Hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

3 - 23 September 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study. Only single test concentration used.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics

EC Number:

920-750-0

Cas Number:

none available

Molecular formula:

None available - not a single isomer - see remarks

IUPAC Name:

Hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics

Details on test material:

- Name of test material (as cited in study report): SBP 100/140. A mixture of hydrocarbon liquids. SICC code: Q 5811
- Substance type: colourless liquid
- Physical state: liquid
- Analytical purity: 100% pure commercial product
- Stability under test conditions: yes
- Storage condition of test material: room temperature in original container
- Other: supplied by sponsor

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Interfauna UK Ltd., Abbots Ripton Road, Wyton, Huntingdon
- Age at study initiation: 6 weeks (male), 8 weeks (female), different ages selected so that both sexes are of same body weight
- Weight at study initiation: 200 g
- Housing: polypropylene cages (38 x 56 x 18 cm) with wire meshes on tops and floors
- Diet (e.g. ad libitum): measured excess amount of food (Labsure LAD 1)
- Water (e.g. ad libitum): measured excess amount of tap water



ENVIRONMENTAL CONDITIONS
- Temperature (°C): mean daily maximum: 25°C (SD 1.3), mean daily minimum: 21°C (SD 0.6)
- Humidity (%): mean relative humidity: 60% (SD 6.4)

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: all parts were made of perspex
- Exposure chamber volume: 120 liters
- Method of holding animals in test chamber: Chamber divided by wire mesh partitions to provide 10 seperate animal compartments
- Source and rate of air: flow rate fo 25 L per minute; air warmed to 30°C to assist vaporisation of test substance. For the exposure a 50 mL syringe filled with the test substance was fitted to the syringe pump and connected to the atomiser with PTFE tubing. A flow rate of approx. 0.9 mL per minute was selected for the exposure. This flow rate was expected to give a concentration of vapour in excess of 20 mg/L of air. The syringe pump was switched on and the exposure timed for 4 hours, following an 11-minute equilibration period (total exposure time 4 hours 11 minutes). The syringe was refilled as required during the exposure.
- Method of conditioning air: The compressed air supply to the generator was dried, filtered and oil-free
- Temperature, humidity, pressure in air chamber: mean of 25.4°C in control and test


TEST ATMOSPHERE
- Brief description of analytical method used: 5 air samples were taken from the chamber during each exposure and analysed to determine the concentration of the test substance in the chamber atmosphere. The samples were drawn through a gas absorption trap, containing approximately 20 mL of acetone and cooled to -70°C in acetone/dry ice(=refrigerant). The sampling rate was 2 liters per minute and the volume of air sample was measured with a wet-type gas meter. One additional sample was taken using a Royco 218 particle size analyser to confirm the absence of droplets.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

GLC

Duration of exposure:

4 h

Concentrations:

mean of 23.3 mg/L of air

No. of animals per sex per dose:

5 males, 5 females

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: observed continuously during exposure and at least twice daily during observation period. Weighed daily from the day of delivery to the end of the observation period
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights, histopathology

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 23.3 mg/L air

Exp. duration:

4 h

Mortality:

One male died during exposure at approximately 2 hours from the start of exposure

Clinical signs:

other: Partial closing of the eyes, restless behaviour and a reduced respiration rate were the main clinical signs evident during exposure. The signs were considered to be consistent with exposure to a slightly irritant vapour. Other signs seen during exposure w

Body weight:

All rats exposed lost weight or had a reduced rate of bodyweight gain for 1-2 days following exposure. Subsequently the rate of bodyweight gain for exposed rats was similar to that of the control rats.

Gross pathology:

Findings for the rat that died following exposure were congestion of the lungs, yellow frothy fluid in the trachea and gas-filled stomach and gastro-intestinal tract

Other findings:

Food consumption was reduced for 1 day following exposure. Water consumption was not affected.

Histopathology: Marked pulmonary congestion and focal alveolar haemorrhage in the single deceased rat. Significance of this finding is uncertain.

Any other information on results incl. tables

Table: Mean Bodyweights (g)

Day	Female Control	Female Test	Male Control	Male Test
-5	174	179	153	148
-4	183	186	164	164
-3	189	185	172	176
-2	194	191	187	194
-1	198	197	196	201
0	203	202	203	211
1	203	199	211	212
2	205	201	222	219
3	213	211	229	232
4	214	212	237	242
5	216	209	240	249
6	219	211	248	255
7	221	212	259	264
8	228	215	273	282
9	230	226	276	285
10	234	227	285	295
11	242	234	297	307
12	242	238	300	315
13	244	238	303	319
14	246	239	308	324

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: other: GHS, EU, 2007

Conclusions:

The purpose of the is study was to examine the inhalation toxicity of hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics to rats. 5 male and 5 female rats were exposed to a concentration of 23.3 mg/L of test substance in the air for 4 hrs. Animals were examined at 0, 0.25, 0.5, 1, 2, 3, and 4 hrs after start of exposure for clinical signs and mortality. Animals were also examined daily for the next 14 days. Animals were weighed daily. Animals were examined for gross pathology and histopathology either after death, or after sacrifice at the end of the experiment. One male rat died during the experiment. The LC50 is > 23.3 mg/L of air. The test substance is not classified as toxic under the OECD GHS guidelines.

Executive summary:

The purpose of the is study was to examine the inhalation toxicity of hydrocarbons, C7-C9, n-alkanes, isoalkanes, cyclics to rats. 5 male and 5 female rats were exposed to a concentration of 23.3 mg/L of test substance in the air for 4 hrs. Animals were examined at 0, 0.25, 0.5, 1, 2, 3, and 4 hrs after start of exposure for clinical signs and mortality. Animals were also examined daily for the next 14 days. Animals were weighed daily. Animals were examined for gross pathology and histopathology either after death, or after sacrifice at the end of the experiment. One male rat died during the experiment. The LC50 is > 23.3 mg/L of air. The test substance is not classified as toxic under the OECD GHS guidelines.