Aromatic hydrocarbons, C10-13, reaction products with branched nonene, sulfonated, sodium salts

Endpoint summary

Description of key information

A Combined 28-day repeated dose toxicity study with the reproduction/developmental toxicity screening test was performed with Sodium alkylnaphthalene sulfonate in 10 Wistar Han rats/dose/sex by oral gavage, followed by a 14-day recovery period for control and high dosed males applying 5 animals/dose. The dose levels selected were 0, 100, 300 and 1000 mg/kgbw/day. Duration of dosing was for males 29 days and females 40-47 days. The study resulted in the following NOAELs:

Parental NOAEL: 300 mg/kg/day

Reproduction NOAEL: at least 1000 mg/kg/day

Developmental NOAEL: at least 1000 mg/kg/day.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

01 December 2011 - 20 January 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EPA, Health Effects Test Guidelines OPPTS 870.3650, Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test, July 2000.

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: OECD Guidelines for Testing of Chemicals, Guideline 421, Reproduction/Developmental Toxicity Screening Test, July 1995.

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: The United States EPA Health Effects Test Guidelines, OPPTS 870.3550, Reproduction/Developmental Toxicity Screening Test, July 2000.

Deviations:

no

Principles of method if other than guideline:

In addition, the procedures described in the report essentially conform to the following guidelines:
- Commission regulation (EC) No 440/2008 Part B: Methods for the Determination of Toxicity and other Health Effects; B.7: "Repeated Dose (28 days) Toxicity (oral)". Official Journal of the European Union No. L142, May 2008.
- OECD Guidelines for Testing of Chemicals, Guideline 407, Repeated Dose 28-day Oral Toxicity Study in Rodents, October 2008.
- The United States EPA Health Effects Test Guidelines, OPPTS 870.3050, Repeated dose 28-day oral toxicity study in rodents, July 2000.

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany.
Nulliparous and nonpregnant females and untreated animals were used at initiation of the study.
- Age at study initiation: Approximately 11 weeks.
- Weight at study initiation: mean weight at start of treatment was 297 gr (males) or 201 gr (females).
- Fasting period before study: no
- Housing:
Pre-mating: Animals were housed in groups of 5 animals/sex/cage in Macrolon cages.
Mating: Females were caged together with males on a one-to-one-basis in Macrolon cages.
Post-mating: Males were housed in their home cage with a maximum of 5 animals/cage. Females were individually housed in Macrolon cages. Pups were kept with the dam until termination.
General: Sterilised sawdust as bedding material and paper as cage enrichment were supplied.
- Diet: Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany).
- Water: Free access to tap water.
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
Environmental controls for the animal room were set to maintain 18 to 24°C, a relative humidity of 40 to 70%, approximately 15 room air changes/hour, and a 12-hour light/12-hour dark cycle.

IN-LIFE DATES: From: 04 December 2011 - 20 January 2012

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

- Method of formulation: Formulations (w/w) were prepared daily within 6 hours prior to dosing and were homogenized to a visually acceptable level. Adjustment was made for density (1.2 g/mL) and purity (52.95 w/w%) of the test substance.
- Storage conditions of formulations: At room temperature in the dark under nitrogen
- Dose volume: 5 mL/kg body weight. Actual dose volumes were calculated according to the latest body weight.
Some animals were not dosed according to the latest body weight. For animals on Day 1 of lactation, the amount of test substance was maximally10% less than intended. For animals on Day 4 of lactation, the amount of test substance was maximally 34% more than intended. Given the incidental nature of this deviation, and since inlife data did not indicate an effect of this deviation, interpretation of the study results was considered to have been unaffected.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analyses were conducted on a single occasion during the treatment phase (22 December 2011), according to a validated method (Project 497219). Samples of formulations were analyzed for homogeneity (highest and lowest concentration) and accuracy of preparation (all concentrations). Stability in vehicle over 6 hours at room temperature under nitrogen was also determined (highest and lowest concentration). The accuracy of preparation was considered acceptable if the mean measured concentrations were 90-110% of the target concentration. Homogeneity was demonstrated if the coefficient of variation was ≤ 10%. Formulations were considered stable if the relative difference before and after storage was maximally 10%.

Duration of treatment / exposure:

Males were exposed for 29 days, i.e. 2 weeks prior to mating, during mating, and up to termination. Females were exposed for 40-47 days, i.e. during 2 weeks prior to mating, during mating, during post-coitum, and during at least 4 days of lactation. Females were not dosed during littering.

Frequency of treatment:

Once daily, 7 d/w

Remarks:

Doses / Concentrations:
0, 100, 300, 1000 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

10, plus an additional 5 males in Groups 1 and 4 (Recovery)

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Based on the results of the dose range finding study (Project 497221), and in consultation with the sponsor.
- Selection of animals for selected measurements: 5 animals/sex/group were randomly selected at allocation for functional observations, clinical pathology, macroscopic examination (full list), organ weights (full list) and histopathology. Only females with live offspring were selected.

Positive control:

Not required.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS:
- Time schedule: At least twice daily. Animals showing pain, distress or discomfort, which was considered not transient in nature or was likely to become more severe, were sacrificed for humane reasons based on OECD guidance document on humane endpoints (ENV/JM/MONO/ 2000/7). The
circumstance of any death was recorded in detail.

DETAILED CLINICAL OBSERVATIONS:
- Time schedule: At least once daily from start of treatment onwards, detailed clinical observations were made in all animals. Once prior to start of treatment and at weekly intervals during the treatment period this was also performed outside the home cage in a standard arena. Arena observations were not performed when the animals were mating, or housed individually. These clinical observations were at least conducted between 0 and 1 hour after dosing (i.e. based on the peak period of anticipated effects after dosing in the dose range finding study (Project 497221)). The time of onset, grade and duration of any observed sign was recorded. Signs were graded for severity.

BODY WEIGHT:
- Time schedule for examinations: Males and females were weighed on the first day of exposure and weekly thereafter. Mated females were weighed on Days 0, 4, 7, 11, 14, 17 and 20 post-coitum, and during lactation on Days 1 and 4.

FOOD CONSUMPTION:
- Weekly, for males and females. Food consumption was not recorded during the mating period. Food consumption of mated females was measured on Days 0, 4, 7, 11, 14, 17 and 20 post-coitum and on Days 1 and 4 of lactation.

FOOD EFFICIENCY: yes.

WATER CONSUMPTION : No.
Subjective appraisal was maintained during the study, but no quantitative investigation introduced as no effect was suspected.

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY:
- Time schedule for collection of blood: immediately prior to scheduled post mortem examination.
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes (with a maximum of 20 hours). Water was provided.
- How many animals: 5 animals/sex/group
- Parameters checked were: According to test guidelines

CLINICAL CHEMISTRY:
- Time schedule for collection of blood: immediately prior to scheduled post mortem examination.
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes (with a maximum of 20 hours). Water was provided.
- How many animals: 5 animals/sex/group
- Parameters checked were: According to test guidelines

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION:
- Time schedule for examinations: The selected males were tested during Week 4 of treatment and the selected females were tested during lactation (all before blood sampling).
- Dose groups that were examined: all
- Battery of functions tested: According to test guidelines
Motor activity of males at the end of the recovery period was not determined, although a (potentially) treatment-related effect was noted at the end of treatment. No clinical signs were noted to support the lower motor activity at the end of the treatment period, nor were any clinical signs noted at the end of the recovery period. The mean motor activity did not show a clear dose-related trend over the dose groups. This suggests that an effect (if any) on motor activity at the end of the recovery phase would have been small, and not have any significant impact on the overall conclusion of the study.

Sacrifice and pathology:

GROSS PATHOLOGY:
- All animals were fasted overnight (with a maximum of 20 hours) prior to planned necropsy, but water was provided. Animals surviving to scheduled necropsy and all moribund animals were deeply anaesthetised and subsequently exsanguinated.
- Selected 5 animals/sex/group and all animals that died spontaneously or were killed in extremis: According to test guidelines
- All remaining females which failed to deliver and the remaining males: According to test guidelines

ORGAN WEIGHTS
- Selected 5 animals/sex/group: According to test guidelines
- All remaining males: Epididymides and Testes

HISTOPATHOLOGY:
- According to test guidelines

Statistics:

The following statistical methods were used to analyse the data:
- If the variables could be assumed to follow a normal distribution, the Dunnett-test (Dunnett, 1955) (many-to-one t-test) based on a pooled variance estimate was applied for the comparison of the treated groups and the control groups for each sex.
- The Steel-test (Miller, 1981) (many-to-one rank test) was applied if the data could not be assumed to follow a normal distribution.
- The Fisher Exact-test (Fisher, 1950) was applied to frequency data.
- Motor activity data was subjected to the Kruskal-Wallis nonparametric ANOVA test to determine intergroup differences followed by the Wilcoxon test to compare the treated groups to the control group.

All tests were two-sided and in all cases p < 0.05 was accepted as the lowest level of significance. Group means were calculated for continuous data and medians were calculated for discrete data (scores) in the summary tables. No statistical analysis was performed on histopathology findings.

Clinical signs:

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):

no effects observed

Food efficiency:

no effects observed

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

no effects observed

Description (incidence and severity):

Based on subjective appraisal.

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

effects observed, treatment-related

Urinalysis findings:

not examined

Behaviour (functional findings):

effects observed, treatment-related

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

not examined

Details on results:

MORTALITY
Two males at 1000 mg/kg were sacrificed in extremis on Days 4 and 5 of the premating period, respectively. Three females at 1000 mg/kg were found dead on Days 20, 39 and 23 of treatment, respectively (i.e. Days 1, 22 and 5 of the post-coitum phase, respectively). One other female at 1000 mg/kg was found dead on Day 25 of treatment (i.e. Day 11 of the mating period). One female at 1000 mg/kg and one female at 100 mg/kg were sacrificed due to total litter loss. The incidence of total litter loss showed no relation to the dose, and the incidence was low. No toxicological relevance was ascribed to these occurrences.

CLINICAL SIGNS
Hunched posture was shown by all males and most females at 1000 mg/kg (except the two males sacrificed in extremis during the first week of treatment), generally from the first week of treatment onwards. Surviving males and females at 1000 mg/kg showed sporadic incidences of lethargy, breathing difficulties (rales and/or shallow respiration), piloerection and pale appearance. Reduced faeces production was noted for males at 1000 mg/kg during the last week of the mating period. For males, all these findings had resolved at commencement of/during the recovery phase. Clinical signs noted among the four females at 1000 mg/kg found dead included lethargy, flat/hunched posture, uncoordinated movements, ptosis, rales, piloerection, lean or pale appearance, abdominal swelling and/or ptosis. The incidence of these findings was not clearly related to the day of death. Two males at 1000 mg/kg were sacrificed in extremis during the first week of treatment based on their significantly deteriorated health condition (clinical signs were not recorded on the day of sacrifice). Salivation seen among all animals at 1000 mg/kg, and at lower incidence at 100 and 300 mg/kg, was considered to be a physiological response rather than a sign of systemic toxicity considering the nature and minor severity of the effect and its time of occurrence (i.e. after dosing). This sign may be related to irritancy/taste of the test substance. Incidental findings that were noted included rales, a dark left eye, alopecia, scabs, hypersensitivity to touch (single day for a single animal), and chromodacryorrhoea. These findings occurred within the
range of background findings to be expected for rats of this age and strain which are housed and treated under the conditions in this study. At the incidence observed, these were considered signs of no toxicological relevance.

FUNCTIONAL OBSERVATIONS
Motor activity (total movements and/or ambulations) was reduced for males at 100, 300 and 1000 mg/kg and for females at 100 and 300 mg/kg with statistical significance at the end of the treatment period, but no clear dose-related trend was apparent and control values were considered to be high (motor activity at the end of the recovery period for males was not determined). All groups showed a similar motor activity habituation profile with high activity in the first interval that decreased over the duration of the test period. Hearing ability, pupillary reflex, static righting reflex and grip strength were normal in all animals.

BODY WEIGHTS
No toxicologically relevant changes in body weights and body weight gain were noted. The slightly lower body weight gain of males at 1000 mg/kg at the end of the premating period did not prevail or became more pronounced as treatment progressed. This change was therefore considered to be of no toxicological significance. One male at 1000 mg/kg and one female at 100 mg/kg showed weight loss of up to 9% over Days 1-8 of the premating period. As these animals again gained weight during the mating period, and similar changes in body weight were absent among other animals of these dose groups, this was considered to be of no toxicological relevance.

FOOD CONSUMPTION
No toxicologically relevant changes in food consumption before or after correction for body weight were noted. Absolute food intake of males and food intake corrected for body weight for both sexes at 1000 mg/kg was lower during the first week of the premating period. Since this change did not prevail or became more pronounced as treatment progressed, it was considered to be of no toxicological significance.

HAEMATOLOGY
The following (statistically significant) changes in haematology parameters distinguished animals at 1000 mg/kg from control animals at the end of the treatment phase:
- Lower red blood cell counts in males and females,
- Higher red cell distribution width (RDW) in two males and one female at 1000 mg/kg
- Lower haemoglobin level in males and females,
- Lower haematocrit level in males and females.
At the end of the recovery phase, males at 1000 mg/kg showed lower red blood cell counts, haemoglobin and haematocrit levels, and a higher mean corpuscular volume (MCV).

CLINICAL BIOCHEMISTRY
The following (statistically significant) changes in clinical biochemistry parameters distinguished treated animals from control animals:
- Higher alkaline phosphatase activity (ALP) in two females at 1000 mg/kg (mean not statistically significant).
- Higher glucose levels in females at 1000 mg/kg (mean not statistically significant).
- Lower total protein levels in males at 300 and 1000 mg/kg,
- Lower total bilirubin levels in males at 100, 300 and 1000 mg/kg, and in females at 300 and 1000 mg/kg.
- Higher cholesterol level in females at 1000 mg/kg.
These findings had resolved during the recovery phase in males at 1000 mg/kg.
The lower bile acid level of males at 100, 300 and 1000 mg/kg was considered to be of no toxicological significance, since the opposite effect would be expected in case of target organ toxicity. This change in bile acid level, as well as the higher chloride level of males at 1000 mg/kg and the lower potassium levels in females at 300 mg/kg at the end of treatment showed no dose-related trend. The apparent higher glucose level of females at 1000 mg/kg was due to a high variation in individual values, the range of which was comparable to the variation encountered among control animals. No
toxicological relevance was therefore ascribed to these changes.

MACROSCOPIC EXAMINATION
The following macroscopic abnormalities at the end of the treatment period in surviving animals at 1000 mg/kg were considered to be directly related to treatment with the test substance:
- Thickened limiting ridge of the stomach in 2/5 females.
- Irregular surface of the stomach in 1/8 males, and irregular surface of the forestomach in 1/5 females,
- Reddish/dark red/black discolouration of the mesenteric lymph nodes in 1/8 males, and 3/5 females.
Findings in sacrificed animals (except for the female with total litter loss) or animals found dead at 1000 mg/kg considered to be directly related to treatment included:
- Dark red/black discolouration of the mesenteric lymph nodes in 3/4 females.
- Thickened limiting ridge of the stomach in 3/4 females.
- Irregular surface of the forestomach in 1/4 females,
- Dark red discolouration or dark red foci of the glandular mucosa of the stomach in 2/2 males.
- Dark red discolouration of the gastro-intestinal tract in 1/2 males.
No treatment-related macroscopic abnormalities were noted at the end of the recovery period in males at 1000 mg/kg. Only a background level of hemorrhage/congestion in the mesenteric lymph node was recorded in 1/4 surviving Recovery males at 1000 mg/kg (minimal). Dark red foci/reddish discolouration of the thymus noted in several surviving animals and intercurrent sacrifices/deaths was considered to be related to necropsy procedures (congestion), and the incidence of microscopic correlates did not indicate a relationship to treatment. Other findings among animals sacrificed in extremis or found dead consisted of a reduced size of the thymus and spleen, enlarged liver, an advanced stage of autolysis, incomplete exsanguination, dilation of the gastrointestinal tract and mucous contents of the gastro-intestinal tract. These were considered to be related to the necropsy procedures and/or to be secondary to the autolytic process. One female at 100 mg/kg and one female at 1000 mg/kg showed total litter loss. One female at 1000 mg/kg showed dead foetuses in the uterus (five in each horn). The incidence of other incidental findings among control and treated animals was within the background range of findings that are encountered among rats of this age and strain, did not show a dose-related incidence trend and/or had no treatment-related microscopic correlates. These necropsy findings were therefore considered to be of no toxicological relevance, and included red foci on the lungs, pelvic dilation of the kidneys, a yellowish or reddish soft or hard nodule on the epididymides, a tan focus on the preputial glands, irregular surface of the liver, a dark red hard nodule on the spleen, uterus containing fluid, tan discolouration of the clitoral glands, and alopecia.

ORGAN WEIGHTS
No toxicologically relevant changes in organ weights and organ to body weight ratios were noted. The (statistically significant) lower absolute thymus weights and thymus to body weight ratio and higher liver to body weight ratio in males at 1000 mg/kg at the end of the treatment phase were slight
in nature, had no morphological correlates, and these organ weights were similar to control levels at the end of the recovery period. The statistically significant lower absolute thyroid weight of males at 100 and 1000 mg/kg and lower thyroid to body weight ratio of males at 100 mg/kg occurred in the absence of a dose-related trend, and means remained within the range considered normal for rats of this age and strain. The higher thyroid weight, thyroid to body weight ratio, and seminal vesicle weight of males at 1000 mg/kg at the end of the recovery period was absent at the end of the treatment period, and the change was slight. No toxicological relevance was therefore ascribed to these variations.

MICROSCOPIC EXAMINATION
The following treatment-related findings were noted in surviving main study animals at 1000 mg/kg:
- Lymphogranulocytic inflammation of the forestomach in 3/4 males.
- Hyperkeratosis of the stomach in 1/4 males (minimal degree).
- Hyperplasia of the squamous epithelium of the forestomach in 1/4 males (minimal) and 2/4 females (minimal-slight).
- Increased incidence and severity of hemorrhage/congestion in the mesenteric lymph nodes of 4/4 males and 4/4 females.
No treatment-related histopathological findings were noted at the end of the Recovery phase. The major histologic findings for the animals found dead or sacrificed in extremis were present in the respiratory tract (trachea/lungs) and/or stomach, and primarily consisted of tracheal/bronchiolar necrosis with inflammation, ulceration/erosion/inflammation of the glandular stomach and subcapsular necrosis of the liver. The presence of lesions in the trachea/lungs suggests a local reaction to aspiration of test article and the possibility of refluxive inhalation or gavage procedure rather than
systemic toxicity. Stomach lesions (most pronounced in animal nos. 40, 48, and 84) were considered to be test substance related. Findings of atrophy and increased apoptosis in the thymus and lymphoid depletion in the spleen of early death animals were considered secondary to stress. Reticuloendothelial hyperplasia in the spleen and histiocytic infiltrates in the mesenteric lymph nodes were possibly treatment related.
Reproductive performance:
No test article related abnormalities were seen in the reproductive organs. Staging of spermatogenesis in testes did not provide any evidence of test article related impairment to the spermatogenetic cycle. Other microscopic findings recorded were considered to be within the normal range of background pathology encountered in Wistar Han rats of this age and strain.

Dose descriptor:

NOAEL

Remarks:

Parental -local effects

Effect level:

300 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Dose descriptor:

NOAEL

Remarks:

parental - systemic effects

Effect level:

300 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: An increased incidence and severity of hemorrhage/congestion was noted in the mesenteric lymph nodes of all surviving selected females at 1000 mg/kg.

Critical effects observed:

not specified

The concentrations analysed in the formulations of Group 2, Group 3 and Group 4 were in agreement with target concentrations (i.e. mean accuracies between 90% and 110%). No test substance was detected in the Group 1 formulation. The formulations of Group 2 and Group 4 were homogeneous (i.e. coefficient of variation ≤ 10%). Formulations at the entire range were stable when stored under nitrogen at room temperature under normal laboratory light conditions for at least 6 hours.

Conclusions:

In an OECD 422 study, oral treatment with Sodium alkylnaphthalene sulfonate resulted in deaths at 1000 mg/kg which were attributed to tracheal/pulmonary lesions associated with aspiration of test article (possibly due to the gavage procedure) and/or acute inflammation/ulceration in the stomach. The primary effects at 1000 mg/kg resulting from treatment in surviving animals and early deaths/sacrifices were confined to local effects in the stomach (being most pronounced in those animals sacrificed of found dead during the study), and an increased incidence and/or severity of hemorrhage in the mesenteric lymph nodes. Based on these results, the following No Observed Adverse Effect Levels (NOAEL) were derived:
Parental NOAEL: 300 mg/kg/day (local and systemic)
Reproduction NOAEL: at least 1000 mg/kg/day
Developmental NOAEL: at least 1000 mg/kg/day

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

300 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The requirement for a study is waived due to the availability of Klimisch 2 Ninety day oral study and the lack of potential for inhalation exposure to the product. The oral NOAEL will not be used in calculating the DNEL as the data from the OECD Combined Repeat 422 is more conservative and is rated a Klimisch 1.

System:

gastrointestinal tract

Organ:

mesenteric lymph node

stomach

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

Inhalation is not expected to be a significant route of exposure. It has a low vapour pressure (0.0015 Pa at 20°C) and it is not expected that any fine aerosols would be generated in it’s handling and use.
The substance shows (severe) irritating effects on skin (especially following repeated exposures leading necrosis) and classified for eye damage cat.1. In view of the low systemic toxicity following oral exposures, it can be expected that exposures via inhalation will be characterised by local effects. Testing for acute systemic toxicity via inhalation is therefore not indicated.

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

The substance shows (severe) irritating effects on skin (especially following repeated exposures leading necrosis) and classified for eye damage cat.1. In view of the low systemic toxicity following oral exposures, it can be expected that exposures via inhalation will be characterised by local effects. Testing for acute systemic toxicity via inhalation is therefore not indicated.

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

Dermal exposure is not expected to be a significant route of exposure. Furthermore, although the substance is classified as irritant, repeated exposures of even 5% have shown to lead to superficial necrosis following repeated dosing in the Buehler study. Consequently, it is not scientifically justified to carry out a dermal study.

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Quality of whole database:

Dermal exposure is not expected to be a significant route of exposure. Furthermore, although the substance is classified as irritant, repeated exposures of even 5% have shown to lead to superficial necrosis following repeated dosing in the Buehler study. Consequently, it is not scientifically justified to carry out a dermal study.

Mode of Action Analysis / Human Relevance Framework

Based on its surfactant properties, the structure is not expected to easily pass membrane structures, but cytotoxicity through disruption of cell membrane is expected. This is supported by study results: All available data indicates that the NOAEL is driven by local effects of the substance on skin and gastro-intestinal tract.

Additional information

A Combined 28-day repeated dose toxicity study with the reproduction/developmental toxicity screening test was performed with Sodium alkylnaphthalene sulfonate in 10 Wistar Han rats/dose/sex by oral gavage, followed by a 14-day recovery period for control and high dosed males applying 5 animals/dose. The dose levels selected were 0, 100, 300 and 1000 mg/kgbw/day. Duration of dosing was for males 29 days and females 40-47 days.

Mortality only occurred in the high dose group of 1000 mg/kg (2/15 males and 4/10 females) which were attributed to tracheal/pulmonary lesions associated with aspiration of test article (possibly due to the gavage procedure) and/or acute inflammation/ulceration in the stomach.

Clinical signs among surviving animals at 1000 mg/kg primarily consisted of hunched posture, generally from the first week of treatment onwards. At lower incidence, lethargy, breathing difficulties, piloerection and pale appearance were noted. Reduced faeces production was noted for males at 1000 mg/kg during the last week of the mating period, but no toxicologically significant changes in body weight and food intake were noted throughout treatment in males (and females) to support this finding. During the recovery phase of males, these signs had resolved. There were no significant clinical findings observed in the other dose groups.

No toxicological relevant effects were observed in functional observations, locomotor activity, body weights, food consumption, haematology, biochemistry, organ weights and reproduction/ developmental parameters.

In surviving animals, macroscopic and microscopic abnormalities were observed in the 1000 mg/kg group that were considered to be related to treatment in stomach (thickened limiting ridge in 2/5 females and irregular surface in 1/8 males and 1/5 females) and mesenteric lymph nodes (haemorrhagic appearance in 1/8 males and 3/5 females). Such effects were also observed in the animals found dead or sacrificed, but not in animals at the end of the recovery period.

The study resulted in the following NOAELs:

- Parental NOAEL: 300 mg/kg/day

- Reproduction NOAEL: at least 1000 mg/kg/day

- Developmental NOAEL: at least 1000 mg/kg/day

There is also a 90 -day repeated dose dog oral toxicity study performed in 1966 available. The study is rated as a Klimisch 2 due to being pre-GLP, and there are some deviations from OECD guidelines.

The study was designed to investigate the systemic toxicity of the test item and complies the recommendations of the OECD Guidelines for Testing of Chemicals No. 409.The test substance was administered daily (1 h/day, 6 days/week) for 90 days via the diet to Beagle dogs. One control group and three treated groups were tested, each consisting of 3 males and 3 females. Dose levels were 0, 500, 1600, and 5000 ppm (corresponding approximately with 8 (males) and 9 (females), 29 (males) and 35 (females) and 90 (males) and 104 (females) mg/kg bw/day) The following parameters were evaluated: clinical signs (daily); body weight (biweekly) and food consumption; haematology, clinical chemistry, and urinalysis (2 times prior to start and in week 6 and 12); pathology and macroscopy at termination; organ weights and histopathology on a selection of tissues. Diet analyses to confirm dietary levels were not carried out.

Treatment up to 5000 ppm (corresponding to 90 mg/kg bw/day in males and 104 mg/kg bw/day in females) was well tolerated; no treatment-related changes were noted in clinical appearance, body weight gain, food consumption, haematology, clinical chemistry, urinalysis, and organ weights. Scattered, non-significant pathological changes were observed at necropsy, controls included. These findings were not considered to be dose-related.

Because no treatment-related alterations or abnormalities were seen at the high dose of 90 mg/kg bw/day in males and 104 mg/kg bw/day in females, the No Observed Adverse Effect Level (NOAEL) of the test item was considered to be equal to or higher than 90 mg/kg bw/day in males and 104 mg/kg bw/day in females.

This study is considered adequate to fulfill the requirement for a 90 day endpoint. The key study to support the oral DNEL will be the more current study utilizing protocol OECD 422.

Justification for classification or non-classification

The available OECD 422 Combined 28-day repeated dose toxicity study with reproduction/developmental toxicity screening test with Sodium alkylnaphthalene sulfonate involved dosing by gavage of dose levels of 0, 100, 300 and 1000 mg/kgbw/day for 29 days in males and up to 40-47 days in females. As no significant toxicity was observed at dose levels at levels at 300 mg/kg bw/day or below, classification for STOT-RE is not required.