

ENVIRONMENTAL CONDITIONS
- Temperature: 20 ± 1°C
- Humidity: 50 ± 5 % RH

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

- Preparation of dosing solutions: Doses were prepared on daily basis as series of graded aqueous solutions for oral dosing.
- Administration of dosage: Standard volume of doses was administered orally by gastric intubation. Control animals were dosed with water.
- Duration of dosage: Doses were commenced on day 6 after detection of vaginal plug in rats and continued daily up to and including day 15 of gestation.

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

Mating was confirmed by the detection of vaginal plug in rats.

Duration of treatment / exposure:

Animals were dosed for 10 days [from Day 6 (after detection of vaginal plug) to Day 15].

Frequency of treatment:

daily from day 6 after detection of the vaginal plug to till day 15

Duration of test:

21 days

Dose / conc.:

0 mg/kg bw/day

Remarks:

(control)

Dose / conc.:

0.2 mg/kg bw/day

Dose / conc.:

2 mg/kg bw/day

Dose / conc.:

300 mg/kg bw/day

Dose / conc.:

600 mg/kg bw/day

No. of animals per sex per dose:

20 female rats per dose

Control animals:

yes

Details on study design:

- Dose selection rationale: Two doses formed the basis for safety evaluation (0.2 and 2.0 mg/kg bw/day) because the likely maximum human intake of detergent from ordinary kitchen use has been estimated at 0.14 mg/kg bw/day, thus providing factors of 1-2 times the human exposure level. Two further doses (300 and 600 mg/kg bw/day) were also investigated 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 malreaction 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:

After euthanasia, uteri were dissected and examined to determine the number of:
a) Implants
b) Viable young
c) Embryonic deaths (abortion/resorption sites)

Ovaries were examined and number of corpora lutea were also recorded.

Fetal examinations:

After weighing, fetus were examined for external malformations, visceral anomalies by free and sectioning and skeletal examination was performed by alizarin staining.

Statistics:

Differences in mean values were statistically analyzed by non-parametric method i.e. Wilcoxon test.

Indices:

Mating index: (number of confirmed mating/ number of animals cohabitated) X 100

Historical control data:

In CD rats, percentage of major malformations, minor visceral anomalies and minor skeletal anomalies were recorded as 0.41%, 2.02% and 2.35%, respectively in 51349 examined fetuses.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Toxic effects were generally associated with the gastrointestinal tract disturbances.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, treatment-related

Description (incidence):

Single mortality was observed at 600 mg/kg bw/day.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Retarded weight gain was observed on 600 mg/kg bw/day.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

Pre-implantation embryonic losses were 18.1%, 23.2%, 36.9%, 15.6% and 20.3% at 0, 0.2, 2, 300 and 600 mg/kg bw/day, respectively.
Post-implantation embryonic losses were 2.8%, 12.4%, 5.9%, 3.6% and 3.1% at 0, 0.2, 2, 300 and 600 mg/kg bw/day, respectively.

Total litter losses by resorption:

not specified

Description (incidence and severity):

Only single litter was lost at 0.2 mg/kg bw/day but not significant as no dose response relationship was followed.

Early or late resorptions:

not specified

Dead fetuses:

no effects observed

Description (incidence and severity):

Embryonic deaths were 0.3, 0.7, 0.6, 0.4 and 0.4 at 0, 0.2, 2, 300 and 600 mg/kg bw/day, respectively.

Changes in pregnancy duration:

not specified

Changes in number of pregnant:

not specified

Description (incidence and severity):

Mating index was also comparable across all doses when compared to the control group.

Other effects:

not specified

Key result

Dose descriptor:

NOAEL

Effect level:

300 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: mortality and retarded weight gain at 600 mg/kg bw/day

Abnormalities:

not examined

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Although the fetal weights differed significantly at 0.2 and 2 mg/kg bw/day, these changes does not represent an adverse change because there was no consistent dose relationship and were invariably due to higher mean pub weight in the test group.

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

No test substance related effect or statistically significant differences were observed.

Changes in sex ratio:

not specified

Changes in litter size and weights:

no effects observed

Description (incidence and severity):

Litter size and weights were comparable across all doses when compared to the control group.

Changes in postnatal survival:

not specified

External malformations:

no effects observed

Description (incidence and severity):

No test substance related or statistically differences in the incidence of major malformations observed even a maternally toxic dosage.

Skeletal malformations:

no effects observed

Description (incidence and severity):

Incidences of skeletal abnormalities were comparable across all doses when compared to the control group.

Visceral malformations:

no effects observed

Description (incidence and severity):

Minor visceral anomalies were increased at 600 mg/kg bw/day (not significant statistically) but same incident was also observed in control group.

Other effects:

not specified

Key result

Dose descriptor:

NOAEL

Effect level:

300 mg/kg bw/day

Based on:

test mat.

Sex:

not specified

Basis for effect level:

other: marginal retardation of sternebral ossification at the highest dose

Key result

Abnormalities:

effects observed, treatment-related

Localisation:

skeletal: sternum

Description (incidence and severity):

Marginal retardation of sternebral ossification at the highest dose level

Key result

Developmental effects observed:

yes

Lowest effective dose / conc.:

600 mg/kg bw/day (nominal)

Treatment related:

not specified

Relation to maternal toxicity:

developmental effects as a secondary non-specific consequence of maternal toxicity effects

Table 1: Mating index of the maternal animals (Palmer et.al., 1975)

Dose	Number of confirmed mating	Number of animals cohabitated	Mating index %
0	15	20	75
0.2	15	20	75
2	18	20	90
300	16	20	80
600	16	19	84

Table 2: Summary of adult performance (Palmer et.al., 1975)

Observations	Number of animals at dosage (mg/kg bw/day)
	0	0.2	2	300	600
Mated	20	20	20	20	20
Died	0	0	0	0	1
Non-pregnant	5	5	2	4	3
Total litter loss	0	1	0	0	0
With viable young	15	14	18	16	16
Body weight change	-	-	-	-	retarded gain

Table 3: Group mean litter data (Palmer et.al., 1975)

Dosage (mg/kg bw/day)	Number of litters	Litter size viable young	Embryogenic deaths	Implantations	Corpora lutea	Embryonic loss %		Litter weight (g)	Fetal weight (g)
						Pre-implantation	Post-implantation
0	15 (A & B)	9.9	0.3	10.3	12.5	18.1	2.8	36.15	3.66
0.2	15 (A)	9.1	0.7	9.8	12.7	23.2	12.4	-	-
	14 (B)	9.8	0.6	10.4	12.8	18.4	6.1	37.14	3.84^a
2	18 (A & B)	8.2	0.6	8.8	13.9	36.9	5.9	31.62	3.94^b
300	16 (A & B)	9.6	0.4	10	12.4	15.6	3.6	35.72	3.78
600	16 (A & B)	10.4	0.4	10.8	13.9	20.3	3.1	37.49	3.63

A: Mean value includes all surviving animals showing evidence of implantation, including those with total litter loss

B: Mean value includes only animals bearing viable young at termination

Difference from controls statistically significant at Wilcoxon test: aP < 0.05 and bP < 0.001.

Table 4:

a)       Group mean incidence for major and minor malformations (Palmer et.al., 1975)

Dosage (mg/kg bw/day)	Number of young
	Major malformations			Minor malformations*
				Gross or visceral			Skeletal
	Examined	Affected		Examined	Affected		Examined	Affected
		Total number	Mean (%)		Total number	Mean (%)		Total number	Mean (%)
0	149	0	0	33	1	2.2	116	2	2
0.2	137	0	0	26	0	0	111	2	1.7
2	147	0	0	22	0	0	125	5	5.5
300	153	1	0.6	30	0	0	122	4	3.6
600	166	0	0	34	1	6.7	132	2	1.8

b) Group mean incidence for pups with extra ribs (Palmer et.al., 1975)

Dosage (mg/kg bw/day)	Mean percent incidences of pups with extra lumber ribs*
0	18.6
0.2	33.1
2	21.3
300	12.9
600	15.3

* Young showing major malformations excluded

Conclusions:

Based on the results, the maternal toxicity and developmental toxicity NOAELs were determined to be 300 mg/kg bw/day based on retarded weight gain and mortality in treated females at higher dose and based on absence of major, minor and skeletal malformations at highest dose respectively.

Executive summary:

A pre-natal developmental toxicity study is conducted with C10-13 LAS, sodium salt in pregnant female CD rats. The test substance was administered to groups of 20 pregnant female rats via oral gavage at doses of 0, 0.2, 2, 300 and 600 mg/kg bw/day from gestation day 6 (GD 6) till GD 15. All animals were observed daily for clinical signs of toxicity and were weighed regularly throughout the gestation. On GD 17, animals were euthanised and uteri were examined for number of implantations, viable youngs and embryonic deaths (abortion or resorption sites). Ovaries were examined and number of corpora lutea were also recorded. Individual foetus was weighed and examined for external malformations. About one third of the foetuses were examined for visceral anomalies and remaining two thirds for skeletal anomalies. Moderate maternal toxicity was observed at the highest dose due to retarded weight gain and mortality. These effects were associated with the gastrointestinal disturbances. No instances of major, minor and skeletal malformations were observed up to the highest dose of 600 mg/kg bw/day with the exception of a marginal retardation of sternebral ossification at 600 mg/kg. Based on the results, the maternal toxicity and developmental toxicity NOAELs were determined to be 300 mg/kg bw/day based on retarded weight gain and mortality in treated females at higher dose and based on absence of major, minor and skeletal malformations at highest dose respectively (Palmer, 1975a).  

Reference 2

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The aim of this study was to evaluate the teratogenic potential of linear alkylbenzene sulphonate (LAS) in mice. Twenty female mice/dose were assigned into 5 groups and administered 0 (water), 0.2, 2.0, 300 and 600 mg/kg bw/day of test substance by oral gavage from day 6 to 15 of gestation. Throughout the experiment animals were observed daily for signs of malreaction and weighed regularly. After euthanasia on day 17, their uterine content was examined for number of implantations, viable young and embryonic deaths. Body weight, incidents of external malformation, visceral and skeletal anomalies were also recorded in pups. Non parametric methods were used for statistical analysis and on the basis of adverse effects, NOAEL value was derived for maternal toxicity and teratogenicity.

GLP compliance:

not specified

Limit test:

no

Species:

mouse

Strain:

CD-1

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Wilmington, Mass., U.S.A. and St-Aubin-les-Elbeuf, France.
- Housing: Femlale mice (5 per cage) were housed in opaque plastic cages.
- Diet: Spratt’s Laboratory Diet No. 1, ad libitum.
- Drinking water: ad libitum.

ENVIRONMENTAL CONDITIONS
- Temperature: 20 ± 1°C
- Humidity: 50 ± 5 % RH

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

- Preparation of dosing solutions: Doses were prepared on daily basis as series of graded aqueous solutions for oral dosing.
- Administration of dosage: Standard volume of doses was administered orally by gastric intubation. Control animals were dosed with water.
- Duration of dosage: Doses were commenced on day 6 after detection of vaginal plug in mice and continued daily up to and including day 15 of gestation.

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

Mating was confirmed by the detection of vaginal plug in mice.

Duration of treatment / exposure:

Animals were dosed for 10 days [from Day 6 (after detection of vaginal plug) to Day 15].

Frequency of treatment:

daily from day 6 after detection of the vaginal plug to till day 15

Duration of test:

18 days

Dose / conc.:

0 mg/kg bw/day

Remarks:

(control)

Dose / conc.:

0.2 mg/kg bw/day

Dose / conc.:

2 mg/kg bw/day

Dose / conc.:

300 mg/kg bw/day

Dose / conc.:

600 mg/kg bw/day

No. of animals per sex per dose:

20 female mice per dose

Control animals:

yes

Details on study design:

- Dose selection rationale: Two doses formed the basis for safety evaluation (0.2 and 2.0 mg/kg bw/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 (300 and 600 mg/kg bw/day) were also investigated 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 malreaction 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:

After euthanasia, uteri were dissected and examined to determine the number of:
a) Implants
b) Viable young
c) Embryonic deaths (abortion/resorption sites)

Fetal examinations:

After weighing, fetus were examined for external malformations, visceral anomalies by free and sectioning and skeletal examination was performed by alizarin staining.

Statistics:

Differences in mean values were statistically analyzed by non-parametric method i.e. Wilcoxon test.

Indices:

Mating index: (number of confirmed mating/ number of animals cohabitated) X 100

Historical control data:

In CD-1 mice, percentage of major malformations, minor visceral anomalies and minor skeletal anomalies were recorded as 0.84%, 3.68% and 5.32%, respectively in 22389 examined fetuses.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Marked maternal toxicity was observed at 300 and 600 mg/kg bw/day. Toxic effects were generally associated with the gastrointestinal tract disturbances.

Dermal irritation (if dermal study):

not specified

Mortality:

mortality observed, treatment-related

Description (incidence):

There was 90 and 35% mortality in 600 and 300 mg/kg bw/day dose groups, respectively while no mortality was observed in 0.2 and 2 mg/kg bw/day.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Body weight gain was retarded in the animals of 300 mg/kg bw/day and weight loss was observed at 600 mg/kg bw/day but due to high mortality rate at this dose, no conclusion can be drawn.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

Marked maternal toxicity was observed in mice at 300 and 600 mg/kg bw/day.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Number of abortions:

effects observed, treatment-related

Description (incidence and severity):

At 300 and 600 mg/kg bw/day, 4 and 1 litters were lost, respectively.

Pre- and post-implantation loss:

effects observed, treatment-related

Description (incidence and severity):

Post-implantation embryonic losses were 6.5%, 11.5%, 9.4%, 38.0% and 100% at 0, 0.2, 2, 300 and 600 mg/kg bw/day, respectively. No information on pre-implantation loss was provided in the research article.

Total litter losses by resorption:

not specified

Early or late resorptions:

not specified

Dead fetuses:

effects observed, treatment-related

Description (incidence and severity):

Embryonic deaths were 0.8, 1.2, 1.2, 4.5 and 12.0 at 0, 0.2, 2, 300 and 600 mg/kg bw/day, respectively.

Changes in pregnancy duration:

not specified

Changes in number of pregnant:

not specified

Description (incidence and severity):

A marked decrease in mating index was observed at 600 mg/kg bw/day.

Other effects:

not specified

Key result

Dose descriptor:

NOAEL

Effect level:

2 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: marked maternal toxicity at 300 and 600 mg/kg bw/day

Abnormalities:

not examined

Fetal body weight changes:

no effects observed

Reduction in number of live offspring:

effects observed, treatment-related

Description (incidence and severity):

Increased fetal loss was observed at maternally toxic doses (i.e. 300 and 600 mg/kg bw/day) due to total litter loses.

Changes in sex ratio:

not specified

Changes in litter size and weights:

effects observed, treatment-related

Description (incidence and severity):

Reduced litter size was observed at maternally toxic doses (i.e. 300 and 600 mg/kg bw/day) due to total litter losses. This effect was a secondary consequence of maternal reaction as litter parameters were comparable with control values in mice. Litter weights were comparable across all doses when compared to the control group.Although the fetal weight differed significantly at 0.2 mg/kg bw/day when compared to control group, these changes does not represent an adverse change because there was no consistent dose relationship and were invariably due to higher mean pub weight in the test group.

Changes in postnatal survival:

not specified

External malformations:

no effects observed

Description (incidence and severity):

No test substance related or statistically differences in the incidence of major malformations observed even at maternally toxic dosages.

Skeletal malformations:

effects observed, treatment-related

Description (incidence and severity):

An increase in incidences of skeletal abnormalities were observed at 300 mg/kg bw/day with respect to both concurrent controls as well as laboratory standard range (2.2 – 30.5%).

Visceral malformations:

effects observed, treatment-related

Description (incidence and severity):

Incidences of minor visceral anomalies were increased at 300 mg/kg bw/day (not significant statistically).

Other effects:

not specified

Key result

Dose descriptor:

NOAEL

Effect level:

300 mg/kg bw/day

Based on:

test mat.

Sex:

not specified

Basis for effect level:

other: higher incidence of skeletal and visceral anomalies at 600 mg/kg bw/day

Key result

Abnormalities:

effects observed, treatment-related

Localisation:

other: skeletal and visceral anomalies

Description (incidence and severity):

higher incidence of skeletal and visceral anomalies were observed at 600 mg/kg bw/day

Key result

Developmental effects observed:

yes

Lowest effective dose / conc.:

600 mg/kg bw/day

Treatment related:

yes

Relation to maternal toxicity:

not specified

Dose response relationship:

yes

Relevant for humans:

yes

Table 1: Mating index of the maternal animals (Palmer et.al., 1975)

Dose	Number of confirmed mating	Number of animals cohabitated	Mating index %
0	17	20	85
0.2	18	20	90
2	18	20	90
300	13	13	100
600	1	2	50

Table 2: Summary of adult performance (Palmer et.al., 1975)

Observations	Number of animals at dosage (mg/kg bw/day)
	0	0.2	2	300^M	600^M
Mated	20	20	20	20	20
Died	0	0	0	7	18
Non-pregnant	3	2	2	0	1
Total litter loss	0	0	0	4	1
With viable young	17	18	18	9	0
Body weight change	-	-	-	retarded gain	loss

M: Marked maternal toxicity

Table 3: Group mean litter data (Palmer et.al., 1975)

Dosage (mg/kg bw/day)	Number of litters	Litter size viable young	Embryogenic deaths	Implantations	Embryonic loss %	Litter weight (g)	Fetal weight (g)
					Post-implantation
0	17 (A & B)	11.7	0.8	12.5	6.5	11.34	0.97
0.2	18 (A & B)	10.4	1.2	11.6	11.5	10.98	1.05^a
2	18 (A & B)	11.4	1.2	12.7	9.4	11.6	1.02
300	13 (A)	7.9	4.5	12.4	38	-	-
	9 (B)	11.3	1.3	12.7	10.5	10.83	0.95
600	1 (A)	0	12	12	100	-	-

A: Mean value includes all surviving animals showing evidence of implantation, including those with total litter loss

B: Mean value includes only animals bearing viable young at termination

a: Difference from controls statistically significant at Wilcoxon test (P < 0.05)

Table 4:

a) Group mean incidence for major and minor malformations (Palmer et.al., 1975)

Dosage (mg/kg bw/day)	Number of young
	Major malformations			Minor malformations*
				Gross or visceral			Skeletal
	Examined	Affected		Examined	Affected		Examined	Affected
		Total number	Mean (%)		Total number	Mean (%)		Total number	Mean (%)
0	198	0	0	49	1	2	149	18	11.7
0.2	187	2	1	42	3	9.8	143	14	10.2
2	206	0	0	59	2	3.5	147	19	13.3
300	102	1	0.8	26	3	12.2	75	26	33.7
600	0	-	-	-	-	-	-	-	-

b) Group mean incidence for pups with extra ribs (Palmer et.al., 1975)

Dosage (mg/kg/day)	Mean percent incidence of pups with extra ribs*
	Cervical	Lumbar
0	32.4	19.1
0.2	41.3	13.3
2	17.3	21.2
300	40.8	6.7
600	-	-

* Young showing major malformations excluded

Conclusions:

Administration of linear alkylbenzene sulphonate (LAS) to female CD-1 mice by oral gavage during days 6-15 of gestation at dose levels of 0, 0.2, 2, 300 and 600 mg/kg bw/day resulted in a NOAEL of 2 mg/kg bw/day for maternal toxicity (based on marked maternal toxicity at 300 and 600 mg/kg bw/day) in treated females as compare to controls. The NOAEL for teratogenicity was also established at 2 mg/kg bw/day (based on higher incidence of skeletal and visceral anomalies at 300 mg/kg bw/day).

Executive summary:

A pre-natal developmental toxicity study is conducted with C10-13LAS, sodium salt in pregnant female CD-1 mice. The test substance was administered to groups of 20 pregnant female mice via oral gavage at doses of 0, 0.2, 2, 300 and 600 mg/kg bw/day from gestation day 6 (GD 6) till GD 15. All animals were observed daily for clinical signs of toxicity and were weighed regularly throughout the gestation. On GD 17, animals were euthanised and uteri were examined for number of implantations, viable youngs and embryonic deaths (abortion or resorption sites). Ovaries were examined and number of corpora lutea were also recorded. Individual foetus was weighed and examined for external malformations. About one third of the foetuses were examined for visceral anomalies and remaining two thirds for skeletal anomalies. Marked maternal toxicity was observed in mice at 300 and 600 mg/kg bw/day. These effects were associated with the gastrointestinal disturbances. Total litter loss (abortion and / or total resorption) also occurred as secondary consequence of the primary effect on mother. Higher incidences of skeletal abnormalities were also detected in mice foetus at 300 mg/kg bw/day group. Because of the very wide range between the 2 mg/kg bw/day and 300 mg/kg bw/day doses, the maternal NOAEL of 2 mg/kg bw/day must be considered very conservative. At 300 mg/kg bw/day, the incidence of total litter 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 and foetal loss, 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 bw/day, there were no live births. Based on these data, the developmental toxicity NOAEL was considered to be 300 mg/kg bw/day (Palmer, 1975b).

Reference 3

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The aim of this study was to evaluate the teratogenic potential of linear alkylbenzene sulphonate (LAS) in rabbits. Thirteen female rabbits/dose were divided into 5 groups and administered 0 (water), 0.2, 2.0, 300 and 600 mg/kg bw/day of test substance by oral gavage from day 6 to 18 of gestation. Throughout the experiment animals were observed daily for signs of malreaction and weighed regularly. After euthanasia on day 29, their uterine content was examined for number of implantations, viable young and embryonic deaths. Ovaries of the rabbits were also examined and number of corpora lutea were counted. Body weight, incidents of external malformation, visceral and skeletal anomalies were also recorded in pups. Non parametric methods were used for statistical analysis and on the basis of adverse effects, NOAEL value was derived for maternal toxicity and teratogenicity.

GLP compliance:

not specified

Limit test:

no

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: East Anglian Rabbitries, Colchester, England
- Housing: Rabbits were housed individually in the metal cages equipped with wire mesh floor.
- Diet: Rabbits SG-1 diet, ad libitum.
- Drinking water: ad libitum.

ENVIRONMENTAL CONDITIONS
- Temperature: 18 ± 2°C

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

- Preparation of dosing solutions: Doses were prepared on daily basis as series of graded aqueous solutions for oral dosing.
- Administration of dosage: Standard volume of doses was administered orally by gastric intubation. Control animals were dosed with water.
- Duration of dosage: Doses were commenced on day 6 after observation of coitus in rabbits and continued daily up to and including day 18 of gestation.

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

Mating was confirmed by observation of coitus in rabbits.

Duration of treatment / exposure:

Animals were dosed for 13 days [from Day 6 (after observation of coitus) to Day 18].

Frequency of treatment:

daily from day 6 after observation of coitus to till day 18

Duration of test:

30 days

Dose / conc.:

0 mg/kg bw/day

Remarks:

(control)

Dose / conc.:

0.2 mg/kg bw/day

Dose / conc.:

2 mg/kg bw/day

Dose / conc.:

300 mg/kg bw/day

Dose / conc.:

600 mg/kg bw/day

No. of animals per sex per dose:

13 female rabbits per dose

Control animals:

yes

Details on study design:

- Dose selection rationale: Two doses formed the basis for safety evaluation (0.2 and 2.0 mg/kg bw/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 (300 and 600 mg/kg bw/day) were also investigated 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 malreaction 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:

After euthanasia, uteri were dissected and examined to determine the number of:
a) Implants
b) Viable young
c) Embryonic deaths (abortion/resorption sites)

Ovaries were examined and number of corpora lutea were also recorded.

Fetal examinations:

After weighing, fetuses were examined for external malformations followed by their dissection and examined for internal organ abnormalities and gonadal inspection for sex determination. The carcasses were preserved in alcohol for subsequent clearing, alizarin staining and skeletal examination.

Statistics:

Differences in mean values were statistically analyzed by non-parametric method i.e. Wilcoxon test.

Indices:

Mating index: (number of confirmed mating/ number of animals cohabitated) X 100

Historical control data:

In rabbits, percentage of major malformations, minor visceral anomalies and minor skeletal anomalies were recorded as 0.74%, 2.53% and 8.60%, respectively in 36508 examined fetuses.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Marked maternal toxicity was observed at 300 and 600 mg/kg bw/day. Toxic effects were generally associated with the gastrointestinal tract disturbances and affected rabbits showed diarrhea, anorexia, weight loss and cachexia prior to death.

Dermal irritation (if dermal study):

not specified

Mortality:

mortality observed, treatment-related

Description (incidence):

There was 100, 84.6% and 7.6% mortality observed at 600, 300 and 2 mg/kg bw/day, respectively while no mortality was observed at 0.2 mg/kg bw/day.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Body weight loss was observed at 300 and 600 mg/kg bw/day.

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Number of abortions:

effects observed, treatment-related

Description (incidence and severity):

At 0.2, 2 and 300 mg/kg bw/day, 1, 1 and 2 litters were lost, respectively.

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

Pre-implantation embryonic losses were 12.6%, 17.7%, 17.0%, and 12.5%at 0, 0.2, 2 and 300 mg/kg bw/day, respectively.
Post-implantation embryonic losses were 14.2%, 15.4%, 20.0% and 100% at 0, 0.2, 2 and 300 mg/kg bw/day, respectively.

Total litter losses by resorption:

not specified

Early or late resorptions:

not specified

Dead fetuses:

effects observed, treatment-related

Description (incidence and severity):

Higher instance of embryonic death (8.5) was observed at 300 mg/kg bw/day. Embryonic deaths were 1.7, 1.0, 1.4, and 8.5 at 0, 0.2, 2 and 300 mg/kg bw/day, respectively.

Changes in pregnancy duration:

not specified

Changes in number of pregnant:

not specified

Description (incidence and severity):

No effect was observed on the mating index.

Other effects:

not specified

Key result

Dose descriptor:

NOAEL

Effect level:

2 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: marked maternal toxicity and mortality at 300 and 600 mg/kg bw/day

Abnormalities:

not examined

Fetal body weight changes:

no effects observed

Description (incidence and severity):

No test substance related / statistically significant differences were observed in treated groups as compared to control group.

Reduction in number of live offspring:

effects observed, treatment-related

Description (incidence and severity):

Increased fetal loss was observed at maternally toxic doses (i.e. 300 and 600 mg/kg bw/day) due to total litter losses and number of young pups available for examination and adequate assessment of results were insufficient at these doses.

Changes in sex ratio:

not specified

Changes in litter size and weights:

effects observed, treatment-related

Description (incidence and severity):

Reduced litter size was observed at maternally toxic doses (i.e. 300 and 600 mg/kg bw/day) due to total litter losses. Litter weights were comparable across all doses when compared to the control group.

Changes in postnatal survival:

not specified

External malformations:

no effects observed

Description (incidence and severity):

At maternally toxic dosages, number of young pups available for examination / adequate assessment of results were insufficient. No test substance related / statistically significant differences in the incidence of major malformations and minor anomalies were observed at 0.2 and 2 mg/ kg bw/day groups on comparison to the control group.

Skeletal malformations:

no effects observed

Description (incidence and severity):

At maternally toxic dosages, number of young pups available for examination / adequate assessment of results were insufficient. No test substance related / statistically significant differences in the incidence of skeletal abnormalities were observed at 0.2 and 2 mg/ kg bw/day on comparison to the control group.

Visceral malformations:

no effects observed

Other effects:

not specified

Key result

Dose descriptor:

NOAEL

Effect level:

2 mg/kg bw/day

Based on:

test mat.

Sex:

not specified

Basis for effect level:

other: no test substance related differences in the incidence of skeletal abnormalities, major malformations and minor anomalies were observed at this dose. Increased fetal mortality was observed at the two higher doses due to maternal toxicity.

Key result

Abnormalities:

no effects observed

Key result

Developmental effects observed:

no

Table 1: Mating index of the maternal animals (Palmer et.al., 1975)

Dose	Number of confirmed mating	Number of animals cohabitated	Mating index %
0	10	11	90
0.2	13	13	100
2	12	12	100
300	2	2	100
600^#	-	-	-

 #: Mating index cannot be calculated as all animals died at this dose.

Table 2: Summary of adult performance (Palmer et.al., 1975)

Observations	Number of animals at dosage (mg/kg bw/day)
	0	0.2	2	300^M	600^M
Mated	13	13	13	13	13
Died	2^a	0	1	11	13
Non-pregnant	1	0	0	0	0
Total litter loss	1^b	1	1	2	0
With viable young	9	12	11	0	0
Body weight change	-	-	-	Loss	loss

a: Includes one animal dying of intubation error

b: Excluded from subsequent calculations due to pus in thoracic cavity and uterus

M: Marked maternal toxicity

Table 3: Group mean litter data (Palmer et.al., 1975)

Dosage (mg/kg bw/day)	Number of litters	Litter size viable young	Embryogenic deaths	Implantations	Corpora lutea	Embryonic loss %		Litter weight (g)	Fetal weight (g)
						Pre-implantation	Post-implantation
0	9 (A & B)	8.3	1.7	10	11.3	12.6	14.2	321.7	39.3
0.2	13 (A)	7.8	1	8.8	10.6	17.7	15.4	-	-
	12 (B)	8.5	0.8	9.3	10.7	13.4	8.4	323.3	38.5
2	12 (A)	7.3	1.4	8.8	11	17	20	-	-
	11 (B)	8	1.3	9.3	10.5	11.9	12.8	314.8	40.1
300	2 (A)	0	8.5	8.5	10	12.5	100	-	-
600	No survivors	-	-	-	-	-	-	-	-

A: Mean value includes all surviving animals showing evidence of implantation, including those with total litter loss

B: Mean value includes only animals bearing viable young at termination

Table 4:

a)  Group mean incidence for major and minor malformations (Palmer et.al., 1975)

Dosage (mg/kg bw/day)	Number of young
	Major malformations			Minor malformations*
				Gross or visceral			Skeletal
	Examined	Affected		Examined	Affected		Examined	Affected
		Total number	Mean (%)		Total number	Mean (%)		Total number	Mean (%)
0	75	3	3	72	7	11	72	8	11.9
0.2	102	0	0	102	3	3.3	102	7	8
2	88	1	1.3	87	1	1	87	8	9.5
300	0	-	-	-	-	-	-	-	-
600	0	-	-	-	-	-	-	-	-

b)  Group mean incidence for pups with extra ribs (Palmer et.al., 1975)

Dosage (mg/kg/day)	Mean percent incidence of pups with extra ribs*
	Lumbar
0	61
0.2	56.1
2	72.8
300	-
600	-

* Young showing major malformations excluded

Conclusions:

Administration of linear alkylbenzene sulphonate (LAS) to female NZW rabbits by oral gavage during days 6-18 of gestation at dose levels of 0, 0.2, 2, 300 and 600 mg/kg bw/day resulted in a NOAEL of 2 mg/kg bw/day for maternal toxicity (based on marked maternal toxicity and mortality at higher dose levels of 300 and 600 mg/kg bw/day) in treated females as compared to controls. The NOAEL for teratogenicity was also established at 2 mg/kg bw/day (based on no test substance related / statistically significant differences in the incidence of skeletal abnormalities, major malformations and minor anomalies at this dose).

Executive summary:

A pre-natal developmental toxicity study is conducted with C10-13LAS, sodium salt in pregnant New Zealand White rabbits. The test substance was administered to groups of 13 pregnant female rabbits via oral gavage at doses of 0, 0.2, 2, 300 and 600 mg/kg bw/day from gestation day 6 (GD 6) till GD 18. All animals were observed daily for clinical signs of toxicity and were weighed regularly throughout the gestation. After euthanasia on day 29, their uterine content was examined for number of implantations, viable young and embryonic deaths. Ovaries of the rabbits were also examined and number of corpora lutea were counted. Body weight, incidents of external malformation, visceral and skeletal anomalies were also recorded in pups. Marked maternal toxicity was observed at 300 and 600 mg/kg bw/day which were primarily associated with the gastrointestinal disturbances and affected rabbits showed diarrhoea, anorexia, weight loss and cachexia prior to death. Maternal mortality rate was 100, 84.6% and 7.6% at 600, 300 and 2 mg/kg bw/day, respectively while no mortality was observed at 0.2 mg/kg bw/day. Higher instance of embryogenic death was (8.5) was observed at 300 mg/kg bw/day. No effect was observed on the mating index. Increased foetal loss was observed at maternally toxic doses (300 and 600 mg/kg bw/day) due to total litter losses and number of young pups available for examination and adequate assessment of growth anomalies or malformations were insufficient at these doses. No test substance related / statistically significant differences in the incidence of major malformations and minor anomalies were observed at 0.2 and 2 mg/ kg bw/day in comparison to the control group.

Based on the results, the maternal toxicity and developmental toxicity NOAELs were determined to be 2 mg/kg bw/day (Palmer, 1975c).  

Reference 4

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

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 corpora 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

Dose / conc.:

0.2 mg/kg bw/day

Dose / conc.:

2 mg/kg bw/day

Dose / conc.:

300 mg/kg bw/day

Dose / conc.:

600 mg/kg bw/day

No. of animals per sex per dose:

no data

Control animals:

yes, concurrent no treatment

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Treatment at 600 mg/kg was associated with a transient diarrhea following initiation of treatment.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Change in body weight 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.

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

The pregnancy rate was comparable at all dosages.

Dose descriptor:

NOAEL

Effect level:

300 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Abnormalities:

not specified

Fetal body weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

Mean pup weights were statistically higher at 0.2, 2.0 and 300 mg/kg.

Reduction in number of live offspring:

no effects observed

Changes in litter size and weights:

no effects observed

Skeletal malformations:

effects observed, treatment-related

Description (incidence and severity):

The distribution of skeletal variants were not statistically significant with the exception of a marginal retardation of sternebral ossification at 600 mg/kg.

Visceral malformations:

no effects observed

Description (incidence and severity):

The incidence of minor visceral anomalies was unaffected by treatment at any dosage.

Dose descriptor:

NOAEL

Effect level:

300 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: teratogenicity

Abnormalities:

not specified

Developmental effects observed:

not specified

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.

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:

mouse

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

Developmental toxicity

Study 1 (C10-13 LAS):

A pre-natal developmental toxicity study is conducted with C10-13 LAS, sodium salt in pregnant female CD rats. The test substance was administered to groups of 20 pregnant female rats via oral gavage at doses of 0, 0.2, 2, 300 and 600 mg/kg bw/day from gestation day 6 (GD 6) till GD 15. All animals were observed daily for clinical signs of toxicity and were weighed regularly throughout the gestation. On GD 17, animals were euthanised and uteri were examined for number of implantations, viable youngs and embryonic deaths (abortion or resorption sites). Ovaries were examined and number of corpora lutea were also recorded. Individual foetus was weighed and examined for external malformations. About one third of the foetuses were examined for visceral anomalies and remaining two thirds for skeletal anomalies. Moderate maternal toxicity was observed at the highest dose due to retarded weight gain and mortality. These effects were associated with the gastrointestinal disturbances. No instances of major, minor and skeletal malformations were observed up to the highest dose of 600 mg/kg bw/day. Based on the results, the maternal toxicity and developmental toxicity NOAELs were determined to be 300 mg/kg bw/day (based on retarded weight gain and mortality in treated females at higher dose) and 600 mg/kg bw/day (based on absence of major, minor and skeletal malformations at highest dose) respectively (Palmer, 1975a).  

 

Study 2 (C10-13 LAS):

A pre-natal developmental toxicity study is conducted with C10-13 LAS, sodium salt in pregnant female CD-1 mice. The test substance was administered to groups of 20 pregnant female mice via oral gavage at doses of 0, 0.2, 2, 300 and 600 mg/kg bw/day from gestation day 6 (GD 6) till GD 15. All animals were observed daily for clinical signs of toxicity and were weighed regularly throughout the gestation. On GD 17, animals were euthanised and uteri were examined for number of implantations, viable youngs and embryonic deaths (abortion or resorption sites). Ovaries were examined and number of corpora lutea were also recorded. Individual foetus was weighed and examined for external malformations. About one third of the foetuses were examined for visceral anomalies and remaining two thirds for skeletal anomalies. Marked maternal toxicity was observed in mice at 300 and 600 mg/kg bw/day. These effects were associated with the gastrointestinal disturbances. Total litter loss (abortion and / or total resorption) also occurred as secondary consequence of the primary effect on mother. Higher incidences of skeletal abnormalities were also detected in mice foetus at 300 mg/kg bw/day group. Because of the very wide range between the 2 mg/kg bw/day and 300 mg/kg bw/day doses, the maternal NOAEL of 2 mg/kg bw/day must be considered very conservative. At 300 mg/kg bw/day, the incidence of total litter 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 and foetal loss, 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 bw/day, there were no live births. Based on these data, the developmental toxicity NOAEL was considered to be 300 mg/kg bw/day (Palmer, 1975b).

Study 3 (C10 -13 LAS):

A pre-natal developmental toxicity study is conducted with C10-13 LAS, sodium salt in pregnant New Zealand White rabbits. The test substance was administered to groups of 13 pregnant female rabbits via oral gavage at doses of 0, 0.2, 2, 300 and 600 mg/kg bw/day from gestation day 6 (GD 6) till GD 18. All animals were observed daily for clinical signs of toxicity and were weighed regularly throughout the gestation. After euthanasia on day 29, their uterine content was examined for number of implantations, viable young and embryonic deaths. Ovaries of the rabbits were also examined and number of corpora lutea were counted. Body weight, incidents of external malformation, visceral and skeletal anomalies were also recorded in pups. Marked maternal toxicity was observed at 300 and 600 mg/kg bw/day which were primarily associated with the gastrointestinal disturbances and affected rabbits showed diarrhoea, anorexia, weight loss and cachexia prior to death. Maternal mortality rate was 100, 84.6% and 7.6% at 600, 300 and 2 mg/kg bw/day, respectively while no mortality was observed at 0.2 mg/kg bw/day. Higher instance of embryogenic death was (8.5) was observed at 300 mg/kg bw/day. No effect was observed on the mating index. Increased foetal loss was observed at maternally toxic doses (300 and 600 mg/kg bw/day) due to total litter losses and number of young pups available for examination and adequate assessment of growth anomalies or malformations were insufficient at these doses. No test substance related / statistically significant differences in the incidence of major malformations and minor anomalies were observed at 0.2 and 2 mg/ kg bw/day in comparison to the control group. Based on the results, the maternal toxicity and developmental toxicity NOAELs were determined to be 2 mg/kg bw/day (Palmer, 1975c).

Study 4 (C10 -13 LAS):

A pre-natal developmental toxicity study is conducted with C10-13 LAS, sodium salt in pregnant pregnant rats. 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 (Palmer and Lovell 1971).

Justification for classification or non-classification

Based on the reproductive toxicity study with C10 – 14 LAS and developmental toxicity studies with C10 -13 LAS in rats, mice and rabbits, no classification is warranted for this endpoint according to EU CLP (1272/2008/EC) criteria.