Nonane

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Basic data given.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

Toxicity of n-C9 to n-C13 alkanes in the rat on short term inhalation.

Author:

Nilsen, O.G et al.

Year:

1988

Bibliographic source:

Pharmacology & Toxicology 62:259-266

Materials and methods

Principles of method if other than guideline:

Ten male Sprague-Dawley rats per concentration were exposed to nonane via inhalation at 2414, 3560, 4438, or 5280 ppm for 8 hours.

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Nonane

EC Number:

203-913-4

EC Name:

Nonane

Cas Number:

111-84-2

Molecular formula:

C9H20

IUPAC Name:

nonane

Details on test material:

- Name of test material (as cited in study report): n-nonane (Fluka)
- Analytical purity: 99.89% (GC); quoted purity: >99%
- Cat. no.: 74525

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Mollegaard A/S, Ll. Skensved, Denmark
- Weight at exposure: 200 g ± 20 %
- Housing: The number of animals in each cage was 4 with a maximum of 4 cages in each inhalation chamber.
- Individual metabolism cages: no
- Diet (e.g. ad libitum): ad libitium except during exposure
- Water (e.g. ad libitum): ad libitium except during exposure
- Acclimation period: 4 to 6 days before the start of exposure


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±1
- Humidity (%): 40-70
- Photoperiod (hrs dark / hrs light): 10/14

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Animals were kept in conically shaped 0.7 cubic metre steel chambers with glass front and walls.
- Method of holding animals in test chamber: a maximum number of 18 animals in each chamber
- System of generating particulates/aerosols: Dynamic exposure was performed by passing high oil-and dust-filtered air under pressure through 4 reservoirs of each containing 0.5 L of the test substance. At an air flow rate of 30-40 L/min an outlet concentration equal to 95% of vapour saturation was achieved. The vapour generating system was located in a water bath. Saturation concentrations of nonane at 20°C were achieved by keeping a constant temperature in the water bath of 22.5°C.
Air from the vapour generating system was introduced at the top of the exposure chamber and drained from the chamber through a perforated bottom outlet.
- Temperature, humidity, pressure in air chamber: 22±1 °C, 40-70%
Air was withdrawn from the inhalation chamber by a ventilation fan creating a negative pressure of 2-5 mm H2O on the inside of the chamber. During exposure the flow of air through the chamber (exposure and control) was 30-40 L/min, corresponding approx. to 3 air changes/hour.


TEST ATMOSPHERE
- Brief description of analytical method used:
Concentration of nonane in the inhalation chamber was monitored automatically every 15 min by on-line gas chromatography. Nonane was detected by a FID detector and quantified by a programmable integrator (Shimadzu C-R3A) which also controlled the frequency and sequence of air sampling.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

8 h

Concentrations:

2414; 3560; 4438; 5280 ppm (corresponding to approx. 12.84; 18.94; 23.61; 28.09 mg/L)

No. of animals per sex per dose:

10

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations: During inhalation all animals were observed at 15 and 30 min. intervals. For the first 8 hours after exposure all animals were observed at hourly, then at 2 hours intervals during daytime for 14 consecutive days.
- Necropsy of survivors performed: yes
- Other examinations performed: All animals were subjected to complete necropsy which included examination of the external surface of the body, all orifices, and the cranial, thoracic and abdominal cavities and their contents according to the OECD procedures (OECD 1987). In addition to general activity, acute effects as coordination difficulties, tremor, spasms and lethality were monitored.

Statistics:

Calculations were performed according to the method described by Finney (1964).

Results and discussion

Preliminary study:

not applicable

Effect levels

Key result

Sex:

male

Dose descriptor:

LC50

Effect level:

ca. 23.76 mg/L air

Exp. duration:

8 h

Remarks on result:

other: LC50= 4467±189 ppm

Mortality:

0/10 (2414 ppm)
1/10 (3560 ppm)
4/10 (4438 ppm)
9/10 (5280 ppm)
Death occured after 4 hours in the group exposed to 5280 ppm. The length of time before the appearance of death increased in proportion with the decrease of n-nonane concentration in the inhaled air.

Clinical signs:

other: Specific symptoms as tremor, spasms and limb paralysis were observed in animals exposed to nonane in the range from 5280 to 3560 ppm. Specific symptoms occured after 2 hours in the group exposed to 5280 ppm. The length of time before the appearance of spe

Body weight:

All rats exposed to n-nonane showed body weight slightly lower (about 10%) than the control groups. Weight curves indicated the difference to be due to an initial lag in the gain of weight during the 3 first days of observation. From day 3 to 14 the increase in weight was equal for exposed and control animals. However, the difference in total weight persisted throughout the observation.

Gross pathology:

No morphological alterations were observed in heart or kidneys or brain.

Other findings:

- Organ weights:
No significant differences in the weight of the heart, kidneys, liver or brain were found in the 4438 ppm test group (see table 2).
- Histopathology:
Liver:
Microscopically, dilatation of the sinusoids were found in all four animals dying during exposure to 4438 ppm nonane, and 3 of these animals also showed definite though slight fatty changes of the liver cells. In animals surviving exposure or among the controls no such changes were found. Occasionally, single necrotic hepatocytes were encountered in animals both form the experimental groups and among the controls.
Lungs:
The total weight of the lungs in 2 of the animals dying during exposure was approx. twice the weight of the control animals 2.86 g and 2.88 g, compared to 1.26 g. Microscopically, 3 animals showed marked pulmonary oedema. These animals died during exposure and in 2 of them the pulmonary weight was also increased. All exposed animals showed a blue discolouration of the skin during exposure, giving the impression of peripheral cyanosis, and thus cardiopulmonary insufficiency.
Brain:
No macroscopical abnormalities were recorded. In exposed animals which died during exposure, no pathological changes were found. Among the 6 surviving animals, 1 animal showed a few severely damaged neurons of the hippocampus. After 14 days after exposure, extensive changes were observed including rarification of Purkinje cells (cerebellar cortex) and in some instances also a high number of severely damaged neurons were observed in the surviving animals. These changes apparently were not entirely random but seemed to some extent to be segmental. In areas showing massive loss of Purkinje cells there was no obvious glial reaction.
Morphometry of the cerebellum:
The results demonstrated a loss of Purkinje cells in the animals which survived exposure. This is reflected by a reduced density of Purkinje cell profiles along the line which defines the Purkinje cell layer. The reduced density of the visible transections is only in part explained by a reduction of the cellsize, as there is also a significantly reduced number of Purkinje cells per unit area of Purkinje cell layer. The results also indicate a reduction of tissue volume in the other layers of the cerebellum as there was decrease in cerebellar volume relative to the extent of the Purkinje cell layer. There was no clear-cut change of the volume distribution between the different layers. There was no detectable difference between the animals which died during exposure and the controls.
- Other observations:
All animals surviving the 8 hours exposure seemed to recover from their specific symptoms during the entire observation period. The time needed for an apparent full recovery was in proportion with the concentration of n-nonane to which the animal had been exposed. The apparent full recovery time was 7 days for the 5280 ppm group (1 animal), 5 days for the 4438 ppm group (6 animals), 1 day for the 3560 ppm group (9 animals) and 0 -4 hours for the 2414 ppm group (10 animals).

Any other information on results incl. tables

In general, no toxic effects were observed in animals exposed to 2414 ppm of nonane.

Table 1: Concentration of nonane in inhaled air.

A period of 1 hour was needed to achieve steady state air concentration.

chamber concentration [ppm ± SD] (measured at 15 min intervals; generated at 22.5°C)

5280 ± 77*

4438 ± 319*

3560 ± 17

2414 ± 7

* saturation level

Table 2: mean total body weights and organs weights [g ± SD] of rats exposed to 4438 ppm nonane

	No.	Total bw	Brain	Lungs	Heart	Liver	Kidney
Dead animals	4	178.8±11.2	1.81±0.03	2.05±0.95	1.00±0.09	9.93±0.82	2.06±0.18
Surviving animals	6	274.8±25.2	1.87±0.04	1.41±0.11	1.19±0.22	11.88±1.52	2.22±0.18
Control animals	3	201.7±12.6	1.85±0.09	1.26±0.17	1.03±0.15	9.85±0.74	1.87±0.10

Applicant's summary and conclusion

Interpretation of results:

other: Not classified

Remarks:

Criteria used for interpretation of results: other: CLP

Conclusions:

Under the conditions of this study, the test substance is not classified.

Executive summary:

Under the conditions of this study, the test substance is not classified.