Distillation residue, butyl alcohols production, rectification

Endpoint summary

Description of key information

There are no studies available made from the target UVCB-substance. Repeated-dose toxicity studies for dermal and oral route are presented from the only identified and quantified constituent of the target substance, 2-ethylhexanol, since testing for these properties would scientifically be unjustified due to nature of the target UVCB-substance. Studies performed with Fischer F344 rats and B6C3F1 mice followed the current U. S. EPA Good Laboratory Practice Guidelines. In the absence of the data of the registered substance these studies serve as a good surrogate studies. The need for further investigations is re-evaluated after registration when more information is expected to be available on the exposure pattern and on the properties of the target substance and potential analogue substances.

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:

key study

Study period:

1995-05-30

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Repeated-dose toxicity studies performed with the only identified and quantified constituent of the registered substance, 2-ethylhexanol. Studies performed with Fischer F344 rats and B6C3F1 mice followed the current U.S. EPA Good Laboratory Practice Guidelines. In the absence of data on the registered substance these studies serve as a good surrogate studies: a) it represents the effects of the only identified and quantified constituent of the substance, since the constituents of this registered UVCB-substance cannot be recognized and its composition varies to the degree that composition cannot be fixed. b) studies have been performed following U.S. EPA Good Laboratory Practice. c) they provide information on effect levels of 2-ethylhexanol when administered via oral cavage.

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

yes

Principles of method if other than guideline:

Similar to that of OECD 408, but with 11 day sub-acute study was performed to adjust the proper doses for the actual 90-day study. Number of animals per treatment group per sex was 10.

GLP compliance:

yes

Remarks:

U.S EPA Good laboratory practice was adopted

Limit test:

no

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

Test animal species: Fischer 344 rats and B6C3F1 mice

TEST ANIMALS
- Source:not disclosed, age: rats 33-35 days upon arrival, mice 43-44 days upon arrival.
- Age at study initiation: 42 days rats, 44 days mice
- Weight at study initiation: rats: males 103g (86-128) and females 81g (64-95), mice: males 23g (21-26) and females 19g (17-23)
- Fasting period before study: 16-20 hours
- Housing: following U.S. EPA GLP: rats housed singly in suspended stainless steel wire mesh cages and mice singly in plastic cages arranged in racks.
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%):30-70
- Air changes (per hr): not disclosed
- Photoperiod (hrs dark / hrs light): 12 hours

Route of administration:

oral: gavage

Vehicle:

polyethylene glycol

Remarks:

polyoxyethylene glycerol triricinoleate, Cremophor EL, BASF Aktien Gesellshaft, Ludwigshafen, Germany

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Rate of preparation of diet (frequency): daily
- Mixing appropriate amounts with (Type of food): cavage solution in Cremophor LE
- Justification for vehicle choice: most stable dose formulation and minimized tract irritation and inflammation.

VEHICLE
- Justification for use and choice of vehicle (if other than water): not disclosed
- Concentration in vehicle:
Subacute: 11-day study 1000 and 1500 mg/kg bw ; 13-week study 25, 125, 250 and 500 mg/kg bw.
Oncogenicity: rats 50, 150, 500 mg/kg bw and mice 0, 50, 200 and 750 mg/kg bw.
- Amount of vehicle (if gavage): 10ml/kg bw or 1ml in mice 3ml in rats (solution of 0,005% Cremophor EL)
- Lot/batch no. (if required):not disclosed
- Purity: not disclosed

HOMOGENEITY AND STABILITY OF TEST MATERIAL: see test material details.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Gas chromatographic analysis of homogeneity and concentrations, start of the study (11-days study) and peridiocally (90-days study).

Duration of treatment / exposure:

11 days sub-acute study
90-days sub-chronic study

Frequency of treatment:

5-times a week, consecutively.

No. of animals per sex per dose:

11-day study: 10 females and 10 males, rats and mice
90-day study: 10 females and 10 males, rats and mice

Positive control:

not needed

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily treatment days, once non-treatment days.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: 11-day study: days -3, 0, 4, 10. 90-day study: day -1 and weekly thereafter

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food and water consumption were measured on 11-day study on days 4 and 10. In 90-day study average food consumption was determined weekly.

HAEMATOLOGY: Yes
- Time schedule for collection of blood: 11-day study: retro-orbital bleeding prior to termination or after decapitation. In 90-days study: from fasted animals on the morning of days 29 and 84.
- Anaesthetic used for blood collection: No data
- Animals fasted: Yes
- How many animals: no data
- Parameters checked in table [No.?] were examined: leucocytes, eryhtrocytes, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelets and differential leucocytes, and reticulocytes (only 90-day study).

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: 11-day study: retro-orbital bleeding prior to termination or after decapitation. In 90-days study: from fasted animals on the morning of days 29 and 84.
- Anaesthetic used for blood collection: No data
- Animals fasted: Yes
- How many animals: no data
- Parameters checked in table [No.?] were examined.: alanine , aspartate aminotransferase, creatine kinase, gamma-glutamyltransferase, glucose, urea, total protein, albumin/globulin, Natrium, Potassium, Calcium, Chlorine, creatinine, cholesterol, triglycerides, total bilirubin.

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.

Sacrifice and pathology:

Moribund animals were euthanized; dead and euthanized animals were immediately necropsied and assessed grossly. Gross and microscopic examinations were made as follows:
11-day study adrenals, brain, kidneys, livers, lungs, spleen, stomach, and testes were weighed and together with any gross lesions and thymuses were processed, fixed in 4% formalin, stained with hematoxylin.eosin and examined microscopically.
In 90-days study: drenals, brain, kidneys, livers, lungs, spleen, stomach, and ovaries from all animals were weighed with other tissues listed in U.S. EPA Health Effect guidelines (1978b) fixed in 4% formalin. Livers were also stained with oil red for lipid content and examined microscopically. Animals in 90-day ancillary studies were used only to determine hepatic peroxisome proliferation. Livers were removed at termination and weighed and cyano-insensitive pCoA activities and protein concentrations were determined.

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

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 and in ancillary studies by ANOVA followed by Student't t-test.

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

reduced body weight

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

higher dose levels groups had reduced food intake 10-20%

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

no effects observed

Haematological findings:

effects observed, treatment-related

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

increased liver, kidney, stomach and testes weights.

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Dose descriptor:

NOAEL

Effect level:

ca. 125 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: overall effects, clinical signs: reduced body weight and increased relative liver, kidney, stomach and testes weight.

Critical effects observed:

not specified

Conclusions:

These studies were peformed in order to derive suitable dose levels for oncogenicity testing (U.S EPA, 1987c) according to U.S EPA requirements. These studies were performed as an oral cavage since irritative effects of oesophagus and mucosa of the GI tract was wanted to be excluded as it is the primary effect on first contact with external surfaces of the body.

A no-effect level for target organ (liver) was established as 125 mg/kg day bodyweight for both rat and mouse.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

125 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

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

Adequacy of study:

key study

Study period:

1998

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Repeated-dose dermal toxicity, following OECD Guideline 413 (Repeated Dose Toxicity - inhalation), studies performed with the only identified and quantified constituent of the registered substance, 2-ethylhexanol. In the absence of data on the registered substance these studies serve as a good surrogate studies: a) it represents the effects of the only identified and quantified constituent of the substance, since the constituents of this registered UVCB-substance cannot be quantified and its composition varies to the degree that composition cannot be fixed. b) studies have been performed with good quality and data is published in a peer-reviewed journal. c) they provide adequate information on effect levels of 2-ethylhexanol when administered via inhalation route. e) further vertebrate testing should not bo commenced since based on the expected exposure based on the uses of this UVCB-substance to human, low vapour pressure of this substance in ambient temperatures and exposure via inhalation is not expected to be continuous therefore chronic effect levels are sufficient to meet the safe handling of this substance and adopted risk management measures (chapter 9 and 10 of CSR).

Qualifier:

according to guideline

Guideline:

OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Male and female rats, SPF-Wistar, Chbb: THOM (supplied by Dr K. Thomae GmbH, D-88400 Biberach/Riss, Germany) were used for the study. They were about 7 wk old on delivery. The mean body weight of the male animals was approximately 238 g (standard error of the mean of max. 2.3 g)
and of the female animals 170 g (standard errorof the mean of max. 2.2 g) at the start of the study. The animals were kept individually in wire cages in
the inhalation chambers. To accustom the animals to the exposure conditions, they were exposed in the inhalation chambers to supply air for 5 days
before the exposure period. The animals were randomly (WTALOC randomization program supplied by Instem) allocated to the test groups and identified by ear tattoos. During the exposure-free periods, the animals were housed individually in wire cages (type DIII, Becker and Co., D-44579 Castrop-Rauxel, Germany) in air-conditioned rooms (temperature range of 20±24 C, relative humidity range of 30-70%). The rooms were maintained with a 12-hr light/12-hr dark cycle. KLIBA rat/mouse laboratory diet 24-343-4 (KlingentalmuÈ hle, AG, CH-4303 Kaiseraugst, Switzerland) and tap water were provided ad lib. during the exposure-free period.

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

clean air

Remarks on MMAD:

MMAD / GSD: not applicable

Details on inhalation exposure:

The test groups were exposed to the different concentrations for 6 hr on workdays over a period of 90 days (65 exposures). A control group of 10 male and 10 female rats inhaled clean air under identical exposure conditions.

The different EH inhalation chamber concentrations were achieved by conveying the substance via continuously operating metering pumps to evaporators. For 15, 40 and 120 ppm EH the vapour generation was carried out in a thermostated glass container (maintained at 46.4±50.48C) with a downstream mixing unit. 40 and 120 ppm atmospheres were generated by means of a two-component atomizer using compressed air and evaporation of the EH-aerosol. The warmed air of the control group (45.78C) and the vapour-air mixture of the EH groups were then mixed with the overall stream and distributed to a horizontal-flow whole-body exposure system (inhalation chamber glass/steel construction with volumes of approx. 1.1 m3, manufactured by BASF AG, Ludwigshafen, Germany). In the inhalation chamber of the control group, the exhaust air system was set lower (positive pressure), in the EH inhalation chambers the exhaust air system was set higher than the supply air system (negative pressure). Pressure (mean chamber pressure from -10.2 to 10.1 Pascal) and temperature (mean temperature 23.18C to 23.88C) were measured continuously. The relative humidity (mean relative humidity 41.8% to 46.2%) was checked and recorded once daily.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Samples of the inhalation atmospheres were analysed at intervals of about 15 min by gas chromatography (Hewlett-Packard gas chromatograph Model HP 5880 A with automatic sampler HP 7671 A, FID, column: 1 m2 mm with 10% Triton305 on Supelcoport, 102/120 mesh, oven temperature: 1208C. C15-paraffin was used as the internal standard).

Duration of treatment / exposure:

6 hr on workdays over a period of 90 days (65 exposures).

Frequency of treatment:

6 hr on workdays over a period of 90 days (65 exposures).

Remarks:

Doses / Concentrations:
15 ppm
Basis:
analytical conc.

Remarks:

Doses / Concentrations:
40 ppm
Basis:
analytical conc.

Remarks:

Doses / Concentrations:
120 ppm
Basis:
analytical conc.

No. of animals per sex per dose:

10

Control animals:

yes

Details on study design:

Dose selection rationale: range-finding study performed earlier. Highest dose 120 ppm equals vapour saturation at 20 Celsius degrees.

Positive control:

no required

Observations and examinations performed and frequency:

Individual body weights were recorded at the beginning of the pre-flow period, 1 day before commencement of the exposure period and then weekly
throughout the study. The difference between the body weight on the day of weighing and that of the preceding weighing was calculated as group mean average (body weight gain). This value was defined as body weight change. All animals were examined for clinical signs and mortality during exposure and daily in the non-exposure times. Ophthalmological examinations were carried out prior to the beginning of the pre-flow period and at the termination of the study using an ophthalmoscope.

Blood for clinical pathology testing was collected in randomized order by retro-orbital bleeding. Haematology (white blood cells, red blood cells,
haemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, platelets,
differential blood count) and clinical chemistry (sodium, potassium, chloride, inorganic phosphate, calcium, urea, creatinine, glucose, total bilirubin, total protein, albumin, globulins, triglycerides, cholesterol, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase) examinations were performed on day 94 of the study. A particle counter (S Plus model, Coulter, Krefeld, Germany) and an automatic analyser (Hitachi 737, Boehringer Company, Mannheim, Germany) were used for determinations of haematological and clinical chemistry parameters, respectively. For investigation of the clotting potential the thromboplastin time was measured. A ball coagulometer (KC 10 model, Amelung, Lemgo, Germany) was used for clotting analyses. For determination of cyanide-insensitive palmitoyl-CoA oxidation (Lazarow, 1981), which was carried out in liver homogenates taken after the animals had been killed, an automatic enzyme analyser (ACP 5040, Eppendorf, Hamburg, Germany) was used. Protein concentrations in liver homogenates were determined (Lowry et al., 1951).

Sacrifice and pathology:

At the end of the 90-day exposure period all animals were necropsied and assessed by gross pathology postmortem. The body weight and the weight
of the lungs, liver, kidneys, adrenal glands and testes were determined. Organs or tissues required by guidelines to be tested as well as all gross lesions were fixed in a 4% formaldehyde solution. Histological examination and assessment of findings were carried out after histotechnical processing and staining with haematoxylin and eosin.

Other examinations:

Analyses of the daily inhalation chamber concentrations revealed that the values obtained closely fit the desired nominal level.

Statistics:

Mean values and standard deviation were calculated for body weight and body weight change, haematological and clinical biochemistry parameters as well as for absolute and relative organ weights. The organ weights were statistically evaluated using the Dunnett's test (Dunnett, 1955 and 1964) for comparison of the exposure groups with the control group. The analysis of variance (Cochran, 1957) with subsequent Dunnett's test (Dunnett, 1955 and 1964) was used to compare body weight, body weight change as well as haematological and clinical biochemistry data of the treatment groups with those of the control group.

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):

not examined

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:

The body weight gain of the female animals of the 40 ppm and 120 ppm exposure groups was decreased in comparison to the control group on
day 37. The males of the 15 ppm exposure group showed a statistically significantly higher increase in body weight on day 93 compared to the control group. The differences in body weight/ body weight gain are incidental not dose-related and therefore of no toxicological relevance.

No clinical signs related to the treatment with EH were observed throughout the study period. The ophthalmological examinations revealed no effects associated with the exposure of the animals to the chemical. No deaths were recorded during the study.

The haematological or clinical biochemistry investigations showed no changes related to exposure to the chemical. The only differences observed were in the values for bilirubin in males exposed to 120 ppm (4.07 mmol/litre compared with 2.99 mmol/litre in the controls) and for glucose in females exposed to 15 ppm (6.98 mmol/litre compared with 7.81 mmol/litre in the controls). Both findings, however, are considered to be of no
toxicological significance, since they occurred only in one sex. The changes in the values for bilirubin were only registered in males, for glucose only in females. Additionally, with regard to the value for glucose, no relationship to the administered substance concentration was observed.

There was no increase in the cyanide-insensitive-palmitoyl-CoA oxidation in any treatment group when compared with the control group.

No exposure-related organ weight changes were observed.

There were no macroscopic findings that could be attributed to the treatment with the chemical. All the histomorphological findings were considered to have occurred incidentally and were not associated with the exposure to EH.

Dose descriptor:

NOAEC

Effect level:

> 120 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: 120 ppm equals 638,4 mg/m3. No adverse effect seen in any of the doses. Highest dose correspond to vapour saturation at 20 Celsius degrees of 2-ethylhexanol.

Remarks on result:

not determinable

Remarks:

no NOAEC identified

Critical effects observed:

not specified

Conclusions:

In conclusion, it may be stated that in the present 90-day inhalation study no treatment-related toxic effects were observed in rats exposed to 2-Ethylhexanol vapour concentrations of up to 120 ppm. The concentration of 120 ppm corresponds to vapour saturation at 20 Celsius degrees. Higher concentrations are only obtainable as aerosols but are not relevant for occupational areas. In particular, there were no indications of any effects of a peroxisome induction or hepatotoxicity caused by EH as could be expected when considering the observations made after oral administration of the chemical to rats. Based on these results, for male and female Wistar rats the NOAEL of inhaled EH was 120 ppm corresponding to 638.4 mg/m3.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

638 mg/m³

Study duration:

subchronic

Species:

rat

Repeated dose toxicity: inhalation - local effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

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

Adequacy of study:

key study

Study period:

1998

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Repeated-dose dermal toxicity, following OECD Guideline 413 (Repeated Dose Toxicity - inhalation), studies performed with the only identified and quantified constituent of the registered substance, 2-ethylhexanol. In the absence of data on the registered substance these studies serve as a good surrogate studies: a) it represents the effects of the only identified and quantified constituent of the substance, since the constituents of this registered UVCB-substance cannot be quantified and its composition varies to the degree that composition cannot be fixed. b) studies have been performed with good quality and data is published in a peer-reviewed journal. c) they provide adequate information on effect levels of 2-ethylhexanol when administered via inhalation route. e) further vertebrate testing should not bo commenced since based on the expected exposure based on the uses of this UVCB-substance to human, low vapour pressure of this substance in ambient temperatures and exposure via inhalation is not expected to be continuous therefore chronic effect levels are sufficient to meet the safe handling of this substance and adopted risk management measures (chapter 9 and 10 of CSR).

Qualifier:

according to guideline

Guideline:

OECD Guideline 413 (Subchronic Inhalation Toxicity: 90-Day Study)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Male and female rats, SPF-Wistar, Chbb: THOM (supplied by Dr K. Thomae GmbH, D-88400 Biberach/Riss, Germany) were used for the study. They were about 7 wk old on delivery. The mean body weight of the male animals was approximately 238 g (standard error of the mean of max. 2.3 g)
and of the female animals 170 g (standard errorof the mean of max. 2.2 g) at the start of the study. The animals were kept individually in wire cages in
the inhalation chambers. To accustom the animals to the exposure conditions, they were exposed in the inhalation chambers to supply air for 5 days
before the exposure period. The animals were randomly (WTALOC randomization program supplied by Instem) allocated to the test groups and identified by ear tattoos. During the exposure-free periods, the animals were housed individually in wire cages (type DIII, Becker and Co., D-44579 Castrop-Rauxel, Germany) in air-conditioned rooms (temperature range of 20±24 C, relative humidity range of 30-70%). The rooms were maintained with a 12-hr light/12-hr dark cycle. KLIBA rat/mouse laboratory diet 24-343-4 (KlingentalmuÈ hle, AG, CH-4303 Kaiseraugst, Switzerland) and tap water were provided ad lib. during the exposure-free period.

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

clean air

Remarks on MMAD:

MMAD / GSD: not applicable

Details on inhalation exposure:

The test groups were exposed to the different concentrations for 6 hr on workdays over a period of 90 days (65 exposures). A control group of 10 male and 10 female rats inhaled clean air under identical exposure conditions.

The different EH inhalation chamber concentrations were achieved by conveying the substance via continuously operating metering pumps to evaporators. For 15, 40 and 120 ppm EH the vapour generation was carried out in a thermostated glass container (maintained at 46.4±50.48C) with a downstream mixing unit. 40 and 120 ppm atmospheres were generated by means of a two-component atomizer using compressed air and evaporation of the EH-aerosol. The warmed air of the control group (45.78C) and the vapour-air mixture of the EH groups were then mixed with the overall stream and distributed to a horizontal-flow whole-body exposure system (inhalation chamber glass/steel construction with volumes of approx. 1.1 m3, manufactured by BASF AG, Ludwigshafen, Germany). In the inhalation chamber of the control group, the exhaust air system was set lower (positive pressure), in the EH inhalation chambers the exhaust air system was set higher than the supply air system (negative pressure). Pressure (mean chamber pressure from -10.2 to 10.1 Pascal) and temperature (mean temperature 23.18C to 23.88C) were measured continuously. The relative humidity (mean relative humidity 41.8% to 46.2%) was checked and recorded once daily.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Samples of the inhalation atmospheres were analysed at intervals of about 15 min by gas chromatography (Hewlett-Packard gas chromatograph Model HP 5880 A with automatic sampler HP 7671 A, FID, column: 1 m2 mm with 10% Triton305 on Supelcoport, 102/120 mesh, oven temperature: 1208C. C15-paraffin was used as the internal standard).

Duration of treatment / exposure:

6 hr on workdays over a period of 90 days (65 exposures).

Frequency of treatment:

6 hr on workdays over a period of 90 days (65 exposures).

Remarks:

Doses / Concentrations:
15 ppm
Basis:
analytical conc.

Remarks:

Doses / Concentrations:
40 ppm
Basis:
analytical conc.

Remarks:

Doses / Concentrations:
120 ppm
Basis:
analytical conc.

No. of animals per sex per dose:

10

Control animals:

yes

Details on study design:

Dose selection rationale: range-finding study performed earlier. Highest dose 120 ppm equals vapour saturation at 20 Celsius degrees.

Positive control:

no required

Observations and examinations performed and frequency:

Individual body weights were recorded at the beginning of the pre-flow period, 1 day before commencement of the exposure period and then weekly
throughout the study. The difference between the body weight on the day of weighing and that of the preceding weighing was calculated as group mean average (body weight gain). This value was defined as body weight change. All animals were examined for clinical signs and mortality during exposure and daily in the non-exposure times. Ophthalmological examinations were carried out prior to the beginning of the pre-flow period and at the termination of the study using an ophthalmoscope.

Blood for clinical pathology testing was collected in randomized order by retro-orbital bleeding. Haematology (white blood cells, red blood cells,
haemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, platelets,
differential blood count) and clinical chemistry (sodium, potassium, chloride, inorganic phosphate, calcium, urea, creatinine, glucose, total bilirubin, total protein, albumin, globulins, triglycerides, cholesterol, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase) examinations were performed on day 94 of the study. A particle counter (S Plus model, Coulter, Krefeld, Germany) and an automatic analyser (Hitachi 737, Boehringer Company, Mannheim, Germany) were used for determinations of haematological and clinical chemistry parameters, respectively. For investigation of the clotting potential the thromboplastin time was measured. A ball coagulometer (KC 10 model, Amelung, Lemgo, Germany) was used for clotting analyses. For determination of cyanide-insensitive palmitoyl-CoA oxidation (Lazarow, 1981), which was carried out in liver homogenates taken after the animals had been killed, an automatic enzyme analyser (ACP 5040, Eppendorf, Hamburg, Germany) was used. Protein concentrations in liver homogenates were determined (Lowry et al., 1951).

Sacrifice and pathology:

At the end of the 90-day exposure period all animals were necropsied and assessed by gross pathology postmortem. The body weight and the weight
of the lungs, liver, kidneys, adrenal glands and testes were determined. Organs or tissues required by guidelines to be tested as well as all gross lesions were fixed in a 4% formaldehyde solution. Histological examination and assessment of findings were carried out after histotechnical processing and staining with haematoxylin and eosin.

Other examinations:

Analyses of the daily inhalation chamber concentrations revealed that the values obtained closely fit the desired nominal level.

Statistics:

Mean values and standard deviation were calculated for body weight and body weight change, haematological and clinical biochemistry parameters as well as for absolute and relative organ weights. The organ weights were statistically evaluated using the Dunnett's test (Dunnett, 1955 and 1964) for comparison of the exposure groups with the control group. The analysis of variance (Cochran, 1957) with subsequent Dunnett's test (Dunnett, 1955 and 1964) was used to compare body weight, body weight change as well as haematological and clinical biochemistry data of the treatment groups with those of the control group.

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):

not examined

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:

The body weight gain of the female animals of the 40 ppm and 120 ppm exposure groups was decreased in comparison to the control group on
day 37. The males of the 15 ppm exposure group showed a statistically significantly higher increase in body weight on day 93 compared to the control group. The differences in body weight/ body weight gain are incidental not dose-related and therefore of no toxicological relevance.

No clinical signs related to the treatment with EH were observed throughout the study period. The ophthalmological examinations revealed no effects associated with the exposure of the animals to the chemical. No deaths were recorded during the study.

The haematological or clinical biochemistry investigations showed no changes related to exposure to the chemical. The only differences observed were in the values for bilirubin in males exposed to 120 ppm (4.07 mmol/litre compared with 2.99 mmol/litre in the controls) and for glucose in females exposed to 15 ppm (6.98 mmol/litre compared with 7.81 mmol/litre in the controls). Both findings, however, are considered to be of no
toxicological significance, since they occurred only in one sex. The changes in the values for bilirubin were only registered in males, for glucose only in females. Additionally, with regard to the value for glucose, no relationship to the administered substance concentration was observed.

There was no increase in the cyanide-insensitive-palmitoyl-CoA oxidation in any treatment group when compared with the control group.

No exposure-related organ weight changes were observed.

There were no macroscopic findings that could be attributed to the treatment with the chemical. All the histomorphological findings were considered to have occurred incidentally and were not associated with the exposure to EH.

Dose descriptor:

NOAEC

Effect level:

> 120 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: 120 ppm equals 638,4 mg/m3. No adverse effect seen in any of the doses. Highest dose correspond to vapour saturation at 20 Celsius degrees of 2-ethylhexanol.

Remarks on result:

not determinable

Remarks:

no NOAEC identified

Critical effects observed:

not specified

Conclusions:

In conclusion, it may be stated that in the present 90-day inhalation study no treatment-related toxic effects were observed in rats exposed to 2-Ethylhexanol vapour concentrations of up to 120 ppm. The concentration of 120 ppm corresponds to vapour saturation at 20 Celsius degrees. Higher concentrations are only obtainable as aerosols but are not relevant for occupational areas. In particular, there were no indications of any effects of a peroxisome induction or hepatotoxicity caused by EH as could be expected when considering the observations made after oral administration of the chemical to rats. Based on these results, for male and female Wistar rats the NOAEL of inhaled EH was 120 ppm corresponding to 638.4 mg/m3.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

638 mg/m³

Study duration:

subchronic

Species:

rat

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: dermal

Type of information:

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

Adequacy of study:

key study

Study period:

1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Repeated-dose dermal toxicity, similar to that of OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test), studies performed with the only identified and quantified constituent of the target UVCB-substance, 2-ethylhexanol. Studies performed with pregnant Fischer F344 rats and they study the developmental toxicity of 2-ethylhexanol. In the absence of data on the target UVCB-substance these studies serve as a good surrogate studies: a) it represents the effects of the only identified and quantified consituent of the substance, since the consituents of this target UVCB-substance cannot be recognized and its composition varies to the degree that composition cannot be fixed. b) studies have been performed with good quality and data is published in a peer-reviewed journal. c) they provide adequate information on effect levels of 2-ethylhexanol when administered via dermal route. d) This target substance is classified as skin irritant, based on its use and exposure scenarios a repeated exposure via dermal route cannot be expected since first contact to skin will exert irritating effects. e) no further vertebrate testing should not be commenced since based on the expected exposure based on the uses of this UVCB-substance to human, dermal route exposure is not expected to be continuous therefore chronic effect levels are sufficient to meet the safe handling of this substance and adopted risk management measures based on its irritant properties are enough (chapter 9 and 10 of CSR).

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

yes

Remarks:

does not follow guidelines but represents similar type of approach.

Principles of method if other than guideline:

Pregnant Fischer 344 rats were studied in two studies with an occluded dermal application:
1. Range-finding study
2. Main study

GLP compliance:

yes

Remarks:

U.S EPA Health effects guidelines and Good Laboratory Practice regulations.

Limit test:

no

Species:

rat

Strain:

Fischer 344

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Virgin F344 rats (CDF(R) F344 Crl./Br.)
- Source: Charles River Breeding Laboratories (Kingston, NY)
- Age at study initiation: 70 days / 63 days
- Weight at study initiation: males 175-200g / females 130-150g
- Gestational day 0: appearance of copulatory plug
- Housing: singly
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 2-week quarantine period

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 42-65
- Air changes (per hr): not disclosed
- Photoperiod (hrs dark / hrs light): 12 hour

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on exposure:

TEST SITE
- Area of exposure: clipped and shaved dorsal skin of 9,7 cm2 (in the report ca. 1,5 cupic inches)
- Type of wrap if used:2 cupic inch gauze square, occluded with a Lycra-Spandex with Velcro closures. A 1.5x2.5 in. polyethylene patch was attached at the application site under the jacket.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): wiped gently with moist gauze and blotted dry.
- Time after start of exposure: 6-hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit):
1.Rangefinding study: 0.5, 1, 2, 3 (ml/kg/day) equivalent to 420, 840, 1680, 2520 (mg/kg/day). Positive control: 2-methoxyethanol: 0.5 and 1.5 (ml/kg/day) equivalent to 420 and 1260 (mg/kg/day). Oral cavage reference compound: Valproic acid 400 mg/kg bw/day.
2. Main study: 0.3, 1, 3 (ml/kg/day) equivalent to 252, 840, 2520 (mg/kg/day).Positive control: 2-methoxyethanol 1 (ml/kg/day) equivalent to 840 (mg/kg/day)
- Concentration (if solution): 100%
- Constant volume or concentration used: no


VEHICLE
- No vehicle

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Gas chromatographic: at the beginning of the studies and in the end of the studies. Test material was verified to be stable over the treatment periods.

Duration of treatment / exposure:

6-hours per day

Frequency of treatment:

daily

Remarks:

Doses / Concentrations:
252 mg/kg bw day
Basis:
analytical per unit body weight

Remarks:

Doses / Concentrations:
420 mg/kg bw day
Basis:
analytical per unit body weight

Remarks:

Doses / Concentrations:
840 mg/kg bw day
Basis:
analytical per unit body weight

Remarks:

Doses / Concentrations:
1680 mg/kg bw day
Basis:
analytical per unit body weight

Remarks:

Doses / Concentrations:
2520 mg/kg bw day
Basis:
analytical per unit body weight

No. of animals per sex per dose:

Range-finding study: 8 animals per study group
Main study: 25 animals per study group

Control animals:

yes, sham-exposed

other: 2-methoxyethanol, positive control... (see attached file)

Details on study design:

- Dose selection rationale: range-finding study performed
- Rationale for animal assignment (if not random): random

Positive control:

2-methoxyethanol (undiluted, dermal route) and valproic acid (2ml cavage).

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

DERMAL IRRITATION (if dermal study): Yes
- Time schedule for examinations: daily, after each 6-hour treatment period. Irritation was scored according to FHSA standard.

BODY WEIGHT: Yes
- Time schedule for examinations: 0, 6, 9, 12, 15 and 21.

FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes, 3-day interval from GDS 0 thorugh 21.

FOOD EFFICIENCY: No data

WATER CONSUMPTION: No data

Sacrifice and pathology:

MATERNAL AND FETAL OBSERVATIONS AT NECROPSY
- females which delivered early were terminated, examined grossly, and removed from the study. Surviving females from both studies were euthanized with CO2 asphyxiation on day 21. Maternal body cavities were opened by midline thoracolaporotomy. Maternal uterine and liver weights (both studies) and spleen, adrenals, kidneys, and thymus weights (main study) were recorded. Corpora lutea and uterine implantation sites were counted, and ovaries, cervices, vaginas, and abdominal and thoracic cavities were examined grossly. Uteri were examined externally, removed, and dissected longitudinally to expose contents. All live and dead fetuses and resorption sites were noted; uteri from nongravid females were tested for early resorptions with ammonium sulfide solution.

MALFORMATIONS AND VARIATIONS

All live fetuses were sexed, weighed, and examined for external malformations and for variations. After external examination approximately 50% of the live fetuses per litter from the main study were examined for visceral and craniofacial abnormalities. The remainder were examined for skeletal malformations and variations after evisceration, fixation in ethanol, and staining with alizarin red S.

Statistics:

The units of comparison were pregnant rat or the litter. Quantitative continuous variables such as maternal body and organ weights were compared to 2-ethylhexanol and sham control groups, between dermal reference (2-methoxyethanol) and sham control groups, and between cavage reference and naive control group. Levene's test for equal variances, ANOVA, and t-tests with Bonferroni probabilities for pairwise comparisons were used. The pooled t-test was used when Levene's test indicated homogeneous variances, all groups were compared by an ANOVA for unequal variances followed when necessary by the separate variance t-test.

Clinical signs:

no effects observed

Dermal irritation:

effects observed, treatment-related

Description (incidence and severity):

Observed daily, measured before and after 6-h treatment period. 252 mg/kg bw/day, suitable as DNEL.

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

1680 and 2520 mg/kg bw/day groups reduced weight gain.

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:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

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:

DERMAL IRRITATION
Treatment -related effects attributable to 2-ethylhexanol at the application site were exfoliation, encrustation and erythema. There was no edema. Exfoliation and encrustation occurred in both range-finding and main studies at all treatment levels of 2-ethylhexanol. There was no erythema or edema in sham controls. Erythema occurred during treatment with 2-ethylhexanol at levels of 830 mg/kg bw/day and above. Draize scores revealed that irritation was essentially mild. Maximum mean treatment scores occurred on gd10 at 1680 mg/kg bw/day (draize-score 0.4, range-finding study), on gd 11 at 2520 mg/kg bw/day (draize-score 1.1, range-finding study), and on gd 14 at 1680 mg/kg bw/day (draize-score 0.3, main study).

There was no exacerbation by continuent treatment. Erythema subsided immediately after cessation of treatment. There was no exfoliation, encrustation, erythema or edema at the application of positive control, 2-methoxyethanol.

Nasal encrustation and ocula encrustation and discharge were seen mostly in the main study with 2-ethylhexanol and 2-methoxyethanol and in sham controls. Since these effects occurred in controls and mostly disappeared after treatment ceased they are attributed to handling stress.

Dose descriptor:

NOAEL

Effect level:

> 252 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: clinical signs: skin irritation

Dose descriptor:

NOAEL

Effect level:

> 840 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: Reduced weight gain with doses 1680 (range-finding study) and 2520 (main study) mg/kg bw/day

Critical effects observed:

not specified

Conclusions:

Repeated dermal exposure of 2-ethylhexanol lead with high doses (1680 and 2520 mg/kg bw/day) to slight reduction in body weight. otherwise It did not indicate properties which would lead to a concern for toxicity via dermal route. Tthere was no exacerbation by continuent treatment. Erythema subsided immediately after cessation of treatment. The only effect was mild skin irritation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

840 mg/kg bw/day

Study duration:

subacute

Species:

rat

Repeated dose toxicity: dermal - local effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: dermal

Type of information:

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

Adequacy of study:

key study

Study period:

1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Repeated-dose dermal toxicity, similar to that of OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test), studies performed with the only identified and quantified constituent of the target UVCB-substance, 2-ethylhexanol. Studies performed with pregnant Fischer F344 rats and they study the developmental toxicity of 2-ethylhexanol. In the absence of data on the target UVCB-substance these studies serve as a good surrogate studies: a) it represents the effects of the only identified and quantified consituent of the substance, since the consituents of this target UVCB-substance cannot be recognized and its composition varies to the degree that composition cannot be fixed. b) studies have been performed with good quality and data is published in a peer-reviewed journal. c) they provide adequate information on effect levels of 2-ethylhexanol when administered via dermal route. d) This target substance is classified as skin irritant, based on its use and exposure scenarios a repeated exposure via dermal route cannot be expected since first contact to skin will exert irritating effects. e) no further vertebrate testing should not be commenced since based on the expected exposure based on the uses of this UVCB-substance to human, dermal route exposure is not expected to be continuous therefore chronic effect levels are sufficient to meet the safe handling of this substance and adopted risk management measures based on its irritant properties are enough (chapter 9 and 10 of CSR).

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

yes

Remarks:

does not follow guidelines but represents similar type of approach.

Principles of method if other than guideline:

Pregnant Fischer 344 rats were studied in two studies with an occluded dermal application:
1. Range-finding study
2. Main study

GLP compliance:

yes

Remarks:

U.S EPA Health effects guidelines and Good Laboratory Practice regulations.

Limit test:

no

Species:

rat

Strain:

Fischer 344

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Virgin F344 rats (CDF(R) F344 Crl./Br.)
- Source: Charles River Breeding Laboratories (Kingston, NY)
- Age at study initiation: 70 days / 63 days
- Weight at study initiation: males 175-200g / females 130-150g
- Gestational day 0: appearance of copulatory plug
- Housing: singly
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 2-week quarantine period

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 42-65
- Air changes (per hr): not disclosed
- Photoperiod (hrs dark / hrs light): 12 hour

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on exposure:

TEST SITE
- Area of exposure: clipped and shaved dorsal skin of 9,7 cm2 (in the report ca. 1,5 cupic inches)
- Type of wrap if used:2 cupic inch gauze square, occluded with a Lycra-Spandex with Velcro closures. A 1.5x2.5 in. polyethylene patch was attached at the application site under the jacket.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): wiped gently with moist gauze and blotted dry.
- Time after start of exposure: 6-hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit):
1.Rangefinding study: 0.5, 1, 2, 3 (ml/kg/day) equivalent to 420, 840, 1680, 2520 (mg/kg/day). Positive control: 2-methoxyethanol: 0.5 and 1.5 (ml/kg/day) equivalent to 420 and 1260 (mg/kg/day). Oral cavage reference compound: Valproic acid 400 mg/kg bw/day.
2. Main study: 0.3, 1, 3 (ml/kg/day) equivalent to 252, 840, 2520 (mg/kg/day).Positive control: 2-methoxyethanol 1 (ml/kg/day) equivalent to 840 (mg/kg/day)
- Concentration (if solution): 100%
- Constant volume or concentration used: no


VEHICLE
- No vehicle

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Gas chromatographic: at the beginning of the studies and in the end of the studies. Test material was verified to be stable over the treatment periods.

Duration of treatment / exposure:

6-hours per day

Frequency of treatment:

daily

Remarks:

Doses / Concentrations:
252 mg/kg bw day
Basis:
analytical per unit body weight

Remarks:

Doses / Concentrations:
420 mg/kg bw day
Basis:
analytical per unit body weight

Remarks:

Doses / Concentrations:
840 mg/kg bw day
Basis:
analytical per unit body weight

Remarks:

Doses / Concentrations:
1680 mg/kg bw day
Basis:
analytical per unit body weight

Remarks:

Doses / Concentrations:
2520 mg/kg bw day
Basis:
analytical per unit body weight

No. of animals per sex per dose:

Range-finding study: 8 animals per study group
Main study: 25 animals per study group

Control animals:

yes, sham-exposed

other: 2-methoxyethanol, positive control... (see attached file)

Details on study design:

- Dose selection rationale: range-finding study performed
- Rationale for animal assignment (if not random): random

Positive control:

2-methoxyethanol (undiluted, dermal route) and valproic acid (2ml cavage).

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

DERMAL IRRITATION (if dermal study): Yes
- Time schedule for examinations: daily, after each 6-hour treatment period. Irritation was scored according to FHSA standard.

BODY WEIGHT: Yes
- Time schedule for examinations: 0, 6, 9, 12, 15 and 21.

FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes, 3-day interval from GDS 0 thorugh 21.

FOOD EFFICIENCY: No data

WATER CONSUMPTION: No data

Sacrifice and pathology:

MATERNAL AND FETAL OBSERVATIONS AT NECROPSY
- females which delivered early were terminated, examined grossly, and removed from the study. Surviving females from both studies were euthanized with CO2 asphyxiation on day 21. Maternal body cavities were opened by midline thoracolaporotomy. Maternal uterine and liver weights (both studies) and spleen, adrenals, kidneys, and thymus weights (main study) were recorded. Corpora lutea and uterine implantation sites were counted, and ovaries, cervices, vaginas, and abdominal and thoracic cavities were examined grossly. Uteri were examined externally, removed, and dissected longitudinally to expose contents. All live and dead fetuses and resorption sites were noted; uteri from nongravid females were tested for early resorptions with ammonium sulfide solution.

MALFORMATIONS AND VARIATIONS

All live fetuses were sexed, weighed, and examined for external malformations and for variations. After external examination approximately 50% of the live fetuses per litter from the main study were examined for visceral and craniofacial abnormalities. The remainder were examined for skeletal malformations and variations after evisceration, fixation in ethanol, and staining with alizarin red S.

Statistics:

The units of comparison were pregnant rat or the litter. Quantitative continuous variables such as maternal body and organ weights were compared to 2-ethylhexanol and sham control groups, between dermal reference (2-methoxyethanol) and sham control groups, and between cavage reference and naive control group. Levene's test for equal variances, ANOVA, and t-tests with Bonferroni probabilities for pairwise comparisons were used. The pooled t-test was used when Levene's test indicated homogeneous variances, all groups were compared by an ANOVA for unequal variances followed when necessary by the separate variance t-test.

Clinical signs:

no effects observed

Dermal irritation:

effects observed, treatment-related

Description (incidence and severity):

Observed daily, measured before and after 6-h treatment period. 252 mg/kg bw/day, suitable as DNEL.

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

1680 and 2520 mg/kg bw/day groups reduced weight gain.

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:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

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:

DERMAL IRRITATION
Treatment -related effects attributable to 2-ethylhexanol at the application site were exfoliation, encrustation and erythema. There was no edema. Exfoliation and encrustation occurred in both range-finding and main studies at all treatment levels of 2-ethylhexanol. There was no erythema or edema in sham controls. Erythema occurred during treatment with 2-ethylhexanol at levels of 830 mg/kg bw/day and above. Draize scores revealed that irritation was essentially mild. Maximum mean treatment scores occurred on gd10 at 1680 mg/kg bw/day (draize-score 0.4, range-finding study), on gd 11 at 2520 mg/kg bw/day (draize-score 1.1, range-finding study), and on gd 14 at 1680 mg/kg bw/day (draize-score 0.3, main study).

There was no exacerbation by continuent treatment. Erythema subsided immediately after cessation of treatment. There was no exfoliation, encrustation, erythema or edema at the application of positive control, 2-methoxyethanol.

Nasal encrustation and ocula encrustation and discharge were seen mostly in the main study with 2-ethylhexanol and 2-methoxyethanol and in sham controls. Since these effects occurred in controls and mostly disappeared after treatment ceased they are attributed to handling stress.

Dose descriptor:

NOAEL

Effect level:

> 252 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: clinical signs: skin irritation

Dose descriptor:

NOAEL

Effect level:

> 840 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: Reduced weight gain with doses 1680 (range-finding study) and 2520 (main study) mg/kg bw/day

Critical effects observed:

not specified

Conclusions:

Repeated dermal exposure of 2-ethylhexanol lead with high doses (1680 and 2520 mg/kg bw/day) to slight reduction in body weight. otherwise It did not indicate properties which would lead to a concern for toxicity via dermal route. Tthere was no exacerbation by continuent treatment. Erythema subsided immediately after cessation of treatment. The only effect was mild skin irritation.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Additional information

Repeated oral toxicity

Subchronic oral study (Astill et al. 1996) was conducted using 2-ethylhexanol. It is the only identified and quantified constituent of the target substance,(> 16 - < 35 % (w/w) 2-ethylhexanol). The NOAEL was determined to be 125 mg/kg bw/day. The result of this study suggests that the target substance does not raise a concern for repeated dose toxicity.

Repeated inhalation toxicity

Due to low vapour pressure of the target substance, inhalation toxicity was deemed scientifically unjustified to be performed since it would have required generation of aerosols, which are considered irrelevant for occupational and general population, and the exposure scenarios expected (see chapter 9 of CSR). Qualitative inhalation assessment for the worker was performed for potential exposures at elevated temperatures (see chapter 9 of CSR). The study (Klimisch, et al., 1998) presented for surrogate substance (2 -ethylhexanol) did not indicate any adverse effects up to its vapour saturation point 120 ppm (638 mg/m³) in chronic 90 -day study.

Repeated dermal toxicity

Repeated-dose toxicity study by Tyl et al. (1992) via dermal route is presented for the only identified and quantified constituent of the target substance, 2-ethylhexanol. The NOAEL (systemic effects) was established to be 840 mg/kg bw/day based on the effects on the body weight gain and the NOAEL (local effects) was established to be 252 mg/kg bw/day based on the skin irritation. These results suggest that the target substance does not raise a concern for repeated dose toxicity via dermal route. These values can be used to derive appropriate effect levels for chemical safety assessment. Dermal route was deemed relevant for human exposure and quantitative ECETOC Tier 1 TRA dermal modelling results for industrial and professional uses and consumer use of a fuel additive.

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
There are no studies available for the target UVCB-substance. Repeated-dose toxicity studies for oral route are presented from the only identified and quantified constituent of the target substance, 2-ethylhexanol.

Justification for selection of repeated dose toxicity inhalation - systemic effects endpoint:
There are no studies available for the target UVCB-substance. Repeated dose inhalation toxicity study is presented from the only identified and quantified constituent of the target substance, 2-ethylhexanol.

Justification for selection of repeated dose toxicity inhalation - local effects endpoint:
There are no studies available for the target UVCB-substance. Repeated-dose toxicity studies for dermal route are presented from the only identified and quantified constituent of the target substance, 2-ethylhexanol.

Justification for selection of repeated dose toxicity dermal - systemic effects endpoint:
There are no studies available for the target UVCB-substance. Repeated-dose toxicity studies for dermal route are presented from the only identified and quantified constituent of the target substance, 2-ethylhexanol.

Justification for selection of repeated dose toxicity dermal - local effects endpoint:
There are no studies available for the target UVCB-substance. Repeated-dose toxicity studies for dermal route are presented from the only identified and quantified constituent of the target substance, 2-ethylhexanol.

Repeated dose toxicity: via oral route - systemic effects (target organ) digestive: esophagus; digestive: liver; neurologic: central nervous system; urogenital: kidneys

Repeated dose toxicity: dermal - systemic effects (target organ) other: skin

Justification for classification or non-classification

Based on the observations made after the subchronic exposures by oral, inhalation and dermal routes, there is no need for classification of the target substance for repeated toxicity in accordance with the criteria of CLP Regulation 1272/2008 and the EU directive 67/548/EEC.