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Administrative data

acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
March 1980
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
equivalent or similar to guideline
OECD Guideline 403 (Acute Inhalation Toxicity)
GLP compliance:
Test type:
standard acute method
Limit test:

Test material

Constituent 1
Chemical structure
Reference substance name:
EC Number:
EC Name:
Cas Number:
Molecular formula:

Test animals

other: Sprague Dawley, albino, CD strain
Details on test animals or test system and environmental conditions:
- Source: Charles River UK, Kent
- Age at study initiation:6-7 weeks old on receipt
- Weight at study initiation: 176-196 g on receipt
- Housing: the rats were caged 5 males or 5 females to a cage.
- Diet: free access to a measured amount of food (Spratrt's Laboratory Diet 1)
- Water : free access to a measured amount of tap water

- Temperature (°C): 20 and 22 °C in the two holding rooms.
- Humidity (%): 33%, (standard deviation 5.4).

IN-LIFE DATES: From: March 3, 1980 To: March 11, 1980

Administration / exposure

Route of administration:
inhalation: aerosol
Type of inhalation exposure:
whole body
clean air
Details on inhalation exposure:
The used chambers were of square section and fitted with pyramidal tops. The chambers were made of perspex and had an internal volume of approx. 0.13 m3. Each chamber was divided by wire mesh partitions to provide 10 separate animal compartments. the test atmosphere entered through a port at the base centre of the chamber and passed out through small holes in the lower edge of the square section. Each chamber was positioned inside a large glass walled cabinet equipped with an extract fan exhausting to atmosphere through a collection filter.

Three groups of ras were exposed continously for 4 hours to test atmospheres containing the test article. A fourth group acting as a control received clean air only for 4 hours.
A supply of clean dry air was connected to the aerosol generator and the supply pressure was adjusted to give a flow rate of 30 litres per minute measured at the generator outlet tube. A 10 or 100 ml glass syringe, filled with 4-chlorobenzotrichloride was fitted to the syringe pump and connected to the generator via a three-way PTFE tap and a lenght of PTFE tubing. A flow rate of between 0.13 and 0.90 ml per minute was selected for the exposure. the rats (5 males and 5 females) were placed into separate compartments of the expsoure chamber. the syringe pump was switched on and the exposure timed from the appearence of an aerosol from the generator outlet. the syringe was refilled as required during the exposure through the three-way tap.
After 4 hours the suppluy of test article was discontinued and the exposure chamber was allowed to clear for 60 minutes before the rats were removed for examination. The exposure procedure was repeated for each test group at a difefrent setting of the syringe pump or with a different syringe to obtain other flow rates of the test substance,.
Following exposure, the rats were kept in a ventilated cabinet for 48 hours and then returned to the holding room for the remainder of the observation period.

- Particle size distribution:
Stage 1: particles freater than 5.5 µm mean aerodynamic diameter (A.d.)
Stage 2: particles between 5.5 and 2.0 µm mean aerodynamic diameter
Stage 3: particles less than 2.0 µm mean aerodynamic diameter

The temperature in the exposure chamber was measured with a mercury bulb thermometer and recorded at 30 minute intervals during the exposure.

Analytical verification of test atmosphere concentrations:
samples drawn through a gas absorption trap containing 15 ml of acetonitrile at a rate of 2 litres per minute.
Duration of exposure:
4 h
0.99, 1.31, 2.32 g/m3 of chamber air.
No. of animals per sex per dose:
3 test groups, each of 5 male and 5 female rats.
Control animals:
Details on study design:
- Duration of observation period following administration: 14 days

Results and discussion

Effect levelsopen allclose all
Dose descriptor:
Effect level:
1.41 other: g/m3
Based on:
test mat.
Exp. duration:
4 h
Remarks on result:
other: Standard error 0.18 g/m3
Dose descriptor:
Effect level:
1.59 other: g/m3
Based on:
test mat.
Exp. duration:
4 h
Remarks on result:
other: Standard Error 0.25 g/m3
Dose descriptor:
Effect level:
1.48 other: g/m3
Based on:
test mat.
Exp. duration:
4 h
Remarks on result:
other: Standard Error 0.13 g/m3
Control Group : 0/5
Group 1 (mean concentration 1.31 g/m3) : 1/5 males and 3/5 females
Group 2 (mean concentration 2.32 g/m3): 5/5 males and 4/5 females
Group 3 (mean concentration 0.99 g/m3): 1/5 males and 0/5 females
Clinical signs:
other: DURING EXPOSURE Normal appearance and behaviour for control group. Abnormal posture, lacrimation, salivation and peripheral vasodilation observed for groups exposed to 4-chlorobenzotrichloride. DURING OBSERVATION PERIOD Normal appearance and behaviour for
Body weight:
A loss of bodyweight over 3-4 days by all groups exposed to the test substance. Subsequent rate of bodyweight gain was irregular with a definite decrease in the rate of bodyweight gain towards the end of the observation period.
Gross pathology:
At the end of the 14 day observation period, the rats were anaesthetised by intraperitoneal injection of pentobarbitone sodium and killed by exsanguination. Findings for rats that died following exposure to the test substance were areas of hepatisation and bright red appearance of the lung and distended gas filled stomachs.
Findings for surviving rats were areas of hepatisation and numerous dark sub-pleural foci in the lung.
Other findings:
Food and water consumption by each cage of rats was daily measured from the day following arrival.

Applicant's summary and conclusion

Interpretation of results:
other: Category 4 based on CLP criteria
LC50 (4 hour) = 1.4 g/m3 of air
Executive summary:

The acute inhalation toxicity of 4 -chlorobenzotrichloride was assessed by exposing 3 groups of rats for a period of 4 hours, to atmospheres containing a respirable aerosol of the test substance (whole body method). The study was performed with albino rats CD strain (SpragueDawley), females and males. One control group exposed to clean air was used too.

At the atmosphere concentartions of 0.99, 1.31 and 2.32 g/m3 of chamber air, the calculated LC50 resulted to be established at 1.48 g/m3 of air. Acute exposure to the aerosol, at the concentrations used for this study, produced irritation to the eyes and skin of the rat and had a marked injurious effect on the lungs and upper airways.