Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Description of key information

Oral NOAEL (Rat): >1000 mg/Kg bw/day, based on weight of evidence from read across studies on structural analogues.

 

Inhalation NOAEC (Rat): > 1160 mg/m3, based on weight of evidence from read across studies on structural analogues.

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:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
1991
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report equivalent or similar to OECD guideline 408: GLP
Justification for type of information:
A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.
Reason / purpose for cross-reference:
read-across: supporting information
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)
Principles of method if other than guideline:
According to EPA guideline 82-1
GLP compliance:
yes
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Harlan Sprague Dawley Inc.
- Age at study initiation: ca. 8 weeks
- Weight at study initiation: 238-295g (males); 180-236g (females)
- Housing: individual
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum):ad libitum
- Acclimation period: 16 days


ENVIRONMENTAL CONDITIONS
- Temperature (°F): 68-76
- Humidity (%): 40-70
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 1990-12-17 To:1991-07-13
Route of administration:
oral: gavage
Vehicle:
corn oil
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:
Test material was mixed with corn oil to ensure a 10ml/kg dose volume at all dose levels.

Test material mixtures were administered by oral gavage at a dose volume of 10ml/kg. The control animals received carrier at a dose of 10ml/kg. The satellite group was dosed at the high dose level for the same duration as main test and allowed to recover for 28 days post-treatment.

VEHICLE
- Amount of vehicle (if gavage): 10ml/kg

Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
13 weeks
Frequency of treatment:
7 days/week
Remarks:
Doses / Concentrations:
5000 mg/kg
Basis:
actual ingested
Remarks:
Doses / Concentrations:
2500 mg/kg
Basis:
actual ingested
Remarks:
Doses / Concentrations:
500 mg/kg
Basis:
actual ingested
No. of animals per sex per dose:
10 animals/sex/dose
Control animals:
yes, concurrent vehicle
Details on study design:
Test material mixtures were administered by oral gavage at three different doses at a dose volume of 10ml/kg. The control animals received carrier at a dose of 10ml/kg. The satellite group was dosed at the high dose level for the same duration as the main test and allowed to recover for 28 days post-treatment.

- Post-exposure recovery period in satellite groups: 28 days post-treatment
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily monday-friday and once daily on weekends and holidays

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: prior to dosing, the day of dose initiation, and weekly thereafter

OPHTHALMOSCOPIC EXAMINATION: Yes
at study initiation and during the final week of the main study

HAEMATOLOGY: Yes
- Time schedule for collection of blood: at main study termination and on satellite animals on the day of recovery sacrifice
- Anaesthetic used for blood collection: No
- Animals fasted: Yes
- How many animals:all

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at main study termination and on satellite animals on the day of recovery sacrifice
- Animals fasted: Yes
- How many animals: all

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Statistics:
The following parameters were statistically analyzed for significant differences: mean hematology parameters, serum chemistry parameters, organ weights, organ to body weight ratios, body weights, mean food consumption. Comparisons were limited to within sex analysis. Statistical evaluation of equality of means was done by an appropriate one way analysis of variance and a test of ordered response in the dose groups. First, Bartlett’s test was performed to determine if the dose groups have equal variance. If the variances were equal, the testing was done using parametric methods, otherwise nonparametric techniques were used.

For the parametric procedures, a standard one way ANOVA using the F distribution to assess significance was used. If significant differences among the means were indicated, Dunnett’s test was used to determine which treatment groups differ significantly from control. In addition to ANOVA, a standard regression analysis for liner response in the dose groups and linear lack of fit were preformed.

For the nonparametric procedure the test of equality of means was performed using the Kruskal-Wallis test. If significant differences among the means was indicated, Dunn’s Summed Rank test was used to determine which treatment group differ significantly from control. In addition, Jonckheere’s test for monotonic trend in the dose response was performed.

The statistical t-test was used to compare the satellite group’s main study termination and recovery termination hematology and clinical chemistry values. In addition, the t-test was used to compare the satellite group's and the control group's relative organ weights. The t-test was also used to compare the high dose and satellite groups to ensure similar results in order to accurately evaluate the recovery effects.
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS AND MORTALITY
One male and 1 female died in the control group, 2 females died in the 2500 mg/kg dose group, 4 females died in the 5000 mg/kg dose group, 2 males and 3 females died in the satellite group. With the exception of one 2500 mg/kg female, all of the other 13 listed spontaneous deaths appear to be a result of dosing trauma and/or aspiration of test material (due to physical characteristics of test material and the high dosage volume).

The majority of animals in the control, low and mid dose groups displayed no observable abnormal clinical signs. Observations included but are not limited to scabs, maloccluded incisors, alopecia and staining of fur, dry/wet rales, dyspnea, nasal discharge. The type and incidence of abnormal clinical signs were similar between the high dose and satellite groups with a dramatic increase in incidence when compared to mid dose group. Clinical signs most frequently noted included swollen anus, ano-genital staining, emaciation, and alopecia. During the satellite recovery period, the incidence of abnormal signs decreased over time with an increase in the number of animals exhibiting no observable abnormalities.

BODY WEIGHT AND WEIGHT GAIN
Statistically significant decreases from controls at the p<=0.05 level of significance were noted for mid dose males on days 77, 84, 91 and termination and for the high dose males on Day 42. A statistically significant decrease (p<=0.01) was noted for the high dose group males on Day 49 and continued through the end of the treatment period. Statistically significant decreases were noted for mid dose females (p<=0.05) on day 91 and for high dose females on days 77 and 91. At termination both mid and high dose females displayed a statistically significant decrease in body weight.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
Statistically significant increases in food consumption which were linearly related to dose were noted for males on Days 28 through 56 and Day 70 through termination. Significance levels were noted for both the mid and high dose males during these periods. These trends were also evident in the females where statistically significant increases in food consumption were noted on Days 21, 42, 49, and 63 through 95.

OPHTHALMOSCOPIC EXAMINATION
No treatment-related findings.

HAEMATOLOGY
A statistically significant increase in platelets which was linearly related to dose in both the males and females was observed. In addition the male animals displayed a linear dose related increase in white blood cells. The mid dose male values were noted to differ significantly from those of controls for hematocrit and hemoglobin at the p<=0.01 level of significance and mean corpuscular volume and mean corpuscular hemoglobin at the p<=0.05 level of significance.

CLINICAL CHEMISTRY
Statistically significant increases in males (p<=0.01) for urea nitrogen and gamma glutamyl transpeptidase for the high dose males and also the mid dose males for urea nitrogen. An increase for cholesterol was noted for the mid and high dose groups of both sexes (p<=0.01). An increase in alanine aminotransferase was also noted for the mid and high dose males (p<=0.01). Glucose levels were significantly lower than the control values (p<=0.01) for both sexes in the mid and high dose and for the male low dose (P<=0.05). A statistically significant increase in bilirubin in the high dose of both sexes was observed. Other parameters showing statistically significant differences from controls included creatinine, chloride, tryglycerides.

ORGAN WEIGHTS
Liver weights were elevated in male and female rats at 2500 and 5000 mg/kg/day. Adrenal weights were significantly increased in male and female rats at 5000 mg/kg and in female rats at 2500 and 5000 mg/kg. Testes weights were elevated in male rats at 5000 mg/kg. Both the male and female relative kidney weights for all treated groups were significantly different from the control value (p<=0.01).

GROSS PATHOLOGY
Most frequently observed abnormalities include small and large intestine distension (mid and high dose groups); swollen anus (high dose groups), staining of the fur (mid and high dose groups).
Key result
Dose descriptor:
NOAEL
Effect level:
>= 5 000 mg/kg bw/day (nominal)
Sex:
male/female
Basis for effect level:
other: No treatment-related mortality or significant adverse clinical effects occurred.
Critical effects observed:
not specified
Conclusions:
The No Observed Adverse Effect Level (NOAEL) for following oral exposure to MRD-89-582 for 90-days is greater than or equal to 5000 mg/kg/day.
Executive summary:

MRD-89-582 was administered by oral gavage to rats at concentrations of 500, 2500 and 5000 mg/kg, 7 days a week for 13 weeks to assess the subchronic toxicity.  An additional group of animals, dosed at 5000 mg/kg/day, was held for 4 weeks to assess reversibility.  No treatment-related mortality was observed; however, male body weights were decreased while food consumption increased in the 2500 and 5000 mg/kg dose groups.  Liver weights were elevated in male and female rats at 2500 and 5000 mg/kg/day.  Adrenal weights were significantly increased in male and female rats at 5000 mg/kg and in female rats at 2500 and 5000 mg/kg.  Testes weights were elevated in male rats at 5000 mg/kg.  Kidney effects occurred in males at all dose levels, and are indicative of alpha-2u-globulin nephropathy.  Alpha-2u-globulin nephropathy, also known as hyaline droplet nephropathy, results from the formation of complexes with a naturally occurring protein (alpha-2u-globulin) in the kidneys of male rats.  These complexes can accumulate in the proximal renal tubule and may produce species-specific histopathological changes.  These kidney effects are specific to male rats and are not considered to be of biological relevance to humans.

Dose-related changes in hematology or serum chemistry parameters were observed and were consistent with the changes seen in the liver.  Histological findings of hepatocellular hypertrophy (liver cell enlargement) were seen in livers of both sexes in all dose groups.  These findings are believed to have been a compensatory response and not an indication of toxicity.  Additionally, these liver effects were reversible and occurred only at high doses that are not typical of hydrocarbon exposures for humans.  Other treatment-related effects were mucosal thickening and other signs of irritation of the stomach and anus which appear to be the direct result of high dose intubation of a the locally irritating test substance.  These effects are believed to have been a compensatory response to local irritation and not an indication of toxicity.  All treatment-related effects were reversible within the 4-week recovery period.  Based on the results, the No Observed Adverse Effect Level (NOAEL) for the 90-day study was greater than 5000 mg/kg/day.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
5 000 mg/kg bw/day
Study duration:
subchronic
Species:
rat
Quality of whole database:
One of four available read across studies.

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Referenceopen allclose all

Endpoint:
sub-chronic toxicity: inhalation
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report equivalent or similar to OECD guideline 413.
Justification for type of information:
A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.
Reason / purpose for cross-reference:
read-across: supporting information
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)
GLP compliance:
yes
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Central Institute for the breeding of laboratory animals TNO, Zeist Netherlands
- Weight at study initiation: 35-50g
- Housing: individually
- Diet (e.g. ad libitum): ad libitum, removed during exposure
- Water (e.g. ad libitum): ad libitum, removed during exposure
- Acclimation period:1 week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.0-20
- Humidity (%): 40-60

IN-LIFE DATES: From: 13 January 1982 To: 16 April 1982
Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
other: unchanged (no vehicle)
Details on inhalation exposure:
The test atmospheres are obtained as follows: filtered and dried air from the compressed—air line was passed through a glass evaporator, filled with isododecane. To obtain the desired isododecane concentration in the test atmosphere the airflow laden with isododecane was mixed in the proper ratio with the main airflow passed through the exposure chambers.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The analysis of test atmospheres to monitor the isododecane concentration was carried out by gas chromatography. Samples were taken automatically at regular intervals by means of a timer controlled 7-port gas-sampling valve. The sample loop was calibrated by comparing the area of the isododecane peak obtained from a loop sample with the area of the isododecane peak obtained from a sample taken simultaneously with a gas— tight syringe. The detector response to isododecane was calibrated by injecting known amounts of a standard solution of isododecane in diethylether.

The actual overall mean concentrations of isododecane in the various test atmospheres were 12.5, 50.2, 99.9 and 201.1 ppm.
Duration of treatment / exposure:
6h/day
Frequency of treatment:
5 days/week for 13 weeks
Remarks:
Doses / Concentrations:
0, 12.5, 50, 100 and 200ppm
Basis:
nominal conc.
No. of animals per sex per dose:
20 males and 20 females/dose group
Control animals:
yes
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations:just before the start of the first exposure and once every week thereafter

OPHTHALMOSCOPIC EXAMINATION:No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: weeks 6 and 12
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: 10 animals/sex/dose

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: weeks 6 and 12.
- Animals fasted: Yes
- How many animals:10 rats/sex/group


URINALYSIS: Yes
- Time schedule for collection of urine: weeks 6 and 12
- Animals fasted: Yes
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes (see table) / No / No data

The following organs were weighed:
adrenals lungs with trachea and larynx
brain pituitary
heart spleen
kidneys testes/ovaries
liver thymus
thyroid (with parathyroid)

Samples of the organs weighed and of the following tissues and organs were preserved in a neutral aqueous phosphate—buffered 4% formaldehyde solution.

Aorta, pancreas, axillary lymph nodes, parotid salivary glands, caecum, prostate coagulating glands, sciatic nerve, colon, seminal vesicles, duodenum, skeletal muscle (thigh), epididymides, skin (flank), spinal cord, eyes, sternum (with bone marrow), ileum, stomach, jejunum, submaxillary salivary glands, mesenteric lymph nodes, sublingual salivary glands, nose (sections at 4 levels), urinary bladder, oesophagus, uterus (with cervix), all gross lesions

The lungs were fixed (after weighing) by intratracheal infusion of the fixative under 10 cm water pressure.
The kidneys of all rats were embedded in paraffin wax, sectioned at 5 um, stained with haematoxylin and eosin, and examined by light microscopy.
Statistics:
Statistical analyses of body weights and organ to-body weight ratios were carried out using analysis of co-variance followed by the Dunnetts Test, whereas the haematological and biochemical data were evaluated by means of the Mann/Whitney U-test. For statistical analysis of the histopathological data, chi-square analysis was used.
Clinical signs:
no effects observed
Mortality:
no mortality observed
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
Ophthalmological findings:
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
no effects observed
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS AND MORTALITY
Health and behaviour of the rats of the test groups were not visibly affected by exposure to the test material. No mortality observed in this study

BODY WEIGHT AND WEIGHT GAIN
The animals, both males and females, of all test groups gained weight at a rate similar to that of the controls.

HAEMATOLOGY
Mean haematologic values include values obtained from rats in week 6 and 13. A few statistically significant differences occurred between test animals and controls. All values were increased with respect to the corresponding items of the control group. The differences occurred haphazardly among the exposure groups. Moreover, all values were within the range of “biological variability’, or expected values for rats of this strain and age, and there never was a clear dose-response relationship for any of the criteria concerned. Therefore, these findings are considered to be of no toxicological significance.

CLINICAL CHEMISTRY
Statistically significant differences between test animals and controls were found in parameters determined in week 7 and 13, most of them in week 13. However, some were increased and other decreased; they occurred randomly among the test groups; all were within the normal range found in rats of this strain and age, and moreover, in all cases there was no indication of a dose-response relationship for any of the criteria concerned. Therefore, no toxicological significance is attached to these findings.

URINALYSIS
No exposure-related alterations were observed for any of the parameters in any of the groups exposed to 12.5, 50, 100 or 200 ppm isododecane. The few statistically significant differences in specific gravity and in volume between males exposed to 50 or 200 ppm and control males in week 13, could not be correlated with the exposure levels and were within the range of normal values for rats of this strain and age.


ORGAN WEIGHTS
Absolute brain weight and lung-to-body weight ratios of males of the 100 ppm groups were statistically significantly different from those of the controls. Because these effects were observed in one of the intermediate dose groups only and because the differences were only marginal, no toxicological significance is attached to these findings.

GROSS PATHOLOGY
Macroscopical examination at autopsy did not reveal any gross lesions that could be attributed to the treatment. All lesions observed were either about equally distributed among the various groups or they occurred in one animal or in a few animals only.


HISTOPATHOLOGY: NON-NEOPLASTIC
Microscopical examination of the kidneys revealed a dose-related increase in incidence of tubular nephrosis. These lesions were characterized by a loss of cytoplasmatic eosinophilia and striation, a loss of the brush border, and an increased cellular and nuclear size of epithelium of mainly the proximal tubules. These changes were occasionally accompanied by very small to small aggregates of mononuclear inflammatory cells.

In males, statistical analysis of the data, comparing the various treatment groups with controls revealed a significant increase of the number of animals showing tubular nephrosis at the 50, 100 and 200 ppm exposure levels. In line with these findings a slight increase was found in the incidence of inflammatory cell infiltrates. Other changes observed in the kidneys, such as hydronephrosis and calcareous deposits occurred in one or two animals only, without any apparent relation to the treatment.
Dose descriptor:
NOAEL
Effect level:
>= 200 ppm (nominal)
Basis for effect level:
other: NOAEL >= 1160 mg/m^3, No treatment-related mortality or significant adverse clinical effects occurred.
Critical effects observed:
not specified
Conclusions:
The NOAEL for isododecane is greater than or equal to 200 ppm (≥1160 mg/m3, nominal, vapor) under the test conditions of this study.
Executive summary:

Five groups of rats, consisting of 20 males and 20 females each, were exposed to atmospheres containing 0, 12.5, 50, 100 and 200 ppm isododecane vapor for 6 hours a day, 5 days a week, for a period of 13 weeks. No treatment-related effects on mortality were observed and there were no significant alterations in hematological, blood chemical or urinary values, or in organ weights, which could be unequivocally attributed to treatment.  An increased incidence of minimal to slight tubular nephrosis was found in the kidneys of males at levels of 50 ppm and above.  These lesions were characterized by a loss of cytoplasmic eosinophilia and striation, a loss of brush border, and an increase in cellular and nuclear size of epithelium of mainly the proximal tubules.  The kidney effects observed in male rats are indicative of alpha-2u-globulin nephropathy.  Alpha-2u-globulin nephropathy, also known as hyaline droplet nephropathy, results from the formation of complexes with a naturally occurring protein (alpha-2u-globulin) in the kidneys of male rats.  These complexes can accumulate in the proximal renal tubule and may produce species-specific histopathological changes.  These kidney effects are specific to male rats and are not considered to be of biological relevance to humans.  Based on these results, the No Observed Adverse Effect Level (NOAEL) was greater than or equal to 200ppm (1160 mg/m3).

Endpoint:
sub-chronic toxicity: inhalation
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
1980
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Acceptable, well-documented study report equivalent or similar to OECD guideline 413.
Justification for type of information:
A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.
Reason / purpose for cross-reference:
read-across: supporting information
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)
GLP compliance:
not specified
Species:
rat
Strain:
other: albino
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Shell Toxicology Laboratory Breding Unit
- Age at study initiation: 10-13 weeks
- Housing: three of one sex per cage
- Diet (e.g. ad libitum): ad libitum except during exposure
- Water (e.g. ad libitum): ad libitum

During the period of the test the laboratory temperature varied between 19.4°C and 26.1°C and the relative humidity between 37% and 74%.
Barometric pressure was within the range 753 to 768 mm Hg


Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
other: no data
Details on inhalation exposure:
The atmospheres were generated by completely evaporating the solvent into the streams of ventilating air entering the chambers using micrometering pumps and vaporizers. The vaporizers consisted of electrically heated quartz tubes whose surface temperatures were adjusted during preliminary experiments to the minimal for complete evaporation of the solvent.

Each chamber was constructed of aluminum, with a volume of 1 m3 and was ventilated by air drawn from the laboratory through dust filters. The exhaust ducts from each chamber entered a common exhaust duct through which the air was drawn by a fan situated on the roof of the laboratory.

The total air flow rate through the main duct exhausting all four chambers was recorded continuously throughout the test by means of an electro—anemometer mounted in the duct. Slight adjustments were made as required to compensate for the effects of wind at the efflux point. The total flow rate was maintained at 2.0 + 0.03 m3 ∙min- 1. The individual flow rates through each chamber were balanced before the exposures began but were not checked further throughout the test since any significant changes would have been detected by the resulting changes in toxicant concentration. The flow rates were adjusted to 0.50 m3 ∙min- 1.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The test atmospheres were analyzed sequentially by means of a total hydrocarbon analyzer fitted with a flame-ionisation detector (Beckman 109A). The analyzer was calibrated during the test by means of known concentrations of SHELLSOL TD, prepared in a Teflon FEP gas sampling bag.

The recorder traces from the analyser were examined daily and a ‘daily mean concentration’ value was estimated by visual inspection. The daily mean concentrations for each of the test atmospheres were then ‘pooled’ to give weekly mean concentrations. The overall means of the weekly mean concentrations are given below:
Nominal concentration Observed concentration
(mg/m3) (mg/m3) (ppm)
10400* 10186 SD 327 1444
5200 5200 SD 207 737
2600 2529 SD 116 359
*83% saturated.

The desired concentrations of solvent in the test atmospheres were reached within 10 mm of the start of each exposure period. They then stayed remarkably constant throughout the 6 h exposure period.
Duration of treatment / exposure:
Six hours/day
Frequency of treatment:
five days/week for 13 weeks
Remarks:
Doses / Concentrations:
0, 2600, 5200, 10400 mg/m3
Basis:
nominal conc.
No. of animals per sex per dose:
6 animals/sex/dose (total of 12 animals/dose)
Control animals:
yes, sham-exposed
Details on study design:
The start and finish of the experiment was staggered in order that the optimum number of animals could be examined histopathologically after exposure. On each of four consecutive days, four male and four female rats per chamber were started on the experiment. The remaining two males and two females were started the next day. Thirteen weeks later, four male and four female rats per chamber were removed from the experiment for pathological examination on each of four consecutive days. The remaining two males and two females were removed the next day.
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule for examinations: daily

DETAILED CLINICAL OBSERVATIONS: Yes


BODY WEIGHT: Yes
- Time schedule for examinations: weekly


FOOD CONSUMPTION:
- Food consumption for each animal determined weekly: Yes


FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: Yes / No / No data


WATER CONSUMPTION: Yes
- Time schedule for examinations: weekly


OPHTHALMOSCOPIC EXAMINATION: No



HAEMATOLOGY: Yes
- Time schedule for collection of blood: 18h after the last 13 week exposure
- How many animals: all


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: 18h after the last 13 week exposure
- How many animals: all



URINALYSIS: Yes / No / No data
- Time schedule for collection of urine:
- Metabolism cages used for collection of urine: Yes / No / No data
- Animals fasted: Yes / No / No data
- Parameters checked in table [No.?] were examined.


NEUROBEHAVIOURAL EXAMINATION: No



OTHER:
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes for all animals exposed to the high and medium concentrations, plus the control animals. Kidneys of low concentration males were also examined.
Other examinations:
Organ weights
After post-mortem examinations the following organs were weighed:
Brain
Liver
Heart
Spleen
Kidneys
Testes

Histopatholgy. Tissues taken for histological examination were:

Mammary gland (posterior site with skin)
Mesenteric lymph node
Pancreas
Stomach
Intestine at 5 levels
Caecum
Spleen
Liver (middle, left and triangular lobes)
Adrenals
Kidneys
Ovaries or testes
Uterus or prostate
Seminal vesicles
Urinary bladder
Thyroid (with oesophagus and trachea)
Trachea (mid course and bifurcation)
Heart
Lungs
Nasal cavity
Thymus
Eye and lacrimal glands
Salivary gland (submaxillary)
Brain
Spinal cord (thoracic)
Pituitary
Tongue
Sciatic nerves
Muscle (femoral)
Knee joint and femur
Plus any other macroscopic lesion in any tissues.
The samples marked were held in 4% neutral formalin and only processed for histological examination if indicated by clinical or other pathological findings.
Statistics:
Body and organ weights were analysed by covariance analysis using initial body weight as the covariate. Reported means were adjusted for initial body weight if a significant covariance relationship existed: where no significant covariance relationship was found, unadjusted means were reported.

Organ weights were further examined by covariance analysis using the terminal body weight as the covariate. The organ weight means are reported as adjusted for terminal body weight if a significant covariance relationship existed. Although not a true covariance analysis (because the terminal body weights are dependent upon treatment), the analysis does provide an aid to the interpretation of organ weights when there are differences in terminal body weights. The analysis attempts to predict what the organ weights would have been, had all the animals had the same terminal body weight.
Clinical, chemical and haematological parameters were examined using analysis of variance.

The analysis allowed for the fact that animals were multihoused. Differences in response can be affected by cage environment as well as by treatment but this effect is minimal in a study of this duration.
The significance of any difference between treated and control group means was tested using the Williams t test (1971, 1972). However, if a monotonic dose response could not be assumed Dunnett’s test (1964) was used.
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
no effects observed
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
No deaths were recorded and clinical signs of toxicity were absent in the low and medium exposure groups; the high exposure groups were slightly lethargic when examined up to one hour after cessation of exposure. Body weight gain was slightly reduced in all female groups and in high exposure males. Water intake was increased in the high exposure males only.

Female aspartate amino transferase and alanine amino transferase were decreased in all female groups exposed to SHELLSOL-TD. No pathological changes were detected which could explain the observed decreases in these enzymes. In view of this lack of supporting evidence and the fact that the control values for these two parameters were high when compared with historical controls in the laboratory, these changes were not considered toxicologically significant.

Male alkaline phosphatase, potassium, chloride and albumin were increased at the high exposure level. These were considered to represent biological variation in the rat and were not considered treatment-related.

Male kidney weights were increased at all exposure levels. Hyaline intracytoplasmic inclusions and an increased incidence of tubular degeneration and/or dilatation were seen in the cortical tubules of all exposed males. These are a common effect observed in repeated-dose animal studies with hydrocarbon solvents. These kidney changes have been identified to result from an alpha2u-globulin-mediated process that because of its sex and species specificity, is not regarded as relevant to humans.

A low grade anemia was evident in all males exposed to SHELLSOL TD, characterized by slight reductions in haemoglobin, packed cell volume and total erythrocyte counts. Splenic weight was increased in the high concentration males. These changes were not seen in females and were not considered dose-related and therefore considered not toxicologically relevant.

Male and female liver weights were increased at the high and medium exposures, and male liver weights at the low exposures also. No lesions were identified histologically in the livers of treated animals that could account for the increased weight. This change was considered a physiological response to exposure rather than a toxic response and as such is not of toxicological significance.
Dose descriptor:
NOAEC
Effect level:
> 10 400 mg/m³ air (nominal)
Sex:
male/female
Basis for effect level:
other: No treatment-related mortality or significant adverse clinical effects occurred.
Critical effects observed:
not specified
Conclusions:
The NOAEC for SHELLSOL TD is 10186 mg/m3 (actual) (1444 ppm) under the test conditions of this study.
Executive summary:

SHELLSOL TD was administered by inhalation to albino rats for 6 hours/day, 5 days/week for 13 weeks at nominal vapor concentrations of 10400 mg/m3, 5200 mg/m3, and 2600 mg/m3 to assess inhalation toxicity.  No mortality or treatment-related effects in any of the hematology and serum chemistry values were observed.  Liver and kidney weights were increased in male rats at all exposure levels, male heart weights were increased at the highest exposure level and liver and kidney weights were increased in female rats at 10400 mg/m3.  In addition, the male rats exposed to SHELLSOL TD at all concentrations showed tubular degeneration and hyaline inclusion-droplets in the epithelium.  There was also scattered degeneration of the proximal renal tubules which showed cytoplasmic pallor and shrinkage. Occasionally the degenerate tubules were surrounded by a lymphocyte infiltrate. Many tubules also showed dilatation of the cortico-medullary junction, the dilated tubule being filled with a flocculent eosinophilic material. The kidney effects observed in male rats are indicative of alpha-2u-globulin nephropathy.  Alpha-2u-globulin nephropathy, also known as hyaline droplet nephropathy, results from the formation of complexes with a naturally occurring protein (alpha-2u-globulin) in the kidneys of male rats.  These complexes can accumulate in the proximal renal tubule and may produce species-specific histopathological changes.  These kidney effects are specific to male rats and are not considered to be of biological relevance to humans.  Histopathological examination did not reveal any abnormalities that were considered treatment related.  As there were no pathologic changes, changes in organ weights mentioned above were judged to have been compensatory rather than toxic effects.  Based on these results, the No Observed Adverse Effect Concentration (NOAEC) was greater than or equal to 10400 mg/m3.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEC
1 160 mg/m³
Study duration:
subchronic
Species:
rat
Quality of whole database:
One of four available read across studies.

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

There is no data available for isoeicosane. However, data is available for structural analogues, Hydrocarbons, C10-C12, isoalkanes, <2% aromatics, Hydrocarbons, C10-C13, n-alkanes, isoalkanes, cyclics, <2% aromatics, Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, <2% aromatics, and isododecane This data is being read across to based on analogue read across and a discussion and report on the read across strategy is provided as an attachment in IUCLID Section 13.

Oral

Hydrocarbons, C10-C13, n-alkanes, isoalkanes, cyclics, < 2% aromatics

In a key sub-chronic oral toxicity study (ExxonMobil, 1991), the test material (Hydrocarbons, C10-C13, n-alkanes, isoalkanes, cyclics, < 2% aromatics) was administered by oral gavage to rats at concentrations of 500, 2500 and 5000 mg/Kg, 7 days a week for 13 weeks. An additional group of animals, dosed at 5000 mg/Kg/day, was held for 4 weeks to assess reversibility. No treatment-related mortality was observed; however, male body weights were decreased while food consumption increased in the 2500 and 5000 mg/Kg dose groups. Liver weights were elevated in male and female rats at 2500 and 5000 mg/Kg/day. Adrenal weights were significantly increased in male and female rats at 5000 mg/Kg and in female rats at 2500 and 5000 mg/Kg. Testes weights were elevated in male rats at 5000 mg/Kg. Kidney effects occurred in males at all dose levels, and are indicative of alpha-2u-globulin nephropathy. Alpha-2u-globulin nephropathy, also known as hyaline droplet nephropathy, results from the formation of complexes with a naturally occurring protein (alpha-2u-globulin) in the kidneys of male rats. These complexes can accumulate in the proximal renal tubule and may produce species-specific histopathological changes. These kidney effects are specific to male rats and are not considered to be of biological relevance to humans.

 

Dose-related changes in hematology or serum chemistry parameters were observed and were consistent with the changes seen in the liver. Histological findings of hepatocellular hypertrophy (liver cell enlargement) were seen in livers of both sexes in all dose groups. These findings are believed to have been a compensatory response and not an indication of toxicity. Additionally, these liver effects were reversible and occurred only at high doses that are not typical of hydrocarbon exposures for humans. Other treatment-related effects were mucosal thickening and other signs of irritation of the stomach and anus which appear to be the direct result of high dose intubation of a the locally irritating test substance. These effects are believed to have been a compensatory response to local irritation and not an indication of toxicity. All treatment-related effects were reversible within the 4-week recovery period. Based on the results, the No Observed Adverse Effect Level (NOAEL) for the 90-day study was greater than 5000 mg/Kg/day.

 

Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, < 2% aromatics

A 90-day sub-chronic study (similar to OECD TG 408) was conducted in Sprague-Dawley rats to assess the toxicity of Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, < 2% aromatics (CAS RN 64742-47-8) following OECD 408 guideline (ExxonMobil, 1991). The test substance was administered by oral gavage at a dose of 0, 100, 500, or 1000 mg/Kg 7 days per week for a period of 13 weeks. The control animals received a carrier (corn oil) dose and a satellite group was dosed at 1000 mg/Kg, 7 days/week for 13 weeks and was then observed for reversibility, persistence or delayed occurrence of toxic effects for 28 days post-treatment. Observations were made as to the nature, onset, severity, and duration of toxicological signs. There were no deaths attributed to the oral administration of Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, < 2% aromatics (two control group females died prior to termination. Kidney weights were elevated in male rats from the mid- and high dose groups, and liver weights were significantly elevated in female rats from the high dose group. The organ weight differences were not significant in animals held for 28 days without treatment. Pathological findings in kidneys from male rats were described as accumulations of hyaline droplets in the cytoplasm of the proximal tubules of the cortex, an increased incidence of multifocal cortical tubular basophilia with changes consistent with both degeneration and regeneration of the tubular epithelium and dilated medullary tubules with granular casts. The microscopic changes in the liver were described as minimal to slight centrilobular hepatocellular hypertrophy. In the satellite group animals there was still evidence of changes in the kidneys but the liver weights had returned to control values. . There were no differences in weights of reproductive organs and no pathological changes. Based on the data recorded in this study, the NOAEL for Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, < 2% aromatics is 1000 mg/Kg.

 

C10-C13 Aromatic Hydrocarbon Solvents

A 90-day sub-chronic, repeated-dose, oral gavage study conducted on a C10-C13 Aromatic Hydrocarbon Solvent (CAS RN. 64742-94-5) showed a low order of systemic toxicity (ExxonMobil, 1991). Animals (10/sex/dose group) were dosed with 0, 300, 600, or 1200 mg/Kg/day (including a 28-day satellite recovery high-dose group) for three days. The doses for the satellite and high-dose animals were adjusted to 1000 mg/Kg bw/day from the 4th day on due to the clinical response displayed in the first 3 days (ano-genital staining, emaciation and hypoactivity) in several animals. The majority of animals in the 300 and 600 mg/Kg bw/day groups displayed no observable abnormalities during the test period. 

 

Changes in the liver were noted and include hypertrophy – predominantly centrilobular seen in the females at all dose levels and sporadically in the males along with a low incidence of periportal hepatocellular hypertrophy was seen in the high dose males and/or female rats. The changes corresponded to the significant increase in the mean liver weights (absolute and relative). A significant increase in the mean kidney weights (absolute and relative) was noted at termination but no corresponding changes in the kidneys were observed by the pathologist. Although the absolute testes weights at the highest dose level were not statistically different from control weights, the relative testes weights (relative to final body weight) were significantly increased only in the highest dose level due to the significantly decreased final body weights. These effects are considered to be an adaptive in response. There were no treatment-related histopathological changes in any testes examined.

 

The changes seen in the spleen, at the main study termination were at lower incidence and/or severity in the satellite recovery group also indicating a trend towards reversibility. Based on the results of this study, the LOAEL for this test material is 600 mg/Kg bw/day and the NOAEL for this test material is less than 300 mg/Kg bw/day.

 

Hydrocarbons, C10-C12, isoalkanes, <2% aromatics

A 90-day sub-chronic study was conducted in rats to assess the toxicity of the test material (Hydrocarbons, C10-C12, isoalkanes, <2% aromatics). The test mixture was administered by oral gavage at a dose of 0, 100, 500, or 1000 mg/Kg, 7 days per week for a period of 13 weeks. The control animals received a carrier (corn oil) dose and a satellite group was dosed at 1000 mg/Kg, 7 days/week for 13 weeks and was then observed for reversibility, persistence or delayed occurrence of toxic effects for 28 days post-treatment. Observations were made as to the nature, onset, severity, and duration of toxicological signs. No treatment-related mortalities or clinical effects were observed. Animals in all dose group exhibited an overall mean weight gain. Minimal changes were noted in the hematology and serum chemistry values, however, all were considered to be either within normal biological variation or not adverse effects. The mean absolute and relative liver weights for both the 500 and 1000 mg/kg dose groups (both sexes) were significantly greater than the corresponding control values; however, these changes were found to be reversible following the 28 day recovery period. Slight increases in mean kidney weights were also noted in the 500 and 1000 mg/Kg female dose groups, however, these changes were not considered to be adverse effects. All histopathological findings were minimal and no treatment related adverse effects were noted. Based on the data recorded in this study, the NOAEL for the test material is greater than 1000 mg/Kg.

Additionally, in order to comply with standard information requirements for Annex X substances, an OECD Guideline 90-day sub-chronic (OECD 408) toxicity test is proposed for structural analogue Isohexadecane (2,2,4,4,6,8,8-heptamethylnonane (EC# 224-506-8)). The testing proposal for the same has been presented in the lead registrant dossier for this substance already submitted to ECHA. This study will be conducted subsequent to ECHA's approval and this endpoint will be updated upon completion of the above study.

 

Inhalation

Isododecane

In a key sub-chronic inhalation toxicity study (Ineos, 1982), five groups of rats, consisting of 20 males and 20 females each, were exposed to atmospheres containing 0, 12.5, 50, 100 and 200 ppm isododecane vapor for 6 hours a day, 5 days a week, for a period of 13 weeks. No treatment-related effects on mortality were observed and there were no significant alterations in hematological, blood chemical or urinary values, or in organ weights, which could be unequivocally attributed to treatment. An increased incidence of minimal to slight tubular nephrosis was found in the kidneys of males at levels of 50 ppm and above. These lesions were characterized by a loss of cytoplasmic eosinophilia and striation, a loss of brush border, and an increase in cellular and nuclear size of epithelium of mainly the proximal tubules. The kidney effects observed in male rats are indicative of alpha-2u-globulin nephropathy. Alpha-2u-globulin nephropathy, also known as hyaline droplet nephropathy, results from the formation of complexes with a naturally occurring protein (alpha-2u-globulin) in the kidneys of male rats. These complexes can accumulate in the proximal renal tubule and may produce species-specific histopathological changes. These kidney effects are specific to male rats and are not considered to be of biological relevance to humans. Based on these results, the No Observed Adverse Effect Level (NOAEL) was greater than or equal to 200ppm (≥1160 mg/m3).

 

Hydrocarbons, C10-C12, isoalkanes, <2% aromatics

In another key sub-chronic study (Shell, 1980), the test material (Hydrocarbons, C10-C12, isoalkanes, <2% aromatics) was administered by inhalation to albino rats for 6 hours/day, 5 days/week for 13 weeks at nominal vapor concentrations of 10400 mg/m3, 5200 mg/m3, and 2600 mg/m3to assess inhalation toxicity. No mortality or treatment-related effects in any of the hematology and serum chemistry values were observed. Liver and kidney weights were increased in male rats at all exposure levels, male heart weights were increased at the highest exposure level and liver and kidney weights were increased in female rats at 10400 mg/m3. In addition, the male rats exposed to the test material at all concentrations showed tubular degeneration and hyaline inclusion-droplets in the epithelium. There was also scattered degeneration of the proximal renal tubules which showed cytoplasmic pallor and shrinkage. Occasionally the degenerate tubules were surrounded by a lymphocyte infiltrate. Many tubules also showed dilatation of the cortico-medullary junction, the dilated tubule being filled with a flocculent eosinophilic material. The kidney effects observed in male rats are indicative of alpha-2u-globulin nephropathy. Alpha-2u-globulin nephropathy, also known as hyaline droplet nephropathy, results from the formation of complexes with a naturally occurring protein (alpha-2u-globulin) in the kidneys of male rats. These complexes can accumulate in the proximal renal tubule and may produce species-specific histopathological changes. These kidney effects are specific to male rats and are not considered to be of biological relevance to humans. Histopathological examination did not reveal any abnormalities that were considered treatment related. As there were no pathologic changes, changes in organ weights mentioned above were judged to have been compensatory rather than toxic effects. Based on these results, the No Observed Adverse Effect Concentration (NOAEC) was greater than or equal to 10400 mg/m3.

 

In another study (ExxonMobil, 1978), the test material identified as “Hydrocarbons, C10 - C12, isoalkanes, < 2% aromatics (CAS RN 64742-48-9)” was administered by inhalation to Sprague-Dawley rats at vapor concentrations of 300 or 900 ppm for 6 hours/day, 5 days/week for 12 weeks following a study design consistent with OECD 413. No treatment-related effects on mortality were observed and there were no significant alterations in hematology or clinical chemistry parameters. Body weights were decreased and kidney weights were elevated in male rats at 300 and 900 ppm. Relative mean liver weights were elevated in males at 900 ppm, but no changes were noted in histopathology. There were no differences in weights of reproductive organs and no pathological changes. Under the conditions of this study, the No Observed Adverse Effect Concentration (NOAEC) was the highest concentration tested (900 ppm or approximately 5220 mg/m3.

 

Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, < 2% aromatics

In a supporting sub-chronic inhalation toxicity study (Shell, 1980), the test material (Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, < 2% aromatics) was administered by inhalation to albino rats for 6 hours/day, 5 days/week for 13 weeks at nominal vapor concentrations of 1500 mg/m3and 3000 mg/m3, and 6000 mg/m3to assess inhalation toxicity. No mortality or treatment-related effects in any of the hematology and serum chemistry values were observed. Liver and kidney weights were increased in male rats at all exposure levels, and liver weights were increased in female rats at 6000 mg/m3. In addition, the male rats exposed to the test material at all concentrations contained multiple, hyaline, intracytoplasmic, inclusion-droplets in the epithelium of the proximal convoluted tubules and showed an increased incidence of focal cortical, tubular basophilia. The kidney effects observed in male rats are indicative of alpha-2u-globulin nephropathy. Alpha-2u-globulin nephropathy, also known as hyaline droplet nephropathy, results from the formation of complexes with a naturally occurring protein (alpha-2u-globulin) in the kidneys of male rats. These complexes can accumulate in the proximal renal tubules and may produce species-specific histopathological changes.  These kidney effects are specific to male rats and are not considered to be of biological relevance to humans. Histopathological examination did not reveal any abnormalities that were considered treatment related. As there were no pathologic changes, changes in liver weight to body weight ratios mentioned above were judged to have been compensatory rather than toxic effects.  Based on these results, the No Observed Adverse Effect Concentration (NOAEC) was greater than or equal to 6000 mg/m3.

Justification for classification or non-classification

Based on available read-across data from structurally related substances, isoeicosane does not meet the criteria for classification for repeated dose toxicity (STOT-RE) under the new Regulation (EC) 1272/2008 on classification, labeling and packaging of substances and mixtures (CLP).

Additonally, an OECD 408 study is proposed on structural analogue isohexadecane and will be conducted subsequent to ECHA's approval of the same. This endpoint will be updated upon completion of the above study subject to ECHA's approval.