Fluorobenzene

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Reference 2

Reference Type:

other: letter

Title:

Letter from E.I. du Pont de Nemours & Co Inc to US EPA regarding submission of studies using p-Fluorotoluene with attachments

Author:

TSCATS

Year:

1990

Bibliographic source:

Doc ID FYI-DTS-1090-0792, Microfiche No. OTS0000792

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Principles of method if other than guideline:

Groups of 6 male Crl:CD BR rats were exposed to vapor atmospheres of fluorobenze for a single 4-hour period.

GLP compliance:

yes

Test type:

other: Inhalation Approximate Lethal Concentration procedure

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Fluorobenzene

EC Number:

207-321-7

EC Name:

Fluorobenzene

Cas Number:

462-06-6

Molecular formula:

C6H5F

IUPAC Name:

fluorobenzene

Details on test material:

- Name of test material (as cited in study report): Fluorobenzene
- CAS No.: 462-06-6
- Physical form: colourless liquid
- Purity: > 99%
- Supplier: Aldrich Chemical Co. Catalog No. F600-1
- Stability: The TS was assumed to be stable throughout the exposure phase of the test

Test animals

Species:

rat

Strain:

other: Crl:CD BR

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories, Kingston, New York
- Age at study initiation: 8 weeks
- Weight at study initiation: 229-269 g
- Housing: single housing in suspended, stainless steel, wire-mesh cages; during the test, rats were housed in pairs.
- Diet: Purina Certified Rodent Chow #5002 ad libitum (except during exposure)
- Water: ad libitum (except during exposure)
- Acclimation period: rats were quarantined for one week upon receipt; afterwards, they were held in stock for up to one week prior to testing

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

nose only

Vehicle:

other: air

Details on inhalation exposure:

EXPOSURE PROTOCOL:
For each exposure, 6 rats were individually restrained in perforated, stainless steel cylinders with conical nose pieces. The restrainers were inserted into a face plate on the exposure chamber such that only-the nose of each rat protruded into the chamber. Each group of 6 rats was exposed nose-only for 4 continuous hours to a vapor atmosphere of fluorobenzene in air.

ATMOSPHERE GENERATION:
Vapor atmospheres of fluorobenzene were generated by pumping the liquid test material with a Harvard Model 975 Compact Infusion Pump into a 3-neck glass mixing flask. The flask was heated to 84-93°C with a Briskeat Model BC-170 heater to facilitate evaporation. The flask temperature was controlled with a Teco Model TC-1000 controller and was monitored with an Omega Type K Thermocouple Thermometer. Air introduced at the flask (approximately 22 L/min) swept the fluorobenzene vapors through a glass dispersion funnel and into the exposure chamber. Additional dilution air (approximately 1-18 L/min depending on desired concentration) was added to the vapor mixture prior to its entry into the chamber. The chamber exhaust was drawn through a dry ice cold trap and a MSA cartridge filter prior to being vented into the hood.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

by gas chromatography approx. every 30 min during exposure

Duration of exposure:

4 h

Concentrations:

50, 520, 3700, 6200 and 10000 ppm

No. of animals per sex per dose:

6 males per dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Rats were weighed and observed prior to exposure. Group observations of clinical signs of toxicity were taken during each exposure and when rats were released from restrainers after exposure. Surviving rats were weighed and observed daily for 14 days post exposure, weekends and holidays included when warranted by the rats' condition.
- Necropsy of survivors performed: no

Results and discussion

Effect levels

Effect levels 1

Sex:

male

Dose descriptor:

other: Approximate Lethal Concentration

Effect level:

6 200 ppm

Exp. duration:

4 h

Remarks on result:

other: equivalent to 24.7 mg/L

Effect levels 2

Sex:

male

Dose descriptor:

LC50

Effect level:

> 6 200 ppm

Exp. duration:

4 h

Remarks on result:

other: equivalent to 24.7 mg/L

Mortality:

Two of 6 rats exposed to 6200 ppm and 5 of 6 rats exposed to 10,000 ppm died during exposure.

Clinical signs:

other: Please see any other information for description.

Body weight:

During the postexposure period, no significant weight loss or adverse clinical signs were observed in rats that survived exposure to fluorobenzene. No adverse clinical signs and average weight losses of 2% or less of initial body weight were observed in rats exposed to 50, 520 or 6200 ppm. Rats exposed to 3700 ppm were not weighed and observed one day after exposure. However, 3 of 6 rats had lost an average of 3% of initial body weight on the 2nd day post exposure, and no adverse clinical signs were observed. The one rat that survived exposure to 10,000 ppm had a dry red ocular discharge and lost 5% of initial body weight one day after exposure.

Any other information on results incl. tables

Concentration of fluorobenzene vapour atmospheres and rat mortality:

Concentration (ppm)			Mortality (# deaths/# exposed)
Mean	SD	Range
50	8.3	40-61	0/6
520	17	500-550	0/6
3700	1100	2000-6000	0/6
6200	630	5400-7400	2/6
10000	740	8800-11000	5/6

 

CLINICAL SIGNS

During or immediately following exposure, rats exposed to 50, 520 or 6200 ppm had red nasal or ocular discharges, effects common to rats under restraint. Rats exposed to 10,000 ppm had no response to sound during exposure. When released from restrainers after exposure, rats exposed to 3700 ppm and rats that survived exposure to 6200 or 10,000 ppm had rapid breathing, tremors, spasms, no righting reflex and clear oculardischarge.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The ALC for fluorobenzene was 6200 ppm (equally to 24.7 mg/L). The TS is considered to have very low toxicity on an acute inhalation basis (ALC > 5000 ppm).