Registration Dossier

Diss Factsheets

Administrative data

Description of key information

Repeated toxicity testing was considered unnecessary since this substance undergoes immediate disintegration and there are sufficient data on cleavage product. The intrinsic properties of this substance, after repeated administration, are related to the main degradation product, Exxal 8.

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 from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
GLP-guideline study read-across justification: The substance is hydrolytically unstable. When it comes in contact with water or moisture complete hydrolysis will take place with no significant reaction products other than alcohol and hydrated titanium dioxide. This rapid hydrolysis (hydrolysis half-life < 3 minutes to < 2 hours) is the driving force for the toxicokinetics of target substance. Because of the rapid hydrolysis, the influence of the mode of administration through inhalation, dermal and oral is related to the hazardous degradation product (alcohol) released from the target substance. The identification of degradation products from the hydrolysis study conducted for the target substance verifies that there are no impurities in the alcohol released from the target substance, which might change the hazardous properties of the target substance compared to the properties of the pure alcohol. As there is a mechanistic reasoning to the read-across, the unnecessary animal testing is avoided by using the read-across data from the degradation product (relevant alcohol) to evaluate irritation, sensitization and the short term and long-term toxicological effects and mutagenicity of the target substance.
Qualifier:
according to guideline
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)
Deviations:
no
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Fischer 344
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Age at study initiation: 42-43 days
- Weight at study initiation: 105-114 g (males); 86-97 g (females)
- Fasting period before study: no data
- Housing: singly in stainless steel cages
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 6 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 30-70
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:
Doses were prepared daily by dispersing 2EH in an aqueous solution of Cremophor EL (5 µg/100 ml) by ultra high speed sonication for 1 min.
Homogeneity was maintained by magnetic stirring throughout dosing.


VEHICLE
- Justification for use and choice of vehicle (if other than water): a surfactant (Cremophor) was used to facilitate mixing 2-EH with water
- Concentration in vehicle: 5 µg/100 ml
- Amount of vehicle (if gavage): dose volume was 10 ml/kg bw
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Concentrations and homogeneity were checked by gas chromatographic analysis of samples from each dose level at the start of the preliminary 11 -day studies and periodically in 13-week studies.
Duration of treatment / exposure:
13 weeks
Frequency of treatment:
5/week
Remarks:
Doses / Concentrations:
0, 25, 125, 250, 500mg/kg bw /day
Basis:
actual ingested
No. of animals per sex per dose:
10
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: based on the results of preliminary 11-day studies
- Rationale for animal assignment (if not random): random
- Rationale for selecting satellite groups: determination of peroxisome prolieferation (3 animals per dose level; Table [4])
- Post-exposure recovery period in satellite groups: none
- Section schedule rationale (if not random): random
Positive control:
not required
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Animals were inspected twice daily for morbidity or mortality, or once daily on nontreatment days. Clinical observations were
made daily.


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: at start and thereafter at weekly intervals


BODY WEIGHT: Yes
- Time schedule for examinations: at start and thereafter at weekly intervals


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): n.a.


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: No data


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data
- Time schedule for examinations:


OPHTHALMOSCOPIC EXAMINATION: No data
- Time schedule for examinations:



HAEMATOLOGY: Yes
- Time schedule for collection of blood: on study days 29 and 84.
- Anaesthetic used for blood collection: No data
- Animals fasted: Yes
- How many animals: not specified
- Parameters examined: leucocytes, erythrocytes, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular
hemoglobin, mean corpuscular hemoglobin concentration, platelets and differential leucocytes, and reticulocytes


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: on study days 29 and 84.
- Animals fasted: No data
- How many animals: not specified
- Parameters checked in table [1] were examined.


URINALYSIS: No
- Time schedule for collection of urine: n.a.
- Metabolism cages used for collection of urine: No
- Animals fasted: No data



NEUROBEHAVIOURAL EXAMINATION: No data



OTHER:
Sacrifice and pathology:
GROSS PATHOLOGY: Yes. Adrenals, brains, kidneys, livers, stomachs, testes, and ovaries from all animals were weighed, and with other
organs and tissues listed in U.S. EPA Health Effects Guidelines (1987b) fixed in 4% formalin.
HISTOPATHOLOGY: Yes. All tissues from high dose and control animals were stained with hematoxylin—eosin and examined microscopically.
Lungs, livers (including gallbladders in mice), spleens, kidneys, stomachs, sternums, femurs, and femur bone marrows were examined microscopically at intermediate dose levels.
Skin, eyes, female mammary glands, thigh musculatures, and extraorbital lacrymatory glands were not examined in the absence of signs of toxicity.
Livers were also stained with oil red for lipid content and examined microscopically.
Other examinations:
Hepatic peroxisome proliferation: livers were removed at termination and weighed, and cyanide-insensitive pCoA
activities (Lazarow, 1981) and protein concentrations (Lowry et al, 1951) were determined (week 13; ancillary group; 3 animals per dose level)
Statistics:
Means and standard deviations were calculated for body weights, food and water consumption, clinical pathology results, and organ weights.
Values for test groups were compared with controls in the main study by ANOVA followed by Dunnett's test (Dunnett, 1955, 1964)
and in ancillary studies by ANOVA followed by Student's t test (Winer, 1971).
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
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:
not specified
Haematological findings:
effects observed, treatment-related
Clinical biochemistry findings:
effects observed, treatment-related
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
There were no mortalities or clinical findings differing from controls at any treatment level.

BODY WEIGHT AND WEIGHT GAIN
There was decreased weight gain in male and female rats at 500 mg/kg, starting at Week 4 in males and Week 11 in females,
amounting to weight losses of 7% in males and 6% in females at termination (both p<0.01).

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
n.a.

FOOD EFFICIENCY
n.a.

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study)
n.a.

OPHTHALMOSCOPIC EXAMINATION
n.a.

HAEMATOLOGY
There was a 25% increase in reticulocyte numbers in male and female rats at 500 mg/kg in Week 13.

CLINICAL CHEMISTRY
Differences from controls rats were seen mostly at 84 days (data not shown).
Males at 500 mg/kg/day: 13% decreases in total protein and albumin concentrations.
Females at 250 mg/kg/day: 30 % decrease in serum ALT activities
Females at 500 mg/kg/day: 36% decreases in serum ALT activities;
16% decrease in serum cholesterol concentration

URINALYSIS
n.a.

NEUROBEHAVIOUR
n.a.

ORGAN WEIGHTS
Relative organ weights: significant differences from control rats were moderate and limited to the brain, kidneys, liver, stomach, and testes at 250 and 500 mg/kg. Organ weights were increased in both male and female rats (cf. table).


Table: Relative organ weights (a) in rats at termination of the 13-Week oral gavage rat study (b)

Males [Dose (mg/kg bw/day)] Females [Dose (mg/kg bw/day)]
0 250 500 0 250 500
--------------------------------------------------------------------
Brain 0.68 0.70 0.72** 1.07 1.1 1.1
Kidneys 0.69 0.75** 0.81** 0.77 0.81* 0.82**
Liver 2.77 2.98** 3.57** 2.67 2.88** 3.07**
Stomach 0.57 0.58 0.63** 0.71 0.75* 0.82**
Testes/Ovaries 1.11 1.16 1.17* 0.041 0.037* 0.039
--------------------------------------------------------------------------------------
values are mean organ/body weight ratios
there were no significant differences from controls in rats at 25 and 125 mg/kg bw/day
* p<0.05; ** p<0.01



GROSS PATHOLOGY
Gross lesions differing from controls in both species were seen at 500 mg/kg bw/day only. In rats 2/10 males and 4/10 females exhibited single
or multiple slightly elevated foci in the forestomach.

HISTOPATHOLOGY: NON-NEOPLASTIC
Dose-related findings in rats (data not shown) were limited to the forestomach and liver at 500 mg/kg.
Forestomach: there was a generalized acanthosis of the forestomach mucosa in 1/10 males with ballooning degeneration of the epithelial wall and acanthosis of the forestomach mucosa in 2/10 males and 5/10 females.
Liver: there was a moderate decrease in hepatic peripheral lobular fatty infiltration in 4/10 males and 2/10 females and adrenal ß-cell hyperplasia in 3/10 female rats.

HISTOPATHOLOGY: NEOPLASTIC (if applicable)
n.a.

HISTORICAL CONTROL DATA (if applicable)
n.a.

OTHER FINDINGS
Peroxisome proliferation:
In Week 13, increases in pCoA activity were 6.5-fold in male rats (p<0.001) and 3.4-fold in females (p<0.05) at 500 mg/kg . Reportedly, decreases in body weight gain were similar to those in the main study animals.

--------------------------------------------------------------------------------------
Dose (mg/kg bw/day)
0 25 125 250 500
--------------------------------------------------------------------
Mean PCoA activity (nanomol/min/mg of protein)
Males 3.38 4.49 5.21 6.24 22.0*
Females 2.95 4.54 5.01 6.6 9.92**
--------------------------------------------------------------------------------------
*p<0.001 and **p<0.05 by ANOVA/Students ttest
Dose descriptor:
NOEL
Effect level:
125 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: absence of treatment-related effects on target organs
Dose descriptor:
NOAEL
Effect level:
250 mg/kg bw/day (actual dose received)
Sex:
male/female
Basis for effect level:
other: absence of treatment-related systemic effects on target organs
Critical effects observed:
not specified
 

    


    
Table: Relative organ weights (a) in rats at termination of the 13-Week 
oral gavage rat study (b)
    
Males [Dose (mg/kg bw/day)]
Females [Dose (mg/kg bw/day)]
0
250
500
0
250
500
Brain
0.68
0.70
0.72**
1.07
1.1
1.1
Kidneys
0.69
0.75**
0.81**
0.77
0.81*
0.82**
Liver 
2.77
2.98**
3.57**
2.67
2.88**
3.07**
Stomach 
0.57
0.58
0.63**
0.71
0.75*
0.82**
Testes/Ovaries
1.11
1.16
1.17*
0.041
0.037*
0.039


    
(a) values are mean organ/body weight ratios
(b) there were no significant differences from controls in rats at 25 and 125 mg/kg bw/day
* p0.05; ** p0.01    
Conclusions:
Valid subchronic oral gavage rat study.
(1) 2-EH was moderately toxic at all dose levels up to and including 500 mg/kg bw/day; based
- on lack of mortality and clinical signs;
- moderately reduced body weights in groups at 500 mg/kg bw/day;
- minor effects of low relevance on clinicochemcial and hematological parameters
(2) Target organs were the liver, forestomach, and the kidneys; based on significantly increased relative organ weights at termination
(3) Local irritating effects prevailed; systemic effects were low; based on
- inflammation in the forestomach,
- and lack of treatment-related findings in other organs, including testes
(4) 2-EH induces peroxisome proliferation in rats; observed at 500 mg/kg bw/day in rats of both sexes
(5) The NOEL (no observable effect level) was 125 mg/kg bw/day. A NOAEL (no observable adverse effect level) was not derived, but may be estimated to be 250 mg/kg bw/day, based on the above
Executive summary:

The subchronic effects of 2 -EH were studied in a 90-day oral gavage study using male and female rats (10 animals per sex and dose). The test dose levels were 0, 25, 125, 250, and 500 mg/kg bw/day, based on the results of preliminary 11-day studies.

Key results include:

  • Mortalities or clinical findings were not different from controls
  • Food consumption was comparable to controls
  • Body weight gain was reduced in the high dose groups, resulting in decreased terminal weights in males (-7%) and females (-6%); (both p<0.01)
  • Clinicochemical changes were seen in high dose groups (males:total protein and albumin -13%; females: serum cholesterol -16%); biological significance is unclear
  • Hematology: reticulocytes were increased (25%) in high dose males and females
  • Organ weights: target organs were liver, forestomach, and kidneys; based on increased relative weights (p<0.01) in male and female groups at 250 and 500 mg/kg bw/day. No weight changes were noted at 25 and 125 mg/kg bw/day.
  • Reproductive organs: relative weight of testes was increased, and that of ovaries decreased, at 250 and 500 mg/kg bw/day.
  • Histopathology revealed changes only in high dose animals. Predominantly inflammatory changes in the forestomach which are attributable to the irritation properties of 2 -EH
  • 2 -EH at 500 mg/kg bw/day caused peroxisome proliferation, as evidenced by a statistically significant increase of the hepatic cyanide-insensitive palmitoyl coenzyme A activity in male (p<0.001) and female (p<0.05) rats in Week 13.
  • The subchronic NOEL was 125 mg/kg bw/day in male and female rats. The estimated NOAEL is 250 mg/kg bw/day.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
250 mg/kg bw/day
Study duration:
subchronic
Species:
rat

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records
Reference
Endpoint:
short-term repeated dose toxicity: inhalation
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
GLP guideline study. Read-across justification: The substance is hydrolytically unstable. When it comes in contact with water or moisture complete hydrolysis will take place with no significant reaction products other than alcohol and hydrated titanium dioxide. This rapid hydrolysis (hydrolysis half-life < 3 minutes to < 2 hours) is the driving force for the toxicokinetics of target substance. Because of the rapid hydrolysis, the influence of the mode of administration through inhalation, dermal and oral is related to the hazardous degradation product (alcohol) released from the target substance. The identification of degradation products from the hydrolysis study conducted for the target substance verifies that there are no impurities in the alcohol released from the target substance, which might change the hazardous properties of the target substance compared to the properties of the pure alcohol. As there is a mechanistic reasoning to the read-across, the unnecessary animal testing is avoided by using the read-across data from the degradation product (relevant alcohol) to evaluate irritation, sensitization and the short term and long-term toxicological effects and mutagenicity of the target substance.
Qualifier:
according to guideline
Guideline:
OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Dr. K. Thomae GmbH, Biberach, Germany
- Age at delivery: 7 weeks
- Weight at study initiation: males 238 (+/- 2.3) g; females 238 (170 +/- 2.2) g
- Housing: singly in wire cages
- Diet: e.g. ad libitum
- Water: ad libitum
- Acclimation period: at least 5 days acclimation to the inhalation chamber


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24°C
- Humidity (%): 30-70%
- Photoperiod (hrs dark / hrs light): 12 hrs light/dark


IN-LIFE DATES: From: day1 To: day 93
Route of administration:
inhalation
Type of inhalation exposure:
whole body
Vehicle:
other: unchanged (no vehicle)
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: whole-body inhalation chamber (glas/steel construction, volumes approx. 1.1 m³)
- Method of holding animals in test chamber: rats were kept individually in wire cages
- Test atmosphere generation: the test substance was delivered to heated evaporators by mean of metering pumps. The warmed air was mixed with compressed air and delivered to teh inhalation chamber.
- Source and rate of air: compressed air; variable rate
- Temperature, humidity, pressure in air chamber: 23.1 to 23.8°C; positive pressure 10.1 Pascal (ciontrol groups), negative pressure -10.2 Pascal (treated groups); 41.8 to 46.2% relative humidity
- Air flow rate: not reported in publication
- Air change rate: not reported in publication
- Treatment of exhaust air: not reported in publication


TEST ATMOSPHERE
- Brief description of analytical method used: samples were analyzed at intervals of about 15 min by gas chromatography (GC-FID; column 1mx22 mm with 10% Triton x 305 on Supelcoport, 102/120 mesh; oven temperature 120 °C; c15-paraffin as internal standard)
- Samples taken from breathing zone: yes


Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Samples were analyzed at intervals of about 15 min by gas chromatography (GC-FID; column 1mx22 mm with 10% Triton x 305 on Supelcoport, 102/120 mesh; oven temperature 120 °C; c15-paraffin as internal standard)
Duration of treatment / exposure:
90 days
Frequency of treatment:
6 hours/day, 5 days/week (total of 65 exposures)
Remarks:
Doses / Concentrations:
0, 15, 40 and 120 ppm
Basis:
nominal conc.
Remarks:
Doses / Concentrations:
15 (SD 0.67), 39.9 (SD 1.33), 120 (SD 4.8) ppm
Basis:
analytical conc.
No. of animals per sex per dose:
10
Control animals:
yes
Details on study design:
Post-exposure period: none
Positive control:
not required
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS:
- Time schedule: daily


DETAILED CLINICAL OBSERVATIONS: yes
- Time schedule: pre-treatment and at termination


BODY WEIGHT: Yes
- Time schedule for examinations: weekly


FOOD CONSUMPTION:
- Food consumption: no data contained in the publication; not required


FOOD EFFICIENCY:
- Body weight gain: yes, but no data contained in the publication; not required


WATER CONSUMPTION: no data contained in the publication; not required


OPHTHALMOSCOPIC EXAMINATION: yes
- Time schedule for examinations: pre-treatment and at termination
- Dose groups that were examined: all animals


HAEMATOLOGY: Yes
- Time schedule for collection of blood: at termination, day 94 of the study
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: all animals
- Parameters: white and red blood cells, hemoglobin, hematocrit, mean corpuscular volume. mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelets, differential blood count


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at termination, day 94 of the study
- Animals fasted: No data
- How many animals: No data
- Parameters: sodium, potassium, chloride, glucose, inorganic phosphate, calcium, urea, creatinine, glucose, total bilirubin, total protein, albumin, globulins, triglycerides, cholesterol, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, clotting time


URINALYSIS: No data




OTHER:
- cyanide-insensitive palmitoyl-CoA oxidation in liver homogenates
- gross pathology of all animals at termination; determination of organ weights (lungs, liver, kidneys, adrenal glands, and testes)
- histopathology of organs/tissues required by guidelines, and all gross lesions
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Statistics:
- Mean values +/- standard deviation: body weight, body weight gain, hematological and clinical biochemistry parameters, absolute and relative organ weights.
Dunnett's test: comparison of exposure groups with the control group.
Analysis of variance subsequent to Dunnett's test: body weight, body weight gain, hematological and clinical biochemistry parameters
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:
not specified
Behaviour (functional findings):
not specified
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:
1) Analysis of the daily inhalation chamber concentrations revealed that the values obtained closely fitted with the desired nominal level.

2) There were no effects regarding the issues below noted at any dose level:

CLINICAL SIGNS AND MORTALITY


BODY WEIGHT AND WEIGHT GAIN


FOOD CONSUMPTION


FOOD EFFICIENCY


WATER CONSUMPTION


OPHTHALMOSCOPIC EXAMINATION


HAEMATOLOGY


CLINICAL CHEMISTRY


URINALYSIS


NEUROBEHAVIOUR


ORGAN WEIGHTS


GROSS PATHOLOGY


HISTOPATHOLOGY: NON-NEOPLASTIC


HISTOPATHOLOGY: NEOPLASTIC (if applicable)


Dose descriptor:
NOAEC
Effect level:
120 ppm (analytical)
Sex:
male/female
Basis for effect level:
other: overall effects
Dose descriptor:
NOAEC
Effect level:
638.4 mg/m³ air (analytical)
Sex:
male/female
Basis for effect level:
other: overall effects
Critical effects observed:
not specified

Read-across justifications and data matrices are presented in IUCLID section 13.

Read-across justifications and data matrices are presented in IUCLID section 13.

Read-across justifications and data matrices are presented in IUCLID section 13.

Under the conditions of the test no treatment-related toxic
effects were found in male and female Wistar rats which were
exposed to 2-ethylhexanol vapor up to 120 ppm. T

The concentration of 120 ppm corresponds to the calculated

saturated vapor concentration at 20°C.

Conclusions:
No treatment-related effects were noted in a OECD Guideline 413 study (Subchronic Inhalation Toxicity: 90-Day) conducted under GLP conditions and using male and female Wistar rats (10 rats per sex and dose).
Executive summary:

Exposure levels were 0, 15, 40, and 120 ppm (120 ppm is equivalent to saturation at 20°C). As there were no effects compared with the control groups in either sex on body weight or body weight gain, clinical signs of toxicity and mortality, hematological and clinical biochemistry parameters, ophthalmological parameters, absolute or relative organ weights including testes, or cyanide-insensitive palmitoyl-CoA oxidation as a parameter for hepatic peroxisome proliferation, the NOAEC was 120 ppm, ie. 638.4 mg/m³ (Klimisch, 1998).

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEC
638.4 mg/m³
Study duration:
subchronic
Species:
rat

Repeated dose toxicity: inhalation - local effects

Link to relevant study records
Reference
Endpoint:
short-term repeated dose toxicity: inhalation
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
GLP guideline study. Read-across justification: The substance is hydrolytically unstable. When it comes in contact with water or moisture complete hydrolysis will take place with no significant reaction products other than alcohol and hydrated titanium dioxide. This rapid hydrolysis (hydrolysis half-life < 3 minutes to < 2 hours) is the driving force for the toxicokinetics of target substance. Because of the rapid hydrolysis, the influence of the mode of administration through inhalation, dermal and oral is related to the hazardous degradation product (alcohol) released from the target substance. The identification of degradation products from the hydrolysis study conducted for the target substance verifies that there are no impurities in the alcohol released from the target substance, which might change the hazardous properties of the target substance compared to the properties of the pure alcohol. As there is a mechanistic reasoning to the read-across, the unnecessary animal testing is avoided by using the read-across data from the degradation product (relevant alcohol) to evaluate irritation, sensitization and the short term and long-term toxicological effects and mutagenicity of the target substance.
Qualifier:
according to guideline
Guideline:
OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Dr. K. Thomae GmbH, Biberach, Germany
- Age at delivery: 7 weeks
- Weight at study initiation: males 238 (+/- 2.3) g; females 238 (170 +/- 2.2) g
- Housing: singly in wire cages
- Diet: e.g. ad libitum
- Water: ad libitum
- Acclimation period: at least 5 days acclimation to the inhalation chamber


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24°C
- Humidity (%): 30-70%
- Photoperiod (hrs dark / hrs light): 12 hrs light/dark


IN-LIFE DATES: From: day1 To: day 93
Route of administration:
inhalation
Type of inhalation exposure:
whole body
Vehicle:
other: unchanged (no vehicle)
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: whole-body inhalation chamber (glas/steel construction, volumes approx. 1.1 m³)
- Method of holding animals in test chamber: rats were kept individually in wire cages
- Test atmosphere generation: the test substance was delivered to heated evaporators by mean of metering pumps. The warmed air was mixed with compressed air and delivered to teh inhalation chamber.
- Source and rate of air: compressed air; variable rate
- Temperature, humidity, pressure in air chamber: 23.1 to 23.8°C; positive pressure 10.1 Pascal (ciontrol groups), negative pressure -10.2 Pascal (treated groups); 41.8 to 46.2% relative humidity
- Air flow rate: not reported in publication
- Air change rate: not reported in publication
- Treatment of exhaust air: not reported in publication


TEST ATMOSPHERE
- Brief description of analytical method used: samples were analyzed at intervals of about 15 min by gas chromatography (GC-FID; column 1mx22 mm with 10% Triton x 305 on Supelcoport, 102/120 mesh; oven temperature 120 °C; c15-paraffin as internal standard)
- Samples taken from breathing zone: yes


Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Samples were analyzed at intervals of about 15 min by gas chromatography (GC-FID; column 1mx22 mm with 10% Triton x 305 on Supelcoport, 102/120 mesh; oven temperature 120 °C; c15-paraffin as internal standard)
Duration of treatment / exposure:
90 days
Frequency of treatment:
6 hours/day, 5 days/week (total of 65 exposures)
Remarks:
Doses / Concentrations:
0, 15, 40 and 120 ppm
Basis:
nominal conc.
Remarks:
Doses / Concentrations:
15 (SD 0.67), 39.9 (SD 1.33), 120 (SD 4.8) ppm
Basis:
analytical conc.
No. of animals per sex per dose:
10
Control animals:
yes
Details on study design:
Post-exposure period: none
Positive control:
not required
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS:
- Time schedule: daily


DETAILED CLINICAL OBSERVATIONS: yes
- Time schedule: pre-treatment and at termination


BODY WEIGHT: Yes
- Time schedule for examinations: weekly


FOOD CONSUMPTION:
- Food consumption: no data contained in the publication; not required


FOOD EFFICIENCY:
- Body weight gain: yes, but no data contained in the publication; not required


WATER CONSUMPTION: no data contained in the publication; not required


OPHTHALMOSCOPIC EXAMINATION: yes
- Time schedule for examinations: pre-treatment and at termination
- Dose groups that were examined: all animals


HAEMATOLOGY: Yes
- Time schedule for collection of blood: at termination, day 94 of the study
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: all animals
- Parameters: white and red blood cells, hemoglobin, hematocrit, mean corpuscular volume. mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelets, differential blood count


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at termination, day 94 of the study
- Animals fasted: No data
- How many animals: No data
- Parameters: sodium, potassium, chloride, glucose, inorganic phosphate, calcium, urea, creatinine, glucose, total bilirubin, total protein, albumin, globulins, triglycerides, cholesterol, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, clotting time


URINALYSIS: No data




OTHER:
- cyanide-insensitive palmitoyl-CoA oxidation in liver homogenates
- gross pathology of all animals at termination; determination of organ weights (lungs, liver, kidneys, adrenal glands, and testes)
- histopathology of organs/tissues required by guidelines, and all gross lesions
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Statistics:
- Mean values +/- standard deviation: body weight, body weight gain, hematological and clinical biochemistry parameters, absolute and relative organ weights.
Dunnett's test: comparison of exposure groups with the control group.
Analysis of variance subsequent to Dunnett's test: body weight, body weight gain, hematological and clinical biochemistry parameters
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:
not specified
Behaviour (functional findings):
not specified
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:
1) Analysis of the daily inhalation chamber concentrations revealed that the values obtained closely fitted with the desired nominal level.

2) There were no effects regarding the issues below noted at any dose level:

CLINICAL SIGNS AND MORTALITY


BODY WEIGHT AND WEIGHT GAIN


FOOD CONSUMPTION


FOOD EFFICIENCY


WATER CONSUMPTION


OPHTHALMOSCOPIC EXAMINATION


HAEMATOLOGY


CLINICAL CHEMISTRY


URINALYSIS


NEUROBEHAVIOUR


ORGAN WEIGHTS


GROSS PATHOLOGY


HISTOPATHOLOGY: NON-NEOPLASTIC


HISTOPATHOLOGY: NEOPLASTIC (if applicable)


Dose descriptor:
NOAEC
Effect level:
120 ppm (analytical)
Sex:
male/female
Basis for effect level:
other: overall effects
Dose descriptor:
NOAEC
Effect level:
638.4 mg/m³ air (analytical)
Sex:
male/female
Basis for effect level:
other: overall effects
Critical effects observed:
not specified

Read-across justifications and data matrices are presented in IUCLID section 13.

Read-across justifications and data matrices are presented in IUCLID section 13.

Read-across justifications and data matrices are presented in IUCLID section 13.

Under the conditions of the test no treatment-related toxic
effects were found in male and female Wistar rats which were
exposed to 2-ethylhexanol vapor up to 120 ppm. T

The concentration of 120 ppm corresponds to the calculated

saturated vapor concentration at 20°C.

Conclusions:
No treatment-related effects were noted in a OECD Guideline 413 study (Subchronic Inhalation Toxicity: 90-Day) conducted under GLP conditions and using male and female Wistar rats (10 rats per sex and dose).
Executive summary:

Exposure levels were 0, 15, 40, and 120 ppm (120 ppm is equivalent to saturation at 20°C). As there were no effects compared with the control groups in either sex on body weight or body weight gain, clinical signs of toxicity and mortality, hematological and clinical biochemistry parameters, ophthalmological parameters, absolute or relative organ weights including testes, or cyanide-insensitive palmitoyl-CoA oxidation as a parameter for hepatic peroxisome proliferation, the NOAEC was 120 ppm, ie. 638.4 mg/m³ (Klimisch, 1998).

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEC
638.4 mg/m³
Study duration:
subchronic
Species:
rat

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records
Reference
Endpoint:
repeated dose toxicity: dermal
Data waiving:
exposure considerations
Justification for data waiving:
other:
Critical effects observed:
not specified
Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Link to relevant study records
Reference
Endpoint:
repeated dose toxicity: dermal
Data waiving:
exposure considerations
Justification for data waiving:
other:
Critical effects observed:
not specified
Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Repeated oral toxicity

Weight of evidence approach was used to evaluate the testing needs of this endpoint as there are no studies available from the titanium tetra(octanolate), branched and linear. In order to avoid unnecessary animal testing, further investigations were considered scientifically unjustified since the substance undergoes immediate disintegration and there are sufficiently data on cleavage products and from the degradation product of the analogue category member. This target substance (titanium tetra(octanolate), branched and linear) is an analogue substance with another organometallic titanate (titanium tetrakis(2-ethylhexanolate) which are grouped into the category of highly water reactive titanates. The target substance contains commercial solvent (Exxal8; alcohols C7 -9-iso, C8-rich) which consists mainly of 93 % of isooctanol. Thus, this solvent can also be considered as an analogue substance with 2 -ethylhexanol; an isomer of octyl alcohol, which is the solvent in the read-across analogue substance of the category. Therefore, the properties of 2-ethylhexanol are also evaluated for this endpoint. Category and read-across justifications are presented in the annexes of the CSR. Titanium tetra(octanolate), branched and linear hydrolyses rapidly (< 10min) when it comes in contact with water or moisture (Brekelmans, M. J. C., 2013). After hydrolysis no significant reaction products other than Exxal 8 (alcohols, C7 -C9 -iso, C8 –rich) and titanium dioxide (TiO2) exist. Thus, the intrinsic properties of the target substance are most likely related to these two decomposition products. Exxal 8 (alcohols C7 -9-iso, C8-rich) being the most relevant decomposition product for CSA. TiO2 exists as solid insoluble precipitate having low bioavailability and possessing very low acute and long-term toxicity (US EPA, 1994; WHO, 1982). Thus, it is concluded that no further assessment of TiO2 is needed for repeated dose toxicity. Repeated oral studies performed with 2-ethylhexanol (solvent released from the analogue category member) are used as a weight of evidence to evaluate repeated oral toxicity of the target substance.

In the 90-day oral gavage study by Astill, et al. (1996a) 2-ethylhexanol was administered in male and female rats (10 animals per sex and dose) at dose levels 0, 25, 125, 250, and 500 mg/kg bw/day. No mortalities or no clinical findings were different from controls. Food consumption was comparable to controls. However, the body weight gain was reduced in the high dose groups. Changes in clinical chemistry were seen in high dose groups (males: total protein and albumin -13%; females: serum cholesterol -16%). Biological significance of these changes is unclear. In Hematology reticulocyte counts were increased (25%) in high dose males and females. Organ weights of liver, forestomach, and kidneys were increased in male and female groups at 250 and 500 mg/kg bw/day. No weight changes were noted at 25 and 125 mg/kg bw/day. Relative weight of testes was increased, and that of ovaries decreased, at 250 and 500 mg/kg bw/day. Histopathology revealed changes only in high dose animals. Predominantly inflammatory changes were seen in the forestomach which are attributable to the irritation properties of 2 –EH. Furthermore, 2 -EH at 500 mg/kg bw/day caused peroxisome proliferation, as evidenced by a statistically significant increase of the hepatic cyanide-insensitive palmitoyl coenzyme A activity in male (p<0.001) and female (p<0.05) rats in Week 13. Based on the above data the subchronic NOEL is 125 mg/kg bw/day in male and female rats. The estimated NOAEL is 250 mg/kg bw/day.

In the other study by Astill, et al. (1996b) the subchronic effects of 2-ethylhexanol were studied in a 90-day oral gavage study using male and female B6C3F1 mice (10 animals per sex and dose). The test dose levels were 0, 25, 125, 250, and 500 mg/kg bw/day, based on the results of preliminary 11-day studies. No mortalities or clinical findings were different from controls. Food consumption and body weight gain was comparable to controls. There were no changes in clinical chemistry or hematological parameters at any dose level. A dose-related weight increase of liver and forestomach was seen in males and females. However, no weight change of male and female reproductive organs was noted. Histopathological evaluation revealed a low incidence of inflammatory changes only in high dose animals which were regarded to be incidental; possibly attributable to the irritation properties of 2 –EH. Based on the above data, the subchronic NOEL was 125 mg/kg bw/day in male and female rats. The estimated NOAEL is 250 mg/kg bw/day.

As conclusion, the NOAEL was estimated in both studies to be 250 mg/kg bw/day. This exceeds the cut-off value, i.e. 100 mg/kg bw/day for the classification.

Repeated inhalation toxicity

Titanium tetra(octanolate), branched and linear hydrolyses rapidly (< 10 min) when it comes in contact with water or moisture (Brekelmans M. J. C. 2013). After hydrolysis no significant reaction products other than Exxal 8 (alcohols, C7-9-iso, C8-rich) and TiO2 exist. TiO2 exists as solid non-hazardous precipitate and therefore it is not further considered in CSA. Weight of evidence approach was used to evaluate the testing needs of this endpoint as there are no studies available from the titanium tetra(octanolate), branched and linear. In order to avoid unnecessary animal testing, further investigations were considered scientifically unjustified since the substance undergoes immediate disintegration and there are sufficiently data on cleavage products and from the degradation product of the analogue category member.

This target substance (titanium tetra(octanolate), branched and linear) is an analogue substance with another organometallic titanate (titanium tetrakis(2-ethylhexanolate) which are grouped into the category of highly water reactive titanates. The target substance contains commercial solvent (Exxal8; alcohols C7 -9-iso, C8-rich) which consists mainly of 93 % of isooctanol. Thus, this solvent can also be considered as an analogue substance with 2 -ethylhexanol; an isomer of octyl alcohol, which is the solvent in the read-across analogue substance of the category. Therefore, the properties of 2-ethylhexanol are also evaluated for this endpoint. Category and read-across justifications are presented in the annexes of the CSR.

There is available one OECD Guideline 413 study (Subchronic Inhalation Toxicity: 90-Day) for 2-ethylhexanol where no treatment related adverse effects was observed. Male and female Wistar rats (10 rats per sex and dose) were exposed at levels 0, 15, 40, and 120 ppm (120 ppm is equivalent to saturation at 20°C). As there were no effects compared with the control groups in either sex on body weight or body weight gain, clinical signs of toxicity and mortality, hematological and clinical biochemistry parameters, ophthalmological parameters, absolute or relative organ weights including testes, or cyanide-insensitive palmitoyl-CoA oxidation as a parameter for hepatic peroxisome proliferation, the NOAEC was 120 ppm, i.e. 638.4 mg/m³ (Klimisch, 1998). Based on this NOAEC value no classification is warranted.

Repeated dermal toxicity

No valid repeated dermal study was identified for titanium tetra(octanolate), branched and linear. Testing is not necessary since skin contact in use and production is not likely and the adequate RMMs are in use (see sections 9&10 of CSR).


Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
Unstable substance and therefore intrinsic properties are related to the main degradation product, Exxal 8; alcohols C7-9-iso, C8-rich. The published study is done using isooctanol, the main component of Exxal 8.

Justification for selection of repeated dose toxicity inhalation - systemic effects endpoint:
Unstable substance and therefore intrinsic properties are related to the main degradation product, Exxal 8. The published study is done using isooctanol, the main component of Exxal 8.

Justification for selection of repeated dose toxicity inhalation - local effects endpoint:
Unstable substance and therefore intrinsic properties are related to the main degradation product, Exxal 8. The published study is done using isooctanol, the main component of Exxal 8.

Justification for selection of repeated dose toxicity dermal - systemic effects endpoint:
Not likely exposure route

Justification for selection of repeated dose toxicity dermal - local effects endpoint:
Not likely exposure route

Justification for classification or non-classification

The intrinsic properties of titanium tetra(octanolate), branched and linear are related to the main degradation product, Exxal 8. The main component of Exxal 8 after repeated oral and inhalation exposures did not induce significant toxicity. Thus, there is no need for classification of the target substance in accordance with the criteria of CLP Regulation 1272/2008 and the EU directive 67/548/EEC.

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