Sulfuric acid, mono-C9-11-alkyl esters, sodium salts

Endpoint summary

Description of key information

For the whole category of alkyl sulfates (AS) a NOAEL of 488 mg/kg bw/day for oral and dermal exposure was established.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: oral

Type of information:

migrated 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: see 'Remark'

Remarks:

Comparable to guideline study with acceptable restrictions. Limited details on test animals and environmental conditions. Not all haematological examinations were performed. Neurobehavioural and ophthalmoscopic examinations are missing due to the year when the study was conducted.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)

Deviations:

yes

Remarks:

limited details on test animals and environmental conditions; not all haematological examinations were performed; neurobehavioural and ophthalmoscopic examinations are missing due to the year when the study was conducted.

GLP compliance:

no

Limit test:

no

Species:

rat

Strain:

other: Colworth Wistar-derived

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 43-87 g (males), 51-79 g (females)
- Housing: animals were housed in individual cages.
- Diet: semi-synthetic purified diet, ad libitum
- Water: ad libitum

Route of administration:

oral: feed

Vehicle:

other: semi-synthetic purified diet

Details on oral exposure:

DIET PREPARATION
- Mixing appropriate amounts with (Type of food): semi-synthetic purified diet

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

13 weeks

Frequency of treatment:

daily, 7 days/week

Remarks:

Doses / Concentrations:
0.07, 0.14, 0.28, 0.56, 1.13, 2.25%
Basis:
nominal in diet

Remarks:

Doses / Concentrations:
58, 113, 228, 470, 961 and 1944 mg/kg bw/day (males)
Basis:
other: reported daily intake of the test substance based on mean body weight and food consumption over the entire 13-week treatment period

Remarks:

Doses / Concentrations:
66, 131, 261, 506, 1070 and 2218 mg/kg bw/day (females)
Basis:
other: reported daily intake of the test substance based on mean body weight and food consumption over the entire 13-week treatment period

No. of animals per sex per dose:

10 test group
20 control group

Control animals:

yes, plain diet

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: animals were observed daily for mortality and general health conditions.

BODY WEIGHT: Yes
- Time schedule for examinations: body weights of all animals were determined once per week.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): twice weekly
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

FOOD EFFICIENCY:
- Body weight gain in g/food consumption in g calculated as time-weighted averages from the consumption and body weight gain data: Yes

WATER CONSUMPTION: Yes
- Time schedule for examinations: twice weekly

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at the end of the experimental period (13 weeks)
- Anaesthetic used for blood collection: Yes (halothane)
- How many animals: all
- Parameters checked: packed cell volume, haemoglobin level, mean corpuscular haemoglobin concentration and white cell count

CLINICAL CHEMISTRY:
- Time schedule for collection of blood: at the end of the experimental period (13 weeks)
- How many animals: all
- Parameters checked: serum levels of sodium, potassium, calcium, magnesium, urea, creatinine, total protein, cholesterol, triglyceride, glutamic oxaloacetic transaminase, glutamic-pyruvic transaminase, lactate dehydrogenase, hydroxybutyrate dehydrogenase, cholinesterase, alkaline phosphatase and creatinine phosphokinase

Sacrifice and pathology:

GROSS PATHOLOGY: Yes, in all animals; absolute and relative organ weights of heart, liver, spleen, kidneys, brain, adrenals, pituitary and testes were determined.
HISTOPATHOLOGY: Yes, in all animals of the control group and the two high dose groups (1.13 and 2.25% in the diet); histopathological examination was performed in heart, liver, spleen, kidneys, brain, adrenals, pituitary, testes, lung, stomach, jejunum, ileum, caecum, colon, thyroid, pancreas, urinary bladder, seminal vesicles, ovaries, uterus, skeletal muscle, thymus, salivary glands, skin, aorta, eye, mesenteric lymph node, tongue and sternum. Since liver changes were determined in the two high dose groups, histopathological examination of all other dose groups was performed.

Statistics:

All relevant parameters, except those for pathology, were statistically examined by analysis of variance for significant effects between treatment groups and controls. Statistical significance between treatment groups and controls was indicated at p < 0.05.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

0.14 and 1.13% in the diet: each one male animal died (not treatment-related)

Mortality:

mortality observed, treatment-related

Description (incidence):

0.14 and 1.13% in the diet: each one male animal died (not treatment-related)

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

2.25% in the diet: significantly lower body weight gain in males (-20%) and females (-16%) compared to controls; 1.13% in the diet: significantly lower body weight gain in males (-10%) compared to controls

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

2.25% in the diet: significantly lower food consumption in males (-9%) and females (-6%) compared to controls (non-adverse)

Food efficiency:

effects observed, treatment-related

Description (incidence and severity):

2.25% in the diet: significantly poorer food utilisation in males (-13%) and females (-10%) compared to controls; 1.13% in the diet: significantly poorer food utilisation in males (-5%) compared to controls

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

effects observed, treatment-related

Description (incidence and severity):

2.25% in the diet: significantly lower water consumption in females (-15%) compared to controls

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

2.25% in the diet: signif. decreased magnesium, protein and cholesterin values (m); signif. increased GOP (m), GPT (m)and AP (m/f); 1.13% in the diet: signif. incraesed AP (m) and GPT (f); 0.28 and 0.56% in the diet: signif. increased AP (m)

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

2.25%: increased in liver (m/f), brain (m/f), testes (m); decreased in spleen (m/f), kidney (m/f) and heart (m/f); 1.13%: increased in liver (m/f), brain (m), testes (m); decreased in spleen (m), kidney (f), heart (m); 0.56%: increased in liver (m/f)

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

2.25% in the diet: no abdominal fat (m) and changes in colour and consistency of intestinal contents (m/f); 1.13% in the diet: changes in colour and consistency of intestinal contents (m)

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

2.25% in the diet: liver (m/f), kidney (f), alimentary tract (m/f), connective tissue (m/f); 0.56-1.13% in the diet: liver (m/f); 0.28% in the diet: liver (f)

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
Two male rats were killed due to ill health during this study. One of these animals, which was fed 0.14% of the test substance in the diet, was killed during Week 3 of the study due to a deformity of the posterior thorax, which is a lesion occasionally observed in Colworth Wistar rats and considered to represent injuries incurrent at birth or in the early post-partum period. The second animal, which was fed with dietary levels of 1.13%, was sacrificed during Week 6 due to rapid loss of weight and respiratory distress, which was associated with severe pulmonary oedema and emphysema and a major congenital cardiac defect, viz. patent interventricular foramen. Lesions of this type are also occasionally observed in young Colworth Wistar. Therefore, none of these lesions was considered to be related to treatment with the test substance in both animals.
No other animal died during the study period and the appearance of all 158 survivors was indicative of good health.

BODY WEIGHT AND WEIGHT GAIN (see Table 1 under “Any other information on results incl. tables”)
Males and females fed 2.25% of the test substance in diet showed significantly lower body weights and body weight gain compared to controls. This effect was also observed in males treated at dietary levels of 1.13%.

FOOD CONSUMPTION (see Table 2 under “Any other information on results incl. tables”)
The food intakes of males and females fed at a dietary dose level of 2.25% were significantly lower compared to controls, which corresponded to the decrease in body weights in both genders at this dose level.

FOOD EFFICIENCY (see Table 3 under “Any other information on results incl. tables”)
Food utilisation by male and female rats fed dietary levels of 2.25% was significantly poorer than by the control animals. This effect was also observed in males treated at dietary levels of 1.13%. The observations of poorer food utilisation corresponded well to the reported lower body weight gains in animals at dietary dose levels of 2.25 and 1.13%.

WATER CONSUMPTION
Significantly lower water consumption compared to controls was observed in females at dietary dose levels of 2.25%.

HAEMATOLOGY
No changes in haematological parameters were observed between animals of all treatment groups and controls.

CLINICAL CHEMISTRY (see Tables 4 and 5 under “Any other information on results incl. tables”)
Serum values of magnesium, total protein and cholesterol were decreased at the highest dose (2.25% in the diet) in males. In males of the same dose group, serum GOT, GPT and AP were elevated. Serum GPT was also increased in males and females receiving the second highest dose group (1.13% in the diet). Serum AP was also elevated in males receiving, 1.13, 0.56 and 0.28% of the test substance in the diet and in females receiving 1.13% and 2.25% of the test substance in the diet.

ORGAN WEIGHTS (see Tables 6 and 7 under “Any other information on results incl. tables”)
Relative liver weights (both sexes) significantly increased in the three highest dose groups (0.56%-2.25%). At the highest dietary level of feeding, the increase in relative liver weight in males and females was 19% and 42%, respectively. Furthermore, absolute weights of the liver were significantly increased in females of the two highest dose groups (1.13 and 2.25%) but not in males.
Absolute spleen weights significantly decreased in males at the two highest dose levels (1.13 and 2.25%) and in females at the highest dose. No changes in relative spleen weights were observed in any of the treated animals compared to controls.
Absolute kidney weights significantly decreased in high dose males, but relative kidney weights were normal compared to controls. Relative kidney weights significantly increased in females at the two highest dose levels (1.13 and 2.25%) while absolute kidney weights were not affected.
Relative brain weights were significantly increased in males fed the two highest dose levels (1.13 and 2.25%) and in females receiving the highest dose.
Relative weights of the testes increased at the two highest dose levels (1.13 and 2.25%).
Absolute heart weights significantly decreased in males fed the two highest dose levels (1.13 and 2.25%) and in females fed the highest dose. Relative heart weights were increased in males at the highest dose level.

GROSS PATHOLOGY
High dose males had virtually no abdominal fat and changes in colour and consistency of intestinal contents. Changes in colour and consistency of intestinal contents were also observed in one male of the 1.13% dose group. Depletion of body fat and changes in intestinal contents were less frequently noted in high dose females. All other lesions noted were not considered to be related to treatment as they were identified to represent normal background pathology in rats of this age and strain.

HISTOPATHOLOGY: NON-NEOPLASTIC
Liver:
Histological changes attributable to treatment with the test substance were found in liver, kidney, alimentary tract and connective tissue. The major histopathological findings were noted in liver.
At the highest dietary level (2.25%), diffuse (6/10 females, 3/10 males) and periportal (4/10 females, 7/10 males) hypertrophy, reduced cytoplasmic (glycogenic) vacuolation (10/10 females, 9/10 males) as well as reduced cytoplasmic neutral fat and hemosiderin content were prominent in the hepatic parenchyma of rats. In addition, the hemosiderin content of Kupffer cell was greatly depleted.
Diffuse hypertrophy was also identified in 5/10 females fed 1.13% of the test substance in the diet. Furthermore, periportal hypertrophy was observed in rats (5/10 females, 8/9 males) at this dose level and the next lower dose level of 0.56% (10/10 females, 5/10 males). In addition, this lesion was also observed in females (4/10 animals), but not in males, at the 0.28% dose level.
Reduced cytoplasmic (glycogenic) vacuolation, reduced cytoplasmic neutral fat, hemosiderin content and depletion of Kupffer cell hemosiderin were observed in males and/or females receiving dietary dose levels of 0.56%-2.25%.
No treatment-related histopathological changes were observed in the livers of rats (both genders) treated with dietary dose levels of 0.07 and 0.14%

Kidney:
The incidence and severity of nephrocalcinosis were significantly reduced in females (7/10 animals) treated with 2.5% in the diet. Normally, nephrocalcinosis is frequently well defined in untreated female rats of this strain and age. Further untreated animals of this age and strain also show small foci of cortical tubular athrophy, cortical interstitial fibrosis and focal lymphocytic infiltration, which are sequelae to mineral deposition in and occlusion of renal tubules. However, in females of the high those groups this three lesions were also reduced.
No changes attributable to treatment were observed in the kidney of male and female rats fed with the second highest dose level of the substance in the diet (1.13%).

Alimentary tract:
Lymphatic dilation of the small intestine was more prominent at the high dose (2.5% in the diet) compared to the controls and the 1.13% dose level. The prominence was attributable to increase in the extent of dilation of individual vessels and to an increase in the number of visible lymphatic channels.At the high dose, a higher protozoan parasite colonisation in the animals compared to controls and the 1.13% dose group was observed within the mucus covering the mucosa. However, these parasites did not colonize the mucus and thus did not result in mucosal and submucosal lesions.

Connective tissue:
At the highest dose level, a reduced quantity of stromal lipid, particularly in pancreas and parotid salivary glands, was observed compared to controls and the 1.13% dietary dose group.

Other organs:
No further treatment-related histopathological changes between treated and control animals were observed in any other organ. Incidence and intensity of histopathological changes occurring in other organs were shown to be normal background pathology observed in rats of this strain and age.

Dose descriptor:

LOAEL

Effect level:

1.13 other: % in the diet

Based on:

act. ingr.

Remarks:

corresponding to 1016 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: systemic effects that could not be regarded solely as adaptive processess, i.e. increased testes weight in males

Dose descriptor:

NOAEL

Effect level:

0.56 other: % in the diet

Based on:

act. ingr.

Remarks:

corresponding to 488 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Critical effects observed:

not specified

Table 1. Average body weight gain of rats over the 13-week treatment period

Dietary level of the test substance (%)	Average body weight gain (g)
	Male rats	Female rats
2.25	213*	117*
1.13	242*	135
0.56	270	131
0.28	263	133
0.14	271	140
0.07	264	141
0.0 (control)	268	140

* Statistically significant (p < 0.05) compared to controls

 

Table 2. Mean total amounts of food consumed by the rats over the 13-week treatment period

Dietary level of the test substance (%)	Mean total amount of food consumed (g)
	Male rats	Female rats
2.25	1502*	1192*
1.13	1581	1250
0.56	1636	1212
0.28	1614	1220
0.14	1609	1272
0.07	1573	1270
0.0 (control)	1643	1269

* Statistically significant (p < 0.05) compared to controls

 

Table 3. Mean body weight gain (g)/mean total food consumed (g) by rats over the 13-week treatment period

Dietary level of the test substance (%)	Mean total amount of food consumed (g)
	Male rats	Female rats
2.25	0.141*	0.099*
1.13	0.154*	0.108
0.56	0.165	0.108
0.28	0.163	0.109
0.14	0.169	0.110
0.07	0.168	0.111
0.0 (control)	0.163	0.111

* Statistically significant (p < 0.05) compared to controls

Table 4. Serum analysis – Changes in biochemical parameters in male rats over the 13-week treatment period (mean values)

Dietary level of the test substance (%)	Magnesium (meq/L)	Creatinine (mg/100 mL)	Total protein (g/100 mL)	Cholesterol (mg/100 mL)	GOT (mu/mL)	GPT (mu/mL)	AP (mu/mL)
2.25	1.3*	0.80	6.1*	77*	73*	41*	1289*
1.13	1.4	0.80	6.4	97	60	29*	1356*
0.56	1.5	0.81	6.2	92	57	26*	1135*
0.28	1.4	0.80	6.5	113	58	20	1048*
0.14	1.5	0.76	6.4	101	63	20	838
0.07	1.7	0.78	6.6	97	63	23	941
0.0 (control)	1.6	0.80	6.5	113	61	20	868

* Statistically significant (p < 0.05) compared to controls

 

Table 5. Serum analysis – Changes in biochemical parameters in female rats over the 13-week treatment period (mean values)

Dietary level of the test substance (%)	Magnesium (meq/L)	Creatinine (mg/100 mL)	Total protein (g/100 mL)	Cholesterol (mg/100 mL)	GOT (mu/mL)	GPT (mu/mL)	AP (mu/mL)
2.25	1.4	0.82	6.2	76	72	24	1350*
1.13	1.4	0.74	6.4	89	73	25*	1169*
0.56	1.4	0.82	6.3	85	61	21	957
0.28	1.5	0.82	6.4	93	72	21	1059
0.14	1.4	0.77	6.2	85	74	24	858
0.07	1.5	0.77	6.2	92	70	20	841
0.0 (control)	1.5	0.79	6.3	88	68	20	859

* Statistically significant (p < 0.05) compared to controls

Table 6. Mean absolute and relative organ weights of male rats after the 13-week treatment period

Dietary level of the test substance (%)	Final body weight (g)	Heart (g)		Liver (g)		Spleen (g)		Kidneys (g)		Brain (g)		Testes (g)
		Abs.	Rel.	Abs.	Rel.	Abs.	Rel.	Abs.	Rel.	Abs.	Rel.	Abs.	Rel.
2.25	285*	0.92*	0.32*	12.5	4.4*	0.45*	0.16	2.26*	0.79	1.92	0.68*	3.10	1.10*
1.13	317*	0.95*	0.30	13.2	4.1*	0.49*	0.16	2.58	0.81	1.93	0.61*	3.21	1.02*
0.56	344	1.05	0.31	13.4	3.9*	0.55	0.16	2.69	0.79	1.95	0.57	3.20	0.93
0.28	339	1.06	0.31	12.7	3.8	0.56	0.17	2.69	0.81	1.90	0.57	3.19	0.95
0.14	348	1.05	0.30	12.9	3.7	0.57	0.16	2.71	0.79	1.98	0.57	3.19	0.92
0.07	338	1.04	0.31	12.4	3.7	0.55	0.16	2.62	0.81	1.95	0.58	3.16	0.94
0.0 (control)	342	1.03	0.30	12.6	3.7	0.55	0.16	2.72	0.79	1.92	0.56	3.19	0.94

* Statistically significant (p < 0.05) compared to controls

 

Table 7. Mean absolute and relative organ weights of female rats after the 13-week treatment period

Dietary level of the test substance (%)	Final body weight (g)	Heart (g)		Liver (g)		Spleen (g)		Kidneys (g)		Brain (g)
		Abs.	Rel.	Abs.	Rel.	Abs.	Rel.	Abs.	Rel.	Abs.	Rel.
2.25	179*	0.63*	0.35	8.4*	4.7*	0.34*	0.19	1.57	0.88*	1.78	1.00*
1.13	199	0.69	0.34	8.4*	4.2*	0.38	0.19	1.66	0.84*	1.80	0.90
0.56	196	0.70	0.35	7.2	3.7*	0.40	0.20	1.57	0.80	1.79	0.91
0.28	197	0.68	0.34	6.7	3.4	0.37	0.19	1.54	0.78	1.77	0.91
0.14	204	0.70	0.35	6.9	3.4	0.39	0.19	1.62	0.80	1.78	0.88
0.07	204	0.70	0.35	6.9	3.4	0.40	0.20	1.66	0.82	1.79	0.88
0.0 (control)	204	0.71	0.35	6.7	3.3	0.40	0.20	1.60	0.79	1.80	0.89

* Statistically significant (p < 0.05) compared to controls

Conclusions:

Since the liver as the target organ showed only adaptive responses, the NOAEL was set at 0.56% (488 mg/kg bw/day). The adaptive changes included elevated relative liver weight due to a lower body weight and reduced food consumption, hepatic periportal hypertrophy as well as increased serum alkaline phosphatase (AP) activity.
An increased serum AP activity is considered to represent a physiological adaptation resulting from changes in hepatic metabolism required for the breakdown and detoxification of the test material. Since AP is mainly localized in the hepatic parenchyma, enlargement of the hepatic parenchymal cells accompanied by an increased organ weight are an obvious consequence.

Executive summary:

C12 -15AS Na (CAS 68890 -70 -0) was tested in a 13 week feeding study on rats. Ten rats/sex/dose in the test groups and 20 rats/sex in the control group were administered dietary levels of 0.07, 0.14, 0.28, 0.56, 1.13 and 2.25% (corresponding to 58, 113, 228, 470, 961 and 1944 mg/kg bw/day in males and 66, 131, 261, 506, 1070 and 2218 mg/kg bw/day in females). The control group received the diet alone. The NOAEL was set at 488 mg/kg bw/day for males and females since only adaptive changes in liver were observed at this dose level.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

488 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: dermal

Type of information:

migrated 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: Comparable to Guideline study.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 411 (Subchronic Dermal Toxicity: 90-Day Study)

Deviations:

yes

Remarks:

Deficiencies in biochemical and haematological data; Application only twice per week. (Study was conducted before the implementation of OECD 411)

GLP compliance:

no

Remarks:

GLP not mandatory at that time.

Species:

mouse

Strain:

C57BL

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Housing: Individual cages on sawdust
- Diet: pelleted diet ad libitum
- Water: ad libitum

Type of coverage:

not specified

Vehicle:

water

Details on exposure:

0.2 mL of an aqueous solution were applied twice weekly.

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

No data

Frequency of treatment:

Twice weekly

Remarks:

Doses / Concentrations:
0, 5, 10, 12.5, 15% a.s.
Basis:
other: nominal

Remarks:

Doses / Concentrations:
0, 200, 400, 500 and 600 mg/kg bw/day
Basis:
other: Based on an average weight of 20 g/mouse and a 5 days/week treatment.

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Observations and examinations performed and frequency:

The mice were weighed weekly, and their water intakes determined twice weekly by subtracting the amount left from that given.

Sacrifice and pathology:

At necropsy the liver, spleen, kidneys, heart, brain and testes were removed and weighed. Blocks of these and various tissues were reserved for histological examination.

Other examinations:

After 13 weeks skin blood samples were taken by cardiac puncture. The blood samples were used for haematological estimations - packed cell volume, haemoglobin level, mean corpuscular haemoglobin concentration and white cell count.

Clinical signs:

effects observed, treatment-related

Dermal irritation:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

effects observed, treatment-related

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
One mouse treated with 12.5% died after 1 week due to dehydration and anorexia.

WATER CONSUMPTION
At 10% and above the water intake was increased.

HAEMATOLOGY
Haemoglobin levels reduced and wbc counts increased in high dose males.

ORGAN WEIGHTS
Absolute and relative heart weights were higher in high dose females. Relative liver weights were increased in both sexes at the 15% and in females at the 12.5% concentration. Increased absolute kidney weights (males) and relative kidney weights (females) were found at the 15% dose level.

GROSS PATHOLOGY & HISTOPATHOLOGY
Exudate adherent to skin (4/20) was observed at the 15% dose level. Loss of hair colour lateral and ventral to application site observed at all treatment levels. Extensive ulceration and necrosis of the epidermis of the decedent at the 12.5% treatment level. Dose-related ulceration of the epidermis (4/20) with inflammatory exudate (11/20) observed at 15% and 12.5% treatment levels.

OTHER FINDINGS
At concentrations of 12.5 and 15%, cytotoxic effects were found in the epidermis.

Dose descriptor:

NOAEL

Effect level:

10 other: %

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: Corresponding to 400 mg/kg bw.

Dose descriptor:

LOAEL

Effect level:

12.5 other: %

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: Extensive necrosis and ulceration of the skin, changes in haematology and organ weights.

Critical effects observed:

not specified

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

400 mg/kg bw/day

Study duration:

subchronic

Species:

mouse

Repeated dose toxicity: dermal - local effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: dermal

Type of information:

migrated 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: Comparable to Guideline study.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 411 (Subchronic Dermal Toxicity: 90-Day Study)

Deviations:

yes

Remarks:

Deficiencies in biochemical and haematological data; Application only twice per week. (Study was conducted before the implementation of OECD 411)

GLP compliance:

no

Remarks:

GLP not mandatory at that time.

Species:

mouse

Strain:

C57BL

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Housing: Individual cages on sawdust
- Diet: pelleted diet ad libitum
- Water: ad libitum

Type of coverage:

not specified

Vehicle:

water

Details on exposure:

0.2 mL of an aqueous solution were applied twice weekly.

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

No data

Frequency of treatment:

Twice weekly

Remarks:

Doses / Concentrations:
0, 5, 10, 12.5, 15% a.s.
Basis:
other: nominal

Remarks:

Doses / Concentrations:
0, 200, 400, 500 and 600 mg/kg bw/day
Basis:
other: Based on an average weight of 20 g/mouse and a 5 days/week treatment.

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Observations and examinations performed and frequency:

The mice were weighed weekly, and their water intakes determined twice weekly by subtracting the amount left from that given.

Sacrifice and pathology:

At necropsy the liver, spleen, kidneys, heart, brain and testes were removed and weighed. Blocks of these and various tissues were reserved for histological examination.

Other examinations:

After 13 weeks skin blood samples were taken by cardiac puncture. The blood samples were used for haematological estimations - packed cell volume, haemoglobin level, mean corpuscular haemoglobin concentration and white cell count.

Clinical signs:

effects observed, treatment-related

Dermal irritation:

effects observed, treatment-related

Mortality:

mortality observed, treatment-related

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

not examined

Food efficiency:

not examined

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

effects observed, treatment-related

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
One mouse treated with 12.5% died after 1 week due to dehydration and anorexia.

WATER CONSUMPTION
At 10% and above the water intake was increased.

HAEMATOLOGY
Haemoglobin levels reduced and wbc counts increased in high dose males.

ORGAN WEIGHTS
Absolute and relative heart weights were higher in high dose females. Relative liver weights were increased in both sexes at the 15% and in females at the 12.5% concentration. Increased absolute kidney weights (males) and relative kidney weights (females) were found at the 15% dose level.

GROSS PATHOLOGY & HISTOPATHOLOGY
Exudate adherent to skin (4/20) was observed at the 15% dose level. Loss of hair colour lateral and ventral to application site observed at all treatment levels. Extensive ulceration and necrosis of the epidermis of the decedent at the 12.5% treatment level. Dose-related ulceration of the epidermis (4/20) with inflammatory exudate (11/20) observed at 15% and 12.5% treatment levels.

OTHER FINDINGS
At concentrations of 12.5 and 15%, cytotoxic effects were found in the epidermis.

Dose descriptor:

NOAEL

Effect level:

10 other: %

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: Corresponding to 400 mg/kg bw.

Dose descriptor:

LOAEL

Effect level:

12.5 other: %

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: Extensive necrosis and ulceration of the skin, changes in haematology and organ weights.

Critical effects observed:

not specified

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Study duration:

subchronic

Species:

mouse

Additional information

For the whole category of alkyl sulfates (AS) a NOAEL of 488 mg/kg bw/day was established.

The possibility of a read-across to other alkyl sulfates in accordance with Regulation (EC) No 1907/2006 Annex XI 1.5. Grouping of substances and read-across approach was assessed. In Annex XI 1.5 it is given that a read-across approach is possible for substances, whose physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity. The AS reported within the AS category show structural similarity. The most important common structural feature of the category members is the presence of a predominantly linear aliphatic hydrocarbon chain with a polar sulfate group, neutralized with a counter ion. This structural feature confers the surfactant properties of the alkyl sulfates. The surfactant property of the members of the AS category in turn represent the predominant attribute in mediating effects on mammalian health. Therefore, the AS of the AS category have similar physico-chemical, environmental and toxicological properties, validating the read across approach within the category. The approach of grouping different AS for the evaluation of their effects on human health and the environment was also made by the OECD in the SIDS initial assessment profile [1] and by a voluntary industry programme carrying out Human and Environmental Risk Assessments (HERA [2]), further supporting the read across approach between structurally related AS. A detailed justification for grouping of alkyl sulfates into a category is provided separately. Please refer for more details on the read-across also to the document “AS Category Approach Justification” attached in section 13 of IUCLID.

 

Therefore this endpoint is covered by read across to structurally related alkyl sulfates. Reliable repeated dose toxicity studies have been conducted with C12 AS Na (CAS 151-21-3), C10-16 AS Na (68585-47-7), C12-14 AS TEA (CAS 90583-18-9), C12-15 AS Na (CAS 68890-70-0), C16-18 AS Na (CAS 68955-20-4) and C13-15 AS Na (CAS 86014-79-1). Hence, alkyl sulfates with chain lengths between C10 and C18 have been tested.

oral gavage RDT

A 90% aqueous solution of C12 AS Na (CAS 151-21-3) was administered for 28 days by gavage to groups of five animals/sex/dose at dose levels of 30, 100 or 300/600 mg/kg bw/day (the dose of 300 mg/kg bw/day was changed into 600 mg/kg bw/day after 10 days of treatment). The study was performed in accordance with OECD 407 except for the functional observation battery and revealed a NOEL of 90 mg a.i./kg bw/day (Potokar et al., 1987a). At the LOAEL (270/540 mg a.i./kg bw/day), feed intake and body weight gain were reduced and water intake increased. Bleeding and ulceration of the stomach, as well as transient alterations of the tongue and myocard were found. There was an increase in leucocytes and in alanine aminotransferase (ALT) activity, as well as a decrease in haematocrit and erythrocyte volume (MCV). Relative weights of adrenals, kidneys, brain, gonads and liver were increased; the relative thymus weight was decreased.

With the same study design (which meets all requirements of the OECD 407 except for functional observation battery tests), C12-14 AS TEA (CAS 90583-18-9) was administered by gavage as a ca. 40% aqueous solution at dose levels of 0, 70, 250 or 750 mg/kg bw/day (corresponding to 0, 29, 102 and 306 mg/kg bw/day active ingredient) to groups of five rats/sex/dose (Potokar et al., 1988). At 250 mg/kg bw/day (i.e. 102 mg a.i./kg bw/day), signs of local irritation were found in the forestomach (inflammation, ulceration in some animals), but no indication of a systemic toxicity. Therefore, this level is considered as the systemic NOAEL. At 750 mg/kg bw/day (i.e. 306 mg a.s./kg bw/day), the severity of gastric irritation increased, and the animals showed leucocytosis (LOAEL).

In a 90 day gavage study, C16-18 AS Na (CAS 68955-20-4) was administered as 55% aqueous solution to groups of 10 rats/sex/dose at dose levels of 100, 300 and 900 mg/kg bw/day, corresponding to ca. 55, 165 and 495 mg a.s./kg bw/day (Potokar et al., 1987b). The NOEL was established at 55 mg a.i./kg bw/day. At the next higher dose level (NOAEL, 165 mg a.i./kg bw/day) food consumption and body weight gain were reduced, and relative liver weight was increased. Other changes were non-specific and probably due to the irritant effect of the test substance to the stomach mucosa. At 495 mg/kg bw/day, there were clear signs of gastritis; absolute and relative liver weights were increased. No signs of toxicity were found in the kidney.

oral feeding RDT 

C12 AS Na (CAS 151-21-3) was tested as well in a 90 day feeding study on rats (Walker et al., 1967). 12 male and 12 female rats/group were fed dietary levels of 40, 200, 1000 or 5000 ppm (corresponding to 3, 17, 86 or 430 mg/kg bw/day). The control group (18 males, 18 females) received the diet alone. Daily observations were made on health. Body weight and food intake were recorded weekly. Urine samples were obtained from the 5000 ppm and control groups during Week 12. The urine was examined for colour, pH, protein, reducing substances, bile salts and microscopic constituents. Terminal blood samples were taken by cardiac puncture and erythrocyte and leukocyte counts and determinations of haematocrit and haemoglobin were made. Total plasma protein and urea were determined. Gross pathological and histological examinations of a wide range of organs were made. The only effects observed occurred at 5000 ppm and comprised increases in liver weights in female animals. Regarding this as an adaptive effect, the NOAEL can be set at the highest dose level of 5000 ppm (430 mg/kg bw/day).

C12 AS Na (CAS 151-21-3) was also tested in a 13 week feeding study on rats by Munday et al. (1976b). Ten rats/sex/dose in the test groups and 20 rats/sex in the control group were administered dietary levels of 0, 0.07, 0.14, 0.28, 0.56, 1.13 and 2.25% (corresponding to 0, 58, 116, 230, 460, 920 and 1840 mg/kg bw/day). The control group received the diet alone. The NOAEL was set at 460 mg/kg bw/day since only adaptive changes were observed at this dose level.

Another subchronic feeding study was done with C10-16 AS Na (CAS 68585-47-7; Killeen and Rapp, 1976). Administration of 0, 0.25, 0.5 and 1% test substance in diet (corresponding to 0, 58, 118 and 228 mg/kg bw/day for males and females based on a.i.) to 20 Sprague-Dawley rats/sex/dose revealed no treatment-related effects either in-life or at necropsy. In addition, histopathological examinations did not show any changes considered to be related to compound administration. Hence, the NOAEL calculated by the mean food consumption was set at 254 mg/kg bw/day based on a.i. for females and 201 mg/kg bw/d based on a.i. for males.

C12-15 AS Na (CAS 68890-70-0) was investigated in a 13 week and in two 2 year studies with rats, all using the dietary route of exposure. When tested for 13 weeks at dietary concentrations of 0, 0, 0.07, 0.14, 0.28, 0.56, 1.13 or 2.25% in groups of ten rats/sex/dose in a study that meets current standards (except for neurotoxicity and immunotoxicity testing; Munday et al., 1976a), the NOEL was set at 0.14% (122 mg/kg bw/day). Since the liver as the target organ showed only adaptive responses, the NOAEL was set at 0.56% (488 mg/kg bw/day). The adaptive changes included elevated relative liver weight due to a lower body weight and reduced food consumption, hepatic periportal hypertrophy as well as increased serum alkaline phosphatase (AP) activity. An increased serum AP activity is considered to represent a physiological adaptation resulting from changes in hepatic metabolism required for the breakdown and detoxification of the test material. Since AP is mainly localized in the hepatic parenchyma, enlargement of the hepatic parenchymal cells accompanied by an increased organ weight are an obvious consequence.

In the chronic dietary repeated dose toxicity studies the NOELs were set at 113 mg/kg bw/day (LOAELs = 1125 mg/kg bw/day; Munday et al., 1995a,b). Animals in the high dose groups in both studies exhibited reduced food and water consumption and slower growth rates. Other pathological findings were increased absolute liver weights and liver to body weight ratios, hypertrophy of the hepatic parenchyma, increased relative testicular weights, reduced incidence and severity of chronic nephropathy and nephrocalcinosis and reduced arterial medial hypertrophy.

In another subchronic study with C13-15 AS Na (CAS 86014-79-1; Munday et al., 1977a), ten animals/sex/group were fed diets containing 0, 0.07, 0.14, 0.28, 0.56, 1.13 or 2.25% (corresponding to 0, 64, 134, 253, 512, 1007, or 2096 mg/kg bw/day), the NOAEL was established at 512 mg/kg bw/day since only adaptive changes (elevated liver weights and hypertrophy of the liver) were observed. At the LOAEL (1007 mg/kg bw/day) and higher dosages effects observed included enlargement of the kidneys without histological identifiable structural change, increased patency of intestinal lymphatics, decreased serum cholesterol concentration and elevated serum activity of the enzymes cholinesterase and glutamic-oxalacetic transaminase.

C16-18 AS Na (CAS 68955-20-4; subchronic, dietary study, Munday et al., 1977b) shows an identical profile with a similar NOAEL (482 mg/kg bw/day) and LOAEL (970 mg/kg bw/day).

dermal RDT 

A repeated dose toxicity study with dermal application is also available. Dose levels employed in the 90 day study were 0, 5, 10, 12.5 and 15% C12-15 AS Na (CAS 68890-70-0) corresponding to 0, 200, 400, 500 and 600 mg/kg bw/day based on an average weight of 20 g bw/mouse and a 5 days/week treatment (McCormick, 1977). Ten C57BL mice per sex and group were treated with a dose volume of 0.2 mL with the control group being sterile water. An unknown area of all animals was with the appropriate dose two times per week. All animals were observed daily for signs of general health, mortality and gross skin irritation effects. Gross signs of toxicity and body weights were recorded on a weekly basis throughout the study. Effects at the site of application were consistent with the irritant properties of the test material. Dose-related ulceration of the epidermis with inflammatory exudate was observed at the 12.5% and 15% concentrations. Dose-dependent increases in edema, vascular dilatation, epidermal acanthosis, hyperkeratosis and hypergranulosis were prominent at the 10% treatment level and above. Haemoglobin levels were reduced and white blood cell counts increased in males of the high dose group. No clinical chemistry measurements were performed. Other noteworthy systemic effects included increases in liver-to-body weight ratios in both sexes at the 15% concentration, and in females at the 12.5% concentration. Absolute kidney weights increased in males and kidney weight-to-body weight ratios increased in females at the 15% treatment level. These target organs are consistent with those observed in the oral studies. Effects at these more distant organs suggest that a higher level of percutaneous absorption of the test material may have occurred at high doses with the longer duration of exposure in this study. The systemic NOAEL was set at 400 mg/kg bw/day. However, the dietary NOAEL of 488 mg/kg bw/day will be used for risk assessment. For details refer to the folowing discussion.

Conclusion 

In summary, gastrointestinal irritation, particularly of the forestomach, was the primary effect after application via gavage but not after application via the diet. This is consistent with the primary irritant properties of the AS and the bolus effect after application by gavage. Notably, gavage studies that included recovery groups indicated that systemic effects other than forestomach irritation were fully reversible. Moreover, administration via gavage (see developmental toxicity studies as well) does not allow differentiating between systemic effects as a consequence of the local irritation or due to specific substance properties (e.g. leucocytosis). The study investigating the dermal route resulted in significant local irritation. It provided some evidence of systemic toxicity however there is insufficient information to determine if these effects represented a direct toxic effect from systemic exposure to AS or if the response was associated with the significant dermal inflammation. Thus, the NOAEL used for the risk assessment should be based on a dietary study to assess potential systemic toxicity resulting from repeated exposures to AS. After administration in the diet, the liver was the only target organ identified. Adaptive effects on this organ included an increase in liver weight, enlargement of liver cells and elevated levels of liver enzymes. Liver effects were more apparent in dietary studies, partly because these allowed administration of higher doses of the test material with less GI tract injury.

The listing of all dietary NOAELs and LOAELs in Table 1 shows that the spacing of the concentrations in the chronic toxicity studies was very high. On the other hand, the NOAELs of the subchronic studies are all in the same range and about 4.5 times higher.

  

Table 1: NOAELs and LOAELs (for a.i.) for repeated dietary dose toxicity studies of AS in rats

Substance	Duration (weeks)	NOAEL (mg/kg bw/day)	LOAEL (mg/kg bw/day)	Reference
C12 AS Na	13	430	> 430	Walker et al. (1967)
C12 AS Na	13	460	920	Munday et al. (1976b)
C10-16 AS Na	13	201/254	> 201/>254	Killeen and Rapp (1976)
C12-15 AS Na	13	488	1016	Munday et al. (1976a)
C13-15 AS Na	13	512	1007	Munday et al. (1977a)
C16-18 AS Na	13	482	970	Munday et al. (1977b)
C12-15 AS Na	104	113	1125	Munday et al. (1995a,b)

 

The NOAELs and LOAELs achieved within the different studies draw a coherent picture. The NOAEL of the chronic toxicity study (113 mg/kg bw/d) as well as the NOAEL of 254 mg/kg bw/d in the study of Killeen and Rapp (1976) represent unreasonably low doses for risk assessment. The relatively low values are due to the chosen dose level and the dose spacing, respectively. No effects were observed at both dose levels. Since the subchronic and chronic LOAELs are in the same range and the subchronic NOAELs do not conflict with the chronic LOAEL, one of the subchronic NOAELs can be chosen as basis for risk assessment. Based on the described effects and argumentations, the dietary NOAEL of 488 mg/kg bw/d (Munday et al., 1976a) representing an average of all NOAEL was chosen for the risk assessment of oral and dermal exposure.

[1] SIDS initial assessment profile, (2007);
http://www.aciscience.org/docs/Alkyl_Sulfates_Final_SIAP.pdf

[2] (HERA Draft report, 2002);
http://www.heraproject.com/files/3-HH-04-%20HERA%20AS%20HH%20web%20wd.pdf

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
The study from which the NOAEL was chosen was selected

Repeated dose toxicity: via oral route - systemic effects (target organ) digestive: liver

Justification for classification or non-classification

The available data on repeated toxicity do not meet the criteria for classification according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.