Hydrocarbons, C10-C12, isoalkanes, <2% aromatics

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1980/09/24 - 1980/10/08

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to or similar to guideline study OECD 403. GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Hydrocarbons, C10-C12, isoalkanes, <2% aromatics

EC Number:

923-037-2

Cas Number:

0

Molecular formula:

None available - not a single isomer - see remarks

IUPAC Name:

Hydrocarbons, C10-C12, isoalkanes, <2% aromatics

Test animals

Species:

rat

Strain:

other: Albino; COX-SD

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Sex: 5 males; 5 females
- Weight at study initiation: 220 - 299 g
- Housing: individually
- Diet (e.g. ad libitum): Purina Rodent Lab Chow, ad libitum
- Water (e.g. ad libitum): ad libitum

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

Undiluted C10-C12 n-Paraffins was introduced into the chamber as a mist, by means of a DeVilbiss Nebulizer, at a delivery flow concentration of approximately 5.6 milligrams per liter of air at a total flow rate of ten liters per minute for a period of four hours (plus a 26-minute equilibration period*). NOTE: Prior to test exposure, exploratory runs were made with the inhalation equipment to establish a dose-setting relation of the equipment and the test compound.

*prior to the actual four-hour exposure, the test compound was introduced into the chamber for twenty-six minutes at the above flow rate in order that the test atmospheric concentration could reach theoretical equilibration (approximately 99%). The animals were within the inhalation chamber during the equilibration period.

Analytical verification of test atmosphere concentrations:

not specified

Duration of exposure:

4 h

Remarks on duration:

plus 26 minute equilibration period

Concentrations:

5.6 mg/L

No. of animals per sex per dose:

5 males; 5 females

Control animals:

no

Details on study design:

Ten albino rats (five males and five females, COX-SD strain), weighing 220 to 299 grams, were used to evaluate the acute (single exposure) inhalation toxicity produced by the test compound, C10-C12 n-Paraffins when introduced in the form of a mist into a 57 liter capacity glass chamber containing the animals. Throughout the study, the animals were individually housed in metal, wire-bottomed cages elevated above the droppings. Each animal was examined before testing and only those animals from the supply on hand without observable defects were used. The animals were not fasted prior to exposure to inhalation of the test compound.

Undiluted C10-C12 n-Paraffins was introduced into the chamber as a mist, by means of a DeVilbiss Nebulizer, at a delivery flow concentration of approximately 5.6 milligrams per liter of air at a total flow rate of ten liters per minute for a period of four hours (plus a 26-minute equilibration period*). NOTE: Prior to test exposure, exploratory runs were made with the inhalation equipment to establish a dose-setting relation of the equipment and the test compound.

*prior to the actual four-hour exposure, the test compound was introduced into the chamber for twenty-six minutes at the above flow rate in order that the test atmospheric concentration could reach theoretical equilibration (approximately 99%). The animals were within the inhalation chamber during the equilibration period.

The animals were observed frequently for gross effects during the exposure. Upon removal from the chamber, the animals were cleaned with lukewarm tap water to remove any test compound having accumulated on their coats and were dried with towels. After drying, the animals were weighed and placed in their individual cages. Feed consisting of Purina Rodent Laboratory Chow (pelletized) and tap water were freely available at all times.

The animals were observed for gross effects at regular intervals during the remainder of the day of exposure and once daily thereafter for fourteen days. Body weights were recorded at seven and fourteen days post—exposure. Following the fourteen—day observation period, all surviving animals were sacrificed and necropsied.

Statistics:

no details

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5 600 mg/m³ air (nominal)

Remarks on result:

other: All animals survived

Mortality:

No mortality noted.

Clinical signs:

other: During the exposure, all of the animals displayed one or more of the following gross signs of test compound induced adverse effects: Slight to pronounced hypoactivity (10/10), malaise (10/10), and proneness (4/10). Following removal from the chamber and t

Body weight:

Body weight records of the animals showed constant weights except for two animals at seven days post-exposure (+/- 3 grams); the remaining animals at seven days, and all animals at fourteen days, post-exposure showed gains within expected limits.

Other findings:

Necropsy of the animals was performed at the termination of the study (fourteen days). Three animals had severe congestion of the lungs (approximately 30 to 50%); the findings for the other seven animals were unremarkable.

Applicant's summary and conclusion

Interpretation of results:

other: Not classified

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

The LC50 for acute inhalation exposure to the test material (aerosol) is >5.6mg/L. Classification as an acute inhalation toxicant is not warranted under the new Regulation (EC) 1272/2008 on classification, labeling and packaging of substances and mixtures (CLP) or under Directive 67/518/EEC for dangerous substances and Directive 1999/45/EC for preparations.

Executive summary:

Ten albino rats (five males and five females, COX-SD strain), weighing 220 to 299 grams, were exposed by the route of inhalation for four hours to undiluted C10-C12 n-paraffins in the form of a mist, at a delivery flow concentration of approximately 5.6 mg/L of test compound. All of the animals survived the exposure and the fourteen-day observation period which followed.

 

The LC50 for acute inhalation exposure to the test material (aerosol) is >5.6mg/L. Classification as an acute inhalation toxicant is not warranted under the new Regulation (EC) 1272/2008 on classification, labeling and packaging of substances and mixtures (CLP) or under Directive 67/518/EEC for dangerous substances and Directive 1999/45/EC for preparations.