Hydrocarbons, C12-C16, n-alkanes, isoalkanes, cyclics, aromatics (2-25%)

Repeated dose toxicity: inhalation

Administrative data

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

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

Adequacy of study:

key study

Study period:

1980

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study.

Justification for type of information:

Hydrocarbons, C12-C16, n-alkanes, isoalkanes, cyclics, aromatics (2-25%) straddles Hydrocarbons, C9-C14, Aliphatics, (2-25% Aromatics) and Hydrocarbons, C14-C20, Aliphatics (2-30% Aromatics). Read across justification documents have been provided for the same in Section 13 of the dossier. For this substance, a worst case scenario approach has been used for each endpoint.

Cross-reference

Reason / purpose for cross-reference:

read-across: supporting information

Reference

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

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

Adequacy of study:

key study

Study period:

1980

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study.

Justification for type of information:

Hydrocarbons, C12-C16, n-alkanes, isoalkanes, cyclics, aromatics (2-25%) straddles Hydrocarbons, C9-C14, Aliphatics, (2-25% Aromatics) and Hydrocarbons, C14-C20, Aliphatics (2-30% Aromatics). Read across justification documents have been provided for the same in Section 13 of the dossier. For this substance, a worst case scenario approach has been used for each endpoint.

Reason / purpose for cross-reference:

read-across source

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 examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
There were no deaths during the experiment. High exposure animals were lethargic when examined 30 minutes after exposure. Animals were fully recovered by the next morning.

BODY WEIGHT AND WEIGHT GAIN
Males in the medium and high exposure groups had body weights significantly than controls. High exposure females also had body weights slower than controls.

FOOD CONSUMPTION
No significant differences in food consumption were observed.

WATER CONSUMPTION
Exposed animals showed significant increase in water consumption, particularly animals in the high exposure group.

HAEMATOLOGY
Male PCV, erythrocyte count, mean cell volume, and mean corpuscular hemoglobin were significantly different from controls at all exposure levels. In females, the number of white cells, and mean cell volume were increased in the high exposure group.

CLINICAL CHEMISTRY
Alkaline phosphatase in both sexes, male aspartate amino transferase, and female albumin levels were significantly higher in the high exposure group. Female total protein was also significantly increased in the medium and high exposure groups.

ORGAN WEIGHTS
Male kidney weights at all exposure levels, and spleen weights in the medium and high exposure levels were significantly increased. Female kidney weights at the medium and high exposure levels, and liver weights at all exposure levels were also increased. However, there were no lesions in these organs found during the histopathology examination. These changes in femals were likely hyperfunctional adaptations of the organs rather than a toxic effect.

GROSS PATHOLOGY
Males in the medium and high exposure groups showed a low incidence of splenic enlargement, renal pallor, and hepatic darkening.

HISTOPATHOLOGY: NON-NEOPLASTIC
Kidneys - Male rats in all exposure group showed multiple, hyaline intracytoplasmic, inclusion droplets in the epithelium of the proximal convoluted tubules of their kidneys. This change did not seem to be dose related. These males also showed increase in the number and size of lysosomes in the cytoplasm of the proximal convoluted tubules. Exposure males also had more frequent focal tubular basophilia. Three males in the high exposure group also showed focal tubular dilatation and inspissated debris in the tubular laminae.

Spleen - Males in the medium and high exposure groups showed accelerated erythropoietic activity and increased hemosiderin deposition. Females in the high exposure group showed increased hemosiderin deposition, and mild extramedullary hematopoiesis.

Lungs - No treatment related effects were noted.

Key result

Dose descriptor:

NOAEC

Effect level:

690 ppm

Sex:

female

Basis for effect level:

other: 3950 mg/m3

Key result

Dose descriptor:

LOAEC

Effect level:

345 ppm

Sex:

male

Basis for effect level:

other: 1975 mg/m3; Increased kidney weights as a result of an alpha2u-globulin-mediated process that is not regarded as relevant to humans

Key result

Dose descriptor:

LOAEC

Effect level:

1 293 ppm

Sex:

female

Basis for effect level:

other: 7400 mg/m3

Critical effects observed:

not specified

Mean Body Weights of Male Rats (g)

Week	Control	345 ppm	690 ppm	1293 ppm	Standard Deviation of a Single Observation
0	397	396	396	398	24.9
1	422	422	396	396	20.9 (cage effect)
2	435	434	400	402	21.7
3	444	441	407	407	26.0
4	450	444	423	413	25.5
5	455	452	432	423	25.4
6	464	461	443	431	25.0
7	471	473	449	437	34.2 (cage effect)
8	480	479	460	445	28.2
9	486	486	466	448	30.9
10	494	490	469	453	35.6
11	495	491	478	458	34.9
12	502	495	481	466	36.7
13	512	503	491	473	38.4

Mean Body Weights of Female Rats (g)

Week	Control	345 ppm	690 ppm	1293 ppm		Standard Deviation of a Single Observation
0	244	245	244	245	14.2
1	249	253	252	245	6.2
2	256	261	257	248	9.0
3	264	264	263	252	10.1
4	264	269	266	254	13.5 (cage effect)
5	266	271	267	261	12.9 (cage effect)
6	269	274	269	261	11.4
7	274	278	273	264	11.5
8	275	277	274	263	12.5
9	275	277	272	266	13.8 (cage effect)
10	274	278	273	264	11.3
11	275	279	276	267	12.0
12	280	284	280	271	12.1
13	286	291	289	273	13.3

Conclusions:

The 90-day LOAEC for male rats was 345 ppm (inhalation). This value is based on increased kidney weights as a result of an alpha2u-globulin-mediated process that is not regarded as relevant to humans. The LOAEC was established at 1293 ppm (7400 mg/m3) due to a significant body weight reduction. No other effects were noted. The NOAEC for female rats was 690 ppm (3950 mg/m3).

Executive summary:

This data is being read across from the source study that tested Hydrocarbons, C9-C12, n-alkanes, isoalkanes, cyclics, aromatics (2-25%) based on analogue read across.

This study evaluated the subchronic toxicity of low aromatic white spirits to rats when exposed via inhalation. Groups of 18 rats per sex were exposed to 345, 690, or 1293 ppm of test substance for 6 hrs/day, 5 days/week, for 13 weeks. The highest concentration, 1293 ppm, was near the saturation point for test substance vapor. Rats were observed for clinical signs, mortality, food consumption, water consumption, and body weight. At the end of the exposure period, the animals were sacrificed, and clinical chemistry, hematology, gross pathology, and histopathology parameters were examined. Male rats at all exposure levels had degenerative effects of the as a result of an alpha2u-globulin-mediated process that is not regarded as relevant to humans. The LOAEC was established at 1293 ppm (7400 mg/m³) due to a significant body weight reduction. No other effects were noted. The LOAEC for female rats was 690 ppm (3950 mg/m³).  

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

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

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Hydrocarbons, C9-C12, n-alkanes, isoalkanes, cyclics, aromatics (2-25%)

EC Number:

919-446-0

Molecular formula:

None available. Not a single isomer, see remarks.

IUPAC Name:

Hydrocarbons, C9-C12, n-alkanes, isoalkanes, cyclics, aromatics (2-25%)

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Shell Toxicology Laboratory (Tunstall) Breeding Unit
- Age at study initiation: 10-13 weeks
- Weight at study initiation: male mean weight: 396-398, female mean weight: 244-245
- Fasting period before study: food removed during exposure
- Housing: three per sex in hanging aluminum cages with stainless steel mesh bases 14 x 10 x 7 in, with two layers of cages for a total of twelve cages per exposure chamber
- Diet (e.g. ad libitum): LAD 1, Spillers Spratts Ltd., replenished daily after exposure
- Water (e.g. ad libitum): tap water ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17-22
- Humidity (%): 32-61

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: 1 m³ aluminum exposure chamber
- Method of holding animals in test chamber: cages
- Source and rate of air: laboratory air
- Method of conditioning air: dust filters
- System of generating particulates/aerosols: Solvent was evaporated into the air stream using micrometering pumps and vaporizers. Vaporizers were quartz tubes heated to a surface temperature required for complete evaporation of the solvent.
- Temperature, humidity, pressure in air chamber: 17-22°C, 32-61%
- Air flow rate: 2.0 ± 0.03 m³/min
- Air change rate:
- Method of particle size determination:
- Treatment of exhaust air: Air was exhausted into the laboratory exhaust which exited on the roof of the laboratory.

TEST ATMOSPHERE
- Brief description of analytical method used: total hydrocarbon analyser fitted with a flame-ionization detector

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Total hydrocarbon analyser fitted with a flame-ionization detector.

Duration of treatment / exposure:

6 hours/day

Frequency of treatment:

5 days/week for 13 weeks

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
1293 ppm (7400 mg/m3)
Basis:
analytical conc.

Doses / concentrations 2

Remarks:

Doses / Concentrations:
690 ppm (3950 mg/m3)
Basis:
analytical conc.

Doses / concentrations 3

Remarks:

Doses / Concentrations:
345 ppm (1975 mg/m3)
Basis:
analytical conc.

No. of animals per sex per dose:

18 per sex

Control animals:

yes, concurrent no treatment

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily
- Cage side observations: general health and behaviour

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION: Yes
- Time schedule for examinations: weekly

WATER CONSUMPTION: Yes
- Time schedule for examinations: weekly

HAEMATOLOGY: Yes
- Time schedule for collection of blood: end of experiment
- How many animals: all animals
- Parameters checked: erythrocyte count, mean cell volume, hemoglobin, leucocyte count, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, hematocrit, red cell fragilities, reticulocyte count, prothrombin time, kaolin-cephalin coagulation time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: end of experiment
- How many animals: all animals
- Parameters checked: total protein, urea nitrogen, alkaline phosphatase, aspartate amino transferase, alanine animo transferase, sodium, potassium, chloride, albumin, bilirubin
- Other: Estimations of blood glucose were made after 10 weeks of exposure using samples taken from the tail vein.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes, all animals were examined and the following organs weighed: brain, liver, heart, spleen, kidneys, and testes.

HISTOPATHOLOGY: Yes, the following tissues of the high and medium exposure animals and the control animals were examined: mammary gland, mesenteric lymph node, pancreas, stomach, intestine at 5 levels, caecum, spleen, liver, adrenals, kidneys, ovaries or testes, uterus or prostate, seminal vesicles, urinary bladder, thyroid, trachea, heart, lungs, nasal cavity, thymus, eye and lachrymal glands, salivary glands, brain, spinal cord, pituitary, tongue, sciatic nerves, muscle, knee joint and femur, and macroscopic lesions. The kidneys of low exposure males were also examined.

Statistics:

Body and organ weights were analysed using covariance analysis, with initial body weight as the covariance. Means were adjusted if a significant covariance was found. Organs weights were also analysed using terminal body weights as the covariance. Clinical chemistry and hematological parameters were analysed using analysis of variance. Differences between treatment groups and controls were analysed using Williams t-test. Dunnett's test was used if a monotonic dose response could not be assumed.

Results and discussion

Results of examinations

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 examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Gross pathological findings:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
There were no deaths during the experiment. High exposure animals were lethargic when examined 30 minutes after exposure. Animals were fully recovered by the next morning.

BODY WEIGHT AND WEIGHT GAIN
Males in the medium and high exposure groups had body weights significantly than controls. High exposure females also had body weights slower than controls.

FOOD CONSUMPTION
No significant differences in food consumption were observed.

WATER CONSUMPTION
Exposed animals showed significant increase in water consumption, particularly animals in the high exposure group.

HAEMATOLOGY
Male PCV, erythrocyte count, mean cell volume, and mean corpuscular hemoglobin were significantly different from controls at all exposure levels. In females, the number of white cells, and mean cell volume were increased in the high exposure group.

CLINICAL CHEMISTRY
Alkaline phosphatase in both sexes, male aspartate amino transferase, and female albumin levels were significantly higher in the high exposure group. Female total protein was also significantly increased in the medium and high exposure groups.

ORGAN WEIGHTS
Male kidney weights at all exposure levels, and spleen weights in the medium and high exposure levels were significantly increased. Female kidney weights at the medium and high exposure levels, and liver weights at all exposure levels were also increased. However, there were no lesions in these organs found during the histopathology examination. These changes in femals were likely hyperfunctional adaptations of the organs rather than a toxic effect.

GROSS PATHOLOGY
Males in the medium and high exposure groups showed a low incidence of splenic enlargement, renal pallor, and hepatic darkening.

HISTOPATHOLOGY: NON-NEOPLASTIC
Kidneys - Male rats in all exposure group showed multiple, hyaline intracytoplasmic, inclusion droplets in the epithelium of the proximal convoluted tubules of their kidneys. This change did not seem to be dose related. These males also showed increase in the number and size of lysosomes in the cytoplasm of the proximal convoluted tubules. Exposure males also had more frequent focal tubular basophilia. Three males in the high exposure group also showed focal tubular dilatation and inspissated debris in the tubular laminae.

Spleen - Males in the medium and high exposure groups showed accelerated erythropoietic activity and increased hemosiderin deposition. Females in the high exposure group showed increased hemosiderin deposition, and mild extramedullary hematopoiesis.

Lungs - No treatment related effects were noted.

Effect levels

1

Key result

Dose descriptor:

NOAEC

Effect level:

690 ppm

Sex:

female

Basis for effect level:

other: 3950 mg/m3

2

Key result

Dose descriptor:

LOAEC

Effect level:

345 ppm

Sex:

male

Basis for effect level:

other: 1975 mg/m3; Increased kidney weights as a result of an alpha2u-globulin-mediated process that is not regarded as relevant to humans

3

Key result

Dose descriptor:

LOAEC

Effect level:

1 293 ppm

Sex:

female

Basis for effect level:

other: 7400 mg/m3

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

Mean Body Weights of Male Rats (g)

Week	Control	345 ppm	690 ppm	1293 ppm	Standard Deviation of a Single Observation
0	397	396	396	398	24.9
1	422	422	396	396	20.9 (cage effect)
2	435	434	400	402	21.7
3	444	441	407	407	26.0
4	450	444	423	413	25.5
5	455	452	432	423	25.4
6	464	461	443	431	25.0
7	471	473	449	437	34.2 (cage effect)
8	480	479	460	445	28.2
9	486	486	466	448	30.9
10	494	490	469	453	35.6
11	495	491	478	458	34.9
12	502	495	481	466	36.7
13	512	503	491	473	38.4

Mean Body Weights of Female Rats (g)

Week	Control	345 ppm	690 ppm	1293 ppm		Standard Deviation of a Single Observation
0	244	245	244	245	14.2
1	249	253	252	245	6.2
2	256	261	257	248	9.0
3	264	264	263	252	10.1
4	264	269	266	254	13.5 (cage effect)
5	266	271	267	261	12.9 (cage effect)
6	269	274	269	261	11.4
7	274	278	273	264	11.5
8	275	277	274	263	12.5
9	275	277	272	266	13.8 (cage effect)
10	274	278	273	264	11.3
11	275	279	276	267	12.0
12	280	284	280	271	12.1
13	286	291	289	273	13.3

Applicant's summary and conclusion

Conclusions:

The 90-day LOAEC for male rats was 345 ppm (inhalation). This value is based on increased kidney weights as a result of an alpha2u-globulin-mediated process that is not regarded as relevant to humans. The LOAEC was established at 1293 ppm (7400 mg/m3) due to a significant body weight reduction. No other effects were noted. The NOAEC for female rats was 690 ppm (3950 mg/m3).

Executive summary:

This study evaluated the subchronic toxicity of low aromatic white spirits to rats when exposed via inhalation. Groups of 18 rats per sex were exposed to 345, 690, or 1293 ppm of test substance for 6 hrs/day, 5 days/week, for 13 weeks. The highest concentration, 1293 ppm, was near the saturation point for test substance vapor. Rats were observed for clinical signs, mortality, food consumption, water consumption, and body weight. At the end of the exposure period, the animals were sacrificed, and clinical chemistry, hematology, gross pathology, and histopathology parameters were examined. Male rats at all exposure levels had degenerative effects of the as a result of an alpha2u-globulin-mediated process that is not regarded as relevant to humans. The LOAEC was established at 1293 ppm (7400 mg/m³) due to a significant body weight reduction. No other effects were noted. The NOAEC for female rats was 690 ppm (3950 mg/m³).